Patent Application
20240423010
An object of the invention is to provide an organic electroluminescence device and an organic electroluminescence display device with enhanced luminous efficiency, an electronic device provided with the organic electroluminescence device, and an electronic device provided with the organic electroluminescence display device.
According to an aspect of the invention, there is provided an organic electroluminescence device including: a cathode; an anode; an emitting region provided between the cathode and the anode; and a hole transporting zone provided between the anode and the emitting region, in which
According to another aspect of the invention, there is provided an organic electroluminescence device including: a cathode; an anode; an emitting region provided between the cathode and the anode; a hole transporting zone provided between the anode and the emitting region; and an electron transporting zone provided between the cathode and the emitting region, in which
In the formula (20):
In the formula (21):
In the phenanthroline compound, R901, R902, R903, R904, R905, R906, R907, R931, R932, R933, R934, R935, R936, and R937 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
According to still another aspect of the invention, there is provided an organic electroluminescence device including: a cathode; an anode; an emitting region provided between the cathode and the anode; and a hole transporting zone provided between the anode and the emitting region, in which
In the formula (H10):
In the formula (H20):
[Formula 4]
-L203-Ar203 (H21)
In the formulae (H20) and (H21):
In the first host material and the first additional host material, R901, R902, R903, R904, R905, R906, and R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
According to a further aspect of the invention, there is provided an organic electroluminescence display device including: an anode and a cathode arranged opposite each other; and a first organic electroluminescence device as a first pixel and a second organic electroluminescence device as a second pixel, in which
According to a still further aspect of the invention, an electronic device including the organic electroluminescence device according to the aspect of the invention is provided.
According to a still further aspect of the invention, there is provided an electronic device provided with the organic electroluminescence display device according to the aspect of the invention.
According to the aspects of the invention, there are provided an organic electroluminescence device and an organic electroluminescence display device with enhanced luminous efficiency, an electronic device provided with the organic electroluminescence device, and an electronic device provided with the organic electroluminescence display device.
Herein, a hydrogen atom includes isotope having different numbers of neutrons, specifically, protium, deuterium and tritium.
In chemical formulae herein, it is assumed that a hydrogen atom (i.e. protium, deuterium and tritium) is bonded to each of bondable positions that are not annexed with signs “R” or the like or “D” representing a deuterium.
Herein, the ring carbon atoms refer to the number of carbon atoms among atoms forming a ring of a compound (e.g., a monocyclic compound, fused-ring compound, crosslinking compound, carbon ring compound, and heterocyclic compound) in which the atoms are bonded to each other to form the ring. When the ring is substituted by a substituent(s), carbon atom(s) contained in the substituent(s) is not counted in the ring carbon atoms. Unless specifically described, the same applies to the “ring carbon atoms” described later. For instance, a benzene ring has 6 ring carbon atoms, a naphthalene ring has 10 ring carbon atoms, a pyridine ring has 5 ring carbon atoms, and a furan ring 4 ring carbon atoms. For instance, a 9,9-diphenylfluorenyl group has 13 ring carbon atoms and 9,9′-spirobifluorenyl group has 25 ring carbon atoms.
When a benzene ring is substituted by, for instance, an alkyl group as a substituent, the number of carbon atoms of the alkyl group is not counted in the number of the ring carbon atoms of the benzene ring. Accordingly, the benzene ring substituted by an alkyl group has 6 ring carbon atoms. When a naphthalene ring is substituted by a substituent in a form of, for instance, an alkyl group, the number of carbon atoms of the alkyl group is not counted in the number of the ring carbon atoms of the naphthalene ring. Accordingly, the naphthalene ring substituted by an alkyl group has 10 ring carbon atoms.
Herein, the ring atoms refer to the number of atoms forming a ring of a compound (e.g., a monocyclic compound, fused-ring compound, cross-linking compound, carbon ring compound, and heterocyclic compound) in which the atoms are bonded to each other to form the ring (e.g., monocyclic ring, fused ring, and ring assembly). Atom(s) not forming the ring (e.g., hydrogen atom(s) for saturating the valence of the atom which forms the ring) and atom(s) in a substituent by which the ring is substituted are not counted as the ring atoms. Unless otherwise specified, the same applies to the “ring atoms” described later. For instance, a pyridine ring has 6 ring atoms, a quinazoline ring has 10 ring atoms, and a furan ring has 5 ring atoms. For instance, the number of hydrogen atom(s) bonded to a pyridine ring or the number of atoms forming a substituent is not counted in the number of the ring atoms of the pyridine ring. Accordingly, a pyridine ring bonded to a hydrogen atom(s) or a substituent(s) has 6 ring atoms. For instance, the hydrogen atom(s) bonded to carbon atom(s) of a quinazoline ring or the atoms forming a substituent are not counted as the quinazoline ring atoms. Accordingly, a quinazoline ring bonded to hydrogen atom(s) or a substituent(s) has 10 ring atoms.
Herein, “XX to YY carbon atoms” in the description of “substituted or unsubstituted ZZ group having XX to YY carbon atoms” represent carbon atoms of an unsubstituted ZZ group and do not include carbon atoms of a substituent(s) of the substituted ZZ group. Herein, “YY” is larger than “XX,” “XX” representing an integer of 1 or more and “YY” representing an integer of 2 or more.
Herein, “XX to YY atoms” in the description of “substituted or unsubstituted ZZ group having XX to YY atoms” represent atoms of an unsubstituted ZZ group and does not include atoms of a substituent(s) of the substituted ZZ group. Herein, “YY” is larger than “XX,” “XX” representing an integer of 1 or more and “YY” representing an integer of 2 or more.
Herein, an unsubstituted ZZ group refers to an “unsubstituted ZZ group” in a “substituted or unsubstituted ZZ group,” and a substituted ZZ group refers to a “substituted ZZ group” in a “substituted or unsubstituted ZZ group.” Herein, the term “unsubstituted” used in a “substituted or unsubstituted ZZ group” means that a hydrogen atom(s) in the ZZ group is not substituted with a substituent(s). The hydrogen atom(s) in the “unsubstituted ZZ group” is protium, deuterium, or tritium.
Herein, the term “substituted” used in a “substituted or unsubstituted ZZ group” means that at least one hydrogen atom in the ZZ group is substituted with a substituent. Similarly, the term “substituted” used in a “BB group substituted by AA group” means that at least one hydrogen atom in the BB group is substituted with the AA group.
Substituents mentioned herein will be described below.
An “unsubstituted aryl group” mentioned herein has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, and more preferably 6 to 18 ring carbon atoms.
An “unsubstituted heterocyclic group” mentioned herein has, unless otherwise specified herein, 5 to 50, preferably 5 to 30, and more preferably 5 to 18 ring atoms.
An “unsubstituted alkyl group” mentioned herein has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, and more preferably 1 to 6 carbon atoms.
An “unsubstituted alkenyl group” mentioned herein has, unless otherwise specified herein, 2 to 50, preferably 2 to 20, and more preferably 2 to 6 carbon atoms.
An “unsubstituted alkynyl group” mentioned herein has, unless otherwise specified herein, 2 to 50, preferably 2 to 20, and more preferably 2 to 6 carbon atoms.
An “unsubstituted cycloalkyl group” mentioned herein has, unless otherwise specified herein, 3 to 50, preferably 3 to 20, and more preferably 3 to 6 ring carbon atoms.
An “unsubstituted arylene group” mentioned herein has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, and more preferably 6 to 18 ring carbon atoms.
An “unsubstituted divalent heterocyclic group” mentioned herein has, unless otherwise specified herein, 5 to 50, preferably 5 to 30, and more preferably 5 to 18 ring atoms.
An “unsubstituted alkylene group” mentioned herein has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, and more preferably 1 to 6 carbon atoms.
Specific examples (specific example group G1) of the “substituted or unsubstituted aryl group” mentioned herein include unsubstituted aryl groups (specific example group G1A) below and substituted aryl groups (specific example group G1B). (Herein, an unsubstituted aryl group refers to an “unsubstituted aryl group” in a “substituted or unsubstituted aryl group”, and a substituted aryl group refers to a “substituted aryl group” in a “substituted or unsubstituted aryl group.”) A simply termed “aryl group” herein includes both of an “unsubstituted aryl group” and a “substituted aryl group”.
The “substituted aryl group” refers to a group derived by substituting at least one hydrogen atom in an “unsubstituted aryl group” with a substituent. Examples of the “substituted aryl group” include a group derived by substituting at least one hydrogen atom in the “unsubstituted aryl group” in the specific example group G1A below with a substituent, and examples of the substituted aryl group in the specific example group G1B below. It should be noted that the examples of the “unsubstituted aryl group” and the “substituted aryl group” mentioned herein are merely exemplary, and the “substituted aryl group” mentioned herein includes a group derived by further substituting a hydrogen atom bonded to a carbon atom of a skeleton of a “substituted aryl group” in the specific example group G1B below, and a group derived by further substituting a hydrogen atom of a substituent of the “substituted aryl group” in the specific example group G1B below.
The “heterocyclic group” mentioned herein refers to a cyclic group having at least one hetero atom in the ring atoms. Specific examples of the hetero atom include a nitrogen atom, oxygen atom, sulfur atom, silicon atom, phosphorus atom, and boron atom.
The “heterocyclic group” mentioned herein is a monocyclic group or a fused-ring group.
The “heterocyclic group” mentioned herein is an aromatic heterocyclic group or a non-aromatic heterocyclic group.
Specific examples (specific example group G2) of the “substituted or unsubstituted heterocyclic group” mentioned herein include unsubstituted heterocyclic groups (specific example group G2A) and substituted heterocyclic groups (specific example group G2B). (Herein, an unsubstituted heterocyclic group refers to an “unsubstituted heterocyclic group” in a “substituted or unsubstituted heterocyclic group,” and a substituted heterocyclic group refers to a “substituted heterocyclic group” in a “substituted or unsubstituted heterocyclic group.”) A simply termed “heterocyclic group” herein includes both of an “unsubstituted heterocyclic group” and a “substituted heterocyclic group.”
The “substituted heterocyclic group” refers to a group derived by substituting at least one hydrogen atom in an “unsubstituted heterocyclic group” with a substituent. Specific examples of the “substituted heterocyclic group” include a group derived by substituting at least one hydrogen atom in the “unsubstituted heterocyclic group” in the specific example group G2A below with a substituent, and examples of the substituted heterocyclic group in the specific example group G2B below. It should be noted that the examples of the “unsubstituted heterocyclic group” and the “substituted heterocyclic group” mentioned herein are merely exemplary, and the “substituted heterocyclic group” mentioned herein includes a group derived by further substituting a hydrogen atom bonded to a ring atom of a skeleton of a “substituted heterocyclic group” in the specific example group G2B below, and a group derived by further substituting a hydrogen atom of a substituent of the “substituted heterocyclic group” in the specific example group G2B below.
The specific example group G2A includes, for instance, unsubstituted heterocyclic groups including a nitrogen atom (specific example group G2A1) below, unsubstituted heterocyclic groups including an oxygen atom (specific example group G2A2) below, unsubstituted heterocyclic groups including a sulfur atom (specific example group G2A3) below, and monovalent heterocyclic groups (specific example group G2A4) derived by removing a hydrogen atom from cyclic structures represented by formulae (TEMP-16) to (TEMP-33) below.
The specific example group G2B includes, for instance, substituted heterocyclic groups including a nitrogen atom (specific example group G2B1) below, substituted heterocyclic groups including an oxygen atom (specific example group G2B2) below, substituted heterocyclic groups including a sulfur atom (specific example group G2B3) below, and groups derived by substituting at least one hydrogen atom of the monovalent heterocyclic groups (specific example group G2B4) derived from the cyclic structures represented by formulae (TEMP-16) to (TEMP-33) below.
In the formulae (TEMP-16) to (TEMP-33), XA and YA are each independently an oxygen atom, a sulfur atom, NH or CH2, and at least one of XA or YA is an oxygen atom, a sulfur atom, or NH.
When at least one of XA or YA in the formulae (TEMP-16) to (TEMP-33) is NH or CH2, the monovalent heterocyclic groups derived from the cyclic structures represented by the formulae (TEMP-16) to (TEMP-33) include a monovalent group derived by removing one hydrogen atom from NH or CH2.
Substituted Heterocyclic Groups Including Nitrogen Atom (Specific Example Group G2B1):
The “at least one hydrogen atom of a monovalent heterocyclic group” means at least one hydrogen atom selected from a hydrogen atom bonded to a ring carbon atom of the monovalent heterocyclic group, a hydrogen atom bonded to a nitrogen atom of at least one of XA or YA in a form of NH, and a hydrogen atom of one of XA and YA in a form of a methylene group (CH2).
Specific examples (specific example group G3) of the “substituted or unsubstituted alkyl group” mentioned herein include unsubstituted alkyl groups (specific example group G3A) and substituted alkyl groups (specific example group G3B) below. (Herein, an unsubstituted alkyl group refers to an “unsubstituted alkyl group” in a “substituted or unsubstituted alkyl group,” and a substituted alkyl group refers to a “substituted alkyl group” in a “substituted or unsubstituted alkyl group.”) A simply termed “alkyl group” herein includes both of an “unsubstituted alkyl group” and a “substituted alkyl group”.
The “substituted alkyl group” refers to a group derived by substituting at least one hydrogen atom in an “unsubstituted alkyl group” with a substituent. Specific examples of the “substituted alkyl group” include a group derived by substituting at least one hydrogen atom of an “unsubstituted alkyl group” (specific example group G3A) below with a substituent, and examples of the substituted alkyl group (specific example group G3B) below. Herein, the alkyl group for the “unsubstituted alkyl group” refers to a chain alkyl group. Accordingly, the “unsubstituted alkyl group” include linear “unsubstituted alkyl group” and branched “unsubstituted alkyl group.” It should be noted that the examples of the “unsubstituted alkyl group” and the “substituted alkyl group” mentioned herein are merely exemplary, and the “substituted alkyl group” mentioned herein includes a group derived by further substituting a hydrogen atom of a skeleton of the “substituted alkyl group” in the specific example group G3B, and a group derived by further substituting a hydrogen atom of a substituent of the “substituted alkyl group” in the specific example group G3B.
Specific examples (specific example group G4) of the “substituted or unsubstituted alkenyl group” mentioned herein include unsubstituted alkenyl groups (specific example group G4A) and substituted alkenyl groups (specific example group G4B). (Herein, an unsubstituted alkenyl group refers to an “unsubstituted alkenyl group” in a “substituted or unsubstituted alkenyl group,” and a substituted alkenyl group refers to a “substituted alkenyl group” in a “substituted or unsubstituted alkenyl group.”) A simply termed “alkenyl group” herein includes both of an “unsubstituted alkenyl group” and a “substituted alkenyl group”.
The “substituted alkenyl group” refers to a group derived by substituting at least one hydrogen atom in an “unsubstituted alkenyl group” with a substituent. Specific examples of the “substituted alkenyl group” include an “unsubstituted alkenyl group” (specific example group G4A) substituted by a substituent, and examples of the substituted alkenyl group (specific example group G4B) below. It should be noted that the examples of the “unsubstituted alkenyl group” and the “substituted alkenyl group” mentioned herein are merely exemplary, and the “substituted alkenyl group” mentioned herein includes a group derived by further substituting a hydrogen atom of a skeleton of the “substituted alkenyl group” in the specific example group G4B with a substituent, and a group derived by further substituting a hydrogen atom of a substituent of the “substituted alkenyl group” in the specific example group G4B with a substituent.
Specific examples (specific example group G5) of the “substituted or unsubstituted alkynyl group” mentioned herein include unsubstituted alkynyl groups (specific example group G5A) below. (Herein, an unsubstituted alkynyl group refers to an “unsubstituted alkynyl group” in a “substituted or unsubstituted alkynyl group.”) A simply termed “alkynyl group” herein includes both of “unsubstituted alkynyl group” and “substituted alkynyl group”.
The “substituted alkynyl group” refers to a group derived by substituting at least one hydrogen atom in an “unsubstituted alkynyl group” with a substituent. Specific examples of the “substituted alkynyl group” include a group derived by substituting at least one hydrogen atom of the “unsubstituted alkynyl group” (specific example group G5A) below with a substituent.
Unsubstituted Alkynyl Group (Specific Example Group G5A): an ethynyl group
Specific examples (specific example group G6) of the “substituted or unsubstituted cycloalkyl group” mentioned herein include unsubstituted cycloalkyl groups (specific example group G6A) and substituted cycloalkyl groups (specific example group G6B). (Herein, an unsubstituted cycloalkyl group refers to an “unsubstituted cycloalkyl group” in a “substituted or unsubstituted cycloalkyl group,” and a substituted cycloalkyl group refers to a “substituted cycloalkyl group” in a “substituted or unsubstituted cycloalkyl group.”) A simply termed “cycloalkyl group” herein includes both of “unsubstituted cycloalkyl group” and “substituted cycloalkyl group”.
The “substituted cycloalkyl group” refers to a group derived by substituting at least one hydrogen atom of an “unsubstituted cycloalkyl group” with a substituent. Specific examples of the “substituted cycloalkyl group” include a group derived by substituting at least one hydrogen atom of the “unsubstituted cycloalkyl group” (specific example group G6A) below with a substituent, and examples of the substituted cycloalkyl group (specific example group G6B) below. It should be noted that the examples of the “unsubstituted cycloalkyl group” and the “substituted cycloalkyl group” mentioned herein are merely exemplary, and the “substituted cycloalkyl group” mentioned herein includes a group derived by substituting at least one hydrogen atom bonded to a carbon atom of a skeleton of the “substituted cycloalkyl group” in the specific example group G6B with a substituent, and a group derived by further substituting a hydrogen atom of a substituent of the “substituted cycloalkyl group” in the specific example group G6B with a substituent.
a 4-methylcyclohexyl group.
Group Represented by —Si(Rsol)(R902)(R903)
Specific examples (specific example group G7) of the group represented herein by —Si(R901)(R902)(R903) include:
where:
Specific examples (specific example group G8) of a group represented by —O—(R904) herein include: —O(G1); —O(G2); —O(G3); and —O(G6);
Specific examples (specific example group G9) of a group represented herein by —S—(R905) include: —S(G1); —S(G2); —S(G3); and —S(G6);
Specific examples (specific example group G10) of a group represented herein by —N(R906)(R907) include: —N(G1)(G1); —N(G2)(G2); —N(G1)(G2); —N(G3)(G3); and —N(G6)(G6),
Specific examples (specific example group G11) of “halogen atom” mentioned herein include a fluorine atom, chlorine atom, bromine atom, and iodine atom.
The “substituted or unsubstituted fluoroalkyl group” mentioned herein refers to a group derived by substituting at least one hydrogen atom bonded to at least one of carbon atoms forming an alkyl group in the “substituted or unsubstituted alkyl group” with a fluorine atom, and also includes a group (perfluoro group) derived by substituting all of hydrogen atoms bonded to carbon atoms forming the alkyl group in the “substituted or unsubstituted alkyl group” with fluorine atoms. An “unsubstituted fluoroalkyl group” has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms. The “substituted fluoroalkyl group” refers to a group derived by substituting at least one hydrogen atom in a “fluoroalkyl group” with a substituent. It should be noted that the examples of the “substituted fluoroalkyl group” mentioned herein include a group derived by further substituting at least one hydrogen atom bonded to a carbon atom of an alkyl chain of a “substituted fluoroalkyl group” with a substituent, and a group derived by further substituting at least one hydrogen atom of a substituent of the “substituted fluoroalkyl group” with a substituent. Specific examples of the “unsubstituted fluoroalkyl group” include a group derived by substituting at least one hydrogen atom of the “alkyl group” (specific example group G3) with a fluorine atom.
The “substituted or unsubstituted haloalkyl group” mentioned herein refers to a group derived by substituting at least one hydrogen atom bonded to carbon atoms forming the alkyl group in the “substituted or unsubstituted alkyl group” with a halogen atom, and also includes a group derived by substituting all hydrogen atoms bonded to carbon atoms forming the alkyl group in the “substituted or unsubstituted alkyl group” with halogen atoms. An “unsubstituted haloalkyl group” has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, and more preferably 1 to 18 carbon atoms. The “substituted haloalkyl group” refers to a group derived by substituting at least one hydrogen atom in a “haloalkyl group” with a substituent. It should be noted that the examples of the “substituted haloalkyl group” mentioned herein include a group derived by further substituting at least one hydrogen atom bonded to a carbon atom of an alkyl chain of a “substituted haloalkyl group” with a substituent, and a group derived by further substituting at least one hydrogen atom of a substituent of the “substituted haloalkyl group” with a substituent. Specific examples of the “unsubstituted haloalkyl group” include a group derived by substituting at least one hydrogen atom of the “alkyl group” (specific example group G3) with a halogen atom. The haloalkyl group is sometimes referred to as a halogenated alkyl group.
Specific examples of a “substituted or unsubstituted alkoxy group” mentioned herein include a group represented by —O(G3), G3 being the “substituted or unsubstituted alkyl group” in the specific example group G3. An “unsubstituted alkoxy group” has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms.
Specific examples of a “substituted or unsubstituted alkylthio group” mentioned herein include a group represented by —S(G3), G3 being the “substituted or unsubstituted alkyl group” in the specific example group G3. An “unsubstituted alkylthio group” has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms.
Specific examples of a “substituted or unsubstituted aryloxy group” mentioned herein include a group represented by —O(G1), G1 being the “substituted or unsubstituted aryl group” in the specific example group G1. An “unsubstituted aryloxy group” has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, more preferably 6 to 18 ring carbon atoms.
Specific examples of a “substituted or unsubstituted arylthio group” mentioned herein include a group represented by —S(G1), G1 being the “substituted or unsubstituted aryl group” in the specific example group G1. An “unsubstituted arylthio group” has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, more preferably 6 to 18 ring carbon atoms.
Specific examples of a “trialkylsilyl group” mentioned herein include a group represented by —Si(G3)(G3)(G3), G3 being the “substituted or unsubstituted alkyl group” in the specific example group G3. A plurality of G3 in —Si(G3)(G3)(G3) are mutually the same or different. Each of the alkyl groups in the “trialkylsilyl group” has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, more preferably 1 to 6 carbon atoms.
Specific examples of a “substituted or unsubstituted aralkyl group” mentioned herein include a group represented by -(G3)-(G1), G3 being the “substituted or unsubstituted alkyl group” in the specific example group G3, G1 being the “substituted or unsubstituted aryl group” in the specific example group G1. Accordingly, the “aralkyl group” is a group derived by substituting a hydrogen atom of the “alkyl group” with a substituent in a form of the “aryl group,” which is an example of the “substituted alkyl group.” An “unsubstituted aralkyl group,” which is an “unsubstituted alkyl group” substituted by an “unsubstituted aryl group,” has, unless otherwise specified herein, 7 to 50 carbon atoms, preferably 7 to 30 carbon atoms, more preferably 7 to 18 carbon atoms.
Specific examples of the “substituted or unsubstituted aralkyl group” include a benzyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group, phenyl-t-butyl group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β-naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, and 2-β-naphthylisopropyl group.
Preferable examples of the substituted or unsubstituted aryl group mentioned herein include, unless otherwise specified herein, a phenyl group, p-biphenyl group, m-biphenyl group, o-biphenyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-terphenyl-4-yl group, o-terphenyl-3-yl group, o-terphenyl-2-yl group, 1-naphthyl group, 2-naphthyl group, anthryl group, phenanthryl group, pyrenyl group, chrysenyl group, triphenylenyl group, fluorenyl group, 9,9′-spirobifluorenyl group, 9,9-dimethylfluorenyl group, and 9,9-diphenylfluorenyl group.
Preferable examples of the substituted or unsubstituted heterocyclic group mentioned herein include, unless otherwise specified herein, a pyridyl group, pyrimidinyl group, triazinyl group, quinolyl group, isoquinolyl group, quinazolinyl group, benzimidazolyl group, phenanthrolinyl group, carbazolyl group (1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, or 9-carbazolyl group), benzocarbazolyl group, azacarbazolyl group, diazacarbazolyl group, dibenzofuranyl group, naphthobenzofuranyl group, azadibenzofuranyl group, diazadibenzofuranyl group, dibenzothiophenyl group, naphthobenzothiophenyl group, azadibenzothiophenyl group, diazadibenzothiophenyl group, (9-phenyl)carbazolyl group ((9-phenyl)carbazole-1-yl group, (9-phenyl)carbazole-2-yl group, (9-phenyl)carbazole-3-yl group, or (9-phenyl)carbazole-4-yl group), (9-biphenylyl)carbazolyl group, (9-phenyl)phenylcarbazolyl group, diphenylcarbazole-9-yl group, phenylcarbazole-9-yl group, phenyltriazinyl group, biphenylyltriazinyl group, diphenyltriazinyl group, phenyldibenzofuranyl group, and phenyldibenzothiophenyl group.
The carbazolyl group mentioned herein is, unless otherwise specified herein, specifically a group represented by one of formulae below.
The (9-phenyl)carbazolyl group mentioned herein is, unless otherwise specified herein, specifically a group represented by one of formulae below.
In the formulae (TEMP-Cz1) to (TEMP-Cz9), * represents a bonding position.
The dibenzofuranyl group and dibenzothiophenyl group mentioned herein are, unless otherwise specified herein, each specifically represented by one of formulae below.
In the formulae (TEMP-34) to (TEMP-41), each * represents a bonding position.
Preferable examples of the substituted or unsubstituted alkyl group mentioned herein include, unless otherwise specified herein, a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, and t-butyl group.
The “substituted or unsubstituted arylene group” mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on an aryl ring of the “substituted or unsubstituted aryl group.” Specific examples of the “substituted or unsubstituted arylene group” (specific example group G12) include a divalent group derived by removing one hydrogen atom on an aryl ring of the “substituted or unsubstituted aryl group” in the specific example group G1.
The “substituted or unsubstituted divalent heterocyclic group” mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on a heterocyclic ring of the “substituted or unsubstituted heterocyclic group.” Specific examples of the “substituted or unsubstituted divalent heterocyclic group” (specific example group G13) include a divalent group derived by removing one hydrogen atom on a heterocyclic ring of the “substituted or unsubstituted heterocyclic group” in the specific example group G2.
The “substituted or unsubstituted alkylene group” mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on an alkyl chain of the “substituted or unsubstituted alkyl group.” Specific examples of the “substituted or unsubstituted alkylene group” (specific example group G14) include a divalent group derived by removing one hydrogen atom on an alkyl chain of the “substituted or unsubstituted alkyl group” in the specific example group G3.
The substituted or unsubstituted arylene group mentioned herein is, unless otherwise specified herein, preferably any one of groups represented by formulae (TEMP-42) to (TEMP-68) below.
In the formulae (TEMP-42) to (TEMP-52), Q1 to Q10 are each independently a hydrogen atom or a substituent.
In the formulae (TEMP-42) to (TEMP-52), each * represents a bonding position.
In the formulae (TEMP-53) to (TEMP-62), Q1 to Q10 are each independently a hydrogen atom or a substituent.
In the formulae, Q9 and Q10 may be mutually bonded through a single bond to form a ring.
In the formulae (TEMP-53) to (TEMP-62), each * represents a bonding position.
In the formulae (TEMP-63) to (TEMP-68), Q1 to Q8 are each independently a hydrogen atom or a substituent.
In the formulae (TEMP-63) to (TEMP-68), each * represents a bonding position.
The substituted or unsubstituted divalent heterocyclic group mentioned herein is, unless otherwise specified herein, preferably a group represented by any one of formulae (TEMP-69) to (TEMP-102) below.
In the formulae (TEMP-69) to (TEMP-82), Q1 to Q9 are each independently a hydrogen atom or a substituent.
In the formulae (TEMP-83) to (TEMP-102), Q1 to Q8 are each independently a hydrogen atom or a substituent.
The substituent mentioned herein has been described above.
Instances where “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded” mentioned herein refer to instances where “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring, “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring,” and “at least one combination of adjacent two or more (of . . . ) are not mutually bonded.”
Instances where “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring” and “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring” mentioned herein (these instances will be sometimes collectively referred to as an instance of “bonded to form a ring” hereinafter) will be described below. An anthracene compound having a basic skeleton in a form of an anthracene ring and represented by a formula (TEMP-103) below will be used as an example for the description.
For instance, when “at least one combination of adjacent two or more of R921 to R930 are mutually bonded to form a ring,” the combination of adjacent ones of R921 to R930 (i.e. the combination at issue) is a combination of R921 and R922, a combination of R922 and R923, a combination of R923 and R924, a combination of R924 and R930, a combination of R930 and R925, a combination of R925 and R926, a combination of R926 and R927, a combination of R927 and R928, a combination of R928 and R929, or a combination of R929 and R921.
The term “at least one combination” means that two or more of the above combinations of adjacent two or more of R921 to R930 may simultaneously form rings. For instance, when R921 and R922 are mutually bonded to form a ring QA and R925 and R926 are simultaneously mutually bonded to form a ring QB, the anthracene compound represented by the formula (TEMP-103) is represented by a formula (TEMP-104) below.
The instance where the “combination of adjacent two or more” form a ring means not only an instance where the “two” adjacent components are bonded but also an instance where adjacent “three or more” are bonded. For instance, R921 and R922 are mutually bonded to form a ring QA and R922 and R923 are mutually bonded to form a ring QC, and mutually adjacent three components (R921, R922 and R923) are mutually bonded to form a ring fused to the anthracene basic skeleton. In this case, the anthracene compound represented by the formula (TEMP-103) is represented by a formula (TEMP-105) below. In the formula (TEMP-105) below, the ring QA and the ring QC share R922.
The formed “monocyclic ring” or “fused ring” may be, in terms of the formed ring in itself, a saturated ring or an unsaturated ring. When the “combination of adjacent two” form a “monocyclic ring” or a “fused ring,” the “monocyclic ring” or “fused ring” may be a saturated ring or an unsaturated ring. For instance, the ring QA and the ring QB formed in the formula (TEMP-104) are each independently a “monocyclic ring” or a “fused ring.” Further, the ring QA and the ring QC formed in the formula (TEMP-105) are each a “fused ring.” The ring QA and the ring QC in the formula (TEMP-105) are fused to form a fused ring. When the ring QA in the formula (TEMP-104) is a benzene ring, the ring QA is a monocyclic ring. When the ring QA in the formula (TEMP-104) is a naphthalene ring, the ring QA is a fused ring.
The “unsaturated ring” represents an aromatic hydrocarbon ring or an aromatic heterocycle. The “saturated ring” represents an aliphatic hydrocarbon ring or a non-aromatic heterocycle.
Specific examples of the aromatic hydrocarbon ring include a ring formed by terminating a bond of a group in the specific examples of the specific example group G1 with a hydrogen atom.
Specific examples of the aromatic heterocyclic ring include a ring formed by terminating a bond of an aromatic heterocyclic group in the specific examples of the specific example group G2 with a hydrogen atom.
Specific examples of the aliphatic hydrocarbon ring include a ring formed by terminating a bond of a group in the specific examples of the specific example group G6 with a hydrogen atom.
The phrase “to form a ring” herein means that a ring is formed only by a plurality of atoms of a basic skeleton, or by a combination of a plurality of atoms of the basic skeleton and one or more optional atoms. For instance, the ring QA formed by mutually bonding R921 and R922 shown in the formula (TEMP-104) is a ring formed by a carbon atom of the anthracene skeleton bonded to R921, a carbon atom of the anthracene skeleton bonded to R922, and one or more optional atoms. Specifically, when the ring QA is a monocyclic unsaturated ring formed by R921 and R922, the ring formed by a carbon atom of the anthracene skeleton bonded to R921, a carbon atom of the anthracene skeleton bonded to R922, and four carbon atoms is a benzene ring.
The “optional atom” is, unless otherwise specified herein, preferably at least one atom selected from the group consisting of a carbon atom, nitrogen atom, oxygen atom, and sulfur atom. A bond of the optional atom (e.g. a carbon atom and a nitrogen atom) not forming a ring may be terminated by a hydrogen atom or the like or may be substituted by an “optional substituent” described later. When the ring includes an optional element other than carbon atom, the resultant ring is a heterocycle.
The number of “one or more optional atoms” forming the monocyclic ring or fused ring is, unless otherwise specified herein, preferably in a range from 2 to 15, more preferably in a range from 3 to 12, further preferably in a range from 3 to 5.
Unless otherwise specified herein, the ring, which may be a “monocyclic ring” or “fused ring,” is preferably a “monocyclic ring.”
Unless otherwise specified herein, the ring, which may be a “saturated ring” or “unsaturated ring,” is preferably an “unsaturated ring.”
Unless otherwise specified herein, the “monocyclic ring” is preferably a benzene ring.
Unless otherwise specified herein, the “unsaturated ring” is preferably a benzene ring.
When “at least one combination of adjacent two or more” (of . . . ) are “mutually bonded to form a substituted or unsubstituted monocyclic ring” or “mutually bonded to form a substituted or unsubstituted fused ring,” unless otherwise specified herein, at least one combination of adjacent two or more of components are preferably mutually bonded to form a substituted or unsubstituted “unsaturated ring” formed of a plurality of atoms of the basic skeleton, and 1 to 15 atoms of at least one element selected from the group consisting of carbon, nitrogen, oxygen and sulfur.
When the “monocyclic ring” or the “fused ring” has a substituent, the substituent is the substituent described in later-described “optional substituent.” When the “monocyclic ring” or the “fused ring” has a substituent, specific examples of the substituent are the substituents described in the above under the subtitle “Substituent Mentioned Herein.”
When the “saturated ring” or the “unsaturated ring” has a substituent, the substituent is the substituent described in later-described “optional substituent.” When the “monocyclic ring” or the “fused ring” has a substituent, specific examples of the substituent are the substituents described in the above under the subtitle “Substituent Mentioned Herein.”
The above is the description for the instances where “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring” and “at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring” mentioned herein (sometimes referred to as an instance of “bonded to form a ring”).
In an exemplary embodiment herein, the substituent for the substituted or unsubstituted group (sometimes referred to as an “optional substituent” hereinafter) is, for instance, a group selected from the group consisting of an unsubstituted alkyl group having 1 to 50 carbon atoms, an unsubstituted alkenyl group having 2 to 50 carbon atoms, an unsubstituted alkynyl group having 2 to 50 carbon atoms, an unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, —Si(R901)(R902)(R903), —O—(R904), —S—(R905), —N(R906)(R907), a halogen atom, a cyano group, a nitro group, an unsubstituted aryl group having 6 to 50 ring carbon atoms, and an unsubstituted heterocyclic group having 5 to 50 ring atoms,
R901 to R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
In an exemplary embodiment, the substituent for the substituted or unsubstituted group is a group selected from the group consisting of an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 ring carbon atoms, and a heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, the substituent for the substituted or unsubstituted group is a group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 ring carbon atoms, and a heterocyclic group having 5 to 18 ring atoms.
Specific examples of the above optional substituent are the same as the specific examples of the substituent described in the above under the subtitle “Substituent Mentioned Herein.”
Unless otherwise specified herein, adjacent ones of the optional substituents may form a “saturated ring” or an “unsaturated ring,” preferably a substituted or unsubstituted saturated five-membered ring, a substituted or unsubstituted saturated six-membered ring, a substituted or unsubstituted unsaturated five-membered ring, or a substituted or unsubstituted unsaturated six-membered ring, more preferably a benzene ring.
Unless otherwise specified herein, the optional substituent may further include a substituent. Examples of the substituent for the optional substituent are the same as the examples of the optional substituent.
Herein, numerical ranges represented by “AA to BB” represent a range whose lower limit is the value (AA) recited before “to” and whose upper limit is the value (BB) recited after “to.”
An organic electroluminescence device (organic EL device) of a first exemplary embodiment includes: a cathode; an anode; an emitting region provided between the cathode and the anode; and a hole transporting zone provided between the anode and the emitting region, in which the emitting region includes at least one emitting layer, the at least one emitting layer includes a first emitting layer, the first emitting layer includes a first host material, a first additional host material different from the first host material, and a first luminescent compound, the hole transporting zone includes a first anode-side organic layer, a second anode-side organic layer, and a third anode-side organic layer, the first anode-side organic layer is in direct contact with the second anode-side organic layer, the second anode-side organic layer is in direct contact with the third anode-side organic layer, the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer are arranged in this order from a side close to the anode between the anode and the emitting region, the second anode-side organic layer contains a second hole transporting zone material, the second hole transporting zone material is a monoamine compound having one substituted or unsubstituted amino group in a molecule or a diamine compound having two substituted or unsubstituted amino groups in a molecule, the third anode-side organic layer contains a third hole transporting zone material, the third hole transporting zone material is a monoamine compound having one substituted or unsubstituted amino group in a molecule or a diamine compound having two substituted or unsubstituted amino groups in a molecule, the third anode-side organic layer has a film thickness of 20 nm or more, the second hole transporting zone material and the third hole transporting zone material are mutually the same or different, the second anode-side organic layer contains at least one compound different from a compound contained in the third anode-side organic layer, the first emitting layer is a fluorescent emitting layer, and a refractive index NM2 of a constituent material contained in the second anode-side organic layer and a refractive index NM3 of a constituent material contained in the third anode-side organic layer satisfy a relationship of a numerical formula (Numerical Formula NM) below.
According to the exemplary embodiment, the device performance of the organic EL device is improvable. In an exemplary arrangement according to the exemplary embodiment, the organic EL device has an improved luminous efficiency. In an exemplary arrangement according to the exemplary embodiment, the organic EL device has a longer lifetime.
Herein, a zone disposed between the anode and the emitting region and formed by a plurality of organic layers is occasionally referred to as a hole transporting zone.
The hole transporting zone includes a first anode-side organic layer, a second anode-side organic layer, and a third anode-side organic layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the anode is in direct contact with the hole transporting zone and the emitting region is in direct contact with the hole transporting zone.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a difference NM2−NM3 between a refractive index NM2 of a constituent material contained in the second anode-side organic layer and a refractive index NM3 of a constituent material contained in the third anode-side organic layer satisfy a relationship of a numerical formula (Numerical Formula NM), thereby improving a light-extraction efficiency. When the second anode-side organic layer contains a single type of compound, the refractive index NM2 of the constituent material contained in the second anode-side organic layer corresponds to a refractive index of the single type of compound. When the second anode-side organic layer contains a plurality of types of compounds, the refractive index NM2 of the constituent material contained in the second anode-side organic layer corresponds to a refractive index of a mixture containing the plurality types of compounds. The refractive index NM3 of the constituent material contained in the third anode-side organic layer is also defined similarly to the refractive index NM2 of the constituent material contained in the second anode-side organic layer. The refractive index can be measured by a measurement method described in Examples below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a difference NM2−NM3 between the refractive index NM2 of the constituent material contained in the second anode-side organic layer and the refractive index NM3 of the constituent material contained in the third anode-side organic layer satisfies a relationship of a numerical formula (Numerical Formula NM1) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the difference NM2−NM3 between the refractive index NM2 of the constituent material contained in the second anode-side organic layer and the refractive index NM3 of the constituent material contained in the third anode-side organic layer satisfies a relationship of a numerical formula (Numerical Formula NM2), a numerical formula (Numerical Formula NM3), or a numerical formula (Numerical Formula NM4) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index NM2 of the constituent material contained in the second anode-side organic layer is 1.90 or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index of the compound contained in the second anode-side organic layer is 1.90 or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index NM2 of the constituent material contained in the second anode-side organic layer is 1.94 or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index of the compound contained in the second anode-side organic layer is 1.94 or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index NM3 of the constituent material contained in third anode-side organic layer is 1.89 or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the refractive index of a compound contained in the third anode-side organic layer is 1.89 or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a refractive index NM1 of a constituent material contained in the first anode-side organic layer and the refractive index NM2 of a constituent material contained in the second anode-side organic layer satisfy a relationship of a numerical formula (Numerical Formula L1) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole transporting zone consists of the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer. In this case, a total film thickness of the hole transporting zone corresponds to a total of a film thickness of the first anode-side organic layer, a film thickness of the second anode-side organic layer, and a film thickness of the third anode-side organic layer.
In the organic EL device of the exemplary embodiment, the third anode-side organic layer has a film thickness of 20 nm or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the third anode-side organic layer has a film thickness of 25 nm or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the third anode-side organic layer has a film thickness in a range from 30 nm to 150 nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the third anode-side organic layer has a film thickness in a range from 30 nm to 80 nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the third anode-side organic layer has a film thickness in a range from 80 nm to 150 nm.
It is considered that the third anode-side organic layer having a film thickness of 20 nm or more readily inhibits the transfer of the excitation energy of the emitting layer.
In the organic EL device of the exemplary embodiment, the first anode-side organic layer has a film thickness of 20 nm or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a ratio TL3/TL2 of a film thickness TL3 of the third anode-side organic layer to a film thickness TL2 of the second anode-side organic layer satisfies a predetermined relationship.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the ratio of the film thickness of the third anode-side organic layer to the film thickness of the second anode-side organic layer satisfies a relationship of a numerical formula (Numerical Formula A1), numerical formula (Numerical Formula A2), numerical formula (Numerical Formula A3), or numerical formula (Numerical Formula A4) below.
In the formulae, TL2 is a film thickness of the second anode-side organic layer, TL3 is a film thickness of the third anode-side organic layer, and a unit of the film thickness is denoted by nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the ratio TL3/TL2 is 1 or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the ratio TL3/TL2 is 2.5 or less.
In the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer are in direct contact with each other.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, in a case where the hole transporting zone consists of the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer, the third anode-side organic layer is in direct contact with the emitting region.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer is in direct contact with the anode.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer each contain at least one compound, the compounds respectively contained in the first, second, and third anode-side organic layers being different from each other.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, although each of the first anode-side organic layer and the second anode-side organic layer may contain a compound represented by the formula (C1) or a compound represented by the formula (C3), the compound(s) contained in the first anode-side organic layer and the second anode-side organic layer is/are different from a compound contained in the third anode-side organic layer in a molecular structure.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, all the compound(s) contained in the second anode-side organic layer (second hole transporting zone material) is/are different from all the compound(s) contained in the third anode-side organic layer (third hole transporting zone material).
An arrangement satisfying the above condition is exemplified by a case where the second anode-side organic layer contains a compound AA and the third anode-side organic layer contains a compound BB.
Further, for instance, the above condition is satisfied also when the second anode-side organic layer contains two types of compounds (compound AA and compound AB) and the third anode-side organic layer contains a compound (compound BB), because both the compounds AA and AB are different from the compound BB. The compounds AA, AB, and BB are compounds different from each other.
On the other hand, for instance, the above condition is not satisfied when the second anode-side organic layer contains two types of compounds (compound AA and compound AB) and the third anode-side organic layer contains a compound (compound AB), because the second anode-side organic layer and the third anode-side organic layer contain the same compound (compound AB).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole mobility of the third hole transporting zone material μh(cHT3) is larger than 1.0×10−5 cm2/Vs.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the energy level of the highest occupied molecular orbital of the third hole transporting zone material HOMO(cHT3) is −5.6 eV or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole mobility of the third hole transporting zone material μh(cHT3) is larger than 1.0×10−5 cm2/Vs, and the energy level of the highest occupied molecular orbital of the third hole transporting zone material HOMO(cHT3) is −5.6 eV or less. When the hole mobility μh(cHT3) and the energy level HOMO(cHT3) of the third hole transporting zone material fall within the above ranges, the third anode-side organic layer has a high hole mobility and a high hole injectability to the emitting layer in the emitting region.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the singlet energy of the third hole transporting zone material is larger than 3.12 eV.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the singlet energy of the third hole transporting zone material is 3.15 eV or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the singlet energy of the third hole transporting zone material is 3.40 eV or less or 3.30 eV or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer does not contain the compound(s) contained in the second anode-side organic layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound contained in the third anode-side organic layer (third hole transporting zone material) is at least one compound selected from the group consisting of a compound represented by a formula (C1) below and a compound represented by a formula (C3) below.
In the formula (C1):
In the formula (C3):
In the formulae (C3-1) and (C3-2), each * represents a bonding position to LC5.
In the compound represented by the formula (C3), the substituent for the “substituted or unsubstituted” group is not a group represented by —N(RC6)(RC7), and RC6 and RC7 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound represented by the formula (C1) is at least one compound selected from the group consisting of a compound represented by the formula (cHT3-1), a compound represented by the formula (cHT3-2), a compound represented by the formula (cHT3-3), and a compound represented by the formula (cHT3-4).
In the formulae (cHT3-1), (cHT3-2), (cHT3-3), and (cHT3-4):
In the formula (1-a):
In the formula (1-b):
In the formula (1-c):
In the formula (1-d):
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, in the compounds represented by the formula (cHT3-1), (cHT3-2), (cHT3-3), and (cHT3-4), the substituent for the “substituted or unsubstituted” group is not a group represented by —N(RC6)(RC7), and RC6 and RC7 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the third third hole transporting zone material is a monoamine compound having one substituted or unsubstituted amino group in a molecule.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound represented by the formula (C1) is a compound represented by a formula (C11) below.
In the formula (C11):
In the compound represented by the formula (C1), at least one of Ar311, Ar312, or Ar313 is preferably a group selected from the group consisting of groups represented by formulae (21a), (21b), (21c), (21d), and (21e) below.
In the compound represented by the formula (C11), at least one of Ar111, Ar112, or Ar113 is preferably a group selected from the group consisting of groups represented by formulae (21a), (21b), (21c), (21d), and (21e) below.
In the formulae (21a), (21 b), (21c), (21d), and (21e):
Ar111, Ar112, and Ar113 not being the group selected from the group consisting of groups represented by the formulae (21a), (21b), (21c), (21d) and (21e) are preferably each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, more preferably a substituted or unsubstituted phenyl group or a substituted or unsubstituted biphenyl group.
In the compound represented by the formula (C1), it is also preferable that two of Ar311, Ar312, and Ar313 are each a group selected from the group consisting of groups represented by the formulae (21a), (21b), (21c), (21d), and (21e), and a remaining one of Ar311, Ar312, and Ar313 is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.
In the compound represented by the formula (C11), it is also preferable that two of Ar111, Ar112, and Ar113 are each a group selected from the group consisting of groups represented by the formulae (21a), (21b), (21c), (21d), and (21e), and a remaining one of Ar111, Ar112, and Ar113 is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.
In the compound represented by the formula (C1), it is also preferable that one of Ar311, Ar312, and Ar313 is a group selected from the group consisting of groups represented by the formulae (21a), (21 b), (21c), (21d), and (21e), and remaining two of Ar311, Ar312, and Ar313 are each a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.
In the compound represented by the formula (C11), it is also preferable that one of Ar111, Ar112, and Ar113 is a group selected from the group consisting of groups represented by the formulae (21a), (21 b), (21c), (21d), and (21e), and remaining two of Ar111, Ar112, and Ar113 are each a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material and the third hole transporting zone material are different compounds.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a hole mobility of the second hole transporting zone material μh(cHT2) is larger than 1.0×10−4 cm2/Vs.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole mobility of the second hole transporting zone material μh(cHT2) is larger than the hole mobility of the third hole transporting zone material μh(cHT3).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, an energy level of the highest occupied molecular orbital of the second hole transporting zone material HOMO(cHT2) and the energy level of the highest occupied molecular orbital of the third hole transporting zone material HOMO(cHT3) satisfy a relationship of a numerical formula (Numerical Formula B1) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole mobility of the second hole transporting zone material μh(cHT2) is larger than 1.0×10−4 cm2/Vs, the hole mobility of the third hole transporting zone material μh(cHT3) is larger than 1.0×10−5 cm2/Vs, and the energy level of the highest occupied molecular orbital of the second hole transporting zone material HOMO(cHT2) and the energy level of the highest occupied molecular orbital of the third hole transporting zone material HOMO(cHT3) satisfy the relationship of the numerical formula (Numerical Formula B1).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material is a compound represented by the formula (C1) or a compound represented by the formula (C3).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, although both the second anode-side organic layer and the third anode-side organic layer may contain a compound represented by the formula (C1), the compound contained in the second anode-side organic layer and the compound contained in the third anode-side organic layer are mutually different in a molecular structure.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, although both the second anode-side organic layer and the third anode-side organic layer may contain a compound represented by the formula (C3), the compound contained in the second anode-side organic layer and the compound contained in the third anode-side organic layer are mutually different in a molecular structure.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer is at least one compound selected from the group consisting of a compound represented by the formula (cHT2-1), a compound represented by the formula (cHT2-2), and a compound represented by the formula (cHT2-3).
In the formulae (cHT2-1), (cHT2-2), and (cHT2-3):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second anode-side organic layer contains at least one compound selected from the group consisting of a compound represented by the formula (cHT2-1), a compound represented by the formula (cHT2-2), and a compound represented by the formula (cHT2-3), and the third anode-side organic layer contains at least one compound selected from the group consisting of a compound represented by the formula (cHT3-1), a compound represented by the formula (cHT3-2), a compound represented by the formula (cHT3-3), and a compound represented by the formula (cHT3-4).
In an the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer is a monoamine compound having one substituted or unsubstituted amino group in a molecule, or a diamine compound having two substituted or unsubstituted amino groups in a molecule.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer is a monoamine compound.
In the monoamine compound and the diamine compound, a nitrogen atom of an amino group is not an atom forming a ring (i.e., a ring atom). When a nitrogen atom is a ring atom in a carbazole ring, an azine ring and the like, the nitrogen atom is not a nitrogen atom as an amino group.
For instance, a compound HT-X below has two nitrogen atoms in a molecule: one nitrogen atom in the compound HT-X is a ring atom of a carbazole ring and the other nitrogen atom is not a ring atom but a nitrogen atom as an amino group. The compound HT-X is a compound having a structure in which 9-phenyl-3-carbazolyl group is bonded to a nitrogen atom of an amino group via a linking group, that is, a monoamine compound.
A compound HT-Y below is also a compound having a structure in which 9-carbazolyl group is bonded to a nitrogen atom of an amino group via a linking group, that is, a monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer has at least one group selected from the group consisting of a group represented by a formula (2-a), a group represented by a formula (2-b), a group represented by a formula (2-c), a group represented by a formula (2-d), a group represented by a formula (2-e), and a group represented by a formula (2-f) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer is a monoamine compound having one substituted or unsubstituted amino group in a molecule, and the group represented by the formula (2-a), the group represented by the formula (2-b), the group represented by the formula (2-c), the group represented by the formula (2-d), the group represented by the formula (2-e), and the group represented by the formula (2-f) are each independently bonded directly, with a phenylene group, or with a biphenylene group to a nitrogen atom of an amino group of the monoamine compound.
In the formula (2-a):
In the formula (2-b):
In the formula (2-c):
In the formula (2-d):
In the formula (2-e):
In the formula (2-f):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the group represented by the formula (2-a), the group represented by the formula (2-b), the group represented by the formula (2-c), the group represented by the formula (2-d), the group represented by the formula (2-e), and the group represented by the formula (2-f) are each independently bonded directly, with a phenylene group, or with a biphenylene group to a nitrogen atom of an amino group of the monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the group represented by the formula (2-e) is a group represented by a formula (2-e1), a formula (2-e2), or a formula (2-e3) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material is a compound represented by the formula (cHT2-1), and at least one of Ar112 or Ar113 is a group selected from the group consisting of a group represented by the formula (2-a), a group represented by the formula (2-b), a group represented by the formula (2-c), a group represented by the formula (2-d), a group represented by the formula (2-e), and a group represented by the formula (2-f).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material is a compound represented by the formula (cHT2-2), and at least one of Ar112 or Ar113 is a group selected from the group consisting of a group represented by the formula (2-a), a group represented by the formula (2-b), a group represented by the formula (2-c), a group represented by the formula (2-d), a group represented by the formula (2-e), and a group represented by the formula (2-f).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material is a compound represented by the formula (cHT2-3), and at least one of Ar121, Ar122, A123, or A124 is a group selected from the group consisting of a group represented by the formula (2-a), a group represented by the formula (2-b), a group represented by the formula (2-c), a group represented by the formula (2-d), a group represented by the formula (2-e), and a group represented by the formula (2-f).
In the formulae (2-e1), (2-e2), and (2-e3):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, ** in the formulae (2-a), (2-b), (2-c), (2-d), (2-e), (2-f), (2-e1), (2-e2), and (2-e3) are each independently a bonding position to LA2, LA3, LB1, LB2, LB3, or LB4, or a bonding position to a nitrogen atom of an amino group.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second hole transporting zone material contained in the second anode-side organic layer is a compound having no thiophene ring in a molecule.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer contains a first hole transporting zone material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first hole transporting zone material and the third hole transporting zone material are different compounds.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first hole transporting zone material and the second hole transporting zone material may be different compounds or the same compound. When the first hole transporting zone material and the second hole transporting zone material are the same compound, the first anode-side organic layer preferably contains a compound (e.g., a doped compound) having a molecular structure different from that of the first hole transporting zone material, the second hole transporting zone material, and the third hole transporting zone material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer contains a first organic material and a second organic material. The second organic material is preferably the first hole transporting zone material. The first organic material is preferably a doped compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer contains a doped compound as the first organic material and the first hole transporting zone material as the second organic material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material contained in the first anode-side organic layer is at least one compound selected from the group consisting of a compound represented by the formula (cHT2-1), a compound represented by the formula (cHT2-2), and a compound represented by the formula (cHT2-3).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material contained in the first anode-side organic layer is a monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material contained in the first anode-side organic layer has at least one group selected from the group consisting of a group represented by the formula (2-a), a group represented by the formula (2-b), a group represented by the formula (2-c), a group represented by the formula (2-d), a group represented by the formula (2-e), and a group represented by the formula (2-f) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material contained in the first anode-side organic layer is a monoamine compound having one substituted or unsubstituted amino group in a molecule, and the group represented by the formula (2-a), the group represented by the formula (2-b), the group represented by the formula (2-c), the group represented by the formula (2-d), the group represented by the formula (2-e), and the group represented by the formula (2-f) are each independently bonded directly, with a phenylene group, or with a biphenylene group to a nitrogen atom of an amino group of the monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material is one compound selected from the group consisting of a compound represented by the formula (cHT2-1) and a compound represented by the formula (cHT2-2).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound represented by the formula (cHT2-1) and the compound represented by the formula (cHT2-2) as the second organic material are each a monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, when the first anode-side organic layer contains the first hole transporting zone material (second organic material) and the doped compound (first organic material), a content of the first organic material in the first anode-side organic layer is 15 mass % or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the content of the first organic material in the first anode-side organic layer is 5 mass % or more.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, when the first anode-side organic layer contains the first hole transporting zone material and the doped compound (first organic material), the content of the doped compound in the first anode-side organic layer is preferably in a range from 0.5 mass % to 5 mass %, and more preferably in a range from 1.0 mass % to 3 mass %. The content of the first hole transporting zone material in the first anode-side organic layer is preferably 40 mass % or more, more preferably 45 mass % or more, and still more preferably 50 mass % or more. The content of the first hole transporting zone material in the first anode-side organic layer is preferably 99.5 mass % or less. The total of a content of the first hole transporting zone material and a content of the doped compound in the first anode-side organic layer is 100 mass % or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the doped compound has at least one of a first cyclic structure represented by a formula (P11) below or a second cyclic structure represented by a formula (P12) below.
The first cyclic structure represented by the formula (P11) is fused to at least one cyclic structure of a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocycle having 5 to 50 ring atoms in a molecule of the doped compound.
A structure represented by =Z10 is represented by a formula (11a), (11 b), (11c), (11d), (11e), (11f), (11g), (11h), (11i), (11j), (11k), or (11m) below.
In the formulae (11a), (11 b), (11c), (11d), (11e), (11f), (11g), (11h), (11i), (11j), (11k), or (11m): R11 to R14 and R1101 to R1110 are each independently a hydrogen atom, a halogen atom, a hydroxy group, a cyano group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkyl halide group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by —Si(R901)(R902)(R903), a group represented by —O—(R904), a group represented by —S—(R905), a group represented by —N(R906)(R907), a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In the formula (P12): Z1 to Z5 are each independently a nitrogen atom, a carbon atom bonded to R15, or a carbon atom bonded to another atom in a molecule of the doped compound;
In the doped compound, R901 to R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
An ester group herein is at least one group selected from the group consisting of an alkyl ester group and an aryl ester group.
An alkyl ester group herein is represented, for instance, by —C(═O)ORE. RE is exemplified by a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms (preferably 1 to 10 carbon atoms).
An aryl ester group herein is represented, for instance, by —C(═O)ORAr. RAr is exemplified by a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.
A siloxanyl group herein, which is a silicon compound group through an ether bond, is exemplified by a trimethylsiloxanyl group.
A carbamoyl group herein is represented by —CONH2.
A substituted carbamoyl group herein is represented, for instance, by —CONH—ArC or —CONH—RC. ArC is, for instance, at least one group selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms (preferably 6 to 10 ring carbon atoms) and a heterocyclic group having 5 to 50 ring atoms (preferably 5 to 14 ring atoms). ArC may be a group in which a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms is bonded to a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
RC is exemplified by a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms (preferably 1 to 6 carbon atoms).
In the doped compound, all groups specified as “substituted or unsubstituted” groups are preferably “unsubstituted” groups.
Specific examples of the doped compound include the following compounds. It should however be noted that the invention is not limited to the specific examples of the doped compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the hole transporting zone further includes a fourth anode-side organic layer disposed between the third anode-side organic layer and the emitting region.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer is in direct contact with the emitting region.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer is in direct contact with the third anode-side organic layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the fourth anode-side organic layer are arranged in this order from a side close to the anode.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer is a blocking layer. For instance, when the blocking layer is disposed on a side of the first emitting layer close to the anode, the blocking layer permits transport of holes and blocks electrons from reaching each organic layer in the hole transporting zone provided closer to the anode with respect to the blocking layer. Alternatively, the blocking layer may be provided in direct contact with the first emitting layer so that excitation energy does not leak out from the first emitting layer toward neighboring layer(s). The blocking layer disposed on the side of the first emitting layer close to the anode blocks excitons generated in the emitting layer from transferring to each organic layer in the hole transporting zone. The first emitting layer is preferably in direct contact with the blocking layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer is thinner than the third anode-side organic layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer has a film thickness of 20 nm or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer has a film thickness of 5 nm or more.
Presumably, the organic EL device according to the exemplary embodiment has a long lifetime by being provided with the fourth anode-side organic layer (preferably an electron blocking layer) smaller in film thickness than that of the third anode-side organic layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer contains a fourth hole transporting zone material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth hole transporting zone material and the third hole transporting zone material are different compounds.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth hole transporting zone material, the third hole transporting zone material, and the second hole transporting zone material are different compounds.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the fourth anode-side organic layer contains a compound represented by the formula (C1) or a compound represented by the formula (C3).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, although the third anode-side organic layer and the fourth anode-side organic layer may each contain a compound represented by the formula (C1), the compound contained in the third anode-side organic layer and the compound contained in the fourth anode-side organic layer are mutually different in a molecular structure.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the fourth anode-side organic layer each contain at least one compound, the compounds respectively contained in the first, second, third, and fourth anode-side organic layers being different from each other.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the fourth anode-side organic layer each contain a monoamine compound having only one substituted or unsubstituted amino group in a molecule.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the fourth anode-side organic layer contain no diamine compound. The diamine compound has two substituted or unsubstituted amino groups in a molecule.
The compound represented by the formula (C1) is preferably a monoamine compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, at least one of the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, or the fourth anode-side organic layer may also contain a diamine compound. The compound represented by the formula (C3) is preferably a diamine compound.
In the organic EL device according to the exemplary embodiment, R901, R902, R903, and R904 in the compounds contained in the hole transporting zone are each independently a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
In the exemplary embodiment, all groups specified as “substituted or unsubstituted” groups are preferably “unsubstituted” groups.
In the exemplary embodiment, the first hole transporting zone material, the second hole transporting zone material, the third hole transporting zone material, and the fourth hole transporting zone material each may be occasionally referred to as a hole transporting zone material.
In the organic EL device according to the exemplary embodiment, the hole transporting zone material may be a compound that contains a substituted or unsubstituted 3-carbazolyl group in a molecule. In the organic EL device according to the exemplary embodiment, the hole transporting zone material may be a compound that does not contain a substituted or unsubstituted 3-carbazolyl group in a molecule.
The hole transporting zone material according to the exemplary embodiment can be produced by a known method or through a known alternative reaction using a known material(s) tailored for the target compound in accordance with the known method.
Specific examples of the hole transporting zone material according to the exemplary embodiment include the following compounds. However, the invention is by no means limited to the specific examples.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second organic material (first hole transporting zone material) contained in the first anode-side organic layer is preferably at least one compound selected from compounds listed below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound (second hole transporting zone material) contained in the second anode-side organic layer is preferably at least one compound selected from compounds listed below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the compound (third hole transporting zone material) contained in the third anode-side organic layer is preferably at least one compound selected from compounds listed below.
The compounds exemplified as the compound contained in any one of the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer sometimes overlap with examples of compounds for other layers. In the exemplary embodiment, different compounds can be appropriately selected from the listed compounds as the compounds usable for the first anode-side organic layer, the second anode-side organic layer, and the third anode-side organic layer.
The emitting region includes at least one emitting layer. The at least one emitting layer includes a first emitting layer.
The first emitting layer includes a first host material, a first additional host material different from the first host material, and a first luminescent compound. The first host material, which is not particularly limited, may be, for instance, a compound selected from the group consisting of a compound represented by a formula (H10) described later and a first compound described later. The first additional host material, which is not particularly limited, may be, for instance, a compound represented by a formula (H20) described later.
The first luminescent compound, which is not particularly limited, may be, for instance, a compound selected from the group consisting of a compound represented by a formula (6), a third compound, and a fourth compound which are described later.
The first luminescent compound preferably emits light having a maximum peak wavelength of 500 nm or less, and more preferably emits light having a maximum peak wavelength in a range from 430 nm to 480 nm. The first luminescent compound is preferably a fluorescent compound that emits fluorescence having a maximum peak wavelength of 500 nm or less, and more preferably a fluorescent compound that emits fluorescence having a maximum peak wavelength in a range from 430 nm to 480 nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first luminescent compound has a full width at half maximum in a range from 1 nm to 30 nm at a maximum peak.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first luminescent compound is a compound containing no azine ring structure in a molecule.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first luminescent compound is preferably not a boron-containing complex, and more preferably not a complex.
For instance, examples of a fluorescent compound that emits blue fluorescence and is usable for the first emitting layer include a pyrene derivative, styrylamine derivative, chrysene derivative, fluoranthene derivative, fluorene derivative, diamine derivative, and triarylamine derivative.
Herein, the blue light emission refers to light emission in which a maximum peak wavelength of emission spectrum is in a range from 430 nm to 500 nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, when the emitting region includes two or more emitting layers, the two or more emitting layers are each a fluorescent emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer does not contain a metal complex. Moreover, in an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer does not contain a boron-containing complex.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer does not contain a phosphorescent material (dopant material).
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer does not contain a heavy metal complex and a phosphorescent rare-earth metal complex. Examples of the heavy-metal complex herein include iridium complex, osmium complex, and platinum complex.
A measurement method of the maximum peak wavelength of the compound is as follows. A toluene solution of a measurement target compound at a concentration of 5 μmol/L is prepared and put in a quartz cell. An emission spectrum (ordinate axis: luminous intensity, abscissa axis: wavelength) of each of the samples is measured at a normal temperature (300K). The emission spectrum can be measured using a spectrophotometer (machine name: F-7000) produced by Hitachi High-Tech Science Corporation. It should be noted that the apparatus for measuring the emission spectrum is not limited to the apparatus used herein.
A peak wavelength of the emission spectrum exhibiting the maximum luminous intensity is defined as the maximum peak wavelength. Herein, the maximum peak wavelength of fluorescence is occasionally referred to as a maximum fluorescence peak wavelength (FL-peak).
In an emission spectrum of the first luminescent compound, where a peak exhibiting a maximum luminous intensity is defined as a maximum peak and a height of the maximum peak is defined as 1, heights of other peaks appearing in the emission spectrum are preferably less than 0.6. It should be noted that the peaks in the emission spectrum are defined as local maximum values.
Moreover, in the emission spectrum of the first luminescent compound, the number of peaks is preferably less than three.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer contains 0.5 mass % or more of the first luminescent compound with respect to the total mass of the first emitting layer.
The first emitting layer contains the first luminescent compound preferably at 10 mass % or less, more preferably at 7 mass % or less, and still more preferably at 5 mass % or less with respect to the total mass of the first emitting layer.
Herein, the “host material” refers to, for instance, a material that accounts for “50 mass % or more of the layer.”
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer contains the first host material and the first additional host material in total preferably at 60 mass % or more, more preferably at 70 mass % or more, still more preferably at 80 mass % or more, still further more preferably at 90 mass % or more, and yet still further more preferably at 95 mass % or more, with respect to the total mass of the first emitting layer.
The first emitting layer preferably contains the first host material and the first additional host material in total at 99 mass % or less with respect to the total mass of the first emitting layer.
The upper limit of a total of the content ratios of the first host material, the first additional host material, and the first luminescent compound in the first emitting layer is 100 mass %.
It should be noted that in the organic EL device according to the exemplary embodiment, the first emitting layer may further may contain any other material than the first host material, the first additional host material, and the first luminescent compound.
The first emitting layer may contain a single type of the first host material alone or may contain two or more types of the first host material. The first emitting layer may contain a single type of the first additional host material alone or may contain two or more types of the first additional host material. The first emitting layer may contain a single type of the first luminescent compound alone or may contain two or more types of the first luminescent compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material has at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material has no deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is a compound represented by a formula (H10) below.
In the formula (H10):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, at least one combination of adjacent two or more of R311 to R314 in the formula (H10) are bonded to each other to form a substituted or unsubstituted benzene ring.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R301 to R308 each independently have at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, L301, L302, Ar301, and R311 to R314 each independently have at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is a compound represented by a formula (H31), (H32) or (H33) below.
In the formulae (H31), (H32), and (H33):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is a compound represented by a formula (H301) or (H302) below.
In the formulae (H301) and (H302):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is a compound represented by a formula (H311), (H312), (H321), (H322), (H331), or (H332) below.
In the formulae (H311), (H312), (H321), (H322), (H331), and (H332):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, L301 and L302 of the first host material are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 14 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, L301 and L302 of the first host material are each independently a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted naphthylene group.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, L301 and L302 of the first host material are each a single bond.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is a compound represented by a formula (H313), (H314), (H323), (H324), (H333), or (H334) below.
In the formulae (H313), (H314), (H323), (H324), (H333), and (H334):
In an exemplary arrangement of the organic EL Device of the exemplary embodiment, R311 to R317 and R321 to R324 of the first host material are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary arrangement of the organic EL Device of the exemplary embodiment, R311 to R317 and R321 to R324 of the first host material are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, Ar301 of the first host material is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, Ar301 of the first host material is a group represented by a formula (a1), (a2), (a3), or (a4) below.
In the formulae (a1), (a2), (a3), and (a4):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, Ar301 of the first host material is a group represented by the formula (a1) or (a2).
In an exemplary embodiment of the organic EL device of the exemplary embodiment, R330 to R335 and R341 to R348 of the first host material are each a hydrogen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, X3 of the first host material is an oxygen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R301 to R308 of the first host material are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R301 to R308 of the first host material are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R301 to R308 of the first host material are each a hydrogen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first additional host material has at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first additional host material has no deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first additional host material is a compound represented by a formula (H20) below.
In the formula (H20):
[Formula 213]
-L203-Ar203 (H21)
In the formulae (H20) and (H21):
In the first additional host material, R901, R902, R903, R904, R905, R906, and R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
In an exemplary arrangement of the organic EL device of the exemplary embodiment, Ar201, Ar202, and Ar203 are each independently a phenyl group, naphthyl group, phenanthryl group, biphenyl group, terphenyl group, diphenylfluorenyl group, dimethylfluorenyl group, benzodiphenylfluorenyl group, benzodimethylfluorenyl group, dibenzofuranyl group, dibenzothienyl group, naphthobenzofuranyl group, or naphthobenzothienyl group.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R201 to R208 each independently have at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, L201, L202, L203, Ar201, Ar202, and Ar203 each independently have at least one deuterium atom.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the compound represented by the formula (H20) is a compound represented by a formula (201), a formula (202), a formula (203), a formula (204), a formula (205), a formula (206), a formula (207), a formula (208), or a formula (209) below.
In the formulae (201) to (209): L201 and Ar201 respectively represent the same as L201 and Ar201 in the formula (H20); and R201 to R208 each independently represent the same as R201 to R208 in the formula (H20).
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the compound represented by the formula (H20) is a compound represented by a formula (221), a formula (222), a formula (223), a formula (224), a formula (225), a formula (226), a formula (227), a formula (228), or a formula (229) below.
In the formulae (221), (222), (223), (224), (225), (226), (227), (228) and (229):
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the compound represented by the formula (H20) is a compound represented by a formula (241), a formula (242), a formula (243), a formula (244), a formula (245), a formula (246), a formula (247), a formula (248), or a formula (249) below.
In the formulae (241), (242), (243), (244), (245), (246), (247), (248) and (249):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is represented by one of the formulae (201) to (209), (221) to (229), and (241) to (249).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material is represented by one of the formulae (201) to (209), (221) to (229), and (241) to (249), the first additional host material is represented by one of the formulae (201) to (209), (221) to (229), and (241) to (249), and the first host material and the first additional host material being mutually different compounds.
In this arrangement, preferably, one of Ar201 of the first host material and Ar201 of the first additional host material is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, and the other of Ar201 of the first host material and Ar201 of the first additional host material is a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
For instance, when the first host material is represented by the formula (203) and the first additional host material is represented by the formula (201), preferably, Ar201 in the formula (203) is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms and Ar201 in the formula (201) is a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
When the first host material is represented by the formula (201) and the first additional host material is represented by the formula (203), preferably, Ar201 in the formula (201) is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms and Ar201 in the formula (203) is a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R201 to R208 in the formula (H20) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, or a group represented by —Si(R901)(R902)(R903).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, in the formula (H20), L201 is a single bond or an unsubstituted arylene group having 6 to 22 ring carbon atoms and Ar201 is a substituted or unsubstituted aryl group having 6 to 22 ring carbon atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, R201 to R208 that are substituents of an anthracene skeleton in the formula (H20) are preferably hydrogen atoms in terms of preventing inhibition of intermolecular interaction and inhibiting decrease in electron mobility. However, R201 to R208 may be a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, when the emitting region at least includes the first emitting layer containing the first host material represented by the formula (H10) and the first additional host material represented by the formula (H20) and the second emitting layer containing the second host material, R301 to R308 that are substituents of an anthracene skeleton in the compound represented by the formula (H10) and R201 to R208 that are substituents of an anthracene skeleton in the compound represented by the formula (H20) are preferably hydrogen atoms in terms of preventing inhibition of intermolecular interaction and inhibiting decrease in electron mobility. However, R301 to R308 and R201 to R208 may be a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
An exemplary arrangement of the organic EL device of the exemplary embodiment may include the anode, the second emitting layer, the first emitting layer, and the cathode in this order. However, the order of the first emitting layer and the second emitting layer may be inversed.
For instance, in a case where the second emitting layer and the first emitting layer are layered in this order from a side close to the anode, the first host material contained in the first emitting layer is a compound represented by the formula (H10), and the first additional host material contained in the first emitting layer is a compound represented by the formula (H20), the following phenomenon may occur. Therefore, R301 to R308 and R201 to R208 in the formulae (H10) and (H20) are each preferably not a bulky substituent.
Assuming that R301 to R308 and R201 to R208 in the formulae (H10) and (H20) are each a bulky substituent such as an alkyl group and a cycloalkyl group, intermolecular interaction may be inhibited to decrease the electron mobility relative to that of the second host material, so that the relationship of μe(H1)>μe(H2) shown by a later-described numerical formula (Numerical Formula 3) may not be satisfied. In a case where the first emitting layer includes the first host material represented by the formula (H10) and the first additional host material represented by the formula (H20), it can be expected that satisfying the relationship of μe(H1)>μe(H2) inhibits a decrease in a recombination ability between holes and electrons and a decrease in luminous efficiency in the second emitting layer. It should be noted that substituents, namely, a haloalkyl group, alkenyl group, alkynyl group, group represented by —Si(R901)(R902)(R903), group represented by —O—(R904), group represented by —S—(R905), group represented by —N(R906)(R907), aralkyl group, group represented by —C(═O)R801, group represented by —COOR802, halogen atom, cyano group, and nitro group are likely to be bulky, and an alkyl group and cycloalkyl group are likely to be further bulky.
In the compounds represented by the formulae (H10) and (H20), R301 to R308 and R201 to R208, which are the substituents on the anthracene skeleton, are each preferably not a bulky substituent and preferably not an alkyl group and cycloalkyl group. More preferably, R301 to R308 and R201 to R208 are each not an alkyl group, cycloalkyl group, haloalkyl group, alkenyl group, alkynyl group, group represented by —Si(R901)(R902)(R903), group represented by —O—(R904), group represented by —S—(R905), group represented by —N(R906)(R907), aralkyl group, group represented by —C(═O)R801, group represented by —COOR802, halogen atom, cyano group, and nitro group.
In the formulae (H10) and (H20), examples of the substituent for the “substituted or unsubstituted” group on R301 to R308 and R201 to R208 also preferably do not include the above-described substituents that are likely to be bulky, especially a substituted or unsubstituted alkyl group and a substituted or unsubstituted cycloalkyl group. When examples of the substituent for the “substituted or unsubstituted” group on R301 to R308 and R201 to R208 do not include a substituted or unsubstituted alkyl group and a substituted or unsubstituted cycloalkyl group, inhibition of intermolecular interaction to be caused by presence of a bulky substituent such as an alkyl group and a cycloalkyl group can be prevented, thereby preventing a decrease in the electron mobility. Moreover, when the compounds described above are used as the first host material and the first additional host material in the first emitting layer, a decrease in a recombination ability between holes and electrons and a decrease in the luminous efficiency can be inhibited in the second emitting layer.
Still more preferably, R301 to R308 and R201 to R208, which are substituents on the anthracene skeleton, are not bulky substituents and R301 to R308 and R201 to R208 as the substituents are unsubstituted. In a case where R301 to R308 and R201 to R208 that are the substituents on the anthracene skeleton are not bulky substituents and substituents are respectively bonded to R301 to R308 and R201 to R208 that are not the bulky substituents, the substituents bonded to R301 to R308 and R201 to R208 are preferably not bulky substituents; and the substituents bonded to R301 to R308 and R201 to R208 being substituents are preferably not an alkyl group and cycloalkyl group, and more preferably not an alkyl group, cycloalkyl group, haloalkyl group, alkenyl group, alkynyl group, group represented by —Si(R901)(R902)(R903), group represented by —O—(R904), group represented by —S—(R905), group represented by —N(R906)(R907), aralkyl group, group represented by —C(═O)R801, group represented by —COOR802, halogen atom, cyano group, and nitro group.
In the first host material, the groups specified to be “substituted or unsubstituted” are each preferably an “unsubstituted” group.
In the first additional host material, the groups specified to be “substituted or unsubstituted” are each preferably an “unsubstituted” group.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first host material does not substantially contain a deuterium atom and the first additional host material contains at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first emitting layer contains a compound represented by the formula (H10) as the first host material and a compound represented by the formula (H20) as the first additional host material, and at least one of the compound represented by the formula (H10) or the compound represented by the formula (H20) has at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first emitting layer contains a compound represented by the formula (H10) as the first host material and a compound represented by the formula (H20) as the first additional host material, the compound represented by the formula (H10) does not substantially contain a deuterium atom and the compound represented by the formula (H20) contains at least one deuterium atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first emitting layer contains a compound represented by the formula (H10) as the first host material and a compound represented by the formula (H20) as the first additional host material, the compound represented by the formula (H10) contains at least one deuterium atom and the compound represented by the formula (H20) does not substantially contain a deuterium atom.
Here, the phrase hat “the compound does not substantially contain a compound having a deuterium atom” means that the compound does not contain a deuterium atom at all or the compound is allowed to contain a deuterium atom in a natural abundance. For instance, the natural abundance of a deuterium atom is 0.015% or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first emitting layer contains a compound represented by the formula (H10) as the first host material and a compound represented by the formula (H20) as the first additional host material, and the compound represented by the formula (H10) and the compound represented by the formula (H20) do not substantially contain a deuterium atom.
The first host material and the first additional host material can be produced by a known method. The first host material and the first additional host material can also be produced based on a known method through a known alternative reaction using a known material(s) tailored for the target compound.
Specific examples of the first host material and the first additional host material include the following compounds. It should however be noted that the invention is by no means limited to the specific examples of the first host material and the first additional host material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first luminescent compound is a compound represented by a formula (6) below.
In the formula (6):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the ring a, ring b and ring c are each a ring (a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocycle having 5 to 50 ring atoms) fused with a fused bicyclic structure formed of a boron atom and two nitrogen atoms at the center of the formula (6).
The “aromatic hydrocarbon ring” for the rings a, b, and c has the same structure as a compound formed by introducing a hydrogen atom to an “aryl group”.
Ring atoms of the “aromatic hydrocarbon ring” for the ring a include three carbon atoms on the fused bicyclic structure at the center of the formula (6).
Ring atoms of the “aromatic hydrocarbon ring” for the rings b and c include two carbon atoms on the fused bicyclic structure at the center of the formula (6).
Specific examples of the “substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms” include a compound formed by introducing a hydrogen atom to the “aryl group” described in the specific example group G1.
The “heterocycle” for the rings a, b, and c has the same structure as a compound formed by introducing a hydrogen atom to the “heterocyclic group” described above.
Ring atoms of the “heterocycle” for the ring a include three carbon atoms on the fused bicyclic structure at the center of the formula (6). Ring atoms of the “heterocycle” for the rings b and c include two carbon atoms on the fused bicyclic structure at the center of the formula (6). Specific examples of the “substituted or unsubstituted heterocycle having 5 to 50 ring atoms” include a compound formed by introducing a hydrogen atom to the “heterocyclic group” described in the specific example group G2.
R601 and R602 may be each independently bonded with the ring a, ring b, or ring c to form a substituted or unsubstituted heterocycle. The “heterocycle” in this arrangement includes a nitrogen atom on the fused bicyclic structure at the center of the formula (6). The heterocycle in the above arrangement optionally includes a hetero atom other than the nitrogen atom. R601 and R602 being bonded with the ring a, ring b, or ring c specifically means that atoms forming R601 and R602 are bonded with atoms forming the ring a, ring b, or ring c. For instance, R601 may be bonded with the ring a to form a bicyclic (or tri-or-more cyclic) fused nitrogen-containing heterocycle, in which the ring including R601 and the ring a are fused. Specific examples of the nitrogen-containing heterocycle include a compound corresponding to the nitrogen-containing bi(or-more)cyclic fused heterocyclic group in the specific example group G2.
The same applies to R601 bonded with the ring b, R602 bonded with the ring a, and R602 bonded with the ring c.
R601 and R602 may be each independently not bonded with the ring a, ring b, or ring c.
In an exemplary embodiment, the ring a, ring b and ring c in the formula (6) are each independently a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms.
In an exemplary embodiment, the ring a, ring b and ring c in the formula (6) are each independently a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthalene ring.
In an exemplary embodiment, R601 and R602 in the formula (6) are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, the compound represented by the formula (6) is a compound represented by a formula (62) below.
In the formula (62):
In the formula (62), R901, R902, R903, R904, R905, R906, and R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
R601A and R602A in the formula (62) are groups corresponding to R601 and R602, respectively, in the formula (6).
For instance, R601A and R611 are optionally bonded with each other to form a bicyclic (or tri-or-more cyclic) fused nitrogen-containing heterocycle, in which the ring including R601A and R611 and a benzene ring corresponding to the ring a are fused. Specific examples of the nitrogen-containing heterocycle include a compound corresponding to the nitrogen-containing bi(or-more)cyclic fused heterocyclic group in the specific example group G2. The same applies to R601A bonded with R621, R602A bonded with R613, and R602A bonded with R614.
At least one combination of adjacent two or more of R611 to R621 may be mutually bonded to form a substituted or unsubstituted monocyclic ring, or mutually bonded to form a substituted or unsubstituted fused ring.
For instance, R611 and R612 are optionally mutually bonded to form a structure in which a benzene ring, indole ring, pyrrole ring, benzofuran ring, benzothiophene ring or the like is fused to the six-membered ring bonded with R611 and R612, the resultant fused ring forming a naphthalene ring, carbazole ring, indole ring, dibenzofuran ring, or dibenzothiophene ring, respectively.
In an exemplary embodiment, R611 to R621 not contributing to ring formation are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, R611 to R621 not contributing to ring formation are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, R611 to R621 not contributing to ring formation are each independently a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, R611 to R621 not contributing to ring formation are each independently a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms; and at least one of R611 to R621 is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, the compound represented by the formula (62) is a compound represented by a formula (63) below.
In the formula (63):
R631 may be bonded with R646 to form a substituted or unsubstituted heterocycle. For instance, R631 and R646 may be bonded with each other to form a tri-or-more cyclic fused nitrogen-containing heterocycle, in which a benzene ring bonded with R646, a ring including a nitrogen atom, and a benzene ring corresponding to the ring a are fused. Specific examples of the nitrogen-containing heterocycle include a compound corresponding to a nitrogen-containing tri(-or-more)cyclic fused heterocyclic group in the specific example group G2. The same applies to R633 bonded with R647, R634 bonded with R651, and R641 bonded with R642.
In an exemplary embodiment, R631 to R651 not contributing to ring formation are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, R631 to R651 not contributing to ring formation are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, R631 to R651 not contributing to ring formation are each independently a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, R631 to R651 not contributing to ring formation are each independently a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms; and at least one of R631 to R651 is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, the compound represented by the formula (63) is a compound represented by a formula (63A) below.
In the formula (63A):
In an exemplary embodiment, R661 to R665 are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, R661 to R665 are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, the compound represented by the formula (63) is a compound represented by a formula (63B) below.
In the formula (63B):
In an exemplary embodiment, the compound represented by the formula (63) is a compound represented by a formula (63B′) below.
In the formula (63B′), R672 to R675 each independently represent the same as R672 to R675 in the formula (63B).
In an exemplary embodiment, at least one of R671 to R675 is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by —N(R906)(R907), or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, R672 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a group represented by —N(R906)(R907), or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms; and
In an exemplary embodiment, the compound represented by the formula (63) is a compound represented by a formula (63C) below.
In the formula (63C):
In an exemplary embodiment, the compound represented by the formula (63) is a compound represented by a formula (63C′) below.
In the formula (63C′), R683 to R686 each independently represent the same as R683 to R686 in the formula (63C).
In an exemplary embodiment, R681 to R686 are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, R681 to R686 are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
The compound represented by the formula (6) is producible by initially bonding the ring a, ring b and ring c with linking groups (a group including N—R601 and a group including N—R602) to form an intermediate (first reaction), and bonding the ring a, ring b and ring c with a linking group (a group including a boron atom) to form a final product (second reaction). In the first reaction, an amination reaction (e.g. Buchwald-Hartwig reaction) is applicable. In the second reaction, Tandem Hetero-Friedel-Crafts Reactions or the like is applicable.
In an exemplary embodiment, the compound represented by the formula (6) is a compound represented by a formula (42-2) below.
In the formula (42-2): R611 to R617, R601A and R602A each independently represent the same as R611 to R617, R601A and R602A in the formula (62);
In the formula (42-2), R901, R902, R903, R904, R905, R906, and R907 each independently represent the same as R901, R902, R903, R904, R905, R906, and R907 in the formula (62).
Specific examples of the compound represented by the formula (6) are shown below. It should however be noted that these specific examples are merely exemplary and do not limit the compound represented by the formula (6).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the emitting region consists of the first emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the emitting region further includes the second emitting layer in addition to the first emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the emitting region consists of the first emitting layer and the second emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the emitting region may include an organic layer different from the first emitting layer and the second emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the emitting region at least includes the first emitting layer containing the first host material and the first additional host material and the second emitting layer containing the second host material. The first host material and the second host material are mutually different and the first additional host material and the second host material are mutually different.
In a case where the emitting region at least includes the first emitting layer and the second emitting layer, luminous efficiency is improvable by using Triplet-Triplet-Annihilation (sometimes referred to as TTA).
TTA is a mechanism in which triplet excitons collide with one another to generate singlet excitons. The TTA mechanism is sometimes also referred to as a TTF mechanism as described in International Publication No. WO2010/134350.
The TTF phenomenon will be described. Holes injected from an anode and electrons injected from a cathode are recombined in an emitting layer to generate excitons. As for the spin state, as is conventionally known, singlet excitons account for 25% and triplet excitons account for 75%. In a conventionally known fluorescent device, light is emitted when singlet excitons of 25% are relaxed to the ground state. The remaining triplet excitons of 75% are returned to the ground state without emitting light through a thermal deactivation process. Accordingly, the theoretical limit value of the internal quantum efficiency of the conventional fluorescent device is believed to be 25%.
The behavior of triplet excitons generated within an organic substance has been theoretically examined. According to S. M. Bachilo et al. (J. Phys. Chem. A, 104, 7711 (2000)), assuming that high-order excitons such as quintet excitons are quickly returned to triplet excitons, triplet excitons (hereinafter abbreviated as 3A*) collide with one another with an increase in density thereof, whereby a reaction shown by the following formula occurs. In the formula, 1A represents the ground state and 1A* represents the lowest singlet excitons.
In other words, 53A*→* 41A+1A* is satisfied, and it is expected that, among triplet excitons initially generated, which account for 75%, one fifth thereof (i.e., 20%) is changed to singlet excitons. Accordingly, the amount of singlet excitons which contribute to emission is 40%, which is a value obtained by adding 15% (75%×(⅕)=15%) to 25%, which is the amount ratio of initially generated singlet excitons. At this time, a ratio of luminous intensity derived from TTF (TTF ratio) relative to the total luminous intensity is 15/40, i.e., 37.5%. Assuming that singlet excitons are generated by collision of initially generated triplet excitons accounting for 75% (i.e., one singlet exciton is generated from two triplet excitons), a significantly high internal quantum efficiency of 62.5% is obtained, which is a value obtained by adding 37.5% (75%×(½)=37.5%) to 25% (the amount ratio of initially generated singlet excitons). At this time, the TTF ratio is 37.5/62.5=60%.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, from the viewpoint of expressing TTF mechanism, the triplet energy of the first host material or the first additional host material T1 and the triplet energy of the second host material T1(H2) preferably satisfy a relationship of a numerical formula (Numerical Formula 1) below, more preferably satisfy a relationship of a numerical formula (Numerical Formula 2) below.
The triplet energy T1 of the first host material or the first additional host material is collectively denoted by T1(H1) in the description below.
When an exemplary arrangement of the organic EL device of the exemplary embodiment includes the first emitting layer and the second emitting layer satisfying the numerical formula (Numerical Formula 1), the luminous efficiency of the device is improvable.
In an exemplary arrangement of the organic EL device according to the first exemplary embodiment, it is considered that since the relationship of the numerical formula (Numerical Formula 1) is satisfied, triplet excitons generated by recombination of holes and electrons in the second emitting layer and present on an interface between the second emitting layer and organic layer(s) in direct contact therewith are not likely to be quenched even under the presence of excessive carriers on the interface between the second emitting layer and the organic layer(s). For instance, the presence of a recombination region locally on an interface between the second emitting layer and a hole transporting layer or an electron blocking layer is considered to cause quenching by excessive electrons. Meanwhile, the presence of a recombination region locally on an interface between the second emitting layer and an electron transporting layer or a hole blocking layer is considered to cause quenching by excessive holes.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, by including the first emitting layer and the second emitting layer so as to satisfy the relationship of the numerical formula (Numerical Formula 1), triplet excitons generated in the second emitting layer can transfer to the first emitting layer without being quenched by excessive carriers and be inhibited from back-transferring from the first emitting layer to the second emitting layer. Consequently, the first emitting layer exhibits the TTF mechanism to effectively generate singlet excitons, thereby improving the luminous efficiency.
Accordingly, the organic EL device includes, as different regions, the second emitting layer mainly generating triplet excitons and the first emitting layer mainly exhibiting the TTF mechanism using triplet excitons having transferred from the second emitting layer, and has a difference in triplet energy provided by using a compound having a smaller triplet energy than that of the second host material in the second emitting layer as the first host material and the first additional host material in the first emitting layer. The luminous efficiency is thus improved.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the first emitting layer and the second emitting layer are in direct contact with each other.
Herein, a layer arrangement in which “the first emitting layer and the second emitting layer are in direct contact with each other” may include, for instance, one of embodiments (LS1), (LS2), and (LS3) below.
(LS1) An embodiment in which a region with the first host material, the first additional host material, and the second host material mixed is generated in a process of vapor-depositing the compound of the first emitting layer and vapor-depositing the compound of the second emitting layer, and is present on the interface between the first emitting layer and the second emitting layer.
(LS2) An embodiment in which in a case of containing an luminescent compound in the first emitting layer and the second emitting layer, a region with the first host material, the first additional host material, the second host material, and the luminescent compound mixed is generated in a process of vapor-depositing the compound of the first emitting layer and vapor-depositing the compound of the second emitting layer, and is present on the interface between the first emitting layer and the second emitting layer.
(LS3) An embodiment in which in a case of containing an luminescent compound in the first emitting layer and the second emitting layer, a region containing the luminescent compound, a region containing the first host material and the first additional host material, or a region containing the second host material is generated in a process of vapor-depositing the compound of the first emitting layer and vapor-depositing the compound of the second emitting layer, and is present on the interface between the first emitting layer and the second emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains the second host material. The second host material, which is not particularly limited, may be, for instance, a compound selected from the group consisting of a first compound described later and a compound represented by the formula (H10).
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains a second luminescent compound. The second luminescent compound, which is not particularly limited, may be, for instance, a compound selected from the group consisting of a compound represented by the formula (6), a third compound and a fourth compound which are described later.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains the second host material and the second luminescent compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second luminescent compound is the same as or different from the first luminescent compound contained in the first emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second host material is a compound different from the first host material contained in the first emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second host material is a compound different from the first additional host material contained in the first emitting layer.
The second luminescent compound preferably emits light having a maximum peak wavelength of 500 nm or less, more preferably emits light having a maximum peak wavelength in a range from 430 nm to 480 nm. The second luminescent compound is preferably a fluorescent compound that emits fluorescence having a maximum peak wavelength of 500 nm or less, and more preferably a fluorescent compound that emits fluorescence having a maximum peak wavelength in a range from 430 nm to 480 nm.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains the second host material and the second luminescent compound that emits light having the maximum peak wavelength of 500 nm or less.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second luminescent compound has a full width at half maximum in a range from 1 nm to 30 nm at a maximum peak.
A method of measuring a maximum peak wavelength of a compound is as described above.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, a triplet energy of the first luminescent compound T1(D1) and a triplet energy of the first host material or the first additional host material T1(H1) preferably satisfy a relationship of a numerical formula (Numerical Formula 4A) below.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, when the first luminescent compound and the first host material or the first additional host material satisfy the relationship of the numerical formula (Numerical Formula 4A), in transfer of triplet excitons generated in the second emitting layer to the first emitting layer, the triplet excitons energy-transfer not onto the first luminescent compound having higher triplet energy but onto molecules of the first host material or the first additional host material. In addition, triplet excitons generated by recombination of holes and electrons on the first host material or the first additional host material do not transfer to the first luminescent compound having higher triplet energy. Triplet excitons generated by recombination on molecules of the first luminescent compound quickly energy-transfer to molecules of the first host material or the first additional host material.
Triplet excitons on the first host material or the first additional host material do not transfer to the first luminescent compound but efficiently collide with one another on the first host material or the first additional host material to generate singlet excitons by the TTF phenomenon.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, a singlet energy of the first host material or the first additional host material S1 and a singlet energy of the first luminescent compound S1(D1) preferably satisfy a relationship of a numerical formula (Numerical Formula 4) below.
Singlet energy S1 of the first host material or the first additional host material is collectively denoted by S1(H1) in the description below.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, when the first luminescent compound and the first host material or the first additional host material satisfy the relationship of the numerical formula (Numerical formula 4), due to the singlet energy of the first luminescent compound being smaller than the singlet energy of the first host material or the first additional host material, singlet excitons generated by the TTF phenomenon energy-transfer from the first host material or the first additional host material to the first luminescent compound, thereby contributing to emission (preferably fluorescence) of the first luminescent compound.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, when the second emitting layer and the first emitting layer are layered in this order from a side close to the anode, the electron mobility of the second host material μe(H2) and the electron mobility of the first host material or the first additional host material μe preferably satisfy a formula (Numerical Formula 3) below. When the first host material or the first additional host material and the second host material satisfy a relationship of the numerical formula (Numerical Formula 3), a recombination ability between holes and electrons in the second emitting layer is improved.
The electron mobility of the first host material or the first additional host material μe is collectively denoted by μe(H1) in the description below.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, when the second emitting layer and the first emitting layer are layered in this order from a side close to the anode, the hole mobility of the second host material μh(H2) and the hole mobility of the first host material or the first additional host material μh preferably satisfy a formula (Numerical Formula 31) below.
The hole mobility of the first host material or the first additional host material μh is collectively denoted by μh(H1) in the description below.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, when the second emitting layer and the first emitting layer are layered in this order from a side close to the anode, the hole mobility of the second host material μh(H2), the electron mobility of the second host material μe(H2), the hole mobility of the first host material or the first additional host material μh(H1), and the electron mobility of the first host material or the first additional host material μe(H1) also preferably satisfy a formula (Numerical Formula 32) below.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, a singlet energy of the second host material S1(H2) and a singlet energy of the second luminescent compound S1(D2) preferably satisfy a relationship of a numerical formula (Numerical Formula 20) below.
When the second host material and the second luminescent compound satisfy the relationship of the numerical formula (Numerical Formula 20), singlet excitons generated on the second host material easily energy-transfer from the second host material to the second dopant material, thereby contributing to emission (preferably fluorescence) of the second luminescent compound.
In the organic EL device according to the second exemplary embodiment, the triplet energy of the second host material T1(H2) and the triplet energy of the second luminescent compound T1(D2) preferably satisfy a relationship of a numerical formula (Numerical Formula 20A) below.
When the second host material and the second luminescent compound satisfy the relationship of the numerical formula (Numerical Formula 20A), triplet excitons generated in the second emitting layer transfer not onto the second luminescent compound having higher triplet energy but onto the second host material, thereby easily transferring to the first emitting layer.
A measurement method of triplet energy T1, singlet energy S1, hole mobility, and electron mobility will be described later.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second luminescent compound is a compound containing no azine ring structure in a molecule.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second luminescent compound is preferably not a boron-containing complex, more preferably not a complex.
For instance, examples of a compound that emits blue fluorescence and is usable for the second emitting layer include a pyrene derivative, styrylamine derivative, chrysene derivative, fluoranthene derivative, fluorene derivative, diamine derivative, and triarylamine derivative.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer does not contain a metal complex. Moreover, in an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer does not contain a boron-containing complex.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer does not contain a phosphorescent material (dopant material).
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer does not contain a heavy metal complex and a phosphorescent rare-earth metal complex.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains 0.5 mass % or more of the luminescent compound with respect to the total mass of the second emitting layer. The second emitting layer contains the luminescent compound preferably at 10 mass % or less, more preferably at 7 mass % or less, and still more preferably at 5 mass % less with respect to the total mass of the second emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the second emitting layer contains the second host material preferably at 60 mass % or more, more preferably at 70 mass % or more, still more preferably at 80 mass % or more, still further more preferably at 90 mass % or more, and yet still further more preferably at 95 mass % or more, with respect to the total mass of the second emitting layer.
The second emitting layer preferably contains the second host material at 99.5 mass % or less with respect to the total mass of the second emitting layer.
When the second emitting layer contains the second host material and the second luminescent compound, the upper limit of the total of the content ratios of the second host material and the second luminescent compound is 100 mass %.
In the organic EL device according to the exemplary embodiment, the second emitting layer may further contain any other material than the second host material and the second luminescent compound.
The second emitting layer may contain a single type of the second host material alone or may contain two or more types of the second host material. The second emitting layer may contain a single type of the second luminescent compound alone or may contain two or more types of the second luminescent compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, a film thickness of the first emitting layer is preferably 5 nm or more, more preferably 15 nm or more. When the film thickness of the first emitting layer is 5 nm or more, when the emitting region includes the second emitting layer, it is easy to inhibit triplet excitons having transferred from the second emitting layer to the first emitting layer from returning to the second emitting layer. Further, when the film thickness of the first emitting layer is 5 nm or more, triplet excitons can be sufficiently separated from the recombination portion in the second emitting layer.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the film thickness of the first emitting layer is preferably 20 nm or less. With the film thickness of the first emitting layer of 20 nm or less, a density of triplet excitons in the first emitting layer is improvable to further facilitate occurrence of the TTF phenomenon.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the film thickness of the first emitting layer is preferably in a range from 5 nm to 20 nm.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the film thickness of the second emitting layer is preferably 3 nm or more, more preferably 5 nm or more. The film thickness of the second emitting layer of 3 nm or more is sufficient for causing recombination of holes and electrons in the second emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the film thickness of the second emitting layer is preferably 15 nm or less, more preferably 10 nm or less. The film thickness of the second emitting layer of 15 nm or less is thin enough for transfer of triplet excitons to the first emitting layer.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the film thickness of the second emitting layer is more preferably in a range from 3 nm to 15 nm.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, in addition to the above-listed compounds (e.g., the compounds represented by the formulae (H10) and (H20)) as the first host material, the first host material is also preferably a compound selected from the group consisting of first compounds represented by formulae (1), (1X), (12X), (13X), (14X), (15X), (16X), (1000B), (16X), (17X-1), (17X-2), (17X-3), and (18) below.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the second host material is preferably a compound selected from the group consisting of the first compounds represented by the formulae (1), (1X), (12X), (13X), (14X), (15X), (16X), (1000B), (16X), (17X-1), (17X-2), (17X-3), and (18) below, the compound represented by the formula (H10), and the compound represented by the formula (H20).
Moreover, the first compound is also usable as the first host material, the first additional host material, and the second host material.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (1) below. The first compound represented by the formula (1) includes at least one group represented by a formula (11) below.
In the formula (1):
In the first compound represented by the formula (1), R901, R902, R903, R904, R905, R906, R907, R801 and R802 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
In an exemplary embodiment, Ar101 is preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment: Ar101 is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted phenanthryl group, or a substituted or unsubstituted fluorenyl group.
In an exemplary embodiment, the first compound is preferably represented by a formula (101) below.
In the formula (101):
In an exemplary embodiment, L101 is preferably a single bond or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, it is preferable that two or more of R101 to R110 are each a group represented by the formula (11).
In an exemplary embodiment, it is preferable that two or more of R101 to R110 are each a group represented by the formula (11) and Ar101 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, it is preferable that Ar101 is not a substituted or unsubstituted pyrenyl group; L101 is not a substituted or unsubstituted pyrenylene group; and the substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms for R101 to R110 not being the group represented by the formula (11) is not a substituted or unsubstituted pyrenyl group.
In an exemplary embodiment, it is preferable that R101 to R110 not being the group represented by the formula (11) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, it is preferable that R101 to R110 not being the group represented by the formula (11) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms.
In an exemplary embodiment, R101 to R110 not being the group represented by the formula (11) are each preferably a hydrogen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by a formula (1X) below.
In the formula (1X):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the group represented by the formula (11X) is a group represented by a formula (111X) below.
In the formula (111X):
Among positions *1 to *8 of carbon atoms in a cyclic structure represented by a formula (111aX) below in the group represented by the formula (111X), L111 is bonded to one of the positions *1 to *4, R141 is bonded to each of three positions of the rest of *1 to *4, L112 is bonded to one of the positions *5 to *8, and R142 is bonded to each of three positions of the rest of *5 to *8.
For instance, in the group represented by the formula (111X), when L111 is bonded to a carbon atom at *2 in the cyclic structure represented by the formula (111 aX) and L112 is bonded to a carbon atom at *7 in the cyclic structure represented by the formula (111aX), the group represented by the formula (111X) is represented by a formula (111 bX) below.
In the formula (111bX):
In the organic EL device according to the exemplary embodiment, the group represented by the formula (111X) is preferably a group represented by the formula (111bX).
In the compound represented by the formula (1X), preferably, ma is 1 or 2 and mb is 1 or 2.
In the compound represented by the formula (1X), preferably, ma is 1 and mb is 1.
In the compound represented by the formula (1X), Ar101 is preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the compound represented by the formula (1X), Ar101 is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted benz[a]anthryl group; a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted phenanthryl group, or a substituted or unsubstituted fluorenyl group.
The compound represented by the formula (1X) is also preferably represented by a formula (101X) below.
In the formula (101X):
In the compound represented by the formula (1X), L101 is preferably a single bond, or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms.
The compound represented by the formula (1X) is also preferably represented by a formula (102X) below.
In the formula (102X):
In the compound represented by the formula (1X), preferably, ma is 1 or 2 and mb is 1 or 2 in the formula (102X).
In the compound represented by the formula (1X), preferably, ma is 1 and mb is 1 in the formula (102X).
In the compound represented by the formula (1X), the group represented by the formula (11X) is also preferably a group represented by a formula (11AX) or a group represented by a formula (11 BX) below.
In the formulae (11 AX) and (11 BX):
The compound represented by the formula (1X) is also preferably represented by a formula (103X) below.
In the formula (103X):
In the compound represented by the formula (1X), L131 is also preferably a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms.
In the compound represented by the formula (1X), L132 is also preferably a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms.
In the compound represented by the formula (1X), two or more of R101 to R112 are each also preferably a group represented by the formula (11X).
In the compound represented by the formula (1X), it is preferable that two or more of R101 to R112 are each a group represented by the formula (11X) and Ar101 in the formula (11X) is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the compound represented by the formula (1X), it is also preferable that Ar101 is not a substituted or unsubstituted benz[a]anthryl group, L101 is not a substituted or unsubstituted benz[a]anthrylene group, and, the substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms for R101 to R110 not being the group represented by the formula (11X) is also preferably not a substituted or unsubstituted benz[a]anthryl group.
In the compound represented by the formula (1X), R101 to R112 not being the group represented by the formula (11X) are preferably each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In the compound represented by the formula (1X), R101 to R112 not being the group represented by the formula (11X) are each preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms.
In the compound represented by the formula (1X), R101 to R112 not being the group represented by the formula (11X) are preferably each a hydrogen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (12X) below.
In the formula (12X):
In the formula (12X), combinations of adjacent two of R1201 to R1210 refer to a combination of R1201 and R1202, a combination of R1202 and R1203, a combination of R1203 and R1204, a combination of R1204 and R1205, a combination of R1205 and R1206, a combination of R1207 and R1208, a combination of R1208 and R1209, and a combination of R1209 and R1210.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (13X) below.
In the formula (13X):
In the organic EL device according to the exemplary embodiment, none of combinations of adjacent two or more of R1301 to R1310 not being the group represented by the formula (131) are bonded to each other. Combinations of adjacent two of R1301 to R1310 in the formula (13X) refer to a combination of R1301 and R1302, a combination of R1302 and R1303, a combination of R1303 and R1304, a combination of R1304 and R1305, a combination of R1305 and R1306, a combination of R1307 and R1308, a combination of R1308 and R1309, and a combination of R1309 and R1310.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (14X) below.
In the formula (14X):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (15X) below.
In the formula (15X):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (16X) below.
In the formula (16X):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (1000B) below.
In the formula (1000B):
In the formula (1000B), X is preferably an oxygen atom.
The compound represented by the formula (1000B) is preferably a compound represented by a formula (100) below and having at least one group represented by the formula (110).
In the formula (100): R10 to R19 each independently represent the same as R10 to R19 in the formula (1000B); and Ar100, L100, and mx respectively represent the same as Ar100, L100, and mx in the formula (110).
A compound represented by the formula (1000B) is also preferably a compound represented by a formula (101) or (102) below.
In the formulae (101) and (102): R10 to R19 each independently represent the same as R10 to R19 in the formula (1000B), and Ar100, L100, and mx respectively represent the same as Ar100, L100, and mx in the formula (110).
In the formula (1000B), R10 to R19 not being a group represented by the formula (110) are preferably each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formula (1000B), R10 to R19 not being the group represented by the formula (110) are each preferably a hydrogen atom.
In the formula (1000B), L100 is preferably a single bond or a substituted or unsubstituted arylene group having three or less benzene rings.
In the formula (1000B), L100 is preferably not a substituted or unsubstituted anthrylene group.
In the formula (1000B), L100 is also preferably a single bond.
In the formula (1000B), a group represented by -(L100)mx- in the formula (110) is also preferably a group represented by one of formulae (111) to (120) below.
* in the formulae (111) to (120) each represent a bonding position.
A group represented by -(L100)mx- in the formula (110) is preferably a group represented by a formula (111) or (112) below.
In the formula (1000B), Ar100 is preferably an aryl group in which four or more substituted or unsubstituted benzene rings are fused.
In the formula (1000B), Ar100 is preferably an aryl group in which four substituted or unsubstituted benzene rings are fused or an aryl group in which five substituted or unsubstituted benzene rings are fused.
In the formula (1000B): Ar100 is preferably a group represented by a formula (1100), (1200), (1300), (1400), (1500), (1600), (1700), or (1800) below.
In the formula (1100), one of R111 to R120 is a bond.
In the formula (1200), one of R1201 to R1212 is a bond.
In the formula (1300), one of R1301 to R1314 is a bond.
In the formula (1400), one of R1401 to R1414 is a bond.
In the formula (1500), one of R1501 to R1514 is a bond.
In the formula (1600), one of R1601 to R1612 is a bond.
In the formula (1700), one of R1701 to R1710 is a bond.
In the formula (1800), one of R1801 to R1812 is a bond.
R111 to R120 not being a bond, R1201 to R1212 not being a bond, R1301 to R1314 not being a bond, R1401 to R1414 not being a bond, R1501 to R1514 not being a bond, R1601 to R1612 not being a bond, R1701 to R1710 not being a bond, and R1801 to R1812 not being a bond are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by —Si(R901)(R902)(R903), a group represented by —O—(R904), a group represented by —S—(R905), a group represented by —N(R906)(R907), a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by —C(═O)R801, a group represented by —COOR802, a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
The group represented by the formula (1100) in which R111 is a bond is a group represented by a formula (1112) below. The group represented by the formula (1100) in which R120 is a bond is a group represented by a formula (1113) below. The group represented by the formula (1100) in which R119 is a bond is a group represented by a formula (1114) below.
In the formulae (1112), (1113), and (1114):
In the formulae (1100), (1200), (1300), (1400), (1500), (1600), (1700), and (1800), R111 to R120 not being a bond, R1201 to R1212 not being a bond, R1301 to R1314 not being a bond, R1401 to R1414 not being a bond, R1501 to R1514 not being a bond, R1601 to R1612 not being a bond, R1701 to R1710 not being a bond, and R1801 to R1812 not being a bond are preferably each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formulae (1100), (1200), (1300), (1400), (1500), (1600), (1700), and (1800), R111 to R120 not being a bond, R1201 to R1212 not being a bond, R1301 to R1314 not being a bond, R1401 to R1414 not being a bond, R1501 to R1514 not being a bond, R1601 to R1612 not being a bond, R1701 to R1710 not being a bond, and R1801 to R1812 not being a bond are preferably each a hydrogen atom.
A compound represented by the formula (1000B) preferably includes a benzoxanthene ring in a molecule.
In a compound represented by each of the formulae (100), (101), and (102), a benzoxanthene ring is also preferably replaced with a benzothioxanthene ring.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (17X-1) below.
In the formula (17X-1):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (17X-2) below.
In the formula (17X-2), R1401 to R1410 and X14 each independently represent the same as R1401 to R1410 and X14 in the formula (17X-1).
A group represented by the formula (171-2) represents the same as a group represented by the formula (171-1). In the formula (171-2), L1701, Ar1701, and mx7 each independently represent the same as L1701, Ar1701, and mx7 in the formula (171-1).
When a plurality of groups represented by the formula (171-2) are present, the plurality of groups represented by the formula (171-2) are mutually the same or different.
* in the formula (171-2) represents a bonding position to a ring represented by the formula (17X-2).
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (17X-3) below.
In the formula (17X-3), R1401 to R1410 and X14 each independently represent the same as R1401 to R1410 and X14 in the formula (17X-1).
A group represented by the formula (171-3) represents the same as a group represented by the formula (171-1). In the formula (171-3), L1701, Ar1701, and mx7 each independently represent the same as L1701, Ar1701, and mx7 in the formula (171-1).
When a plurality of groups represented by the formula (171-3) are present, the plurality of groups represented by the formula (171-3) are mutually the same or different.
* in the formula (171-3) represents a bonding position to a ring represented by the formula (17X-3).
In the formulae (17X-1), (17X-2), and (17X-3), X14 is preferably an oxygen atom.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (18) below.
In the formula (18):
In the formula (18), X18 is preferably an oxygen atom.
In first compound, the groups specified to be “substituted or unsubstituted” are each preferably an “unsubstituted” group.
In the organic EL device according to the exemplary embodiment, also preferably, the second host material has, in a molecule, a linking structure including a benzene ring and a naphthalene ring linked to each other with a single bond, in which the benzene ring and the naphthalene ring in the linking structure are each independently fused or not fused with a further monocyclic ring or fused ring, and the benzene ring and the naphthalene ring in the linking structure are further linked to each other by cross-linking at at least one site other than the single bond.
When the second host material has the linking structure including such cross-linking, deterioration in the chromaticity of the organic EL device is expected to be inhibited.
The second host material in the above case is only required to have a linking structure as the minimum unit in a molecule, the linking structure including a benzene ring and a naphthalene ring linked to each other with a single bond (occasionally referred to as a benzene-naphthalene linking structure), the linking structure being as represented by a formula (X1) or a formula (X2) below. Further, the benzene ring may be fused with a monocyclic ring or fused ring, and the naphthalene ring may be fused with a monocyclic ring or fused ring. For instance, also in a case where the second host material has, in a molecule, a linking structure including a naphthalene ring and a naphthalene ring linked to each other with a single bond (occasionally referred to as a naphthalene-naphthalene linking structure) and being as represented by a formula (X3), a formula (X4), or a formula (X5) below, the naphthalene-naphthalene linking structure is regarded as including the benzene-naphthalene linking structure since one of the naphthalene rings includes a benzene ring.
In the organic EL device according to the exemplary, the cross-linking also preferably includes a double bond. Specifically, the first host material also preferably has a structure in which the benzene ring and the naphthalene ring are further linked to each other at any other site than the single bond by the cross-linking structure including a double bond.
Assuming that the benzene ring and the naphthalene ring in the benzene-naphthalene linking structure are further linked to each other at at least one site other than the single bond by cross-linking, for instance, a linking structure (fused ring) represented by a formula (X11) below is obtained in a case of the formula (X1), and a linking structure (fused ring) represented by a formula (X31) below is obtained in a case of the formula (X3).
Assuming that the benzene ring and the naphthalene ring in the benzene-naphthalene linking structure are further linked to each other at any other site than the single bond by cross-linking including a double bond, for instance, a linking structure (fused ring) represented by a formula (X12) below is obtained in a case of the formula (X1), a linking structure (fused ring) represented by a formula (X21) or formula (X22) below is obtained in a case of the formula (X2), a linking structure (fused ring) represented by a formula (X41) below is obtained in a case of the formula (X4), and a linking structure (fused ring) represented by a formula (X51) below is obtained in a case of the formula (X5).
Assuming that the benzene ring and the naphthalene ring in the benzene-naphthalene linking structure are further linked to each other at at least one site other than the single bond by cross-linking including a hetero atom (e.g., an oxygen atom), for instance, a linking structure (fused ring) represented by a formula (X13) below is obtained in a case of the formula (X1).
In the organic EL device according to the exemplary embodiment, also preferably, the second host material has, in a molecule, a biphenyl structure including a first benzene ring and a second benzene ring linked to each other with a single bond, and the first benzene ring and the second benzene ring in the biphenyl structure are further linked to each other by cross-linking at at least one site other than the single bond.
In the organic EL device according to the exemplary embodiment, also preferably, the first benzene ring and the second benzene ring in the biphenyl structure are further linked to each other by the cross-linking at one site other than the single bond. When the second host material has the biphenyl structure including such cross-linking, deterioration in the chromaticity of the organic EL device is expected to be inhibited.
In the organic EL device according to the exemplary, the cross-linking also preferably includes a double bond.
In the organic EL device according to the exemplary embodiment, the cross-linking also preferably includes no double bond.
Also preferably, the first benzene ring and the second benzene ring in the biphenyl structure are further linked to each other by the cross-linking at two sites other than the single bond.
In the organic EL device according to the exemplary embodiment, also preferably, the first benzene ring and the second benzene ring in the biphenyl structure are further linked to each other by the cross-linking at two sites other than the single bond, and the cross-linking includes no double bond. When the second host material has the biphenyl structure including such cross-linking, deterioration in the chromaticity of the organic EL device is expected to be inhibited.
For instance, assuming that the first benzene ring and the second benzene ring in the biphenyl structure represented by a formula (BP1) below are further linked to each other by cross-linking at at least one site other than the single bond, the biphenyl structure is exemplified by linking structures (fused rings) represented by formulae (BP11) to (BP15) below.
The formula (BP11) represents a linking structure in which the first benzene ring and the second benzene ring are linked to each other at one site other than the single bond by cross-linking including no double bond.
The formula (BP12) represents a linking structure in which the first benzene ring and the second benzene ring are linked to each other at one site other than the single bond by cross-linking including a double bond.
The formula (BP13) represents a linking structure in which the first benzene ring and the second benzene ring are linked to each other at two sites other than the single bond by cross-linking including no double bond.
The formula (BP14) represents a linking structure in which the first benzene ring and the second benzene ring are linked to each other by cross-linking including no double bond at one of two sites other than the single bond, and the first benzene ring and the second benzene ring are linked to each other by cross-linking including a double bond at the other of the two sites other than the single bond.
The formula (BP15) represents a linking structure in which the first benzene ring and the second benzene ring are linked to each other at two sites other than the single bond by cross-linking including a double bond.
In the first compound, the groups specified to be “substituted or unsubstituted” are each preferably an “unsubstituted” group.
The first compound usable for the organic EL device according to the exemplary embodiment can be produced by a known method. The first compound can also be produced based on a known method through a known alternative reaction using a known material(s) tailored for the target compound.
Specific examples of the first compound usable for the organic EL device according to the exemplary embodiment include compounds below. It should however be noted that the invention is not limited to the specific examples of the first compound.
In the specific examples of the compounds herein, D represents a deuterium atom, Me represents a methyl group, and tBu represents a tert-butyl group.
In an exemplary arrangement of the organic EL device according to the above exemplary embodiment, the first luminescent compound and the second luminescent compound are, for instance, a third compound and a fourth compound below other than the above-listed compound (e.g., compound represented by the formula (6)).
The third compound and the fourth compound are each independently at least one compound selected from the group consisting of a compound represented by a formula (3) below, a compound represented by a formula (3X) below, a compound represented by a formula (4) below, a compound represented by a formula (5) below, a compound represented by a formula (7) below, a compound represented by a formula (8) below, a compound represented by a formula (9) below, and a compound represented by a formula (10) below.
The compound represented by the formula (3) will be described below.
In the formula (3):
In the formula (31):
In the third and fourth compounds, R901, R902, R903, R904, R905, R906, and R907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, preferably, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms;
In the formula (3), two of R301 to R310 are preferably each a group represented by the formula (31).
In an exemplary embodiment, the compound represented by the formula (3) is a compound represented by a formula (33) below.
In the formula (33):
In the formula (31), L301 is preferably a single bond, and L302 and L303 are each preferably a single bond.
In an exemplary embodiment, the compound represented by the formula (3) is represented by a formula (34) or a formula (35) below.
In the formula (34):
In the formula (35):
In the formula (31), at least one of Ar301 or Ar302 is preferably a group represented by a formula (36) below.
In the formulae (33) to (35), at least one of Ar312 or Ar313 is preferably a group represented by the formula (36).
In the formulae (33) to (35), at least one of Ar315 or Ar316 is preferably a group represented by the formula (36).
In the formula (36):
X3 is preferably an oxygen atom.
At least one of R321 to R327 is preferably a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In the formula (31), preferably, Ar301 is a group represented by the formula (36) and Ar302 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formulae (33) to (35), preferably, Ar312 is a group represented by the formula (36) and Ar313 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formulae (33) to (35), preferably, Ar315 is a group represented by the formula (36) and Ar316 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, the compound represented by the formula (3) is represented by a formula (37) below.
In the formula (37):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the first compound is a compound represented by the formula (3X) below.
In the formula (3X):
In the formula (31X):
In the third compound and the fourth compound, R901, R902, R903, R904, R905, R906, and R907 each independently represent the same as R901, R902, R903, R904, R905, R906, and R907 in the formula (3).
In the formula (3X), two of R3011 to R3018 are each preferably a group represented by the formula (31X).
In the formula (3X), preferably, a combination of R3013 and R3014 are mutually bonded to form a substituted or unsubstituted monocyclic ring or are mutually bonded to form a substituted or unsubstituted fused ring.
In the formula (3X), preferably, a combination of R3015 and R3016 are mutually bonded to form a substituted or unsubstituted monocyclic ring or are mutually bonded to form a substituted or unsubstituted fused ring.
In the formula (3X), R3019 and R3020 are each independently preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, and more preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, the compound represented by the formula (3X) is a compound represented by a formula (33X) below.
In the formula (33X):
In the formula (31X), L3011 is preferably a single bond, and L3012 and L3013 are each preferably a single bond.
In an exemplary embodiment, the compound represented by the formula (3X) is represented by a formula (34X) or a formula (35X) below.
In the formula (34X):
In the formula (35X):
In the formula (31X), at least one of Ar3011 or Ar3012 is preferably a group represented by a formula (36X) below.
In the formulae (33X) to (35X), at least one of Ar3112 or Ar3113 is preferably a group represented by the formula (36X) below.
In the formulae (33X) to (35X), at least one of Ar3115 or Ar3116 is preferably a group represented by the formula (36X) below.
In the formula (36X):
X36 is preferably an oxygen atom.
At least one of R3211 to R3217 is preferably a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In the formula (31X), preferably, Ar3011 is a group represented by the formula (36X) and Ar3012 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formulae (33X) to (35X), preferably, Ar3112 is a group represented by the formula (36X) and Ar3113 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In the formulae (33X) to (35X), preferably, Ar3115 is a group represented by the formula (36X) and Ar3116 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, the compound represented by the formula (3X) is represented by a formula (37X) below.
In the formula (37X):
In an exemplary embodiment, the compound represented by the formula (3X) is represented by a formula (38X) or a formula (39X) below.
In the formulae (38X) to (39X):
Specific examples of the compounds represented by the formulae (3) and (3X) include compounds shown below.
The compound represented by the formula (4) will be described below.
In the formula (4):
The “aromatic hydrocarbon ring” for the A1 ring and A2 ring has the same structure as a compound formed by introducing a hydrogen atom to the “aryl group” described above.
Ring atoms of the “aromatic hydrocarbon ring” for the A1 ring and A2 ring include two carbon atoms on a fused bicyclic structure at the center of the formula (4).
Specific examples of the “substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms” include a compound formed by introducing a hydrogen atom to the “aryl group” described in the specific example group G1.
The “heterocycle” for the A1 ring and A2 ring has the same structure as a compound formed by introducing a hydrogen atom to the “heterocyclic group” described above.
Ring atoms of the “heterocycle” for the A1 ring and A2 ring include two carbon atoms on a fused bicyclic structure at the center of the formula (4).
Specific examples of the “substituted or unsubstituted heterocycle having 5 to 50 ring atoms” include a compound formed by introducing a hydrogen atom to the “heterocyclic group” described in the specific example group G2.
Rb is bonded to any one of carbon atoms forming the aromatic hydrocarbon ring as the A1 ring or any one of atoms forming the heterocycle as the A1 ring.
Rc is bonded to any one of carbon atoms forming the aromatic hydrocarbon ring as the A2 ring or any one of atoms forming the heterocycle as the A2 ring.
At least one of Ra, Rb, or Rc is preferably a group represented by a formula (4a) below. More preferably, at least two of Ra, Rb, or Rc are each a group represented by the formula (4a).
[Formula 368]
L401-Ar401 (4a)
In the formula (4a):
In the formula (4b):
In an exemplary embodiment, the compound represented by the formula (4) is represented by a formula (42) below.
In the formula (42):
At least one of R401 to R411 is preferably a group represented by the formula (4a). More preferably, at least two of R401 to R411 are each a group represented by the formula (4a).
R404 and R411 are preferably each a group represented by the formula (4a).
In an exemplary embodiment, the compound represented by the formula (4) is a compound formed by bonding a structure represented by a formula (4-1) or a formula (4-2) below to the A1 ring.
Further, in an exemplary embodiment, the compound represented by the formula (42) is a compound formed by bonding the structure represented by the formula (4-1) or the formula (4-2) to a ring bonded to R404 to R407.
In the formula (4-1), two * are each independently bonded to a ring carbon atom of the aromatic hydrocarbon ring or a ring atom of the heterocycle as the A1 ring in the formula (4) or bonded to one of R404 to R407 in the formula (42);
In an exemplary embodiment, the compound represented by the formula (4) is a compound represented by a formula (41-3), a formula (41-4) or a formula (41-5) below.
In the formulae (41-3), (41-4), and (41-5):
In an exemplary embodiment, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms as the A1 ring in the formula (41-5) is a substituted or unsubstituted naphthalene ring or a substituted or unsubstituted fluorene ring.
In an exemplary embodiment, a substituted or unsubstituted heterocycle having 5 to 50 ring atoms as the A1 ring in the formula (41-5) is a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted carbazole ring, or a substituted or unsubstituted dibenzothiophene ring.
In an exemplary embodiment, the compound represented by the formula (4) or the formula (42) is selected from the group consisting of compounds represented by formulae (461) to (467) below.
In the formulae (461), (462), (463), (464), (465), (466), and (467):
In an exemplary embodiment, at least one combination of adjacent two or more of R401 to R411 in the compound represented by the formula (42) are mutually bonded to form a substituted or unsubstituted monocyclic ring, or mutually bonded to form a substituted or unsubstituted fused ring. In this exemplary embodiment, the compound represented by the formula (42) will be described in detail below as a compound represented by a formula (45) below.
The compound represented by the formula (45) will be described below.
In the formula (45):
In the formula (45), Rn and Rn+1 (n being an integer selected from 461, 462, 464 to 466, and 468 to 470) are mutually bonded to form a substituted or unsubstituted monocyclic ring or fused ring together with two ring carbon atoms bonded to Rn and Rn+1. The ring is preferably formed of atoms selected from the group consisting of a carbon atom, an oxygen atom, a sulfur atom, and a nitrogen atom, and is made of preferably 3 to 7 atoms, and more preferably 5 or 6 atoms.
The number of the above cyclic structures in the compound represented by the formula (45) is, for instance, 2, 3, or 4. The two or more of the cyclic structures may be present on the same benzene ring or may be present on different benzene rings on the basic skeleton represented by the formula (45). For instance, when three cyclic structures are present, the three cyclic structures may be present on the respective three benzene rings of the formula (45).
Examples of the above cyclic structures in the compound represented by the formula (45) include structures represented by formulae (451) to (460) below.
In the formulae (451) to (457):
In the formulae (458) to (460):
In the formula (45), preferably, at least one of R462, R464, R465, R470, or R471 (preferably, at least one of R462, R465, or R470, and more preferably R462) is a group forming no cyclic structure.
In the formulae (461) to (464):
In an exemplary embodiment, the compound represented by the formula (45) is represented by one of formulae (45-1) to (45-6) below.
In the formulae (45-1) to (45-6):
In an exemplary embodiment, the compound represented by the formula (45) is represented by one of formulae (45-7) to (45-12) below.
In the formulae (45-7) to (45-12):
In an exemplary embodiment, the compound represented by the formula (45) is represented by one of formulae (45-13) to (45-21) below.
In the formulae (45-13) to (45-21):
When the ring g or the ring h further has a substituent, examples of the substituent include a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a group represented by the formula (461), a group represented by the formula (463), and a group represented by the formula (464).
In an exemplary embodiment, the compound represented by the formula (45) is represented by one of formulae (45-22) to (45-25) below.
In the formulae (45-22) to (45-25):
In an exemplary embodiment, the compound represented by the formula (45) is represented by a formula (45-26) below.
In the formula (45-26):
Specific examples of the compound represented by the formula (4) include compounds shown below. In the specific examples below, Ph represents a phenyl group, and D represents a deuterium atom.
The compound represented by the formula (5) will be described below. The compound represented by the formula (5) corresponds to a compound represented by the formula (41-3).
In the formula (5):
“A combination of adjacent two or more of R501 to R507 and R511 to R517” refers to, for instance, a combination of R501 and R502, a combination of R502 and R503, a combination of R503 and R504, a combination of R505 and R506, a combination of R506 and R507, and a combination of R501, R502, and R503.
In an exemplary embodiment, at least one, preferably two of R501 to R507 or R511 to R517 are each a group represented by —N(R906)(R907).
In an exemplary embodiment, R501 to R507 and R511 to R517 are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms,
In an exemplary embodiment, the compound represented by the formula (5) is a compound represented by a formula (52) below.
In the formula (52):
In an exemplary embodiment, the compound represented by the formula (5) is a compound represented by a formula (53) below.
In the formula (53), R551, R552 and R561 to R564 each independently represent the same as R551, R552 and R561 to R564 in the formula (52).
In an exemplary embodiment, R561 to R564 in the formulae (52) and (53) are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms (preferably a phenyl group).
In an exemplary embodiment, R521 and R522 in the formula (5) and R551 and R552 in the formulae (52) and (53) are each a hydrogen atom.
In an exemplary embodiment, the substituent for the “substituted or unsubstituted” group in the formulae (5), (52) and (53) is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
Specific examples of the compound represented by the formula (5) include compounds shown below.
The compound represented by the formula (7) will be described below.
In the formula (7):
In the formula (7), each of the p ring, q ring, r ring, s ring, and t ring is fused with an adjacent ring(s) sharing two carbon atoms. The fused position and orientation are not limited but may be defined as required.
In an exemplary embodiment, in the formula (72) or the formula (73) representing the r ring, m1=0 or m2=0 is satisfied.
In an exemplary embodiment, the compound represented by the formula (7) is represented by any one of formulae (71-1) to (71-6) below.
In the formulae (71-1) to (71-6), R701, X7, Ar701, Ar702, L701, m1 and m3 respectively represent the same as R701, X7, Ar701, Ar702, L701, m1 and m3 in the formula (7).
In an exemplary embodiment, the compound represented by the formula (7) is represented by any one of formulae (71-11) to (71-13) below.
In the formulae (71-11) to (71-13), R701, X7, Ar701, Ar702, L701, m1, m3 and m4 respectively represent the same as R701, X7, Ar701, Ar702, L701, m1, m3 and m4 in the formula (7).
In an exemplary embodiment, the compound represented by the formula (7) is represented by any one of formulae (71-21) to (71-25) below.
In the formulae (71-21) to (71-25), R701, X7, Ar701, Ar702, L701, m1 and m4 respectively represent the same as R701, X7, Ar701, Ar702, L701, m1 and m4 in the formula (7).
In an exemplary embodiment, the compound represented by the formula (7) is represented by any one of formulae (71-31) to (71-33) below.
In the formulae (71-31) to (71-33), R701, X7, Ar701, Ar702, L701, and m2 to m4 respectively represent the same as R701, X7, Ar701, Ar702, L701, and m2 to m4 in the formula (7).
In an exemplary embodiment, Ar701 and Ar702 are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, one of Ar701 and Ar702 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, and the other of Ar701 and Ar702 is a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
Specific examples of the compound represented by the formula (7) include compounds shown below.
The compound represented by the formula (8) will be described below.
In the formula (8):
At least one of R801 to R804 not forming the divalent group represented by the formula (82) or R811 to R814 is a monovalent group represented by a formula (84) below;
In the formula (84):
In the formula (8), the positions for the divalent group represented by the formula (82) and the divalent group represented by the formula (83) to be formed are not specifically limited but the divalent groups may be formed at any possible positions on R801 to R805.
In an exemplary embodiment, the compound represented by the formula (8) is represented by any one of formulae (81-1) to (81-6) below.
In the formulae (81-1) to (81-6):
In an exemplary embodiment, the compound represented by the formula (8) is represented by any one of formulae (81-7) to (81-18) below.
In the formulae (81-7) to (81-18):
R801 to R808 not forming the divalent group represented by the formula (82) or (83) and not being the monovalent group represented by the formula (84), and R811 to R814 and R821 to R824 not being the monovalent group represented by the formula (84) are preferably each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
The monovalent group represented by the formula (84) is preferably represented by a formula (85) or (86) below.
In the formula (85):
In the formula (86):
In the formula (87):
Specific examples of the compound represented by the formula (8) include compounds shown below as well as the compounds disclosed in WO 2014/104144.
The compound represented by the formula (9) will be described below.
In the formula (9):
In the formula (92):
At least one ring selected from the group consisting of A91 ring and A92 ring is bonded to * of a structure represented by the formula (92). In other words, the ring carbon atoms of the aromatic hydrocarbon ring or the ring atoms of the heterocycle of the A91 ring in an exemplary embodiment are bonded to * in a structure represented by the formula (92). Further, the ring carbon atoms of the aromatic hydrocarbon ring or the ring atoms of the heterocycle of the A92 ring in an exemplary embodiment are bonded to * in a structure represented by the formula (92).
In an exemplary embodiment, a group represented by a formula (93) below is bonded to one or both of the A91 ring and A92 ring.
In the formula (93):
In an exemplary embodiment, in addition to the A91 ring, the ring carbon atoms of the aromatic hydrocarbon ring or the ring atoms of the heterocycle of the A92 ring are bonded to * in a structure represented by the formula (92). In this case, the structures represented by the formula (92) may be mutually the same or different.
In an exemplary embodiment, R91 and R92 are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, R91 and R92 are mutually bonded to form a fluorene structure.
In an exemplary embodiment, the rings A91 and A92 are each independently a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms, example of which is a substituted or unsubstituted benzene ring.
In an exemplary embodiment, the ring A93 is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms, example of which is a substituted or unsubstituted benzene ring.
In an exemplary embodiment, X9 is an oxygen atom or a sulfur atom.
Specific Examples of Compound Represented by Formula (9) Specific examples of the compound represented by the formula (9) include compounds shown below.
The compound represented by the formula (10) will be described below.
In the formula (10):
In an exemplary embodiment, Ar1001 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.
In an exemplary embodiment, Ax3 ring is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms, example of which is a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, or a substituted or unsubstituted anthracene ring.
In an exemplary embodiment, R1003 and R1004 are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.
In an exemplary embodiment, ax is 1.
Specific examples of the compound represented by the formula (10) include compounds shown below.
In an exemplary embodiment, the substituent for “the substituted or unsubstituted” group in each of the formulae is an unsubstituted alkyl group having 1 to 50 carbon atoms, an unsubstituted aryl group having 6 to 50 ring carbon atoms, or an unsubstituted heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, the substituent for “the substituted or unsubstituted” group in each of the formulae is an unsubstituted alkyl group having 1 to 18 carbon atoms, an unsubstituted aryl group having 6 to 18 ring carbon atoms, or an unsubstituted heterocyclic group having 5 to 18 ring atoms.
An exemplary arrangement of the organic EL device according to the exemplary embodiment further includes an electron transporting zone between the cathode and the emitting region, in which the electron transporting zone includes at least one electron transporting layer. The at least one electron transporting layer in the electron transporting zone contains a nitrogen-containing compound having at least one of a five-membered ring having a nitrogen atom or a six-membered ring having a nitrogen atom.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, at least one electron transporting layer in the electron transporting zone contains, as a nitrogen-containing compound, at least one compound selected from the group consisting of an imidazole derivative, benzimidazole derivative, azine derivative, carbazole derivative, and phenanthroline derivative.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, at least one electron transporting layer in the electron transporting zone contains a phenanthroline derivative as a nitrogen-containing compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the phenanthroline derivative (phenanthroline compound) contained in the electron transporting layer is a compound represented by a formula (20) below and having at least one group represented by a formula (21) below.
In the formula (20):
In the formula (21):
In the phenanthroline compound: R901, R902, R903, R904, R905, R906, R907, R931, R932, R933, R934, R935, R936, and R937 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
A group represented by —O—(R904) herein in which R904 is a hydrogen atom is a hydroxy group.
A group represented by —S—(R905) herein in which R905 is a hydrogen atom is a thiol group.
A group represented by —S(═O)2R933 herein in which R933 is a substituent is a substituted sulfo group.
A group represented by —B(R934)(R935) herein in which R934 and R935 are each a substituent is a substituted boryl group.
A group represented by —P(═O)(R936)(R937) herein is a substituted phosphine oxide group when R936 and R937 are each a substituent, and an aryl phosphoryl group when R936 and R937 are each an aryl group.
An “unsubstituted polyvalent linear, branched or cyclic aliphatic hydrocarbon group” mentioned herein has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, more preferably 1 to 6 carbon atoms.
An “unsubstituted polyvalent aromatic hydrocarbon group” mentioned herein has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, more preferably 6 to 18 ring carbon atoms.
An “unsubstituted polyvalent heterocyclic group” mentioned herein has, unless otherwise specified, 5 to 50, preferably 5 to 30, more preferably 5 to 18 ring atoms.
In an exemplary embodiment, a heterocyclic group having 5 to 50 ring atoms as Ar2 in the formula (21) includes a substituted or unsubstituted group derived from the cyclic structure represented by the formula (20).
In an exemplary embodiment, X21 and X28 in the formula (20) are each a carbon atom bonded to a group represented by the formula (21).
In an exemplary embodiment, one of X21 and X28 in the formula (20) is a carbon atom bonded to a group represented by the formula (21) and the other of X21 and X28 is a carbon atom bonded to a hydrogen atom.
In an exemplary embodiment, X21 to X28 in the formula (20) are each independently CR21 or a carbon atom bonded to a group represented by the formula (21).
In an exemplary embodiment, the rest of X21 to X28 in the formula (20) other than carbon atom(s) bonded to a group represented by the formula (21) is CR21. Specifically, in an exemplary embodiment, the compound represented by the formula (20) is a 1,10-phenanthroline derivative.
In an exemplary embodiment, Ar2 in the formula (21) is a substituted or unsubstituted fused aromatic hydrocarbon group having 8 to 20 ring carbon atoms.
In an exemplary embodiment, a fused aromatic hydrocarbon group having 8 to 20 ring carbon atoms is a group derived from any aromatic hydrocarbon selected from the group consisting of, for instance, naphthalene, anthracene, acephenanthrylene, aceanthrylene, benzanthracene, triphenylene, pyrene, chrysene, naphthacene, fluorene, phenanthrene, fluoranthene, and benzofluoranthene.
In an exemplary embodiment, Ar2 in the formula (21) is a substituted or unsubstituted anthryl group.
In an exemplary embodiment, Ar2 in the formula (21) is a substituted or unsubstituted heterocyclic group having 5 to 40 ring carbon atoms.
In an exemplary embodiment, Ar2 in the formula (21) is a substituted or unsubstituted group derived from the cyclic structure represented by the formula (20).
In an exemplary embodiment, Ar2 in the formula (21) is a group represented by a formula (23) below.
In the formula (23):
In a formula representing a phenanthroline compound:
In an exemplary embodiment, X21 to X28 in the formula (23) are preferably each independently a nitrogen atom, CR21, or a carbon atom bonded to L22 or L23, more preferably CR21, or a carbon atom bonded to L22 or L23.
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (24) below.
In the formula (24):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (24A) below.
In the formula (24A):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (24B) below.
In the formula (24B):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25) below.
In the formula (25):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25A) below.
In the formula (25A):
In an exemplary embodiment, L2 in the formulae (24), (24A), (24B), (25) and (25A) is a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent heterocyclic group having 5 to 50 ring atoms.
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25B) below.
In the formula (25B):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25C) below.
In the formula (25C):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25D) below.
In the formula (25D):
In an exemplary embodiment, the phenanthroline compound is a compound represented by a formula (25E) below.
In the formula (25E):
L3 in the formulae (25B), (25C), (25D) and (25E) is also preferably a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent heterocyclic group having 5 to 50 ring atoms.
The phenanthroline compound can be produced by a known method. The phenanthroline compound can also be produced based on a known method through a known alternative reaction using a known material(s) tailored for the target compound.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, at least one electron transporting layer in the electron transporting zone contains an azine derivative as a nitrogen-containing compound.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the azine derivative contained in the electron transporting layer is a compound represented by a formula (E42) below.
In the formula (E42):
R901 to R907 in the azine derivative are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the azine derivative contained in the electron transporting layer is a compound represented by a formula (E421) below.
In the formula (E421):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the azine derivative contained in the electron transporting layer is a compound represented by each of a formula (E422) and a formula (E423) below.
In the formula (E422):
In the formula (E423):
In the formulae (E422) and (E423), R901 to R907 each independently represent the same as R901 to R907 in the azine derivative.
For instance, in the formula (E421), when n4 is 1, a group represented by (Ar421)n4-L421-* is represented by a formula (E421-1) below. In this arrangement, L421 is a divalent linking group. * represents a bonding position to a six-membered ring in the formula (E421).
In the formula (E421), when n4 is 2, a group represented by (Ar421)n4-L421-* is represented by a formula (E421-2) below. Ar421 are mutually the same or different. In this arrangement, L421 is a trivalent linking group.
In the formula (E421), when n4 is 3, a group represented by (Ar421)n4-L421-* is represented by a formula (E421-3) below. Ar421 are mutually the same or different. In this arrangement, L421 is a tetravalent linking group.
The same applies for a group represented by (Ar422)n4-L421-* in the formula (E422).
In the formulae (E421) to (E422), L421 as a linking group is preferably a divalent or trivalent group derived from any one of benzene, biphenyl, terphenyl, naphthalene, and phenanthrene.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, a substituent for “a substituted or unsubstituted” group in the azine derivative is at least one group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, aryl group having 6 to 18 ring carbon atoms, and heterocyclic group having 5 to 18 ring atoms.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, a substituent for “the substituted or unsubstituted” group in the azine derivative is an alkyl group having 1 to 5 carbon atoms.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the groups specified to be “substituted or unsubstituted” in the azine derivative are each an “unsubstituted” group.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, at least one electron transporting layer in the electron transporting zone contains a benzimidazole derivative.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the benzimidazole derivative contained in the electron transporting layer is a compound represented by a formula (E41) below.
In the formula (E41):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the benzimidazole derivative contained in the electron transporting layer is a compound represented by a formula (E41E), (E41B), (E41C), (E41D), or (E41E) below.
In the formulae (E41A), (E41B), (E41C), (E41D), and (E41E):
In an exemplary arrangement of the organic EL device of the exemplary embodiment, Ar41 in the formulae (E41A), (E41B), (E41C), (E41D), and (E41E) is a group represented by a formula (E412) below.
In the formula (E412):
In the formulae (E41A), (E41B), (E41C), (E41D), and (E41E), L41 is preferably a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridinylene group, or a substituted or unsubstituted 9,9′-spirobifluorenylene group.
In the formulae (E41A), (E41B), (E41C), (E41D), and (E41E), L41 is more preferably an unsubstituted phenyl group, an unsubstituted biphenylene group, an unsubstituted naphthylene group, an unsubstituted pyridinylene group, or an unsubstituted 9,9′-spirobifluorenylene group.
In the formulae (E41A), (E41B), (E41C), (E41D), and (E41E), Ar41 is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted pyrenyl group, or a substituted or unsubstituted fluorenyl group.
In the formulae (E41A), (E41B), (E41C), (E41D), and (E41E), Ar41 is more preferably an unsubstituted phenyl group, an unsubstituted biphenyl group, an unsubstituted terphenyl group, an unsubstituted naphthyl group, an unsubstituted phenanthryl group, an unsubstituted fluoranthenyl group, an unsubstituted pyrenyl group, or an unsubstituted 9,9-dimethylfluorenyl group.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the benzimidazole derivative is a compound represented by a formula (E413) below.
In the formula (E413):
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the groups specified to be “substituted or unsubstituted” in the benzimidazole derivative are each an “unsubstituted” group.
Specific examples of the nitrogen-containing compound include the following compounds. It should however be noted that the invention is not limited to the specific examples of the nitrogen-containing compound.
A second exemplary embodiment and a third exemplary embodiment will be described below.
An organic EL device of each of the second exemplary embodiment and the third exemplary embodiment has an exemplary arrangement of the organic EL device of the first exemplary embodiment.
Accordingly, constituent elements that can be contained in the organic EL device of the second exemplary embodiment are the same as constituent elements that can be contained in the organic EL device described in the first exemplary embodiment.
Further, constituent elements that can be contained in the organic EL device of the third exemplary embodiment are the same as constituent elements that can be contained in the organic EL device described in the first exemplary embodiment.
The organic EL device according to the second exemplary embodiment includes: a cathode; an anode; an emitting region provided between the cathode and the anode;
According the second exemplary embodiment, the device performance of the organic EL device is improvable. In an exemplary arrangement of the second exemplary embodiment, the organic EL device has an improved luminous efficiency. In an exemplary arrangement of the second exemplary embodiment, the organic EL device has a longer lifetime.
The organic EL device according to the third exemplary embodiment includes a cathode; an anode; an emitting region provided between the cathode and the anode;
According the third exemplary embodiment, the device performance of the organic EL device is improvable. In an exemplary arrangement of the third exemplary embodiment, the organic EL device has an improved luminous efficiency. In an exemplary arrangement of the third exemplary embodiment, the organic EL device has a longer lifetime.
The organic EL device according to each of the first to third exemplary embodiments may include one or more organic layers in addition to the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the first emitting layer. Examples of the organic layer include, for instance, at least one layer selected from the group consisting of the above-described fourth anode-side organic layer, the second emitting layer, the electron transporting layer, an electron injecting layer, a hole blocking layer, and an electron blocking layer.
The organic layers of the organic EL device according to each of the first to third exemplary embodiments may consist of the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the first emitting layer, alternatively, may further include, for instance, at least one layer selected from the group consisting of the fourth anode-side organic layer, the second emitting layer, the electron injecting layer, the electron transporting layer, and the hole blocking layer.
An organic EL device 1 includes a substrate 2, an anode 3, a cathode 4, and organic layers 10 provided between the anode 3 and the cathode 4. The organic layers 10 includes a first anode-side organic layer 61, a second anode-side organic layer 62, a third anode-side organic layer 63, a first emitting layer 51, an electron transporting layer 8, and an electron injecting layer 9, which are layered in this order on the anode 3.
An organic EL device 1A includes the substrate 2, the anode 3, the cathode 4, and organic layers 11 provided between the anode 3 and the cathode 4. The organic layers 11 include the first anode-side organic layer 61, the second anode-side organic layer 62, the third anode-side organic layer 63, a fourth anode-side organic layer 64, the first emitting layer 51, the electron transporting layer 8, and the electron injecting layer 9, which are layered in this order on the anode 3.
An organic EL device 1B includes the substrate 2, the anode 3, the cathode 4, and organic layers 12 provided between the anode 3 and the cathode 4. The organic layers 12 include the first anode-side organic layer 61, the second anode-side organic layer 62, the third anode-side organic layer 63, a second emitting layer 52, the first emitting layer 51, the electron transporting layer 8, and the electron injecting layer 9, which are layered in this order on the anode 3.
An organic EL device 1C includes the substrate 2, the anode 3, the cathode 4, and organic layers 13 provided between the anode 3 and the cathode 4. The organic layers 13 include the first anode-side organic layer 61, the second anode-side organic layer 62, the third anode-side organic layer 63, the fourth anode-side organic layer 64, the second emitting layer 52, the first emitting layer 51, the electron transporting layer 8, and the electron injecting layer 9, which are layered in this order on the anode 3.
In the organic EL device 1 of
In the organic EL device 1B of
In the organic EL device 1 of
In the organic EL device 1A of
The arrangements of the organic EL devices illustrated in
The invention is not limited to the exemplary arrangements of the organic EL devices illustrated in
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the emitting region when including the first emitting layer and the second emitting layer may include an interposed layer as an organic layer disposed between the first emitting layer and the second emitting layer.
In an exemplary embodiment, in order to inhibit an overlap between a Singlet emitting region and a TTF emitting region, the interposed layer contains no luminescent compound or may contain a luminescent compound in an insubstantial amount provided that the overlap can be inhibited.
For instance, the interposed layer contains 0 mass % of a luminescent compound. Alternatively, for instance, the interposed layer may contain a luminescent compound provided that the luminescent compound contained is a component accidentally mixed in a producing process or a component contained as impurities in a material.
For instance, when the interposed layer consists of a material A, a material B, and a material C, the content ratios of the materials A, B, and C in the interposed layer are each 10 mass % or more, and the total of the content ratios of the materials A, B, and C is 100 mass %.
In the following, the interposed layer is occasionally referred to as a “non-doped layer”. A layer containing the luminescent compound is occasionally referred to as a “doped layer”.
It is considered that luminous efficiency is improvable in an arrangement including layered emitting layers because the Singlet emitting region and the TTF emitting region are typically likely to be separated from each other.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, when the interposed layer (non-doped layer) is disposed between the first emitting layer and the second emitting layer in the emitting region, it is expected that a region where the Singlet emitting region and the TTF emitting region overlap with each other is reduced to inhibit a decrease in TTF efficiency which may otherwise be caused by collision between triplet excitons and carriers. That is, it is considered that providing the interposed layer (non-doped layer) between the emitting layers contributes to the improvement in TTF emission efficiency.
The interposed layer is the non-doped layer.
The interposed layer contains no metal atom. The interposed layer thus contains no metal complex.
The interposed layer contains an interposed layer material. The interposed layer material is not a luminescent compound.
The interposed layer material may be any material except for the luminescent compound.
Examples of the interposed layer material include: 1) a heterocyclic compound such as an oxadiazole derivative, benzimidazole derivative, or phenanthroline derivative; 2) a fused aromatic compound such as a carbazole derivative, anthracene derivative, phenanthrene derivative, pyrene derivative or chrysene derivative; and 3) an aromatic amine compound such as a triarylamine derivative or a fused polycyclic aromatic amine derivative.
One or both of the first host material and the second host material may be used as the interposed layer material. The interposed layer material may be any material provided that the Singlet emitting region and the TTF emitting region are separated from each other and the Singlet emission and the TTF emission are not hindered.
In an exemplary arrangement of the organic EL device according to the exemplary embodiment, the respective content ratios of all the materials forming the interposed layer in the interposed layer are 10 mass % or more.
The interposed layer contains the interposed layer material as a material forming the interposed layer.
The interposed layer preferably contains 60 mass % or more of the interposed layer material, more preferably contains 70 mass % or more of the interposed layer material, still more preferably contains 80 mass % or more of the interposed layer material, still further more preferably 90 mass % or more of the interposed layer material, and yet still further more preferably 95 mass % or more of the interposed layer material, with respect to the total mass of the interposed layer.
The interposed layer may contain a single type of the interposed layer material or may contain two or more types of the interposed layer material.
When the interposed layer contains two or more types of the interposed layer material, the upper limit of the total of the content ratios of the two or more types of the interposed layer material is 100 mass %.
It should be noted that the interposed layer of the exemplary embodiment may further contain any other material than the interposed layer material.
The interposed layer may be provided in the form of a single layer or a laminate of two or more layers.
As long as the overlap between the Singlet emitting region and the TTF emitting region is inhibited, the film thickness of the interposed layer is not particularly limited, but each layer in the interposed layer is preferably in a range from 3 nm to 15 nm, and more preferably in a range from 5 nm to 10 nm.
The interposed layer having a film thickness of 3 nm or more easily separates the Singlet emitting region from the emitting region derived from TTF.
The interposed layer having a film thickness of 15 nm or less easily inhibits a phenomenon in which the host material of the interposed layer emits light.
It is preferable that the interposed layer contains the interposed layer material as a material forming the interposed layer and the triplet energy of the first host material T1(H1), the triplet energy of the second host material T1(H2), and a triplet energy of at least one interposed layer material T1(Mmid) satisfy a relationship of a numerical formula (Numerical Formula 21) below.
When the interposed layer contains two or more interposed layer materials as a material forming the interposed layer, the triplet energy of the first host material T1(H1), the triplet energy of the second host material T1(H2), and a triplet energy of each interposed layer material T1(MEA) more preferably satisfy a relationship of a numerical formula (Numerical Formula 21A) below.
An exemplary arrangement of the organic EL device according to the exemplary embodiment may further include a diffusion layer.
When the exemplary arrangement of the organic EL device according to the exemplary embodiment includes the diffusion layer, the diffusion layer is preferably disposed between the first emitting layer and the second emitting layer.
The arrangements of the organic EL devices will be further described below. It should be noted that the reference numerals are occasionally omitted below.
The substrate is used as a support for the organic EL device. For instance, glass, quartz, plastics and the like are usable for the substrate. A flexible substrate is also usable. The flexible substrate is a bendable substrate, which is exemplified by a plastic substrate. Examples of the material for the plastic substrate include polycarbonate, polyarylate, polyethersulfone, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyimide, and polyethylene naphthalate. Further, an inorganic vapor deposition film is also usable.
Metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a large work function (specifically, 4.0 eV or more) is preferably used as the anode formed on the substrate. Specific examples of the material include ITO (Indium Tin Oxide), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide, and graphene. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chrome (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), and nitrides of a metal material (e.g., titanium nitride) are usable.
The material is typically formed into a film by a sputtering method. For instance, the indium oxide-zinc oxide can be formed into a film by the sputtering method using a target in which zinc oxide in a range from 1 mass % to 10 mass % is added to indium oxide. Moreover, for instance, the indium oxide containing tungsten oxide and zinc oxide can be formed by the sputtering method using a target in which tungsten oxide in a range from 0.5 mass % to 5 mass % and zinc oxide in a range from 0.1 mass % to 1 mass % are added to indium oxide. In addition, the anode may be formed by a vacuum deposition method, a coating method, an inkjet method, a spin coating method or the like.
Among the organic layers formed on the anode, since the hole injecting layer adjacent to the anode is formed of a composite material into which holes are easily injectable irrespective of the work function of the anode, a material usable as an electrode material (e.g., metal, an alloy, an electroconductive compound, a mixture thereof, and the elements belonging to the group 1 or 2 of the periodic table) is also usable for the anode.
A material having a small work function such as elements belonging to Groups 1 and 2 in the periodic table of the elements, specifically, an alkali metal such as lithium (Li) and cesium (Cs), an alkaline earth metal such as magnesium (Mg), calcium (Ca) and strontium (Sr), alloys (e.g., MgAg and AILi) including the alkali metal or the alkaline earth metal, a rare earth metal such as europium (Eu) and ytterbium (Yb), and alloys including the rare earth metal are also usable for the anode. It should be noted that the vacuum deposition method and the sputtering method are usable for forming the anode using the alkali metal, alkaline earth metal and the alloy thereof. Further, when a silver paste is used for the anode, the coating method and the inkjet method are usable.
It is preferable to use metal, an alloy, an electroconductive compound, a mixture thereof, or the like having a small work function (specifically, 3.8 eV or less) for the cathode. Examples of the material for the cathode include elements belonging to Groups 1 and 2 in the periodic table of the elements, specifically, an alkali metal such as lithium (Li) and cesium (Cs), an alkaline earth metal such as magnesium (Mg), calcium (Ca) and strontium (Sr), alloys (e.g., MgAg and AILi) including the alkali metal or the alkaline earth metal, a rare earth metal such as europium (Eu) and ytterbium (Yb), and alloys including the rare earth metal.
It should be noted that the vacuum deposition method and the sputtering method are usable for forming the cathode using the alkali metal, alkaline earth metal and the alloy thereof. Further, when a silver paste is used for the cathode, the coating method and the inkjet method are usable.
By providing the electron injecting layer, various conductive materials such as Al, Ag, ITO, graphene, and indium oxide-tin oxide containing silicon or silicon oxide may be used for forming the cathode regardless of the work function. The conductive materials can be formed into a film using the sputtering method, inkjet method, spin coating method and the like.
In an exemplary arrangement of the organic EL device of the exemplary embodiment, the electron transporting layer is provided between the emitting region and the cathode.
The electron transporting layer is a layer containing a highly electron-transporting substance. For the electron transporting layer, 1) a metal complex such as an aluminum complex, beryllium complex, and zinc complex, 2) a hetero aromatic compound such as imidazole derivative, benzimidazole derivative, azine derivative, carbazole derivative, and phenanthroline derivative, and 3) a high polymer compound are usable. Specifically, as a low-molecule organic compound, for instance, a metal complex such as Alq, tris(4-methyl-8-quinolinato)aluminum (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: BeBq2), BAlq, Znq, ZnPBO and ZnBTZ is usable. In addition to the metal complex, a heteroaromatic compound such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(ptert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), and 4,4′-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs) is usable. In an exemplary arrangement of the exemplary embodiment, a nitrogen-containing compound (preferably benzimidazole compound) is usable. The above-described substances mostly have an electron mobility of 10−6 cm2/Vs or more. It should be noted that any substance other than the above substance may be used for the electron transporting layer as long as the substance exhibits a higher electron transportability than the hole transportability. The electron transporting layer may be provided in the form of a single layer or a laminate of two or more layers of the above substance(s).
Further, a high polymer compound is usable for the electron transporting layer. For instance, poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)](abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy) are usable.
The electron injecting layer is a layer containing a highly electron-injectable substance. Examples of a material for the electron injecting layer include an alkali metal, alkaline earth metal and a compound thereof, examples of which include lithium (Li), cesium (Cs), calcium (Ca), lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), and lithium oxide (LiOx). In addition, the alkali metal, alkaline earth metal or the compound thereof may be added to the substance exhibiting the electron transportability in use. Specifically, for instance, magnesium (Mg) added to Alq may be used. In this case, the electrons can be more efficiently injected from the cathode.
Alternatively, the electron injecting layer may be provided by a composite material in a form of a mixture of the organic compound and the electron donor. Such a composite material exhibits excellent electron injectability and electron transportability since electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, the above examples (e.g., the metal complex and the hetero aromatic compound) of the substance forming the electron transporting layer are usable. As the electron donor, any substance exhibiting electron donating property to the organic compound is usable. Specifically, the electron donor is preferably alkali metal, alkaline earth metal and rare earth metal such as lithium, cesium, magnesium, calcium, erbium and ytterbium. The electron donor is also preferably alkali metal oxide and alkaline earth metal oxide such as lithium oxide, calcium oxide, and barium oxide. Moreover, a Lewis base such as magnesium oxide is usable. Further, the organic compound such as tetrathiafulvalene (abbreviation: TTF) is usable.
An organic electroluminescence display device (hereinafter also referred to as an organic EL display device) according to a fourth exemplary embodiment will be described below. In the description of the second exemplary embodiment, the same components as those in the first exemplary embodiment are denoted by the same reference signs and names to simplify or omit an explanation of the components. In the second exemplary embodiment, the same materials and compounds as described in the first exemplary embodiment are usable, unless otherwise specified.
An organic electroluminescence display device of the exemplary embodiment includes an anode and a cathode arranged opposite each other; and
According to the organic EL display device of the exemplary embodiment, since the first pixel includes the organic EL device of the first exemplary embodiment as the first organic EL device, the luminous efficiency of the first organic EL device is improved. As a result, the performance of the organic EL display device is improved.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the maximum peak wavelength of the first luminescent compound is different from the maximum peak wavelength of the third luminescent compound.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the maximum peak wavelength of the luminescent compound contained in the emitting layer of the first emitting region is different from the maximum peak wavelength of the luminescent compound contained in the emitting layer of the second emitting region.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the maximum peak wavelength of the first luminescent compound is shorter than the maximum peak wavelength of the third luminescent compound.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the maximum peak wavelength of the luminescent compound contained in the emitting layer of the first emitting region is shorter than the maximum peak wavelength of the luminescent compound contained in the emitting layer of the second emitting region.
An exemplary arrangement of the organic EL display device of the exemplary embodiment includes a fourth anode-side organic layer between the third anode-side organic layer and the first emitting layer in the first pixel.
An exemplary arrangement of the organic EL display device of the exemplary embodiment includes a fifth anode-side organic layer between the third anode-side organic layer and the third emitting layer in the second pixel. For instance, in later-described cases illustrated in
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the first pixel and the second pixel are each independently a blue pixel, a green pixel or a red pixel.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the first pixel is a blue pixel and the second pixel is a green pixel.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the first pixel is a blue pixel and the second pixel is a red pixel.
For instance, when the first pixel is a blue pixel, the first organic EL device contained in the first pixel may be referred to as a blue-emitting organic EL device, the first emitting region contained in the blue-emitting organic EL device may be referred to as a blue emitting region, and the first emitting layer contained in the blue emitting region may be referred to as a blue emitting layer.
For instance, when the second pixel is a green pixel, the second organic EL device contained in the second pixel may be referred to as a green-emitting organic EL device, the second emitting region contained in the green-emitting organic EL device may be referred to as a green emitting region, and the third emitting layer contained in the green emitting region may be referred to as a green emitting layer.
In an organic EL display device of a first arrangement of the exemplary embodiment, the first pixel is a blue pixel and the second pixel is a green pixel.
For instance, the organic EL display device of the first arrangement of the exemplary embodiment includes an anode and a cathode arranged opposite each other; and
In an organic EL display device of a second arrangement of the exemplary embodiment, the first pixel is a blue pixel and the second pixel is a red pixel.
For instance, the organic EL display device of the second arrangement of the exemplary embodiment includes an anode and a cathode arranged opposite each other, and a blue-emitting organic EL device as a blue pixel and a red-emitting organic EL device as a red pixel, in which
An exemplary arrangement of the organic EL display device according to the exemplary embodiment further includes a third pixel. The third pixel is, for instance, a blue pixel, a green pixel or a red pixel.
For instance, when the third pixel is a red pixel, the third organic EL device contained in the third pixel may be referred to as a red-emitting organic EL device, the third emitting region contained in the red-emitting organic EL device may be referred to as a red emitting region, and a fourth emitting layer contained in the red emitting region may be referred to as a red emitting layer.
In an organic EL display device of a third arrangement of the exemplary embodiment, the first pixel is a blue pixel, the second pixel is a green pixel, and the third pixel is a red pixel.
For instance, in the organic EL display device of the third arrangement of the exemplary embodiment,
The organic EL display device according to the first, second or third arrangement of the exemplary embodiment includes a fourth anode-side organic layer between the third anode-side organic layer and the blue emitting layer in the blue pixel. This prolongs a lifetime of the blue-emitting organic EL device of the blue pixel.
The organic EL display device according to the first or third arrangement of the exemplary embodiment includes a fifth anode-side organic layer between the third anode-side organic layer and the green emitting layer in the green pixel. In later-described cases illustrated in
The organic EL display device according to the second or third arrangement of the exemplary embodiment includes a sixth anode-side organic layer between the third anode-side organic layer and the red emitting layer in the red pixel. In later-described cases illustrated in
The organic EL display device according to the first, second or third arrangement of the exemplary embodiment includes, as the blue-emitting organic EL device, the organic EL device according to an exemplary embodiment of the first exemplary embodiment, thereby improving the luminous efficiency of the blue-emitting organic EL device. As a result, the performance of the organic EL display device is improved.
Herein, a layer provided in a shared manner across a plurality of devices is occasionally referred to as a common layer. Herein, a layer not provided in a shared manner across a plurality of devices is occasionally referred to as a non-common layer.
Herein, a zone provided in a shared manner across a plurality of devices is occasionally referred to as a common zone. The hole transporting zone, which is provided between the anode and each of the blue emitting region of the blue-emitting organic EL device, the green emitting layer of the green-emitting organic EL device, and the red emitting layer of the red-emitting organic EL device in a shared manner across the blue-emitting organic EL device, the green-emitting organic EL device, and the red-emitting organic EL device, is a common zone.
Herein, “blue”, “green”, or “red” used for each element, such as “pixel”, “emitting layer”, or “material”, is used to distinguish one from another. Although “blue”, “green”, or “red” may represent a color of light emitted from “pixel”, “emitting layer”, or “material”, “blue”, “green”, or “red” does not mean the color of appearance of each element.
Referring to
The organic EL display device 100A includes electrodes and organic layers supported by a substrate 2A.
The organic EL display device 100A includes the anode 3 and the cathode 4 arranged opposite each other.
The organic EL display device 100A includes a blue-emitting organic EL device 10B as a blue pixel, and a green organic EL device 10G as a green pixel.
It should be noted that
In the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G of the organic EL display device 100A, a hole transporting zone as the common zone is provided between the anode 3 and the respective emitting regions of the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G.
In the hole transporting zone of the organic EL display device 100A, a first anode-side organic layer 61A, a second anode-side organic layer 62A, and a third anode-side organic layer 63A are layered in this order from the side close to the anode 3. In the organic EL display device 100A, the hole transporting zone is provided in a shared manner across the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G.
In the organic EL display device 100A, the electron transporting layer 8 and the electron injecting layer 9 as the common layers are layered in this order between the cathode and the respective emitting regions of the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G.
A blue emitting region 5 of the blue-emitting organic EL device 10B of the organic EL display device 100A is similar to the emitting region 5 according to the first exemplary embodiment. The blue emitting region 5 includes a blue emitting layer 50B. The blue emitting layer 50B corresponds to the first emitting layer 51 according to the first exemplary embodiment.
The green emitting region of the green-emitting organic EL device 10G of the organic EL display device 100A includes the green emitting layer 53 (the third emitting layer).
The anode 3 is independently provided for each of the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G. Thus, the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G can be individually driven in the organic EL display device 100A. The respective anodes of the organic EL devices 10B, 10G are insulated from each other by an insulation material (not depicted). The cathode 4 is commonly provided for each of the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G.
In an exemplary embodiment, the blue-emitting organic EL device 10B and the green-emitting organic EL device 10G as pixels are arranged in parallel with each other on the substrate 2A.
An organic EL display device 100B illustrated in
The green-emitting organic EL device 11G includes the fifth anode-side organic layer 531 as a non-common layer between the green emitting layer 53 and the third anode-side organic layer 63A. In a case illustrated in
An organic EL display device 1000 illustrated in
In the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R of the organic EL display device 1000, a hole transporting zone as the common zone is provided between the anode 3 and the respective emitting regions of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
In the hole transporting zone of the organic EL display device 1000, the hole transporting zone (the first anode-side organic layer 61A, the second anode-side organic layer 62A, and the third anode-side organic layer 63A) is provided in a shared manner across the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
The red emitting region of the red-emitting organic EL device 10R of the organic EL display device 1000 includes the red emitting layer 54. In the red-emitting organic EL device 10R, the six anode-side organic layer 541 as the non-common layer is provided between the red emitting layer 54 and the third anode-side organic layer 63A.
An organic EL display device 100D illustrated in
The blue-emitting organic EL device 11B includes a fourth anode-side organic layer 64A as the non-common layer between the blue emitting layer 50B and the third anode-side organic layer 63A. In
An organic EL display device 100E illustrated in
A blue emitting region 5B of the blue-emitting organic EL device 12B is similar to the emitting region 5 of the first exemplary embodiment. The blue emitting region 5B includes the first emitting layer 51 and the second emitting layer 52. The second emitting layer 52 and the first emitting layer 51 are layered in this order from a side close to the anode.
An organic EL display device 100F illustrated in
The blue-emitting organic EL device 13B includes a fourth anode-side organic layer 64A as the non-common layer between the second emitting layer 52 of the blue emitting region 5B and the third anode-side organic layer 63A. In a case illustrated in
The invention is not limited to the arrangements of the organic EL display device illustrated in
For instance, in an exemplary arrangement of the organic EL display device of the exemplary embodiment, the sixth anode-side organic layer 541 is not provided between the red emitting layer 54 and the third anode-side organic layer 63A, and the red emitting layer 54 is in direct contact with the third anode-side organic layer 63A.
For instance, in
For instance, in an exemplary arrangement of the organic EL display device of the exemplary embodiment, the blue-emitting organic EL device, the green-emitting organic EL device, and the red-emitting organic EL device may each independently further include a layer different from the layers illustrated in
For instance, in an exemplary arrangement of the organic EL display device of the exemplary embodiment, the blue-emitting organic EL device, the green-emitting organic EL device, and the red-emitting organic EL device may be each independently a device that fluoresces or a device that phosphoresces. The blue-emitting organic EL device is preferably a device that fluoresces.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the third anode-side organic layer as the common layer contains a third hole transporting zone material, and a hole mobility of the third hole transporting zone material μh(cHT3) is larger than 1.0×10−5 cm2/Vs, and an energy level of a highest occupied molecular orbital of the third hole transporting zone material HOMO(cHT3) is −5.6 eV or less. When the third anode-side organic layer as the common layer contains the third hole transporting zone material having such a hole mobility and HOMO, hole injectability to the emitting regions of the blue pixel, the green pixel, and the red pixel is improved. Further, when the organic EL display device includes the fourth anode-side organic layer, the fifth anode-side organic layer 531, and the sixth anode-side organic layer 541, the hole injectability to those layers is high.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the first anode-side organic layer as the common layer contains the first hole transporting zone material of the first exemplary embodiment.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the second anode-side organic layer as the common layer contains the second hole transporting zone material of the first exemplary embodiment.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the third anode-side organic layer as the common layer contains the third hole transporting zone material of the first exemplary embodiment.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the fourth anode-side organic layer as the non-common layer contains the fourth hole transporting zone material of the first exemplary embodiment.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the green emitting layer contains a host material. For instance, the green emitting layer contains 50 mass % or more of the host material with respect to the total mass of the green emitting layer.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the green emitting layer of the green-emitting organic EL device contains a green luminescent compound that emits light having a maximum peak wavelength in a range from 500 nm to 550 nm. For instance, the green luminescent compound is a fluorescent compound that exhibits fluorescence having a maximum peak wavelength in a range from 500 nm to 550 nm. For instance, the green luminescent compound is a phosphorescent compound that exhibits phosphorescence having a maximum peak wavelength in a range from 500 nm to 550 nm. Herein, the green light emission refers to light emission in which a maximum peak wavelength of emission spectrum is in a range from 500 nm to 550 nm.
The fluorescent compound is a compound capable of emitting in a singlet state. The phosphorescent compound is a compound capable of emitting in a triplet state.
Examples of a green fluorescent compound usable for the green emitting layer include an aromatic amine derivative. Examples of a green phosphorescent compound usable for the green emitting layer include an iridium complex.
A maximum peak wavelength (maximum phosphorescence peak wavelength) of a phosphorescent compound is measurable by the following method. A measurement target compound is dissolved in EPA (diethylether:isopentane:ethanol=5:5:2 in volume ratio) so as to fall within a range from 10−5 mol/L to 10−4 mol/L, and the obtained solution is encapsulated in a quartz cell to provide a measurement sample. A phosphorescence spectrum (ordinate axis: phosphorescent luminous intensity, abscissa axis: wavelength) of the measurement sample is measured at a low temperature (77K). The local maximum value closest to the short-wavelength region among the local maximum values of the phosphorescence spectrum is defined as the maximum phosphorescence peak wavelength. A spectrophotofluorometer F-7000 produced by Hitachi High-Tech Science Corporation can be used to measure phosphorescence. The measurement apparatus is not limited to this arrangement. A combination of a cooling unit, a low temperature container, an excitation light source and a light-receiving unit may be used for measurement. Herein, the maximum peak wavelength of phosphorescence is occasionally referred to as the maximum phosphorescence peak wavelength (PH-peak).
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the green-emitting organic EL device includes a fifth anode-side organic layer between the green emitting layer and the third anode-side organic layer. The fifth anode-side organic layer may be in direct contact with the hole transporting zone. The fifth anode-side organic layer may be in direct contact with the green emitting layer. An emission position in the green-emitting organic EL device is easily adjustable by providing the fifth anode-side organic layer in the green-emitting organic EL device.
The fifth anode-side organic layer contains, for instance, a green organic material. The hole transporting zone material according to the first exemplary embodiment is usable as the green organic material. Although the green organic material and the hole transporting zone material contained in the hole transporting zone may be the same compound or different compounds, the green organic material is preferably different from the hole transporting zone material. The hole mobility of the green organic material is preferably larger than the hole mobility of the hole transporting zone material contained in the hole transporting zone. The green organic material is a compound different from the host material and the green luminescent compound contained in the green emitting layer.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the red emitting layer contains a host material. For instance, the red emitting layer contains 50 mass % or more of the host material with respect to the total mass of the red emitting layer.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the red emitting layer of the red organic EL device contains a red luminescent compound that emits light having a maximum peak wavelength in a range from 600 nm to 640 nm. For instance, the red luminescent compound is a fluorescent compound that exhibits fluorescence having a maximum peak wavelength in a range from 600 nm to 640 nm. For instance, the red luminescent compound is a phosphorescent compound that exhibits phosphorescence having a maximum peak wavelength in a range from 600 nm to 640 nm. Herein, the red light emission refers to light emission in which a maximum peak wavelength of emission spectrum is in a range from 600 nm to 640 nm.
Examples of a red fluorescent compound usable for the red emitting layer include a tetracene derivative and a diamine derivative. Examples of a red phosphorescent compound usable for the red emitting layer include metal complexes such as an iridium complex, platinum complex, terbium complex, and europium complex.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the red-emitting organic EL device preferably includes the sixth anode-side organic layer between the red emitting layer and the third anode-side organic layer. The sixth anode-side organic layer may be in direct contact with the hole transporting zone. The sixth anode-side organic layer may be in direct contact with the red emitting layer. In an exemplary arrangement of the organic EL display device of the exemplary embodiment, an emission position in the red-emitting organic EL device is easily adjustable by providing the six anode-side organic layer in the red-emitting organic EL device.
The sixth anode-side organic layer contains, for instance, a red organic material. The hole transporting zone material according to the first exemplary embodiment is usable as the red organic material. Although the red organic material and the hole transporting zone material contained in the hole transporting zone may be the same compound or different compounds, the red organic material is preferably different from the hole transporting zone material. The hole mobility of the red organic material is preferably larger than the hole mobility of the hole transporting zone material contained in the hole transporting zone. The red organic material is a compound different from the host material and the red luminescent compound contained in the red emitting layer.
Although the red organic material contained in the sixth anode-side organic layer of the red-emitting organic EL device and the green organic material contained in the fifth anode-side organic layer of the green-emitting organic EL device may be the same compound or different compounds, the red organic material is preferably different from the green organic material. The hole mobility of the red organic material is preferably larger than the hole mobility of the green organic material.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the film thickness of the sixth anode-side organic layer is preferably larger than the film thickness of the fifth anode-side organic layer.
In an exemplary arrangement of the organic EL display device of the exemplary embodiment, the host material contained in the green emitting layer and the host material contained in the red emitting layer are, for instance, a compound for dispersing a highly emittable substance (dopant material) in the emitting layers. As the host material contained in the green emitting layer and the host material contained in the red emitting layer, it is possible to use, for instance, a substance having a higher Lowest Unoccupied Molecular Orbital (LUMO) level and a lower Highest Occupied Molecular Orbital (HOMO) level than the highly emittable substance.
For instance, the following compounds (1) to (4) can be each independently used as the host material contained in the green emitting layer and the host material contained in the red emitting layer.
Referring to
In an exemplary embodiment, the anode 3 is arranged opposite to the cathode 4.
In an exemplary embodiment, the anode 3 is typically the non-common layer. In an exemplary embodiment, for instance, when the anode 3 is the non-common layer, the respective anodes in the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G and the red-emitting organic EL device 10R are physically separated from each other, and specifically, may be insulated from each other by an insulation material (not illustrated in the drawings) or the like.
In an exemplary embodiment, the cathode 4 is arranged opposite to the anode 3.
In an exemplary embodiment, the cathode 4 may be the common layer or the non-common layer.
In an exemplary embodiment, the cathode 4 is preferably the common layer provided in a shared manner across the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
In an exemplary embodiment, the cathode 4 is in direct contact with the electron injecting layer 9.
In an exemplary embodiment, when the cathode 4 is the common layer, the film thickness of the cathode 4 is constant over the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R. When the cathode 4 is the common layer, the cathode 4 provided for the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R can be produced without changing a mask or the like. The organic EL display device 100B thus has enhanced productivity.
In an exemplary embodiment, the electron transporting layer 8 is the common layer provided in a shared manner across the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
In an exemplary embodiment, the electron transporting layer 8 is provided between the electron injecting layer 9 and the emitting layers of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
In an exemplary embodiment, the side of the electron transporting layer 8 close to the anode 3 is in direct contact with the second emitting layer 52, the green emitting layer 53, and the red emitting layer 54.
The side of the electron transporting layer 8 close to the cathode 4 is in direct contact with the electron injecting layer 9.
In an exemplary embodiment, the electron transporting layer 8 is the common layer. In this case, the film thickness of the electron transporting layer 8 is constant over the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R. When the electron transporting layer 8 is the common layer, the electron transporting layer 8 provided for the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R can be produced without changing a mask or the like. The organic EL display device 100A thus has enhanced productivity.
In an exemplary embodiment, the electron injecting layer 9 is the common layer provided in a shared manner across the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R.
In an exemplary embodiment, the electron injecting layer 9 is disposed between the electron transporting layer 8 and the cathode 4.
In an exemplary embodiment, the electron injecting layer 9 is in direct contact with the electron transporting layer 8.
In an exemplary embodiment, the electron injecting layer 9 is the common layer. In this case, the film thickness of the electron injecting layer 9 is constant over the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R. When the electron injecting layer 9 is the common layer, the electron injecting layer 9 provided for the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R can be produced without changing a mask or the like. The organic EL display device 100A thus has enhanced productivity.
In an exemplary embodiment, any other layer than the emitting layer(s), the first emitting layer, the second emitting layer, the fourth anode-side organic layer, the green emitting layer, the red emitting layer, the fifth anode-side organic layer, and the sixth anode-side organic layer is preferably provided in a shared manner across the blue-emitting organic EL device, the green-emitting organic EL device, and the red-emitting organic EL device. Reducing the number of the non-common layers in the organic EL display device improves productivity of the device.
As an exemplary method of producing the organic EL display device of the exemplary embodiment, explanation is made about a method of producing the organic EL display device 100B illustrated in
First, the anode 3 is formed on the substrate 2A.
Subsequently, the anode-side organic layers as the common layers (first anode-side organic layer 61A, second anode-side organic layer 62A, and third anode-side organic layer 63A) are sequentially formed in a shared manner across the anode 3, forming the hole transporting zone as the common zone. Respective organic layers in the hole transporting zone of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R are formed to have the same film thickness.
Subsequently, the blue emitting layer 50B is formed on the third anode-side organic layer 63A in a region corresponding to the anode 3 of the blue-emitting organic EL device 10B using a predetermined film-forming mask (mask for the blue-emitting organic EL device).
Subsequently, the fifth anode-side organic layer 531 is formed on the third anode-side organic layer 63A in a region corresponding to the anode 3 of the green-emitting organic EL device 11G using a predetermined film-forming mask (mask for the green-emitting organic EL device). Subsequent to formation of the fifth anode-side organic layer 531, the green emitting layer 53 is formed on the fifth anode-side organic layer 531.
Subsequently, the sixth anode-side organic layer 541 is formed on the third anode-side organic layer 63A in a region corresponding to the anode 3 of the red-emitting organic EL device 10R using a predetermined film-forming mask (mask for the red-emitting organic EL device). Subsequent to formation of the sixth anode-side organic layer 541, the red emitting layer 54 is formed on the sixth anode-side organic layer 541.
The emitting layer 50, the green emitting layer 53, and the red emitting layer 54 are formed from mutually different materials.
After the formation of the third anode-side organic layer 63A, the order of forming the non-common layers of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R is not particularly limited.
For instance, after forming the third anode-side organic layer 63A, the fifth anode-side organic layer 531 and the green emitting layer 53 of the green-emitting organic EL device 11G may be formed, then the sixth anode-side organic layer 541 and the red emitting layer 54 of the red-emitting organic EL device 10R may be formed, and then the blue emitting layer 50B of the blue-emitting organic EL device 10B may be formed.
Alternatively, for instance, after forming the third anode-side organic layer 63A, the sixth anode-side organic layer 541 and the red emitting layer 54 of the red-emitting organic EL device 10R may be formed, then the fifth anode-side organic layer 531 and the green emitting layer 53 of the green-emitting organic EL device 11G may be formed, and then the blue emitting layer 50B of the blue-emitting organic EL device 10B may be formed.
Subsequently, the electron transporting layer 8 as the common layer is formed in a shared manner across the blue emitting layer 50B, the green emitting layer 53, and the red emitting layer 54. The electron transporting layer 8 of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R is formed to have a constant film thickness using the same material.
Subsequently, the electron injecting layer 9 as the common layer is formed on the electron transporting layer 8. The electron injecting layer 9 of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R is formed to have a constant film thickness using the same material.
Subsequently, the cathode 4 as the common layer is formed on the electron injecting layer 9. The cathode 4 of the blue-emitting organic EL device 10B, the green-emitting organic EL device 11G, and the red-emitting organic EL device 10R is formed to have a constant film thickness using the same material.
The organic EL display device 100B illustrated in
The organic EL display device 100D illustrated in
The organic EL display device 100E illustrated in
The organic EL display device 100F illustrated in
An electronic device according to a fifth exemplary embodiment is installed with the organic EL device according to any of the above exemplary embodiments or the organic EL display device according to any of the above exemplary embodiments. Examples of the electronic device include a display device and a light-emitting unit. Examples of the display device include a display component (e.g., an organic EL panel module), TV, mobile μhone, tablet and personal computer. Examples of the light-emitting unit include an illuminator and a vehicle light.
The scope of the invention is not limited by the above exemplary embodiments but includes any modification and improvement as long as such modification and improvement are compatible with the invention.
For instance, the number of emitting layers is not limited to one or two, and more than two emitting layers may be layered. For instance, the rest of the emitting layers may be a fluorescent emitting layer or a phosphorescent emitting layer with use of emission caused by electron transfer from the triplet excited state directly to the ground state. When the organic EL device includes a plurality of emitting layers, these emitting layers may be in direct contact with each other, or may form a so-called tandem organic EL device, in which a plurality of emitting units are layered via an intermediate layer (sometimes referred to as a charge generating layer or the like).
Further, for instance, a blocking layer is optionally provided adjacent to a side of the emitting layer close to the cathode. The blocking layer provided in direct contact with the side of the emitting layer close to the cathode preferably blocks at least one of holes or excitons.
For instance, when the blocking layer is provided in contact with the side of the emitting layer close to the cathode, the blocking layer permits transport of electrons, and blocks holes from reaching a layer provided closer to the cathode (e.g., the electron transporting layer) beyond the blocking layer. When the organic EL device includes the electron transporting layer, the blocking layer may be disposed between the emitting layer and the electron transporting layer.
Alternatively, the blocking layer may be provided adjacent to the emitting layer so that the excitation energy does not leak out from the emitting layer toward neighboring layer(s). The blocking layer blocks excitons generated in the emitting layer from being transferred to a layer(s) closer to the electrode(s) (e.g., the electron transporting layer and the like) beyond the blocking layer. The emitting layer is preferably in direct contact with the blocking layer.
Specific structure, shape and the like of the components in the invention may be designed in any manner as long as an object of the invention can be achieved.
The invention will be described in more detail below with reference to Examples. The invention is by no means limited to these Examples.
Structures of compounds used as the first organic material for producing organic EL devices in Examples are shown below.
Structures of compounds used as the first hole transporting zone material, the second hole transporting zone material, the third hole transporting zone material, and the fourth hole transporting zone material for producing organic EL devices in Examples are shown below.
Structures of compounds used as the first host material, the first additional host material, and the first luminescent compound for producing organic EL devices in Examples are shown below.
Structures of other compounds used for producing organic EL devices in Examples are shown below.
Organic EL devices were produced and evaluated as follows.
A glass substrate (size: 25 mm×75 mm×1.1 mm thick, produced by Geomatec Co., Ltd.) having an ITO transparent electrode (anode) was ultrasonic-cleaned in isopropyl alcohol for five minutes, and then UV-ozone-cleaned for 30 minutes. The film thickness of the ITO transparent electrode was 130 nm.
After the glass substrate having the transparent electrode line was cleaned, the glass substrate was mounted on a substrate holder of a vacuum evaporation apparatus. First, a compound HT-1-3 and a compound HA were co-deposited on a surface of the glass substrate, where the transparent electrode line was provided, to cover the transparent electrode, thereby forming a 10-nm-thick first anode-side organic layer (occasionally also referred to as a hole injecting layer). The ratios of the compound HT-1-3 and the compound HA in the first anode-side organic layer were 97 mass % and 3 mass %, respectively.
The compound HT-1-3 was vapor-deposited on the first anode-side organic layer to form a 40-nm-thick second anode-side organic layer (occasionally also referred to as a first hole transporting layer).
A compound HT-2-3 was vapor-deposited on the second anode-side organic layer to form a 40-nm-thick third anode-side organic layer (occasionally also referred to as a second hole transporting layer).
A compound BH-5 (first host material), a compound BH-4 (first additional host material) and a compound BD-4 (first luminescent compound) were co-deposited on the third anode-side organic layer to form a 25-nm-thick first emitting layer. The ratios of the compound BH-5, the compound BH-4, and the compound BD-4 in the first emitting layer were 50 mass %, 47 mass %, and 3 mass %, respectively.
A compound ET-3 was vapor-deposited on the first emitting layer to form a 5-nm-thick first electron transporting layer (occasionally also referred to as a hole blocking layer (HBL)).
A compound ET-2 was vapor-deposited on the first electron transporting layer to form a 20-nm-thick second electron transporting layer (ET).
A compound LiF was vapor-deposited on the second electron transporting layer to form a 1-nm-thick electron injecting layer.
Metal (Al) was vapor-deposited on the electron injecting layer to form an 80-nm-thick cathode.
A device arrangement of the organic EL device in Example 1 is roughly shown as follows.
Numerals in parentheses represent a film thickness (unit: nm).
The numerals (97%:3%) represented by percentage in the same parentheses indicate a ratio (mass %) between the compound HT-1-3 and the compound HA in the first anode-side organic layer. The numerals (50%:47%:3%) represented by percentage in the same parentheses indicate a ratio (mass %) between the first host material (compound BH-5), the first additional host material (compound BH-4) and the first luminescent compound (compound BD-4) in the first emitting layer.
An organic EL device in Reference Example 1 was produced in the same manner as the organic EL device in Example 1 except that the compound BH-4 and the compound BD-4 were co-deposited on the third anode-side organic layer to form the first emitting layer. The ratios of the compound BH-4 and the compound BD-4 in the first emitting layer were 97 mass % and 3 mass %, respectively.
An organic EL device in Reference Example 2 was produced in the same manner as the organic EL device in Example 1 except that the compound BH-5 and the compound BD-4 were co-deposited on the third anode-side organic layer to form the first emitting layer. The ratios of the compound BH-5 and the compound BD-4 in the first emitting layer were 97 mass % and 3 mass %, respectively.
An organic EL device in Comparative 1 was produced in the same manner as in Example 1 except that the compound HT-1-3 was vapor-deposited on the second anode-side organic layer to form the third anode-side organic layer having a film thickness of 35 nm, the compound HT-2-3 was vapor-deposited on the third anode-side organic layer to form the fourth anode-side organic layer having a film thickness of 5 nm, and the first emitting layer was formed on the fourth anode-side organic layer.
An organic EL device in Comparative 2 was produced in the same manner as in Reference Example 1 except that the compound HT-1-3 was vapor-deposited on the second anode-side organic layer to form the third anode-side organic layer having a film thickness of 35 nm, the compound HT-2-3 was vapor-deposited on the third anode-side organic layer to form the fourth anode-side organic layer having a film thickness of 5 nm, and the first emitting layer was formed on the fourth anode-side organic layer.
An organic EL device in Comparative 3 was produced in the same manner as in Reference Example 2 except that the compound HT-1-3 was vapor-deposited on the second anode-side organic layer to form the third anode-side organic layer having a film thickness of 35 nm, the compound HT-2-3 was vapor-deposited on the third anode-side organic layer to form the fourth anode-side organic layer having a film thickness of 5 nm, and the first emitting layer was formed on the fourth anode-side organic layer.
A glass substrate (size: 25 mm×75 mm×1.1 mm thick, produced by Geomatec Co., Ltd.) having an ITO transparent electrode (anode) was ultrasonic-cleaned in isopropyl alcohol for five minutes, and then UV-ozone-cleaned for 30 minutes. The film thickness of the ITO transparent electrode was 130 nm.
After the glass substrate having the transparent electrode line was cleaned, the glass substrate was mounted on a substrate holder of a vacuum evaporation apparatus. First, a compound HT10 and a compound HA were co-deposited on a surface of the glass substrate, where the transparent electrode line was provided, to cover the transparent electrode, thereby forming a 10-nm-thick first anode-side organic layer (occasionally also referred to as a hole injecting layer). The ratios of the compound HT10 and the compound HA in the first anode-side organic layer were 97 mass % and 3 mass %, respectively.
The compound HT10 was vapor-deposited on the first anode-side organic layer to form a 40-nm-thick second anode-side organic layer (occasionally also referred to as a first hole transporting layer).
A compound HT20 was vapor-deposited on the second anode-side organic layer to form a 40-nm-thick third anode-side organic layer (occasionally also referred to as a second hole transporting layer).
A compound EBL10 was vapor-deposited on the third anode-side organic layer to form a 10-nm-thick fourth anode-side organic layer (occasionally also referred to as a third hole transporting layer).
A compound BH10 (first host material), a compound BH20 (first additional host material) and a compound BD10 (first luminescent compound) were co-deposited on the fourth anode-side organic layer to form a 25-nm-thick first emitting layer. The ratios of the compound BH10, the compound BH20, and the compound BD10 in the first emitting layer were 49.5 mass %, 49.5 mass %, and 1 mass %, respectively.
A compound HBL10 was vapor-deposited on the first emitting layer to form a 10-nm-thick first electron transporting layer (occasionally also referred to as a hole blocking layer (HBL)).
A compound ET-2 was vapor-deposited on the first electron transporting layer to form a 15-nm-thick second electron transporting layer (ET).
A compound LiF was vapor-deposited on the second electron transporting layer to form a 1-nm-thick electron injecting layer.
Metal (Al) was vapor-deposited on the electron injecting layer to form an 80-nm-thick cathode.
A device arrangement of the organic EL device in Example 2 is roughly shown as follows.
Numerals in parentheses represent a film thickness (unit: nm).
The numerals (97%:3%) represented by percentage in the same parentheses indicate a ratio (mass %) between the compound HT10 and the compound HA in the first anode-side organic layer. The numerals (49.5%:49.5%:1%) represented by percentage in the same parentheses indicate a ratio (mass %) between the first host material (compound BH10), the first additional host material (compound BH20) and the first luminescent compound (compound BD10) in the first emitting layer.
Organic EL devices of Examples 3 to 5 were produced in the same manner as in Example 2 except that compounds contained in the respective first, second, third anode-side organic layers, and first emitting layer were replaced with compounds listed in Table 2.
An organic EL device of Comparative 4 was produced in the same manner as in Example 2 except that compounds contained in the respective first, second, third anode-side organic layers, and first emitting layer were replaced with compounds listed in Table 2.
The organic EL devices produced were evaluated as follows. Tables 1 and 2 show evaluation results.
The voltage (unit: V) when electric current was applied to between the anode and the cathode so that the current density was 10 mA/cm2 was measured.
Voltage was applied to the organic EL devices such that a current density was 10 mA/cm2, where spectral radiance spectrum was measured with a spectroradiometer CS-2000 (produced by Konica Minolta, Inc.). The external quantum efficiency EQE (unit: %) was calculated based on the obtained spectral radiance spectra, assuming that the spectra was provided under a Lambertian radiation.
Voltage was applied to the produced organic EL device such that a current density was 50 mA/cm2, where a time (LT95 (unit: hr)) elapsed before a luminance intensity was reduced to 95% of the initial luminance intensity was measured as a lifetime. The luminance intensity was measured with a spectroradiometer CS-2000 (manufactured by Konica Minolta, Inc.).
Evaluation results of Example 1 in which the relationship of the numerical formula (Numerical Formula NM) (NM2>NM3) was satisfied and the first emitting layer contained two types of host materials (the first host material and the first additional host material) are shown below.
Example 1 exhibited light emission with higher efficiency and longer lifetime than Comparative 1 in which the relationship of the numerical formula (Numerical Formula NM) was not satisfied.
Example 1 exhibited light emission with higher efficiency and longer lifetime than Reference Examples 1 and 2 in each of which the emitting layer contained only one type of host material. Further, the organic EL device in Example 1 was driven at lower voltage than the organic EL devices in Reference Examples 1 and 2.
Example 1 exhibited light emission with higher efficiency than Comparatives 2 to 3 in each of which the relationship of the numerical formula (Numerical Formula NM) was not satisfied and the emitting layer contained only one type of host material.
In Examples 2 to 5 and Comparative 4 in which the hole transporting zone includes the first anode-side organic layer, the second anode-side organic layer, the third anode-side organic layer, and the fourth anode-side organic layer and the first emitting layer contains two types of host materials (the first host material and the first additional host material), Examples 2 to 4 satisfying the relationship of the numerical formula (Numerical Formula NM) (NM2>NM3) exhibited light emission with higher efficiency and longer lifetime than Comparative 4 not satisfying the relationship of the numerical formula (Numerical Formula NM).
Example 5 satisfying the relationship of the numerical formula (Numerical Formula NM) (NM2>NM3) exhibited light emission with higher efficiency than Comparative 4 not satisfying the relationship of the numerical formula (Numerical Formula NM).
A toluene solution of a measurement target compound at a concentration of 10 μmol/L was prepared and put in a quartz cell. An absorption spectrum (ordinate axis: absorption intensity, abscissa axis: wavelength) of the thus-obtained sample was measured at a normal temperature (300K). A tangent was drawn to the fall of the absorption spectrum close to the long-wavelength region, and a wavelength value λedge (nm) at an intersection of the tangent and the abscissa axis was assigned to a conversion equation (F2) below to calculate singlet energy.
A spectrophotometer (U3310 manufactured by Hitachi, Ltd.) was used for measuring absorption spectrum.
The tangent to the fall of the absorption spectrum close to the long-wavelength region is drawn as follows. While moving on a curve of the absorption spectrum from the local maximum value closest to the long-wavelength region, among the local maximum values of the absorption spectrum, in a long-wavelength direction, a tangent at each point on the curve is checked. An inclination of the tangent is decreased and increased in a repeated manner as the curve falls (i.e., a value of the ordinate axis is decreased). A tangent drawn at a point where the inclination of the curve is the local minimum closest to the long-wavelength region (except when absorbance is 0.1 or less) is defined as the tangent to the fall of the absorption spectrum close to the long-wavelength region.
The local maximum absorbance of 0.2 or less is not counted as the above-mentioned local maximum absorbance closest to the long-wavelength region.
A measurement target compound was dissolved in EPA (diethylether:isopentane:ethanol=5:5:2 in volume ratio) at a concentration of 10 μmol/L, and the obtained solution was put in a quartz cell to provide a measurement sample. A phosphorescence spectrum (ordinate axis: phosphorescent luminous intensity, abscissa axis: wavelength) of the measurement sample was measured at a low temperature (77K). A tangent was drawn to the rise of the phosphorescence spectrum close to the short-wavelength region. An energy amount was calculated by a conversion equation (F1) below on a basis of a wavelength value λedge [nm] at an intersection of the tangent and the abscissa axis. The calculated energy amount was defined as triplet energy T1. It should be noted that the triplet energy T1 may have an error of about plus or minus 0.02 eV depending on measurement conditions.
The tangent to the rise of the phosphorescence spectrum close to the short-wavelength region is drawn as follows. While moving on a curve of the phosphorescence spectrum from the short-wavelength region to the local maximum value closest to the short-wavelength region among the local maximum values of the phosphorescence spectrum, a tangent is checked at each point on the curve toward the long-wavelength of the phosphorescence spectrum. An inclination of the tangent is increased along the rise of the curve (i.e., a value of the ordinate axis is increased). A tangent drawn at a point of the local maximum inclination (i.e., a tangent at an inflection point) is defined as the tangent to the rise of the phosphorescence spectrum close to the short-wavelength region.
A local maximum point where a peak intensity is 15% or less of the maximum peak intensity of the spectrum is not counted as the above-mentioned local maximum peak intensity closest to the short-wavelength region. The tangent drawn at a point that is closest to the local maximum peak intensity closest to the short-wavelength region and where the inclination of the curve is the local maximum is defined as a tangent to the rise of the phosphorescence spectrum close to the short-wavelength region.
For phosphorescence measurement, a spectrophotofluorometer body F-4500 manufactured by Hitachi High-Technologies Corporation was used.
A measurement target compound was dissolved in toluene at a concentration of 4.9×10−6 mol/L to prepare a toluene solution. Using a fluorescence spectrometer (spectrophotofluorometer F-7000 produced by Hitachi High-Tech Science Corporation), the toluene solution of the measurement target compound was excited at 390 nm, where a maximum fluorescence peak wavelength A (unit: nm) was measured.
Table 3 shows measurement values of the singlet energy S1 and the triplet energy T1, and fluorescent maximum peak wavelength A of the compounds used for producing the organic EL devices.
The refractive index of the constituent material (compound) forming the organic layer was measured as follows.
A measurement target material was vacuum-deposited on a glass substrate to form a film having an approximately 50 nm thickness. Using a spectroscopic ellipsometer (M-2000UI, produced by J. A. Woollam Co., Inc. (US)), the obtained sample film was irradiated with incident light (from ultraviolet light through visible light to near-infrared light) every 5 degrees in a measurement angle range of 45 degrees to 75 degrees to measure change in a deflection state of the light reflected on the sample surface. In order to improve the measurement accuracy of the extinction coefficient, a transmission spectrum in a substrate normal direction (direction perpendicular to a surface of the substrate of the organic EL device) was also measured by M-2000UI. Similarly, the same measurement was performed also on the glass substrate on which no measurement target material was vapor-deposited. The obtained measurement information was fitted using analysis software (Complete EASE) produced by J. A. Woollam Co., Inc.
Refractive indices in an in-plane direction and a normal direction, extinction coefficients in the in-plane direction and the normal direction, and an order parameter of an organic film formed on the substrate were calculated under fitting conditions of using an anisotropic model rotationally symmetric about one axis and setting a parameter MSE indicating a mean square error in said analysis software to be 3.0 or less. A peak close to the long-wavelength region of the extinction coefficient (in-plane direction) was defined as S1, and the order parameter was calculated by a peak wavelength of S1. As fitting conditions for the glass substrate, an isotropic model was used.
Typically, a film formed by vacuum-depositing a low molecular material on the substrate is rotationally symmetric about one axis extending along the substrate normal direction. When an angle formed by the substrate normal direction and a molecular axis in a thin film formed on the substrate is defined as θ and the extinction coefficients in a substrate parallel direction (Ordinary direction) and a substrate perpendicular direction (Extra-Ordinary direction) obtained by performing the variable-angle spectroscopic ellipsometry measurement on the thin film are respectively defined as ko and ke, S′ represented by a formula below is the order parameter.
An evaluation method of the molecular orientation is a publicly known method, and details thereof are described in Organic Electronics, volume 10, page 127 (2009). Further, the method for forming the thin film is a vacuum deposition method.
The order parameter S′ obtained by the variable-angle spectroscopic ellipsometry measurement is 1.0 when all the molecules are oriented in parallel with the substrate. When molecules are random without being oriented, the order parameter S′ is 0.66.
Herein, a value at 2.7 eV in the substrate parallel direction (Ordinary direction), from among the values measured above, is defined as a refractive index of the measurement target material.
When a layer was formed by a constituent material containing a plurality of compounds, a refractive index of the constituent material of the layer, the layer being a film formed by co-depositing the plurality of compounds as the measurement target material on the glass substrate or a film formed by vapor-depositing a mixture containing the plurality of compounds as the measurement target material, was measured using a spectroscopic ellipsometer in the same manner as above.
Tables 1 to 2 show refractive indexes of the respective constituent materials (compounds) for a combination of the second anode-side organic layer and the third anode-side organic layer and a difference in the refractive indexes NM2−NM3 thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-163151 | Oct 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/036719 | 9/30/2022 | WO |
