Patent Application
20240196732
The present invention relates to an organic electronic device comprising a compound and a display device comprising the organic electronic device. The invention further relates to novel compounds which can be of use in organic electronic devices.
Organic electronic devices, such as organic light-emitting diodes OLEDs, which are self-emitting devices, have a wide viewing angle, excellent contrast, quick response, high brightness, excellent operating voltage characteristics, and color reproduction. A typical OLED comprises an anode, a hole transport layer HTL, an emission layer EML, an electron transport layer ETL, and a cathode, which are sequentially stacked on a substrate. In this regard, the HTL, the EML, and the ETL are thin films formed from organic compounds.
When a voltage is applied to the anode and the cathode, holes injected from the anode move to the EML, via the HTL, and electrons injected from the cathode move to the EML, via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted. The injection and flow of holes and electrons should be balanced, so that an OLED having the above-described structure has excellent efficiency and/or a long lifetime.
Performance of an organic light emitting diode may be affected by characteristics of the semiconductor layer, and among them, may be affected by characteristics of metal complexes which are also contained in the semiconductor layer.
WO 2017/029370 A1 relates to an organic electroluminescence device having a hole injection layer comprising a metal complex containing a deprotonated N-sulphonimide is disclosed.
WO 2017/029366 A1 discloses a thick hole injection layer comprising a matrix compound and a metal complex containing a deprotonated N-sulfonimide.
JP 2002-246179 A discloses an organic electroluminescence element which is provided at least with a positive electrode, a light-emitting layer containing an organic luminous substance, and a negative electrode. The organic electroluminescence element contains a metal complex.
There remains a need to improve performance of organic semiconductor materials, semiconductor layers, as well as organic electronic devices thereof, in particular to achieve improved operating voltage, improved lifetime, current efficiency and/or improved operating voltage stability over time through improving the characteristics of the compounds comprised therein.
Additionally, there is a need to provide compounds with improved thermal properties.
An aspect of the present invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound comprising a metal M and at least one ligand L represented by formula (1)
wherein
It should be noted that throughout the application and the claims any Rn, Mn, etc. always refer to the same moieties, unless otherwise noted.
In the present specification, the term “ligand” refers to an anionic molecule which binds to a cationic metal either by a dative bond or ionic interaction, preferably a dative bond, wherein the nature of the dative bond can have a character ranging from a covalent bond to an ionic bond.
In the present specification, when a definition is not otherwise provided, “partially fluorinated” refers to an alkyl group, an aryl group, a heteroaryl group etc. in which only part of the hydrogen atoms are replaced by fluorine atoms.
In the present specification, when a definition is not otherwise provided, “perfluorinated” refers to an alkyl group, an aryl group, a heteroaryl group etc. in which all hydrogen atoms are replaced by fluorine atoms.
Unless otherwise noted the term “metal” as used herein includes metal cations if the metal is referred to together with an anion, wherein the positive charge of the metal cation and the negative charge of the anion balance each other.
In the present specification, an electron withdrawing group (EWG) is a group that reduces electron density in a molecule through the carbon atom it is bonded to. Typical examples of electron withdrawing groups are halogen, in particular F and Cl, —COR, —COH, —COOR, —COOH, partially fluorinated or perfluorinated alkyl, partially fluorinated or perfluorinated aryl, partially fluorinated or perfluorinated heteroaryl, partially fluorinated or perfluorinated carbocyclyl, partially fluorinated or perfluorinated C2 to C20 heterocyclyl, —NO2, and —CN.
In the present specification, when a definition is not otherwise provided, “substituted” refers to one substituted with a deuterium, C6 to C12 aryl, C3 to C11 heteroaryl, and C1 to C12 alkyl, D, C1 to C12 alkoxy, C3 to C12 branched alkyl, C3 to C12 cyclic alkyl, C3 to C12 branched alkoxy, C3 to C12 cyclic alkoxy, partially or perfluorinated C1 to C12 alkyl, partially or perfluorinated C1 to C12 alkoxy, partially or perdeuterated C1 to C12 alkyl, partially or perdeuterated C1 to C12 alkoxy, halogen, CN or PY(R10)2, wherein Y is selected from O, S or Se, preferably O and R10 is independently selected from C6 to C12 aryl, C3 to C12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy.
In the present specification, when a definition is not otherwise provided, an “alkyl group” refers to a saturated aliphatic hydrocarbyl group. The alkyl group may be a C1 to C12 alkyl group. More specifically, the alkyl group may be a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, a C1 to C4 alkyl group includes 1 to 4 carbons in alkyl chain, and may be selected from methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and tert-butyl.
Specific examples of the alkyl group may be a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, a hexyl group.
In the context of the present invention, “iCnH(2n+1)” denotes an iso-alkyl group and “iCnF(2n+1)” denotes a perfluorinated iso-alkyl group.
The term “carbocyclyl” as used herein includes all types of not fully saturated organic ring systems, for example, cycloalkyl, partially unsaturated cycloalkyl etc. monocycles, bicycles, fused ring systems, bridged ring systems, and spirocyclic ring systems are included.
The term “heterocyclyl” as used herein refers to a heterocarbocyclyl.
The term “cycloalkyl” refers to saturated hydrocarbyl groups derived from a cycloalkane by formal abstraction of one hydrogen atom from a ring atom comprised in the corresponding cycloalkane. Examples of the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, an adamantly group and the like.
The term “hetero” is understood the way that at least one carbon atom, in a structure which may be formed by covalently bound carbon atoms, is replaced by another polyvalent atom. Preferably, the heteroatoms are selected from B, Si, N, P, O, S; more preferably from N, P, O, S.
In the present specification, “aryl group” refers to a hydrocarbyl group which can be created by formal abstraction of one hydrogen atom from an aromatic ring in the corresponding aromatic hydrocarbon. Aromatic hydrocarbon refers to a hydrocarbon which contains at least one aromatic ring or aromatic ring system. Aromatic ring or aromatic ring system refers to a planar ring or ring system of covalently bound carbon atoms, wherein the planar ring or ring system comprises a conjugated system of delocalized electrons fulfilling Hückel's rule. Examples of aryl groups include monocyclic groups like phenyl or tolyl, polycyclic groups which comprise more aromatic rings linked by single bonds, like biphenyl, and polycyclic groups comprising fused rings, like naphthyl or fluorenyl.
Analogously, under heteroaryl, it is especially where suitable understood a group derived by formal abstraction of one ring hydrogen from a heterocyclic aromatic ring in a compound comprising at least one such ring.
Under heterocycloalkyl, it is especially where suitable understood a group derived by formal abstraction of one ring hydrogen from a saturated cycloalkyl ring in a compound comprising at least one such ring.
The term “fused aryl rings” or “condensed aryl rings” is understood the way that two aryl rings are considered fused or condensed when they share at least two common sp2-hybridized carbon atoms.
In the present specification, the single bond refers to a direct bond.
In the context of the present invention, “different” means that the compounds do not have an identical chemical structure.
The term “free of”, “does not contain”, “does not comprise” does not exclude impurities which may be present in the compounds prior to deposition. Impurities have no technical effect with respect to the object achieved by the present invention.
The term “contacting sandwiched” refers to an arrangement of three layers whereby the layer in the middle is in direct contact with the two adjacent layers.
The terms “light-absorbing layer” and “light absorption layer” are used synonymously.
The terms “light-emitting layer”, “light emission layer” and “emission layer” are used synonymously.
The terms “OLED”, “organic light-emitting diode” and “organic light-emitting device” are used synonymously.
The terms anode, anode layer and anode electrode are used synonymously.
The terms cathode, cathode layer and cathode electrode are used synonymously.
In the specification, hole characteristics refer to an ability to donate an electron to form a hole when an electric field is applied and that a hole formed in the anode may be easily injected into the emission layer and transported in the emission layer due to conductive characteristics according to a highest occupied molecular orbital (HOMO) level.
In addition, electron characteristics refer to an ability to accept an electron when an electric field is applied and that electrons formed in the cathode may be easily injected into the emission layer and transported in the emission layer due to conductive characteristics according to a lowest unoccupied molecular orbital (LUMO) level.
The different embodiments described herein may separately or in combination of two or more embodiments be material for realizing the invention.
Surprisingly, it was found that the compounds of formulas (1) to (3) and (5) as characterized herein have improved thermal properties and that organic electronic devices containing the same as a semiconductor layer, preferably as hole injection layer or hole transport layer, have improved performance in particular current efficiency, stability and life time.
According to one embodiment of the present invention, the compound is represented by Formula (2)
Mn+Ln (2)
wherein n is an integer from 1 to 4, preferably 1 or 3, preferably 1 or 2; and each L is selected independently, preferably each L is the same.
According to one embodiment of the present invention, the compound is represented by Formula (2)
Mn+Ln (2)
wherein n is an integer of 1 or 2; and each L is the same.
According to one embodiment of the present invention, the compound is represented by Formula (3)
wherein n is an integer from 1 to 4, preferably 1 or 3, preferably 1 or 2.
According to one embodiment of the present invention, the compound is represented by Formula (3)
wherein
According to one embodiment of the present invention, the metal M is selected from an alkali metal, an alkaline earth metal, a transition metal, or a rare earth metal.
According to one embodiment of the present invention, the metal M is selected from an alkali metal, an alkaline earth metal, or a transition metal.
According to one embodiment of the present invention, the metal M is selected from alkali metals, alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd; rare earth metals in oxidation state (II) or (III); Al, Ga, In; and from Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd; rare earth metals in oxidation state (II) or (III); Al, Ga, In; and from Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from an alkali metal, an alkaline earth metal, Cu, Ag, Fe, Co, Ti, Zr, Hf, Mo, or W.
According to one embodiment of the present invention, the metal M is selected from Na, Cu, or Ag.
R1 and R2
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl, or a substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R2 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl, or a substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R2 is independently selected from a substituted C1 to C20 alkyl, a substituted C6 to C20 aryl, or a substituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R2 is independently selected from a substituted C1 to C20 alkyl.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl;
R2 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl;
R1 and R2 can be connected via a direct bond; and
R1 and R2 taken together with the neighboring sulfur, nitrogen or carbon atom can form a ring, and the ring may be a substituted or substituted C6 to C20 ring or C6 to C20 polycyclic ring, or a substituted or unsubstituted condensed C6 to C20 rings.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl;
R2 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl; and
R1 and R2 can be connected via a direct bond.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl; and
R2 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl;
R2 is independently selected from a substituted C1 to C20 alkyl preferably perfluorinated C1 to C12 alkyl, perfluorinated C1 to C10 alkyl, perfluorinated C1 to C8 alkyl, perfluorinated C1 to C6 alkyl, perfluorinated C1 to C4 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl;
R1 and R2 can be connected via a direct bond; and
R1 and R2 taken together with the neighboring sulfur, nitrogen or carbon atom can form a ring, and the ring may be a substituted or substituted C6 to C20 ring or C6 to C20 polycyclic ring, or a substituted or unsubstituted condensed C6 to C20 rings.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl; and
R2 is independently selected from a substituted C1 to C20 alkyl preferably perfluorinated C1 to C12 alkyl, perfluorinated C1 to C10 alkyl, perfluorinated C1 to C8 alkyl, perfluorinated C1 to C6 alkyl, perfluorinated C1 to C4 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl; and
R1 and R2 can be connected via a direct bond.
According to one embodiment of the present invention, R1 is independently selected from a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl; and
R2 is independently selected from a substituted C1 to C2 alkyl preferably perfluorinated C1 to C12 alkyl, perfluorinated C1 to C10 alkyl, perfluorinated C1 to C8 alkyl, perfluorinated C1 to C6 alkyl, perfluorinated C1 to C4 alkyl, a substituted or unsubstituted C6 to C20 aryl or a substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, for each R1 and R2 aryl is independently phenyl, naphthyl, anthracene, or 9-phenanthryl.
According to one embodiment of the present invention, for each R1 and R2 aryl is independently phenyl or naphthyl.
According to one embodiment of the present invention, for each R1 and R2 aryl is independently phenyl.
According to one embodiment of the present invention, for each R1 and R2 heteroaryl is independently pyridinyl, pyrimidinyl, pyriazinyl or pirazinyl.
According to one embodiment of the present invention, for each R1 and R2 heteroaryl is independently pyridinyl.
According to one embodiment of the present invention, for each R1 and R2 heteroaryl is independently F or CF3-substituted pyrimidinyl, pyriazinyl, pirazinyl
According to one embodiment of the present invention, R2 substituted heteroaryl is independently F or CF3-substituted pyridinyl, pyrimidinyl, pirazinyl.
According to one embodiment of the present invention, for each R1 and R2 alkyl is independently branched or unbranched alkyl or cycloalkyl.
According to one embodiment of the present invention, for each R1 and R2 alkyl is independently branched or unbranched alkyl.
According to one embodiment of the present invention, for each R1 and R2 alkyl is independently C1 to C20 alkyl, C1 to C18 alkyl, C1 to C16 alkyl, C1 to C14 alkyl, C1 to C12, C1 to C10, C1 to C8 alkyl, C1 to C6 alkyl, or C1 to C4 alkyl.
According to one embodiment of the present invention, R1 and R2 are independently selected from
—CH3, —CH2CH3, —CH2CH2CH3, —CH(CH3)2, —CH2CH2CH2CH3, —CH(CH3)(CH2CH3), —C(CH3)3, —CH2CH2CH2CH2CH3, —CH2CH2CH2CH2CH2CH3, —CF3, —CF2CF3, —CF2CF2CF3, —CF(CF3)2, —CH2CF2CF3, —CH(CF3)2, —CF2CF2CF2CF3, —C(CF3)3, —CF(CF3)(CF2CF3), —CF2CF2CF2CF2CF3, —CF2CF2CF2CF2CF2CF3,
According to one embodiment of the present invention, R1 and R2 are independently selected from
—CH3, —CH2CH3, —CH2CH2CH3, —CH(CH3)2, —CH2CH2CH2CH3, —CH(CH3)(CH2CH3), —C(CH3)3, —CF3, —CF2CF3, —CF2CF2CF3, —CF(CF3)2, —CH2CF2CF3, —CH(CF3)2, —CF2CF2CF2CF3, —C(CF3)3, —CF(CF3)(CF2CF3), —CF2CF2CF2CF2CF3, —CF2CF2CF2CF2CF2CF3,
According to one embodiment of the present invention, R1 is selected from
—CH3, —CH2CH3, —CH2CH2CH3, —CH(CH3)2, —CH2CH2CH2CH3, —CH(CH3)(CH2CH3), —C(CH3)3, —CF3, —CF2CF3, —CF2CF2CF3, —CF(CF3)2, —CH2CF2CF3, —CH(CF3)2, —CF2CF2CF2CF3, —(CF3)3, —CF(CF3)(CF2CF3), —CF2CF2CF2CF2CF3, —CF2CF2CF2CF2CF2CF3,
According to one embodiment of the present invention, R2 is selected from
—CF3, —CF2CF3, —CF2CF2CF3, —CF(CF3)2, —CF2CF2CF3, —C(CF3)3, —CF(CF3)(CF2CF3), —CF2CF2CF2CF2CF3, —CF2CF2CF2CF2CF2CF3,
According to one embodiment of the present invention, if at least one of R1 and R2 is substituted then at least one substituent on R1 and/or R2 is an electron-withdrawing group.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group.
According to one embodiment of the present invention, the electron-withdrawing group is selected from halogen, preferably Cl or F, CN, COR3, COOR3, a partially fluorinated or perfluorinated C1 to C10 alkyl, partially fluorinated or perfluorinated C6 to C20 aryl, partially fluorinated or perfluorinated C2 to C20 heteroaryl, a partially fluorinated or perfluorinated C3 to C20 carbocyclyl, or a partially fluorinated or perfluorinated C2 to C20 heterocyclyl; wherein R3 is selected from hydrogen, a substituted or unsubstituted C1 to C8 alkyl, a substituted or unsubstituted C3 to C20 carbocyclyl, a substituted or unsubstituted C2 to C20 heterocyclyl, a substituted or unsubstituted C6 to C20 aryl, or a substituted or unsubstituted C2 to C20 heteroaryl. Preferably R3 is selected from hydrogen, a substituted or unsubstituted C1 to C8 alkyl, a substituted or unsubstituted C6 to C20 aryl, or a substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, the electron-withdrawing group is independently selected from halogen, Cl, F, CN, a partially fluorinated or perfluorinated C1 to C10 alkyl, partially fluorinated or perfluorinated C6 to C20, aryl, and partially fluorinated or perfluorinated C2 to C20 heteroaryl.
According to one embodiment of the present invention, the electron-withdrawing group is independently selected from halogen, preferably Cl, F, CN, and a partially fluorinated or perfluorinated C1 to C10 alkyl.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group, wherein the electron-withdrawing group is independently selected from halogen, Cl, F, CN, a partially fluorinated or perfluorinated C1 to C10 alkyl, partially fluorinated or perfluorinated C6 to C20, aryl, and partially fluorinated or perfluorinated C2 to C20 heteroaryl.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group, wherein the electron-withdrawing group is independently selected from halogen, preferably Cl, F, CN, and a partially fluorinated or perfluorinated C1 to C10 alkyl.
According to one embodiment of the present invention, the ligand L is selected from A-1 to A-129
According to one embodiment of the present invention, the ligand L is selected from
According to one embodiment the present invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound comprising a metal M and at least one ligand L represented by formula (1)
wherein
According to one embodiment the present invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound comprising a metal M and at least one ligand L represented by formula (1)
wherein
According to one embodiment the present invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound comprising a metal M and at least one ligand L represented by formula (1)
wherein
According to one embodiment the invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one of the at least one semiconductor layer comprises a compound represented by formula (3)
According to one embodiment the invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound represented by formula (3)
According to one embodiment the invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound represented by formula (3)
According to one embodiment the invention provides an organic electronic device comprising an anode, a cathode, at least one photoactive layer, and at least one semiconductor layer; wherein the at least one semiconductor layer is arranged between the anode and at least one photoactive layer, wherein the at least one semiconductor layer comprises a compound represented by formula (3)
wherein M is Na, Cu, or Ag,
According to one embodiment of the present invention, the compound is selected from B-1 to B-8
According to one embodiment of the present invention, the organic electronic device is a light emitting device, or a photovoltaic cell, preferably a light emitting device.
According to one embodiment of the present invention, the semiconductor layer and/or the compound of formula (1) to (3) and (5) are non-emissive.
In the context of the present specification the term “essentially non-emissive” or “non-emissive” means that the contribution of the compound or layer to the visible emission spectrum from the device is less than 10%, preferably less than 5% relative to the visible emission spectrum. The visible emission spectrum is an emission spectrum with a wavelength of about ≥380 nm to about ≥780 nm.
According to one embodiment of the present invention, the photoactive layer is a light emitting layer.
According to one embodiment of the present invention, the semiconductor layer is a hole injection layer or a hole transport layer.
According to one embodiment of the present invention, the semiconductor layer is a hole injection layer.
According to one embodiment of the present invention, the at least semiconductor layer and the at least one photoactive layer are arranged between the anode and the cathode.
According to one embodiment of the present invention, the organic electronic device comprises at least two or at least three semiconductor layers, wherein the at least two semiconductor layers or the at least three semiconductor layers are arranged between the anode and the at least one photoactive layer.
According to one embodiment of the present invention, the organic electronic device comprises a first and a second semiconductor layer, wherein the first and the second semiconductor layer are arranged between the anode and the at least one photoactive layer, wherein the first semiconductor layer comprises said compounds wherein the first semiconductor layer is closer to the anode than the second semiconductor layer.
According to one embodiment of the present invention, the organic electronic device comprises a first semiconductor layer, a second semiconductor layer and a third semiconductor layer, wherein the first, the second and third semiconductor layer are arranged between the anode and the at least one photoactive layer, wherein the first semiconductor layer comprises said compounds, wherein the first semiconductor layer is closer to the anode than the second and third semiconductor layer.
According to one embodiment of the present invention, the anode layer comprises a first anode sub-layer and a second anode sub-layer.
According to one embodiment of the present invention, the first anode sub-layer comprises a first metal having a work function in the range of ≥4 and ≤6 eV, and/or the second anode sub-layer comprises a transparent conductive oxide; and/or the second anode sub-layer is arranged closer to the hole injection layer.
According to one embodiment of the present invention, the at least one semiconductor layer comprises a compound of formula (1) to (3) or (5) in an amount in the range of about >50 wt.-% to about <100 wt.-%, preferably about >60 wt.-% to about <100 wt.-%, further preferred about >70 wt.-% to about <100 wt.-%, in addition preferred about >80 wt.-% to about <100 wt.-%, or about >95 wt.-% to about <100 wt.-%, or about >98 wt.-% to about <100 wt.-%, with respect to the total weight of the semiconductor layer, respectively.
According to one embodiment of the present invention, the organic semiconductor layer may comprise:
According to one embodiment of the present invention, the at least one semiconductor layer further comprises a matrix compound.
According to one embodiment of the present invention, the matrix is non-polymeric.
According to one embodiment the organic semiconductor layer may further comprises a substantially covalent matrix compound.
According to one embodiment the substantially covalent matrix compound may be selected from at least one organic compound. The substantially covalent matrix may consist substantially of covalently bound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
According to one embodiment of the organic electronic device, the organic semiconductor layer further comprises a substantially covalent matrix compound, wherein the substantially covalent matrix compound may be selected from organic compounds consisting substantially from covalently hound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
Organometallic compounds comprising covalent bonds carbon-metal, metal complexes comprising organic ligands and metal salts of organic acids are further examples of organic compounds that may serve as substantially covalent matrix compounds of the hole injection layer.
In one embodiment, the substantially covalent matrix compound lacks metal atoms and majority of its skeletal atoms may be selected from C, O, S, N. Alternatively, the substantially covalent matrix compound lacks metal atoms and majority of its skeletal atoms may be selected from C and N.
According to one embodiment, the substantially covalent matrix compound may have a molecular weight Mw of ≥400 and ≤2000 g/mol, preferably a molecular weight Mw of ≥450 and ≤1500 g/mol, further preferred a molecular weight Mw of ≥500 and ≤1000 g/mol, in addition preferred a molecular weight Mw of ≥550 and ≤900 g/mol, also preferred a molecular weight Mw of ≥600 and ≤800 g/mol.
Preferably, the substantially covalent matrix compound comprises at least one arylamine moiety, alternatively a diarylamine moiety, alternatively a triarylamine moiety.
In one embodiment, the HOMO level of the substantially covalent matrix compound may be more negative than the HOMO level of N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine (CAS 207739-72-8) when determined under the same conditions.
In one embodiment, the HOMO level of the substantially covalent matrix compound may be more negative than the HOMO level of N,N′-Bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine (CAS 123847-85-8) when determined under the same conditions.
In one embodiment, the HOMO level of the substantially covalent matrix compound may be more negative than the HOMO level of N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (CAS 1242056-42-3) when determined under the same conditions.
In one embodiment, the HOMO level of the substantially covalent matrix compound, when calculated using TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) by applying the hybrid functional B3LYP with a 6-31G* basis set in the se, may be more negative than −4.27 eV, preferably more negative than −4.3 eV, alternatively more negative than −4.5 eV, alternatively more negative than −4.6 eV, alternatively more negative than −4.65 eV.
In one embodiment, the HOMO level of the substantially covalent matrix compound may be more negative than the HOMO level of N2,N2,N2′,N2′,N7,N7′,N7′-oetakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine (CAS 207739-72-8) and more positive than the HOMO level of N-([1,1′-biphenyl]-4-yl)-N-(2-(9,9-diphenyl-9H-fluoren-4-yl)phenyl)-9,9-dimethyl-9H-fluoren-2-amine when determined under the same conditions.
In one embodiment of the present invention, the substantially covalent matrix compound may be free of alkoxy groups.
In one embodiment, the HOMO level of the substantially covalent matrix compound, when calculated using TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase, may be selected in the range of <−4.27 eV and ≥−4.84 eV, alternatively in the range of <−4.3 eV and ≥−4.84 eV, alternatively in the range of <−4.5 eV and ≥−4.84 eV, alternatively in the range of <−4.5 eV and ≥−4.84 eV, alternatively in the range of <−4.6 eV and ≥−4.84 eV.
In the context of the present specification, “more negative” means that the absolute value is more positive than the comparative value.
Preferably, the substantially covalent matrix compound is free of metals and/or ionic bonds.
According to another aspect of the present invention, the at least one matrix compound, also referred to as “substantially covalent matrix compound”, may comprises at least one arylamine compound, diarylamine compound, triarylamine compound, a compound of formula (VI) or a compound of formula (VII):
wherein:
According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from a single bond, phenylene, biphenylene or terphenylene. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene, biphenylene or terphenylene and one of T1, T2, T3, T4 and T5 are a single bond. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene or biphenylene and one of T1, T2, T3, T4 and T5 are a single bond. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene or biphenylene and two of T1, T2, T3, T4 and T5 are a single bond.
According to an embodiment wherein T1, T2 and T3 may be independently selected from phenylene and one of T1, T2 and T3 are a single bond. According to an embodiment wherein T1, T2 and T3 may be independently selected from phenylene and two of T1, T2 and T3 are a single bond.
According to an embodiment wherein T6 may be phenylene, biphenylene, terphenylene. According to an embodiment wherein T6 may be phenylene. According to an embodiment wherein T6 may be biphenylene. According to an embodiment wherein T6 may be terphenylene.
According to an embodiment wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from D1 to D16:
wherein the asterix “*” denotes the binding position.
According to an embodiment, wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from D1 to D15; alternatively selected from D1 to D10 and D13 to D15.
According to an embodiment, wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from the group consisting of D1, D2, D5, D7, D9, D10, D13 to D16.
The rate onset temperature may be in a range particularly suited to mass production, when Ar1, Ar2, Ar3, Ar4 and Ar5 are selected in this range.
The “matrix compound of formula (VI) or formula (VII)” may be also referred to as “hole transport compound”.
According to one embodiment, the substantially covalent matrix compound comprises at least one naphthyl group, carbazole group, dibenzofurane group, dibenzothiophene group and/or substituted fluorenyl group, wherein the substituents are independently selected from methyl, phenyl or fluorenyl.
According to an embodiment of the electronic device, wherein the matrix compound of formula (VI) or formula (VII) are selected from F1 to F17:
The substantially covalent matrix compound may be free of HTM014, HTM081, HTM163, HTM222, EL-301, HTM226, HTM355, HTM133, HTM334, HTM604 and/or EL-22T. The abbreviations denote the manufacturers' names, for example, of Merck or Lumtec.
According to one embodiment of the invention, at least one semiconductor layer is arranged and/or provided adjacent to the anode layer. According to one embodiment of the invention, at least one semiconductor layer is arranged in direct contact with the anode layer.
According to one embodiment of the invention, at least one semiconductor layer of the present invention is a hole-injection layer.
According to one embodiment of the invention, at least one semiconductor layer is arranged in direct contact with the anode layer consists essentially of the compound of formula (1) to (3) or (5).
In case the at least one semiconductor layer of the present invention is a hole-injection layer and/or is arranged and/or provided adjacent to the anode layer then it is especially preferred that this layer consists essentially of the compound of formula (1) to (3) or (5).
In the context of the present specification the term “consisting essentially of” especially means and/or includes a concentration of ≥90% (vol/vol) more preferred ≥95% (vol/vol) and most preferred ≥99% (vol/vol).
According to another aspect, the at least one semiconductor layer may have a layer thickness of at least about ≥0.5 nm to about ≤10 nm, preferably of about ≥2 nm to about ≤8 nm, also preferred of about ≥3 nm to about ≤5 nm.
In accordance with the invention, the organic electronic device may comprise, besides the layers already mentioned above, further layers. Exemplary embodiments of respective layers are described in the following:
The substrate may be any substrate that is commonly used in manufacturing of, electronic devices, such as organic light-emitting diodes. If light is to be emitted through the substrate, the substrate shall be a transparent or semitransparent material, for example a glass substrate or a transparent plastic substrate. If light is to be emitted through the top surface, the substrate may be both a transparent as well as a non-transparent material, for example a glass substrate, a plastic substrate, a metal substrate or a silicon substrate.
The anode layer may be formed by depositing or sputtering a material that is used to form the anode electrode. The material used to form the anode electrode may be a high work-function material, so as to facilitate hole injection. The anode material may also be selected from a low work function material (i.e. aluminum). The anode layer may be a transparent or reflective electrode. Transparent conductive oxides, such as indium tin oxide (ITO), indium zinc oxide (IZO), tin-dioxide (SnO2), aluminum zinc oxide (AlZO) and zinc oxide (ZnO), may be used to form the anode electrode. The anode layer may also be formed using metals, typically silver (Ag), gold (Au), or metal alloys.
According to a preferred embodiment the organic electrode device comprises an anode layer, whereby the anode layer comprises a first anode sub-layer and a second anode sub-layer, wherein
According to one embodiment of the present invention, the first metal of the first anode sub-layer may be selected from the group comprising Ag, Mg, Al, Cr, Pt, Au, Pd, Ni, Nd, Ir, preferably Ag, Au or Al, and more preferred Ag.
According to one embodiment of the present invention, the first anode sub-layer has have a thickness in the range of 5 to 200 nm, alternatively 8 to 180 nm, alternatively 8 to 150 nm, alternatively too to 150 nm.
According to one embodiment of the present invention, the first anode sub-layer is formed by depositing the first metal via vacuum thermal evaporation.
It is to be understood that the first anode layer is not part of the substrate.
According to one embodiment of the present invention, the transparent conductive oxide of the second anode sub layer is selected from the group selected from the group comprising indium tin oxide or indium zinc oxide, more preferred indium tin oxide.
According to one embodiment of the present invention, the second anode sub-layer may have a thickness in the range of 3 to 200 nm, alternatively 3 to 180 nm, alternatively 3 to 150 nm, alternatively 3 to 20 nm.
According to one embodiment of the present invention, the second anode sub-layer may be formed by sputtering of the transparent conductive oxide.
According to one embodiment of the present invention, anode layer of the organic electronic device comprises in addition a third anode sub-layer comprising a transparent conductive oxide, wherein the third anode sub-layer is arranged between the substrate and the first anode sub-layer.
According to one embodiment of the present invention, the third anode sub-layer comprises a transparent oxide, preferably from the group selected from the group comprising indium tin oxide or indium zinc oxide, more preferred indium tin oxide.
According to one embodiment of the present invention, the third anode sub-layer may have a thickness in the range of 3 to 200 nm, alternatively 3 to 180 nm, alternatively 3 to 150 nm, alternatively 3 to 20 nm.
According to one embodiment of the present invention, the third anode sub-layer may be formed by sputtering of the transparent conductive oxide.
It is to be understood that the third anode layer is not part of the substrate.
According to one embodiment of the present invention, the hole injection layer is in direct contact with the anode layer.
A hole injection layer (HIL) may be formed on the anode electrode by vacuum deposition, spin coating, printing, casting, slot-die coating, Langmuir-Blodgett (LB) deposition, or the like. When the HIL is formed using vacuum deposition, the deposition conditions may vary according to the compound that is used to form the HIL, and the desired structure and thermal properties of the HIL. In general, however, conditions for vacuum deposition may include a deposition temperature of 100° C. to 500° C., a pressure of 10−8 to 10−3 Torr (1 Torr equals 133·322 Pa), and a deposition rate of 0.1 to 10 nm/sec.
When the HIL is formed using spin coating or printing, coating conditions may vary according to the compound that is used to form the HIL, and the desired structure and thermal properties of the HIL. For example, the coating conditions may include a coating speed of about 2000 rpm to about 5000 rpm, and a thermal treatment temperature of about 80° C. to about 200° C. Thermal treatment removes a solvent after the coating is performed.
The HIL may be formed of any compound that is commonly used to form a HIL. Examples of compounds that may be used to form the HIL include a phthalocyanine compound, such as copper phthalocyanine (CuPc), 4,4′,4″-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), TDATA, 2T-NATA, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (Pani/CSA), and polyaniline)/poly(4-styrenesulfonate (PANI/PSS).
The HIL may comprise or consist of p-type dopant and the p-type dopant may be selected from tetrafluoro-tetracyanoquinonedimethane (F4TCNQ), 2,2′-(perfluoronaphthalen-2,6-diylidene) dimalononitrile or 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) but not limited hereto. The HIL may be selected from a hole-transporting matrix compound doped with a p-type dopant. Typical examples of known doped hole transport materials are: copper phthalocyanine (CuPc), which HOMO level is approximately −5.2 eV, doped with tetrafluoro-tetracyanoquinonedimethane (F4TCNQ), which LUMO level is about −5.2 eV; zinc phthalocyanine (ZnPc) (HOMO=−5.2 eV) doped with F4TCNQ; α-NPD (N,N′-Bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine) doped with F4TCNQ. α-NPD doped with 2,2′-(perfluoronaphthalen-2,6-diylidene) dimalononitrile. The p-type dopant concentrations can be selected from 1 to 20 wt.-%, more preferably from 3 wt.-% to 10 wt.-%.
The thickness of the HIL may be in the range from about 1 nm to about 100 nm, and for example, from about 1 nm to about 25 nm. When the thickness of the HIL is within this range, the HIL may have excellent hole injecting characteristics, without a substantial penalty in driving voltage.
A hole transport layer (HTL) may be formed on the HIL by vacuum deposition, spin coating, slot-die coating, printing, casting, Langmuir-Blodgett (LB) deposition, or the like. When the HTL is formed by vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for the vacuum or solution deposition may vary, according to the compound that is used to form the HTL.
The HTL may be formed of any compound that is commonly used to form a HTL. Compounds that can be suitably used are disclosed for example in Yasuhiko Shirota and Hiroshi Kageyama, Chem. Rev. 2007, 107, 953-1010 and incorporated by reference. Examples of the compound that may be used to form the HTL are: carbazole derivatives, such as N-phenylcarbazole or polyvinylcarbazole; benzidine derivatives, such as N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD), or N,N′-di(naphthalen-1-yl)-N,N′-diphenyl benzidine (alpha-NPD); and triphenylamine-based compound, such as 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA). Among these compounds, TCTA can transport holes and inhibit excitons from being diffused into the EML.
According to one embodiment of the present invention, the hole transport layer may comprise the same substantially covalent matrix compound as the semiconductor layer of the present invention.
The thickness of the HTL may be in the range of about 5 nm to about 250 nm, preferably, about 10 nm to about 200 nm, further about 20 nm to about 190 nm, further about 40 nm to about 180 nm, further about 60 nm to about 170 nm, further about 80 nm to about 160 nm, further about 100 nm to about 160 nm, further about 120 nm to about 140 nm. A preferred thickness of the HTL may be 170 nm to 200 nm.
When the thickness of the HTL is within this range, the HTL may have excellent hole transporting characteristics, without a substantial penalty in driving voltage.
The function of an electron blocking layer (EBL) is to prevent electrons from being transferred from an emission layer to the hole transport layer and thereby confine electrons to the emission layer. Thereby, efficiency, operating voltage and/or lifetime may be improved. Typically, the electron blocking layer comprises a triarylamine compound. The triarylamine compound may have a LUMO level closer to vacuum level than the LUMO level of the hole transport layer. The electron blocking layer may have a HOMO level that is further away from vacuum level compared to the HOMO level of the hole transport layer. The thickness of the electron blocking layer may be selected between 2 and 20 nm.
If the electron blocking layer has a high triplet level, it may also be described as triplet control layer.
The function of the triplet control layer is to reduce quenching of triplets if a phosphorescent green or blue emission layer is used. Thereby, higher efficiency of light emission from a phosphorescent emission layer can be achieved. The triplet control layer is selected from triarylamine compounds with a triplet level above the triplet level of the phosphorescent emitter in the adjacent emission layer. Suitable compounds for the triplet control layer, in particular the triarylamine compounds, are described in EP 2 722 908 A1.
The photoactive layer converts an electrical current into photons or photons into an electrical current.
The PAL may be formed on the HTL by vacuum deposition, spin coating, slot-die coating, printing, casting, LB deposition, or the like. When the PAL is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for deposition and coating may vary, according to the compound that is used to form the PAL.
It may be provided that the photoactive layer does not comprise the compound of Formula (1).
The photoactive layer may be a light-emitting layer or a light-absorbing layer.
The EML may be formed on the HTL by vacuum deposition, spin coating, slot-die coating, printing, casting, LB deposition, or the like. When the EML is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for deposition and coating may vary, according to the compound that is used to form the EML.
It may be provided that the emission layer does not comprise the compound of Formula (1).
The emission layer (EML) may be formed of a combination of a host and an emitter dopant. Example of the host are Alq3, 4,4′-N,N′-dicarbazole-biphenyl (CBP), poly(n-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4′,4″-tris(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI), 3-tert-butyl-9,10-di-2-naphthylanthracenee (TBADN), distyrylarylene (DSA) and bis(2-(2-hydroxyphenyl)benzo-thiazolate)zinc (Zn(BTZ)2).
The emitter dopant may be a phosphorescent or fluorescent emitter. Phosphorescent emitters and emitters which emit light via a thermally activated delayed fluorescence (TADF) mechanism may be preferred due to their higher efficiency. The emitter may be a small molecule or a polymer.
Examples of red emitter dopants are PtOEP, Ir(piq)3, and Btp2lr(acac), but are not limited thereto. These compounds are phosphorescent emitters, however, fluorescent red emitter dopants could also be used.
Examples of phosphorescent green emitter dopants are Ir(ppy)3 (ppy=phenylpyridine), Ir(ppy)2(acac), Ir(mpyp)3.
Examples of phosphorescent blue emitter dopants are F2Irpic, (F2ppy)2Ir(tmd) and Ir(dfppz)3 and ter-fluorene. 4⋅4′-bis(4-diphenyl amiostyryl)biphenyl (DPAVBi), 2,5,8,11-tetra-tert-butyl perylene (TBPe) are examples of fluorescent blue emitter dopants.
The amount of the emitter dopant may be in the range from about 0.01 to about 50 parts by weight, based on 100 parts by weight of the host. Alternatively, the emission layer may consist of a light-emitting polymer. The EML may have a thickness of about 10 nm to about 100 nm, for example, from about 20 nm to about 60 nm. When the thickness of the EML is within this range, the EML may have excellent light emission, without a substantial penalty in driving voltage.
A hole blocking layer (HBL) may be formed on the EML, by using vacuum deposition, spin coating, slot-die coating, printing, casting, LB deposition, or the like, in order to prevent the diffusion of holes into the ETL. When the EML comprises a phosphorescent dopant, the HBL may have also a triplet exciton blocking function.
The HBL may also be named auxiliary ETL or a-ETL.
When the HBL is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for deposition and coating may vary, according to the compound that is used to form the HBL. Any compound that is commonly used to form a HBL may be used. Examples of compounds for forming the HBL include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives and triazine derivatives.
The HBL may have a thickness in the range from about 5 nm to about 100 nm, for example, from about 10 nm to about 30 nm. When the thickness of the HBL is within this range, the HBL may have excellent hole-blocking properties, without a substantial penalty in driving voltage.
The organic electronic device according to the present invention may further comprise an electron transport layer (ETL).
According to another embodiment of the present invention, the electron transport layer may further comprise an azine compound, preferably a triazine compound.
In one embodiment, the electron transport layer may further comprise a dopant selected from an alkali organic complex, preferably LiQ.
The thickness of the ETL may be in the range from about 15 nm to about 50 nm, for example, in the range from about 20 nm to about 40 nm. When the thickness of the EIL is within this range, the ETL may have satisfactory electron-injecting properties, without a substantial penalty in driving voltage.
According to another embodiment of the present invention, the organic electronic device may further comprise a hole blocking layer and an electron transport layer, wherein the hole blocking layer and the electron transport layer comprise an azine compound. Preferably, the azine compound is a triazine compound.
An optional EIL, which may facilitates injection of electrons from the cathode, may be formed on the ETL, preferably directly on the electron transport layer. Examples of materials for forming the EIL include lithium 8-hydroxyquinolinolate (LiQ), LiF, NaCl, CsF, Li2O, BaO, Ca, Ba, Yb, Mg which are known in the art. Deposition and coating conditions for forming the EIL are similar to those for formation of the HIL, although the deposition and coating conditions may vary, according to the material that is used to form the EIL.
The thickness of the EIL may be in the range from about 0.1 nm to about 10 nm, for example, in the range from about 0.5 nm to about 9 nm. When the thickness of the EIL is within this range, the EIL may have satisfactory electron-injecting properties, without a substantial penalty in driving voltage.
The cathode electrode is formed on the ETL or optional EIL. The cathode electrode may be formed of a metal, an alloy, an electrically conductive compound, or a mixture thereof. The cathode electrode may have a low work function. For example, the cathode electrode may be formed of lithium (Li), magnesium (Mg), aluminum (Al), aluminum (Al)-lithium (Li), calcium (Ca), barium (Ba), ytterbium (Yb), magnesium (Mg)-indium (In), magnesium (Mg)-silver (Ag), or the like. Alternatively, the cathode electrode may be formed of a transparent conductive oxide, such as ITO or IZO.
The thickness of the cathode electrode may be in the range from about 5 nm to about 1000 nm, for example, in the range from about 10 nm to about 100 nm. When the thickness of the cathode electrode is in the range from about 5 nm to about 50 nm, the cathode electrode may be transparent or semitransparent even if formed from a metal or metal alloy.
It is to be understood that the cathode electrode is not part of an electron injection layer or the electron transport layer.
The organic electronic device according to the invention may be an organic light-emitting device.
According to one aspect of the present invention, there is provided an organic light-emitting diode (OLED) comprising: a substrate; an anode electrode formed on the substrate; an semiconductor layer comprising compound of formula (1) to (3) or (5), a hole transport layer, an emission layer, an electron transport layer and a cathode electrode.
According to another aspect of the present invention, there is provided an OLED comprising: a substrate; an anode electrode layer formed on the substrate; a semiconductor layer comprising a compound of Formula (1) to (3) or (5), a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer and a cathode layer.
According to another aspect of the present invention, there is provided an OLED comprising: a substrate; an anode layer formed on the substrate; a semiconductor layer comprising a compound of Formula (1) to (3) or (5), a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode layer.
According to various embodiments of the present invention, there may be provided OLEDs layers arranged between the above mentioned layers, on the substrate or on the top layer.
According to one aspect, the OLED may comprise a layer structure of a substrate that is adjacent arranged to an anode layer, the anode layer is adjacent arranged to a first hole injection layer, the first hole injection layer is adjacent arranged to a first hole transport layer, the first hole transport layer is adjacent arranged to a first electron blocking layer, the first electron blocking layer is adjacent arranged to a first emission layer, the first emission layer is adjacent arranged to a first electron transport layer, the first electron transport layer is adjacent arranged to an n-type charge generation layer, the n-type charge generation layer is adjacent arranged to a hole generating layer, the hole generating layer is adjacent arranged to a second hole transport layer, the second hole transport layer is adjacent arranged to a second electron blocking layer, the second electron blocking layer is adjacent arranged to a second emission layer, between the second emission layer and the cathode layer an optional electron transport layer and/or an optional injection layer are arranged.
The semiconductor layer according to the invention may be the first hole injection layer and p-type charge generation layer.
For example, the OLED according to
The organic semiconductor layer may be formed on the anode layer or cathode layer by vacuum deposition, spin coating, printing, casting, slot-die coating, Langmuir-Blodgett (LB) deposition, or the like. When the Organic semiconductor layer is formed using vacuum deposition, the deposition conditions may vary according to the compound(s) that are used to form the layer, and the desired structure and thermal properties of the layer. In general, however, conditions for vacuum deposition may include a deposition temperature of 100° C. to 350° C., a pressure of 10−8 to 10−3 Torr (1 Torr equals 133.322 Pa), and a deposition rate of 0.1to 10 nm/sec.
When the organic semiconductor layer is formed using spin coating or printing, coating conditions may vary according to the compound(s) that are used to form the layer, and the desired structure and thermal properties of the organic semiconductor layer. For example, the coating conditions may include a coating speed of about 2000 rpm to about 5000 rpm, and a thermal treatment temperature of about 80° C. to about 200° C. Thermal treatment removes a solvent after the coating is performed.
The thickness of the organic semiconductor layer may be in the range from about 1 nm to about 20 nm, and for example, from about 2 nm to about 15 nm, alternatively about 2 nm to about 12 nm.
When the thickness of the organic semiconductor layer is within this range, the organic semiconductor layer may have excellent hole injecting and/or hole generation characteristics, without a substantial penalty in driving voltage.
According to another aspect of the present invention, there is provided a method comprising the step of applying said compound of formula (1) to (3) or (5) on a surface.
According to one embodiment of the invention, the method comprises fabricating the organic electronic device according to the invention by depositing a compound of formula (1) to (3) or (5) between the anode and least one photoactive layer preferably onto the anode layer, more preferably onto the surface of the anode layer
According to another aspect of the present invention, there is provided a method of manufacturing an organic electronic device, the method using:
The methods for deposition that can be suitable comprise:
According to various embodiments of the present invention, there is provided a method using:
According to various embodiments of the present invention, the method may further include forming on the anode layer, at least one layer selected from the group consisting of forming a hole transport layer or forming a hole blocking layer, and an emission layer between the anode layer and the first electron transport layer. Preferably, the compound of formula (1) to (3) or (5) is deposited from the gas phase. Method comprising a further step of transferring a compound of formula (1) to (3) or (5) from the solid state into the gas phase. Preferably, the source is a vacuum thermal evaporation (VTE) source. Preferably, the compound of formula (1) to (3) or (5) is transferred from solid state into the gas phase from a first VTE source and the compound of formula (1) to (3) or (5) is transferred from the solid state into the gas phase from a second source.
According to various embodiments of the present invention, the method may further include the steps for forming an organic light-emitting diode (OLED), wherein
According to various embodiments, the OLED may have the following layer structure, wherein the layers having the following order:
anode, semiconductor layer comprising a compound of Formula (1) to (3) or (5) according to the invention, first hole transport layer, second hole transport layer, emission layer, optional hole blocking layer, electron transport layer, optional electron injection layer, and cathode.
The present invention furthermore relates to a display device comprising an organic electronic device according to the present invention.
The present invention furthermore relates to a represented by formula (3)
wherein
and compounds are excluded which are represented by the formula (4)
wherein
According to one embodiment of the invention
Preferred embodiments described herein with respect to compounds (1) to (3) in context of the organic electronic device are also preferred embodiments of the compound per se as long as the embodiments are encompassed by the definition of the compound.
According to one embodiment of the present invention, there is provided a compound represented by formula (3)
wherein
According to one embodiment of the present invention, the metal M is selected from an alkali metal, alkaline earth metal, transition metal.
According to one embodiment of the present invention, the metal M is selected from alkali metals, alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd, Al, Ga, In, Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd, Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from an alkali metal, an alkaline earth metal, Cu, Ag, Fe, Co, Ti, Zr, Hf, Mo, or W.
According to one embodiment of the present invention, the metal M is selected from Na, Cu, or Ag.
R1 and R1
According to one embodiment of the present invention, R1 is independently selected from an unsubstituted C1 to C8 alkyl, partially or perfluorinated C2 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R1 is independently selected from perfluorinated propyl, perfluorinated butyl, or 3,5-bis(trifluormethyl)phenyl.
According to one embodiment of the present invention, R1 is independently selected from branched or unbranched C3F7 or C4F.
According to one embodiment of the present invention, R2 is independently selected from a substituted or unsubstituted C1 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, or substituted or unsubstituted C2 to C20 heteroaryl.
According to one embodiment of the present invention, R2 is independently selected from perfluorinated propyl, perfluorinated butyl, or 3,5-bis(trifluormethyl)phenyl.
According to one embodiment of the present invention, if at least one of R1 and R2 is substituted then at least one substituent on R1 and/or R2 is an electron-withdrawing group.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group, wherein the electron-withdrawing group is independently selected from halogen, Cl, F, CN, a partially fluorinated or perfluorinated C1 to C10 alkyl, partially fluorinated or perfluorinated C6 to C20, aryl, and partially fluorinated or perfluorinated C2 to C20 heteroaryl.
According to one embodiment of the present invention, at least one of R1 and R2 is substituted and at least one substituent on R1 and/or R2 is an electron-withdrawing group, wherein the electron-withdrawing group is independently selected F, CN, partially or perfluorinated C1 to C8 alkyl.
According to one embodiment of the present invention, R1 is independently selected from an unsubstituted C1 to C8 alkyl, partially or perfluorinated C2 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C2to C20 heteroaryl, substituted or unsubstituted C3 to C20 carbocyclyl, substituted or unsubstituted C2 to C20 heterocyclyl;
R2 is independently selected from a substituted or unsubstituted C1 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, or substituted or unsubstituted C2 to C20 heteroaryl, substituted or unsubstituted C3 to C20 carbocyclyl, substituted or unsubstituted C2 to C20 heterocyclyl;
wherein the substituent on aryl and heteroaryl is independently selected from F, CN, partially or perfluorinated C1 to C8 alkyl.
According to one embodiment of the present invention R1 is independently selected from an unsubstituted C1 to C8 alkyl, partially or perfluorinated C2 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C2 to C20 heteroaryl, substituted or unsubstituted C3 to C20 carbocyclyl, substituted or unsubstituted C2 to C20 heterocyclyl;
R2 is independently selected from a substituted or unsubstituted C1 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, or substituted or unsubstituted C2 to C20 heteroaryl, substituted or unsubstituted C3 to C20 carbocyclyl, substituted or unsubstituted C2 to C20 heterocyclyl;
wherein the substituent on aryl and heteroaryl is independently selected from F, CN, partially or perfluorinated C1 to C8 alkyl.
According to one embodiment of the present invention, R1 is independently selected from an unsubstituted C1 to C8 alkyl, partially or perfluorinated C2 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C2 to C20 heteroaryl;
R2 is independently selected from a substituted or unsubstituted C1 to C8 alkyl, substituted or unsubstituted C6 to C20 aryl, or substituted or unsubstituted C2 to C20 heteroaryl;
if there is a substituent on aryl and heteroaryl the substituent is independently selected from F, CN, partially or perfluorinated C2 to C8 alkyl, and substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, preferably the substituent on aryl and heteroaryl is independently selected from F, CN, partially or perfluorinated C1 to C8 alkyl.
According to one embodiment of the present invention, there is provided a compound represented by formula (3)
wherein
According to one embodiment of the present invention, the compound is selected from B-1 and B-3 to B-8
The present invention furthermore relates to a compound represented by formula (5)
wherein
According to one embodiment of the present invention, the metal M is selected from an alkali metal, alkaline earth metal, and transition metal.
According to one embodiment of the present invention, the metal M is selected from alkali metals, alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd, Al, Ga, In, Sn, Ti, Zr, Hf, V, NU, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from alkaline earth metals, Pb, Mn, Fe, Co, Ni, Cu, Zn, Ag Cd, Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
According to one embodiment of the present invention, the metal M is selected from an alkali metal, an alkaline earth metal, Cu, Ag, Fe, Co, Ti, Zr, Hf, Mo, or W.
According to one embodiment of the present invention, the metal M is selected from Na, Cu, or Ag, preferably is Cu or Ag.
According to one embodiment of the present invention, R2a, R2b, and R2c are selected from a partially or perfluorinated C3 to C4 alkyl, a substituted phenyl or unsubstituted or substituted C3 to C5 heteroaryl, wherein the substituents are in the 3-position and in the 5-position and selected from fluorine, trifluoromethyl, or CN.
According to one embodiment of the present invention, R3a and R3b are independently selected from CF3 or CN.
The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations.
Additional details, characteristics and advantages of the object of the invention are disclosed in the dependent claims and the following description of the respective figures which in an exemplary fashion show preferred embodiments according to the invention. Any embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention as claimed.
Hereinafter, the
Herein, when a first element is referred to as being formed or disposed “on” or “onto” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” or “directly onto” a second element, no other elements are disposed there between.
In the description above the method of manufacture an organic electronic device 101 of the present invention is for example started with a substrate (110) onto which an anode layer (120) is formed, on the anode layer (120), a semiconductor layer comprising compound of Formula (1) to (3) or (5) (130), a photoactive layer (151) and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.
In the description above the method of manufacture an OLED 100 of the present invention is started with a substrate (110) onto which an anode layer (120) is formed, on the anode layer (120), a semiconductor layer comprising compound of Formula (1) to (3) or (5) (130), optional a hole transport layer (140), optional an electron blocking layer (145), an emission layer (150), optional a hole blocking layer (155), optional an electron transport layer (160), optional an electron injection layer (180), and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.
The semiconductor layer comprising a compound of Formula (1) to (3) or (5) (130) can be a hole injection layer.
While not shown in
Hereinafter, one or more exemplary embodiments of the present invention will be described in detail with, reference to the following examples. However, these examples are not intended to limit the purpose and scope of the one or more exemplary embodiments of the present invention.
The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.
To a mixture of 3.05 g (1.0 eq) of carbonyl chloride and 4.56 g (3.0 eq) potassium carbonate in a baked out Schlenk-flask 30 ml dry acetone were added. The mixture was cooled in an ice-bath and 3.29 g (1.0 eq) sulphonamide were added. The reaction was stirred at room temperature for 2 days. The solid was filtered off and the solvent removed under reduced pressure. The crude product was treated with 300 ml 30% sulphuric acid and extracted portion wise with diethyl ether. The combined organic layers were washed with water and the solvent removed under reduced pressure. The crude product was slurry washed two times with chloroform. Yield: 3.34 g (57%)
Synthesis of the Protonated ligand 2,3,3,3-tetrafluoro-N-((perfluoropropyl)sulfonyl)-2-(trifluoromethyl)propanamide for B3 and B4
1st Step: 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanamide
A mixture of 4.99 g (21.9 mmol) methyl 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanoate and 63 ml of a 7 M solution of NH3 in MeOH was stirred together under argon at room temperature for 20 h. Then the solvents were distilled off and the residue was triturated in 50 ml hexane, filtered, washed with 2×25 ml hexane and dried.
Yield: 3.27 g (70%) white solid
2nd Step: 2,3,3,3-tetrafluoro-N-((perfluorobutyl)sulfonyl)-2-(trifluoromethyl)propanamide
A mixture of 5.33 g (25 mmol) 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanamide, 7.55 g (25 mmol) 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonyl fluoride and 20 ml of triethylamine was stirred at 90° C. for 48 h. After cooling the reaction mixture was concentrated and the residue dissolved in 500 ml of DCM. The DCM-solution washed with 3×150 ml of water, dried (Na2SO4) and concentrated. The resulting brownish oil (3.74 g, 92%) of product-triethylammonium salt was stirred in a sublimation setup with 12.5 ml of conc. H2SO4. The free acid product was sublimed off in a fine vacuum and was sublimed again at 55° C. to give the title compound. Yield: 10.06 g (80%) white solid
1st Step: Synthesis of triethylammonium 2,2,3,3,4,4,5,5,5-nonafluoro-N-((perfluoropropan-2-yl)sulfonyl)pentanamide
To a solution of 3.99 g (1 eq) sulphonyl amide and 4.44 mL (2 eq) trimethylamine in 80 mL dry THF the 4.89 g (1.05 eq) sulfonyl chloride was added dropwise at 0° C. The mixture was stirred at RT for 30 h. The reaction mixture was diluted with 200 mL water and extracted two times with 300 mL dichloromethane. The combined organic phases were washed with too ml water, dried over sodium sulphate and concentrated. Yield: 9.15 g (96%)
2nd Step: Synthesis of 2,2,3,3,4,4,5,5,5-nonafluoro-N-((perfluoropropan-2-yl)sulfonyl)pentanamide
8.3 mL (to eq) sulfuric acid (98%) was added to the ammonium salt and the mixture was stirred in a distillation apparatus at 70° C. The product was collected at 38-40° C. in high vacuum (0.05 mbar) as a colourless oil. Yield: 6.67 g (88%)
3.13 g (2.05 eq) of the starting material was suspended in 15 mL water and 0.57 g (1.0 eq) copper acetate were added. The resulting mixture was stirred at room temperature for 2 h. Two phases formed, and after separation the organic phase was washed with water. The solvent was evaporated and the residue was dried in high vacuum at 80° C. Yield. 2.75 g (85%)
To a solution of 2.5 g (5.05 mmol) of 2,3,3,3-tetrafluoro-N-((perfluorobutyl)sulfonyl)-2-(trifluoromethyl)propanamide in 30 ml MeOH was added 0.84 g (3 mmol) Ag2CO3. The resulting suspension was stirred over night at room temperature, then filtered and the clear filtrate was evaporate to dryness and was further dried overnight in vacuum. Yield: 2.90 (95%), white powder.
To a solution of 2.5 g (5.05 mmol) of ((perfluorobutyl)sulfonyl)(2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanoyl)amide in 10 ml of water was added a 1 M solution of NaOH until pH was neutral (pH-paper). The resulting solution was evaporated to dryness. The white solid residue was dried overnight in vacuum. Yield: 2.41 g (92%), white powder.
To a solution of 1.55 g (3.13 mmol) 2,2,3,3,4,4,5,5,5-nonafluoro-N-((perfluoropropan-2-yl)sulfonyl)pentanamide in 20 ml of water was added 0.7 g (2.5 mmol) of Ag2CO3. The resulting suspension was stirred over night at room temperature, then filtered and the clear filtrate evaporated to dryness to give white crystals, which were dried overnight in vacuum. Yield: 1.66 g (88%).
To a solution of 1.26 g (2.54 mmol) of 2,2,3,3,4,4,5,5,5-nonafluoropentanoyl)((perfluoropropan-2-yl)sulfonyl)amide in 20 ml of water was added a solution of 100 mg (2.5 mmol) NaOH in 3 ml of water dropwise until pH of solution was neutral (pH-paper). The solution was evaporated to dryness and dried further overnight in vacuum. Yield: 1.04 g (77%), white powder.
Under nitrogen in a glovebox, 0.5 to 5 g compound are loaded into the evaporation source of a sublimation apparatus. The sublimation apparatus consists of an inner glass tube consisting of bulbs with a diameter of 3 cm which are placed inside a glass tube with a diameter of 3.5 cm. The sublimation apparatus is placed inside a tube oven (Creaphys DSU 05/2.1). The sublimation apparatus is evacuated via a membrane pump (Pfeiffer Vacuum MVP 055-3C) and a turbo pump (Pfeiffer Vacuum THM071 YP). The pressure is measured between the sublimation apparatus and the turbo pump using a pressure gauge (Pfeiffer Vacuum PKR 251). When the pressure has been reduced to 10−5 mbar, the temperature is increased in increments of 10 to 30 K till the compound starts to be deposited in the harvesting zone of the sublimation apparatus. The temperature is further increased in increments of 10 to 30 K till a sublimation rate is achieved where the compound in the source is visibly depleted over 30 min to 1 hour and a substantial amount of compound has accumulated in the harvesting zone.
The sublimation temperature, also named Tsubl, is the temperature inside the sublimation apparatus at which the compound is deposited in the harvesting zone at a visible rate and is measured in degree Celsius.
In the context of the present invention, the term “sublimation” may refer to a transfer from solid state to gas phase or from liquid state to gas phase.
The decomposition temperature, also named Tdec, is determined in degree Celsius.
The decomposition temperature is measured by loading a sample of 9 to 11 mg into a Mettler Toledo 100 μL aluminum pan without lid under nitrogen in a Mettler Toledo TGA-DSC machine. The following heating program was used: 25° C. isothermal for 3 min; 25° C. to 600° C. with 10 K/min.
The decomposition temperature was determined based on the onset of the decomposition in TGA.
The HOMO and LUMO are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected.
For Examples 1 to 4 and comparative examples 1 and 2 according to table 2, a glass substrate with an anode layer comprising a first anode sub-layer of 120 nm Ag, a second anode sub-layer of 8 nm ITO and a third anode sub-layer of 10 nm ITO was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment, see Table 2, to prepare the anode layer. The plasma treatment was performed in an atmosphere comprising 97.6 vol.-% nitrogen and 2.4 vol.-% oxygen.
Then, F2 (as disclosed herein with respect to exemplary matrix compounds) as a substantially covalent matrix compound and a compound of formula (1) were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm. The composition of the HIL can be seen in Table 2.
Then, the substantially covalent matrix compound was vacuum deposited on the HIL, to form a HTL having a thickness of 123 nm. The formula of the substantially covalent matrix compound in the HTL was identical to the substantially covalent matrix compound used in the HIL.
Then N-([1,1′-biphenyl]-4-yl)-9,9-diphenyl-N-(4-(triphenylsilyl)phenyl)-9H-fluoren-2-amine (CAS 1613079-70-1) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
Then 97 vol.-% H09 (Sun Fine Chemicals, Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant were deposited on the EBL, to form a blue-emitting first emission layer (EML) with a thickness of 20 nm.
Then a hole blocking layer was formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer EML.
Then the electron transporting layer having a thickness of 31 nm was formed on the hole blocking layer by depositing 50 wt.-% 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile and 50 wt.-% of LiQ.
Then Ag:Mg (90:10 vol.-%) was evaporated at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode layer with a thickness of 13 nm on the electron transporting layer.
Then, compound of formula F3 was deposited on the cathode layer to form a capping layer with a thickness of 75 nm.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing an operating voltage U in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values.
Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm2, using a Keithley 2400 sourcemeter, and recorded in hours. The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.
To determine the voltage stability over time U(50 h)-(1 h), a current density of at 30 mA/cm2 was applied to the device. The operating voltage was measured after 1 hour and after 50 hours, followed by calculation of the voltage stability for the time period of 1 hour to 50 hours.
In order to investigate the usefulness of the inventive compound preferred materials were tested in view of their thermal properties.
As materials for organic electronics are typically purified by sublimation, a high decomposition temperature Tdec and/or a large offset between decomposition and sublimation temperature Tdec-Tsubl are highly desirable. Thereby, a high sublimation rate may be achievable.
In Table 1 are shown the temperature at which thermal decomposition is observed (Tdec), difference between decomposition and sublimation temperature Tdec-Tsubl are shown. It is apparent that the inventive compounds B-1 to B-6 may show a higher decomposition temperature and/or a much larger gap between decay and sublimation temperature.
As can be seen from Table 2, the current efficiency (CEff) may be higher than for the comparative example. A high efficiency may be beneficial for reduced power consumption and improved battery life, in particular in mobile devices.
The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by way of example only and is not intended as limiting. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21164584.1 | Mar 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/056630 | 3/15/2022 | WO |
