Patent Application
20240244950
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0187752, filed on Dec. 28, 2022, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the entire content of which is incorporated by reference herein.
The present subject matter relates to an organic light-emitting device and an electronic apparatus including the same.
Organic light-emitting devices (OLEDs) are self-emissive devices, which have improved characteristics in terms of viewing angles, response time, brightness, driving voltage, and response speed. In addition, OLEDs can produce full-color images.
A typical organic light-emitting device includes an anode, a cathode, and an organic layer arranged between the anode and the cathode and including an emission layer. A hole transport region may be arranged between the anode and the emission layer, and an electron transport region may be arranged between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons may then recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thus generating light.
Provided are an organic light-emitting device having a high luminescence efficiency, a high color purity, a long lifespan, and excellent processability, and an electronic apparatus including the organic light-emitting device.
Additional aspects will be set forth in part in the detailed description that follows and, in part, will be apparent from the detailed description, or may be learned by practice of the presented exemplary embodiments provided herein.
According to an aspect, a light-emitting device includes:
According to another aspect, an electronic apparatus includes the organic light-emitting device.
The above and other aspects, features, and advantages of certain exemplary embodiments will be more apparent from the following detailed description taken in conjunction with the FIGURE, which shows a schematic cross-sectional view of an organic light-emitting device according to one or more embodiments.
Reference will now be made in further detail to exemplary embodiments, examples of which are illustrated in the accompanying drawing, wherein like reference numerals refer to like elements throughout. In this regard, the present exemplary embodiments may have different forms and should not be construed as being limited to the detailed descriptions set forth herein. Accordingly, the exemplary embodiments are merely described in further detail below, and by referring to the FIGURE, to explain certain aspects and features. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
The terminology used herein is for the purpose of describing one or more exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “or” means “and/or.” It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present embodiments.
Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.
It will be understood that when an element is referred to as being “on” another element, it can be directly in contact with the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this general inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.
As used herein, an “energy level” (e.g., a highest occupied molecular orbital (HOMO) energy level or a triplet (T1) energy level) is expressed as an absolute value from a vacuum level. In addition, when the energy level is referred to as being “deep,” “high,” or “large,” the energy level has a large absolute value based on “0 electron Volts (eV)” of the vacuum level, and when the energy level is referred to as being “shallow,” “low,” or “small,” the energy level has a small absolute value based on “0 eV” of the vacuum level.
As used herein, when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (for example, phenyl, naphthyl, or the like) or as if it were the whole molecule (for example, benzene, naphthalene, or the like). It is to be understood that the nomenclature may be used interchangeably herein.
According to an aspect, an organic light-emitting device includes a first electrode; a second electrode; and an organic layer arranged between the first electrode and the second electrode,
The organic light-emitting device may have an excellent luminescence efficiency, a long lifespan, and/or a high color purity.
In general, an organic light-emitting device including at least one organometallic compound including a silyl group and/or a germyl group may have an excellent luminescence efficiency and a high color purity, and may have excellent processability due to a low deposition temperature. However, as the silyl group and/or the germyl group are decomposed and the organometallic compound is degraded, the lifespan may drastically decreased.
Although not limited to a particular theory, it is assumed that the organometallic compound may be degraded because the silyl group and/or the germyl group is decomposed by a cation formed from an anode of an organic light-emitting device.
In the organic light-emitting device according to one or more embodiments, the cation formed from the anode may be effectively removed or suppressed by a free electron formed from an n-doped layer, thereby preventing the silyl group and/or the germyl group of the organometallic compound from becoming decomposed. Accordingly, by including the at least one organometallic compound including the silyl group and/or the germyl group in the emission layer, the organic light-emitting device may achieve a high luminescence efficiency, a high color purity, and excellent processability, and the degradation of the organometallic compound may be prevented or reduced, to provide a high luminescence efficiency and/or a long lifespan.
In one or more embodiments, the at least one organometallic compound may be represented by Formula 1:
wherein M1 in Formula 1 may be a transition metal.
In one or more embodiments, M1 in Formula 1 may be iridium, platinum, osmium, titanium, zirconium, hafnium, europium, terbium, thulium, or rhodium.
n1 in Formula 1 may be 1, 2, or 3.
n2 in Formula 1 may be 0, 1, or 2.
In one or more embodiments, in Formula 1, M1 may be iridium, and a sum of n1 and n2 may be 3; or M1 may be Pt and the sum of n1 and n2 may be 2.
Ln1 in Formula 1 may be a ligand represented by Formula 1A:
wherein * and *′ each indicates a binding site to M1 in Formula 1.
Ring CY1 and ring CY2 in Formula 1A may each independently be a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
T1 in Formula 1A may be —Si(Q1)(Q2)(Q3) or —Ge(Q1)(Q2)(Q3).
a1 in Formula 1A may be 1, 2, 3, 4, or 5.
R10 and R20 in Formula 1A may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C1-C60 alkylthio group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C7-C60 alkyl aryl group, a substituted or unsubstituted C7-C60 aryl alkyl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted C1-C60 heteroaryloxy group, a substituted or unsubstituted C1-C60 heteroarylthio group, a substituted or unsubstituted C1-C60 heteroaryloxy group, a substituted or unsubstituted C1-C60 heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q1)(Q2)(Q3), —Ge(Q1)(Q2)(Q3), —C(═O)(Q1), —S(═O)(Q1), —S(═O)2(Q1), —N(Q4)(Q5), —B(Q6)(Q7), —P(Q8)(Q9), —P(═O)(Q8)(Q9), or —P(═S)(Q8)(Q9).
In one or more embodiments, R10 and R20 may each independently be hydrogen, deuterium, —F, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C6-C10 aryl group, —Si(Q1)(Q2)(Q3), or —Ge(Q1)(Q2)(Q3).
In one or more embodiments, Ln1 may be represented by one of Formulae 4-1 to 4-20:
wherein, in Formulae 4-1 to 4-20,
Two or more of a plurality of R10 in Formula 1A may be optionally linked to each other to form a substituted or unsubstituted C5-C30 carbocyclic group or a substituted or unsubstituted C1-C30 heterocyclic group,
b10 and b20 in Formula 1A may each independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.
Ln2 in Formula 1 may be an organic ligand.
In one or more embodiments, Ln2 may be represented by at least one of Formulae 2A to 2C:
wherein, in Formulae 2A to 2C,
In one or more embodiments, Ln2 may be represented by one of Formulae 21-1 to 21-4:
wherein, in Formulae 21-1 to 21-4,
In one or more embodiments, Ln2 may be represented by Formula 22-1:
wherein, in Formula 22-1,
In one or more embodiments, Ln2 may be represented by Formula 23-1:
wherein, in Formula 23-1,
In one or more embodiments, ring CY1, ring CY2, and ring CY4 to ring CY6 may each independently be i) a first ring, ii) a second ring, iii) a condensed ring group in which at least two first rings are condensed together, iv) a condensed ring group in which at least two second rings are condensed together, or v) a condensed ring group in which at least one first ring is condensed with at least one second ring,
In one or more embodiments, ring CY1, ring CY2, and ring CY4 to ring CY6 may each independently be a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, a 9H-fluoren-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluoren-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a furopyridine group, a benzofuropyridine group, a thienopyridine group, a benzothienopyridine group, a quinoxaline group, a quinazoline group, a phenanthroline group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, an adamantane group, a norbornane group, or a norbornene group.
In one or more embodiments, ring CY1, ring CY2, and ring CY4 to ring CY6 may each independently be a benzene group, a naphthalene group, a phenanthrene group, a pyridine group, a pyrimidine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a furanopyridine group, a benzofuropyridine group, a thienopyridine group, a benzothienopyridine group, a phthalazine group, a naphthyridine group, a quinoxaline group, or a quinazoline group.
In one or more embodiments, R10, R20, R31 to R37, R40, R50, and R60 may each independently be:
In one or more embodiments, R10, R20, R31 to R37, R40, R50, and R60 may each independently be:
wherein, in Formulae 9-1 to 9-61, 9-201 to 9-244, 10-1 to 10-154, and 10-201 to 10-350, * represents a binding site to an adjacent atom, “Ph” represents a phenyl group, “TMS” represents a trimethylsilyl group, and “TMG” represents a trimethylgermyl group.
In one or more embodiments, two or more of a plurality of R10; two or more of a plurality of R20; two or more of R31 to R37; two or more of a plurality of R40; two or more of a plurality of R50; two or more of a plurality of R60; and/or two or more of R50 and R60 may be optionally linked together via a single bond, a double bond, or a first linking group to form a C5-C30 carbocyclic group that is unsubstituted or substituted with at least one R10a, or a C1-C30 heterocyclic group that is unsubstituted or substituted with at least one R10a (for example, a fluorene group, a xanthene group, an acridine group, or the like, each unsubstituted or substituted with at least one R10a). R10a may be as described herein for R10.
In one or more embodiments, two or more of R11 to R18; two or more of R21 to R26; two or more of R31 to R37; two or more of R41 to R44; two or more of R51 to R54; and/or two or more of R61 to R64 may be optionally linked together via a single bond, a double bond, or a first linking group to form a C5-C30 carbocyclic group that is unsubstituted or substituted with at least one R10a, or a C1-C30 heterocyclic group that is unsubstituted or substituted with at least one R10a (for example, a fluorene group, a xanthene group, an acridine group, or the like, each unsubstituted or substituted with at least one R10a). R10a may be as described herein for R10.
The first linking group may be *—N(R8)—*′, *—B(R8)—*′, *—P(R8)—*′, *—C(R8)(R9)—*′, *—Si(R8)(R9)—*′, *—Ge(R8)(R9)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)2—*′, *—C(R8)═*′, *═C(R8)—*′, *—C(R8)═C(R9)—*′, *—C(═S)—*′, or *—C≡C—*′, R8 and R9 may be as described for R10, and each of * and *′ indicates a binding site to a neighboring atom.
At least one substituent of the substituted C5-C30 carbocyclic group, the substituted C1-C30 heterocyclic group, the substituted C1-C60 alkyl group, the substituted C2-C60 alkenyl group, the substituted C2-C60 alkynyl group, the substituted C1-C60 alkoxy group, the substituted C1-C60 alkylthio group, the substituted C3-C10 cycloalkyl group, the substituted C1-C10 heterocycloalkyl group, the substituted C3-C10 cycloalkenyl group, the substituted C1-C10 heterocycloalkenyl group, the substituted C6-C60 aryl group, the substituted C7-C60 alkyl aryl group, the substituted C7-C60 aryl alkyl group, the substituted C6-C60 aryloxy group, the substituted C6-C60 arylthio group, the substituted C1-C60 heteroaryl group, the substituted C2-C60 alkyl heteroaryl group, the substituted C2-C60 heteroaryl alkyl group, the substituted C1-C60 heteroaryloxy group, the substituted C1-C60 heteroarylthio group, the substituted monovalent non-aromatic condensed polycyclic group, the substituted monovalent non-aromatic condensed heteropolycyclic group, the substituted C3-C10 cycloalkylene group, the substituted C1-C10 heterocycloalkylene group, the substituted C3-C10 cycloalkenylene group, the substituted C1-C10 heterocycloalkenylene group, the substituted C6-C60 arylene group, the substituted C1-C60 heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, and the substituted divalent non-aromatic condensed heteropolycyclic group may be:
Q1 to Q9, Q11 to Q19, Q21 to Q29, and Q31 to Q39 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C1-C60 alkylthio group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C7-C60 alkyl aryl group, a substituted or unsubstituted C7-C60 aryl alkyl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted C2-C60 alkyl heteroaryl group, a substituted or unsubstituted C2-C60 heteroaryl alkyl group, a substituted or unsubstituted C1-C60 heteroaryloxy group, a substituted or unsubstituted C1-C60 heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.
For example, Q1 to Q9, Q11 to Q19, Q21 to Q29, and Q31 to Q39 may each independently be:
In one or more embodiments, the organometallic compound may be at least one of Compounds 1 to 6, but embodiments are not limited thereto:
By including at least one silyl group or at least one germyl group in the organometallic compound included in the organic light-emitting device, the organic light-emitting device may have a low deposition temperature, and the emission wavelength thereof may be easily controlled so as to have a target wavelength characteristic (for example, shortening of the wavelength). For example, compared to a compound that does not include a silyl group or a germyl group or a compound having a structure in which an alkyl group such as a methyl group, an ethyl group, a t-butyl group, or the like is substituted instead of a silyl group or a germyl group, the organometallic compound may have a shorter maximum emission wavelength. In other words, the organometallic compound that is substituted with at least one silyl group or at least one germyl group on a ligand thereof, rather than a group such as an alkyl group at the corresponding position(s) of the ligand, may have a shorter maximum emission wavelength.
The term “C1-C60 alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms. The term “C1-C60 alkylene group” as used herein refers to a divalent group having the same structure as the C1-C60 alkyl group.
Non-limiting examples of the C1-C60 alkyl group, the C1-C20 alkyl group, and/or the C1-C10 alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, a tert-decyl group, or the like, each unsubstituted or substituted with at least one of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, a tert-decyl group, or the like, or a combination thereof. For example, Formula 9-33 is a branched C6 alkyl group, for example, a tert-butyl group that is substituted with two methyl groups.
The term “C1-C60 alkoxy group” as used herein refers to a monovalent group represented by —OA101 (wherein A101 is the C1-C60 alkyl group). Non-limiting examples of the C1-C60 alkoxy group, a C1-C20 alkoxy group or C1-C10 alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, or the like.
The term “C1-C60 alkylthio group” as used herein refers to a monovalent group represented by —SA101′ (wherein A101′ is the C1-C60 alkyl group).
The term “C2-C60 alkenyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, a butenyl group, or the like. The term “C2-C60 alkenylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group, and non-limiting examples thereof include an ethynyl group, a propynyl group, or the like. The term “C2-C60 alkynylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkynyl group.
The term “C3-C10 cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms. The term “C3-C10 cycloalkylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkyl group.
Non-limiting examples of the C3-C10 cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl(norbornanyl) group, a bicyclo[2.2.2]octyl group, or the like.
The term “C1-C10 heterocycloalkyl group” as used herein refers to a monovalent saturated cyclic group having at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom and 1 to 10 carbon atoms as ring-forming atom(s). The term “C1-C10 heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkyl group.
Non-limiting examples of the C1-C10 heterocycloalkyl group include a silolanyl group, a silinanyl group, tetrahydrofuranyl group, a tetrahydro-2H-pyranyl group, a tetrahydrothiophenyl group, or the like.
The term “C3-C10 cycloalkenyl group” as used herein refers to a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, or the like. The term “C3-C10 cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein refers to a monovalent cyclic group that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, 2 to 10 carbon atoms as ring-forming atom(s), and at least one double bond in its ring. Non-limiting examples of the C1-C10 heterocycloalkenyl group include a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, or the like. The term “C2-C10 heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic ring system having 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group having a carbocyclic aromatic ring system having 6 to 60 carbon atoms. Non-limiting examples of the C6-C60 aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a chrysenyl group, or the like. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the rings may be fused to each other.
The term “C7-C60 alkyl aryl group” as used herein refers to a C6-C60 aryl group substituted with at least one C1-C60 alkyl group. The term “C7-C60 aryl alkyl group” as used herein refers to a C1-C60 alkyl group substituted with at least one C6-C60 aryl group.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic ring system that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, and 1 to 60 carbon atoms as ring-forming atom(s). The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic ring system that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, and 1 to 60 carbon atoms as ring-forming atom(s). Non-limiting examples of the C1-C60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, or the like. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the rings may be fused to each other.
The term “C2-C60 alkyl heteroaryl group” as used herein refers to a C1-C60 heteroaryl group substituted with at least one C1-C60 alkyl group. The term “C2-C60 heteroaryl alkyl group” as used herein refers to a C1-C60 alkyl group substituted with at least one C1-C60 heteroaryl group.
The term “C6-C60 aryloxy group” as used herein indicates —OA102 (wherein A102 is a C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein indicates —SA103 (wherein A103 is a C6-C60 aryl group).
The term “C1-C60 heteroaryloxy group” as used herein indicates —OA104 (wherein A104 is a C1-C60 heteroaryl group), and the term “C1-C60 heteroarylthio group” as used herein indicates —SA105 (wherein A105 is the C1-C60 heteroaryl group).
The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group or the like. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed with each other, at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group or the like. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C5-C30 carbocyclic group” as used herein refers to a saturated or unsaturated ring group having, as ring-forming atoms, 5 to 30 carbon atoms only. The C5-C30 carbocyclic group may be a monocyclic group or a polycyclic group. Non-limiting examples of the “C5-C30 carbocyclic group (unsubstituted or substituted with at least one R1a)” as used herein may include an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane(norbornane) group, a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a cyclopentadiene group, a silole group, a fluorene group, or the like (each unsubstituted or substituted with at least one R1a).
The term “C1-C30 heterocyclic group” as used herein refers to a saturated or unsaturated ring group having, as a ring-forming atom, at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B, other than 1 to 30 carbon atoms as ring-forming atom(s). The C1-C30 heterocyclic group may be a monocyclic group or a polycyclic group. Non-limiting examples of the “C1-C30 heterocyclic group (unsubstituted or substituted with at least one R1a)” include a thiophene group, a furan group, a pyrrole group, a silole group, borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, a 9H-fluoren-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluoren-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, or the like (each unsubstituted or substituted with at least one R1a).
As used herein, “TMS” represents *—Si(CH3)3, and as used herein “TMG” represents *—Ge(CH3)3.
At least one substituent of the substituted C5-C30 carbocyclic group, the substituted C1-C30 heterocyclic group, the substituted C1-C60 alkyl group, the substituted C2-C60 alkenyl group, the substituted C2-C60 alkynyl group, the substituted C1-C60 alkoxy group, the substituted C1-C60 alkylthio group, the substituted C3-C10 cycloalkyl group, the substituted C1-C10 heterocycloalkyl group, the substituted C3-C10 cycloalkenyl group, the substituted C1-C10 heterocycloalkenyl group, the substituted C6-C60 aryl group, the substituted C7-C60 alkyl aryl group, the substituted C7-C60 aryl alkyl group, the substituted C6-C60 aryloxy group, the substituted C6-C60 arylthio group, the substituted C1-C60 heteroaryl group, the substituted C2-C60 alkyl heteroaryl group, the substituted C2-C60 heteroaryl alkyl group, the substituted C1-C60 heteroaryloxy group, the substituted C1-C60 heteroarylthio group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be:
In one or more embodiments, a full width at half maximum (FWHM) of an emission peak of an emission spectrum or an electroluminescence spectrum of the organometallic compound may be about 60 nanometers (nm) or less. For example, a FWHM of the emission spectrum or the electroluminescence spectrum of the organometallic compound may be about 5 nm to about 50 nm, about 7 nm to about 40 nm, or about 10 nm to about 30 nm.
n-doped Layer
In one or more embodiments, the n-doped layer may include an electron transport compound and an n-dopant.
In one or more embodiments, the electron transport compound may include at least one of a cyano group, a π electron-deficient nitrogen-containing cyclic group, an electron transport moiety, or a combination thereof.
In one or more embodiments, the term “π electron-deficient nitrogen-containing cyclic group” as used herein refers to a ring group having at least one *—N═*′ moiety, and for example, may be an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, or the like; or a condensed cyclic group wherein two or more π electron-deficient nitrogen-containing cyclic groups are condensed with each other.
In one or more embodiments, the electron transport moiety as used herein may be at least one of a cyano group, a π electron-deficient nitrogen-containing cyclic group, or a group including one of the following Formulae:
wherein, in the above Formulae, *, *′, and *″ each indicate a binding site to a neighboring atom.
In one or more embodiments, the electron transport compound may include a cyano group, pyridine group, a pyrimidine group, pyrazine group, a triazine group, a quinoline group, an isoquinoline group, or a combination thereof.
In one or more embodiments, the electron transport compound may be understood by referring to the description of a material for the electron transport region.
In one or more embodiments, the n-dopant may include a metal.
In one or more embodiments, the n-dopant may include at least one of an alkali metal, an alkali metal-containing compound, an alkali metal complex, an alloy of an alkali metal, an alkaline earth metal, an alloy of an alkaline earth metal, an alkaline earth metal-containing compound, an alkaline earth-metal complex, a rare earth metal, an alloy of a rare earth metal, a rare earth metal-containing compound, or a rare earth metal complex, for example, a lanthanide metal, an alloy of a lanthanide metal, a lanthanide metal-containing compound, or a lanthanide metal complex.
In one or more embodiments, the alkali metal may be Li, Na, K, Rb, Cs, or a combination thereof.
In one or more embodiments, the alkaline earth metal may be Mg, Ca, Sr, Ba, or a combination thereof.
In one or more embodiments, the rare earth metal may be Sc, Y, Ce, Tb, Yb, Gd, or a combination thereof.
In one or more embodiments, the lanthanide metal may be lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or a combination thereof.
In one or more embodiments, the alkali metal-containing compound may include an alkali metal oxides, for example Li2O, Cs2O, K2O, or the like; an alkali metal halide, for example LiF, NaF, CsF, KF, LiI, NaI, CsI, KI, or the like; or a combination thereof.
In one or more embodiments, the alkaline earth metal-containing compound may include an alkaline earth metal compound, for example BaO, SrO, CaO, BaxSr1-xO (wherein x is a real number satisfying the condition of 0<x<1), BaxCa1-xO (wherein x is a real number satisfying the condition of 0<x<1), or the like.
In one or more embodiments, the rare earth metal-containing compound may include YbF3, ScF3, SC2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, ScI3, TbI3, or the like, or a combination thereof. In some embodiments, the rare earth metal-containing compound may include a lanthanide metal telluride.
In one or more embodiments, the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, HO2Te3, Er2Te3, Tm2Te3, Yb2Te3, Lu2Te3, or the like, or a combination thereof.
In one or more embodiments, the alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal, and ii), as a ligand linked to the metal ion, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenyl benzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or a combination thereof.
In one or more embodiments, the n-dopant may include an organic dopant.
In one or more embodiments, the organic layer may further include a hole transport region arranged between the first electrode and the emission layer.
In one or more embodiments, the hole transport region may further include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof.
In one or more embodiments, the n-doped layer may be arranged between the first electrode and the hole transport region.
In one or more embodiments, the organic layer may further include a p-doped layer.
In one or more embodiments, the p-doped layer may be arranged between the n-doped layer and the hole transport region.
In one or more embodiments, the p-doped layer may include a hole transport compound and a p-dopant. The hole transport compound may be understood by referring to the description herein of the p-dopant.
In one or more embodiments, the organic layer may further include an electron transport region arranged between the emission layer and the second electrode.
In one or more embodiments, the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
In one or more embodiments, the emission layer may include a host and a dopant, and the dopant may include at least one of the organometallic compounds described herein.
In one or more embodiments, based on weight, an amount of the host in the emission layer may be greater than an amount of the at least one organometallic compound in the emission layer.
In one or more embodiments, the emission layer may emit a red light, a green light, or a blue light. For example, the emission layer may emit a red light having a maximum emission wavelength of about 600 nm to about 750 nm, such as about 600 nm to about 650 nm or about 610 nm to about 630 nm. For example, the emission layer may emit a green light having a maximum emission wavelength of about 495 nm to about 580 nm. For example, the emission layer may emit a blue light having a maximum emission wavelength of about 410 nm to about 490 nm.
Since the organic light-emitting device has an emission layer including at least one organometallic compound, for example at least one organometallic compound represented by Formula 1, the organic light-emitting device may have a relatively narrow FWHM in the emission peak of the electroluminescence spectrum and also have excellent efficiency and lifespan characteristics.
In one or more embodiments, the at least one organometallic compound may act as a dopant (for example, an emitter or a sensitizer) in the emission layer, and the emission layer may further include a host (that is, the amount of the at least one organometallic compound in the emission layer may be less than the amount of the host in the emission layer, based on weight). In one or more embodiments, an amount of the host in the emission layer may be greater than an amount of the at least one organometallic compound in the emission layer, based on weight.
The expression “(an emission layer) includes at least one organometallic compound (represented by Formula 1)” as used herein may include a case in which “(an emission layer) includes identical organometallic compounds (represented by Formula 1)” and a case in which “(an emission layer) includes two or more different organometallic compounds (represented by Formula 1).”
For example, the emission layer may include, as the at least one organometallic compound, only Compound 1. In this regard, Compound 1 may be present in the emission layer of the organic light-emitting device. In some embodiments, the emission layer may include, as the at least one organometallic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be present in the emission layer of the organic light-emitting device.
In the organic light-emitting device according to one or more embodiments, the organic layer may include n emission units; and n-1 charge generation units arranged between two neighboring emission units. Each of the n emission units may include an emission layer.
In one or more embodiments, n may be an integer of 2 or greater.
That is, the organic light-emitting device may have a tandem structure in which a plurality of emission units are vertically stacked between the first electrode and the second electrode. For example, n may be 2, 3, 4, 5, 6, 7, 8, 9, or 10. In one or more embodiments, n may be 2, 3, 4, 5, or 6.
A light emitted from each of the n emission units may be identical to or different from each other.
In one or more embodiments, a light emitted from each of the n emission units may be a red light.
In one or more embodiments, a light emitted from each of the n emission units may be a green light.
In one or more embodiments, a light emitted from each of the n emission units may be a blue light.
In some embodiments, a light emitted from at least one emission unit among the n emission units may be a red light. In some embodiments, a light emitted from at least one emission unit among the n emission units may be a green light, and a light emitted from at least one emission unit among the remaining emission units may be a blue light.
The organic light-emitting device may further include a substrate including a red subpixel, a green subpixel, and/or a blue subpixel, wherein the first electrode may be patterned for each red subpixel, green subpixel, and/or blue subpixel, the emission layer may include a red emission layer arranged in the red subpixel area, a green emission layer arranged in the green subpixel area, and/or a blue emission layer arranged in the blue subpixel area, and at least one of the red emission layer, green emission layer, and/or blue emission layer may include the at least one organometallic compound. That is, the organic light-emitting device may be a full color light-emitting device.
In one or more embodiments, at least one of the n emission units may include an emission layer including the at least one organometallic compound.
In one or more embodiments, the n-doped layer may be arranged between the first electrode and the hole transport region, or at least one of the n-1 charge generation units may include the n-doped layer.
In one or more embodiments, the n emission units may include an m emission unit that is the mth nearest to the first electrode. Here, m may be an integer from 1 to n. That is, the emission unit that is mth nearest to the first electrode among the n emission units may be referred to as the mth emission unit.
In one or more embodiments, the at least one organometallic compound may be included in any one of the emission units excluding the first emission unit among the n emission units.
In one or more embodiments, the n emission units may include a kth emission unit which is kth nearest to the first electrode, and k may be an integer from 2 to n, and the kth emission unit may include an emission layer including the at least one organometallic compound. That is, the emission unit that is kth nearest to the first electrode among the n emission units may be referred to as the kth emission unit.
In one or more embodiments, the mth emission unit may include an mth emission layer.
In one or more embodiments, the mth emission unit may further include an mth hole transport region arranged between the first electrode and the mth emission layer.
In one or more embodiments, the mth hole transport region may include an mth hole injection layer, an mth hole transport layer, an mth electron blocking layer, an mth buffer layer, or a combination thereof.
In one or more embodiments, the mth emission unit may further include an mth electron transport region arranged between the mth emission layer and the second electrode.
In one or more embodiments, the mth electron transport region may include an mth hole blocking layer, an mth electron transport layer, an mth electron injection layer, or a combination thereof.
In one or more embodiments, the n-1 charge generation units may include a jth charge generation unit that is the jth nearest to the first electrode. Here, j may be an integer from 1 to n-1. That is, the charge generation unit that is jth nearest to the first electrode among the n-1 charge generation units may be referred to as the jth charge generation unit.
In one or more embodiments, the jth charge generation unit may include a jth n-type charge generation layer and a jth p-type charge generation layer.
In one or more embodiments, the jth n-type charge generation layer may be arranged nearer to the first electrode than the jth p-type charge generation layer. For example, the organic light-emitting device may have a structure in which the first electrode, the jth emission unit, the jth n-type charge generation layer, and the jth p-type charge generation layer are sequentially stacked in the stated order.
In one or more embodiments, the jth n-type charge generation layer may be the n-doped layer.
In one or more embodiments, the jth p-type charge generation layer may be the p-doped layer.
In one or more embodiments, the n-doped layer may be arranged nearer to the first electrode than to the emission layer.
In one or more embodiments, the kth emission unit may include the emission layer including the at least one organometallic compound, and the (k-1)th charge generation unit may include the n-doped layer, wherein k may be an integer of 2 to n.
Because the organic light-emitting device has a structure as described herein, the cation formed from the anode may be effectively removed by a free electron formed from an n-doped layer, thereby preventing the silyl group and/or the germyl group of the at least one organometallic compound from being decomposed. Accordingly, by including the at least one organometallic compound including the at least one silyl group and/or the at least one germyl group in the emission layer, the organic light-emitting device may achieve a high luminescence efficiency, a high color purity, and/or an excellent processability, and the degradation of the at least one organometallic compound may be prevented to provide a high luminescence efficiency and/or a long lifespan.
The FIGURE is a schematic cross-sectional view of an organic light-emitting device 10 according to one or more embodiments, but embodiments are not limited thereto. Hereinafter, the structure and manufacturing method of the organic light-emitting device 10 according to one or more exemplary embodiments will be described in further detailed with connection to the FIGURE. The organic light-emitting device 10 includes a first electrode 11, an organic layer 15, and a second electrode 19, which are sequentially stacked in the stated order.
A substrate may be additionally disposed under the first electrode 11 or on the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, for example, a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water repellency.
The first electrode 11 may be produced by depositing or sputtering, onto the substrate, a material for forming the first electrode 11. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials with a high work function for easy hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for forming the first electrode 11 may be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), or zinc oxide (ZnO). In some embodiments, the material for forming the first electrode 11 may be metal, such as magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).
The first electrode 11 may have a single-layered structure or a multi-layered structure including a plurality of layers. For example, the first electrode 11 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 11 is not limited thereto.
The organic layer 15 may be located on the first electrode 11.
The organic layer 15 may include a hole transport region, an emission layer, and an electron transport region.
The hole transport region may be arranged between the first electrode 11 and the emission layer.
The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof.
The hole transport region may include only either a hole injection layer, or a hole transport layer. In some embodiments, the hole transport region may have a hole injection layer/hole transport layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein, for each structure, respective layers are sequentially stacked in this stated order from the first electrode 11.
When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition, but embodiments are not limited thereto.
When the hole injection layer is formed by vacuum deposition, the deposition conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the deposition conditions may include a deposition temperature of about 100° C. to about 500° C., a vacuum pressure in a range of about 10−8 torr to about 10−3 torr, and a deposition rate of about 0.01 angstroms per second (Å/sec) to about 100 Å/sec. However, the deposition conditions are not limited thereto.
When the hole injection layer is formed by spin coating, the coating conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the coating conditions may include a coating speed of about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a heat treatment temperature for removing a solvent after coating may be about 80° C. to about 200° C. However, the coating conditions are not limited thereto.
The conditions for forming the hole transport layer and the electron blocking layer may be similar to or the same as the conditions for forming the hole injection layer.
The hole transport region may include a hole transport compound.
The hole transport compound may include at least one of 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), B-NPB, N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD), spiro-TPD, spiro-NPB, methylated NPB, 4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), (polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201, or a compound represented by Formula 202, but embodiments are not limited thereto:
Ar101 and Ar102 in Formula 201 may each independently be:
xa and xb in Formula 201 may each independently be an integer from 0 to 5, or 0, 1, or 2. For example, xa may be 1 and xb may be 0, but xa and xb are not limited thereto.
R101 to R108, R111 to R119 and R121 to R124 in Formulae 201 and 202 may each independently be:
R109 in Formula 201 may be:
According to one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments are not limited thereto:
R101, R111, R112, and R109 in Formula 201A may each be as described herein.
For example, the compound represented by Formula 201 and the compound represented by Formula 202 may include one or more of Compounds HT1 to HT21, but embodiments are not limited thereto:
A thickness of the hole transport region may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. Without wishing to be bound to theory, when the thicknesses of the hole transport region, the hole injection layer and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.
The charge-generation material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, or a cyano group-containing compound, but embodiments are not limited thereto. Non-limiting examples of the p-dopant include a quinone derivative, for example tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F6-TCNNQ), or the like; a metal oxide, for example a tungsten oxide, a molybdenum oxide, or the like; or a cyano group-containing compound, such as one of Compounds HT-D1 or F12, but embodiments are not limited thereto:
The hole transport region may include a buffer layer.
In one or more embodiments, the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, efficiency of a formed organic light-emitting device may be improved.
Then, an emission layer may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied in forming the hole injection layer, although the deposition or coating conditions may vary according to a material that is used to form the emission layer.
Meanwhile, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be selected from materials for the hole transport region described above and materials for a host to be explained later. However, the material for the electron blocking layer is not limited thereto. For example, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be mCP, which will be explained later.
The emission layer may include a host and a dopant, and the dopant may include the at least one organometallic compound including at least one silyl group or at least one germyl group, for example at least one organometallic compound represented by Formula 1.
The host may include at least one of 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), 9,10-di(naphthalene-2-yl)anthracene (ADN) (also referred to as “DNA”), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP), 1,3,5-tris(carbazole-9-yl)benzene (TCP), 1,3-bis(N-carbazolyl)benzene (mCP), Compound H50, or Compound H51, but embodiments are not limited thereto:
In some embodiments, the host may further include a compound represented by Formula 301, but embodiments are not limited thereto:
Ar111 and Ar112 in Formula 301 may each independently be:
Ar113 to Ar116 in Formula 301 may each independently be:
g, h, i, and j in Formula 301 may each independently be an integer from 0 to 4, and g, h, i, and j may each independently be, for example, 0, 1, or 2.
Ar113 to Ar116 in Formula 301 may each independently be:
but embodiments are not limited thereto.
In some embodiments, the host may include a compound represented by Formula 302, but embodiments are not limited thereto:
Ar122 to Ar125 in Formula 302 may be as described for Ar113 in Formula 301.
Ar126 and Ar127 in Formula 302 may each independently be a C1-C10 alkyl group (for example, a methyl group, an ethyl group, a propyl group, or the like).
k and I in Formula 302 may each independently be an integer from 0 to 4. For example, k and I may each independently be 0, 1, or 2.
When the organic light-emitting device 10 is a full-color organic light-emitting device 10, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In some embodiments, due to a stacked structure including a red emission layer, a green emission layer, and/or a blue emission layer, the emission layer may emit a white light.
The dopant in the emission layer may further include a compound including at least one metal, in addition to the at least one organometallic compound described herein.
In one or more embodiments, the compound including a metal may include at least one metal (M21) that is a transition metal, and an organic ligand (L21), and L21 and M21 may form 1, 2, 3, or 4 cyclometallated rings.
In one or more embodiments, the compound including the metal may be represented by Formula 101:
wherein, in Formula 101,
wherein, in Formulae 1-1 to 1-4,
In one or more embodiments, M21 may be platinum, palladium, gold, iridium, osmium, titanium, zirconium, hafnium, europium, terbium, thulium, or rhodium.
When the emission layer includes a host and a dopant, an amount of the dopant may be about 0.01 part by weight to about 15 parts by weight, based on 100 parts by weight of the host, but embodiments are not limited thereto.
A thickness of the emission layer may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. Without wishing to be bound to theory, when the thickness of the emission layer is within these ranges, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
An electron transport region may be located on the emission layer.
The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure, or an electron transport layer/electron injection layer structure, but the structure of the electron transport region is not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.
Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer which constitute the electron transport region may be understood by referring to the conditions for forming the hole injection layer.
When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), or bis(2-methyl-8-quinolinolato-N1,O8)-(1,1′-biphenyl-4-olato)aluminum (BAlq), but embodiments are not limited thereto:
A thickness of the hole blocking layer may be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. Without wishing to be bound to theory, when the thickness of the hole blocking layer is within these ranges, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may further include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), tris(8-hydroxy-quinolinato)aluminum (Alq3), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1′-biphenyl-4-olato)aluminum (BAlq), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), or 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), but embodiments are not limited thereto:
In some embodiments, the electron transport layer may include at least one of ET1 to ET25, but embodiments are not limited thereto:
A thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Without wishing to be bound to theory, when the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transporting characteristics without a substantial increase in driving voltage.
The electron transport layer may include a metal-containing material in addition to the material as described herein.
The metal-containing material may include a Li complex. The Li complex may include, for example, at least one of Compounds ET-D1 (lithium 8-hydroxyquinolate, LiQ) or ET-D2, but embodiments are not limited thereto:
The electron transport region may include an electron injection layer that promotes the flow of electrons from the second electrode 19 thereinto.
The electron injection layer may include LiF, NaCl, CsF, Li2O, BaO, or a combination thereof.
A thickness of the electron injection layer may be about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. Without wishing to be bound to theory, when the thickness of the electron injection layer is within the ranges described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 may be located on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a metal, a metal alloy, an electrically conductive compound, or a combination thereof, which have a relatively low work function. For example, lithium (Li), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) may be used as the material for forming the second electrode 19. In some embodiments, to manufacture a top-emission light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19.
Hereinbefore, the organic light-emitting device has been described in further detail with reference to the FIGURE, but embodiments are not limited thereto.
In some embodiments, an electronic apparatus may include the organic light-emitting device.
The electronic apparatus may further include a thin-film transistor (TFT) in addition to the organic light-emitting device as described herein. The thin-film transistor may include a source electrode, a drain electrode, and an active layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the organic light-emitting device, but embodiments are not limited thereto.
Hereinafter, an organic light-emitting device according to one or more exemplary embodiments will be described in further detail with reference to Examples. However, it is to be understood that embodiments are not limited to the following examples.
10 milligrams (mg) of a compound as specified in Table 1 was subjected to thermal gravimetric analysis (TGA) in a vacuum of 1 Pascal (Pa), and a temperature at which the weight of the compound was reduced by 10% was measured, and results thereof are shown in Table 1.
Referring to Table 1, the organometallic compounds represented by Formula 1 were found to have a reduced deposition temperature as compared with Compounds A to F, which did not include at least one silyl group or at least one germyl group.
As an anode, an ITO-patterned glass substrate was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated with isopropyl alcohol and deionized (DI) water each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. The resultant glass substrate was subjected to N2:O2 plasma processing in a vacuum deposition apparatus for 10 minutes and loaded onto a vacuum organic deposition apparatus.
ET3 and Yb were co-deposited by vacuum on the ITO anode at a weight ratio of 3 weight percent (wt %) to form an n-doped layer having a thickness of 100 Å.
HT3 and F6TCNNQ were vacuum co-deposited on the n-doped layer at a weight ratio of 98:2 to form a hole injection layer having a thickness of 100 Å, and then, HT3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,350 Å.
Then, H52 (host) and Compound 1 (dopant) were co-deposited by vacuum on the hole transport layer at a weight ratio of 97:3 to form an emission layer having a thickness of 400 Å.
Subsequently, ET3 and ET-D1 were co-deposited by vacuum at a volume ratio of 50:50 on the emission layer to form an electron transport layer having a thickness of 350 Å, and ET-D1 was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 A, and Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 1,000 Å, thereby completing the manufacture of an organic light-emitting device.
An organic light-emitting device was manufactured in a similar manner as in Example 1, except that the compounds shown in Table 2 were used in forming the dopant and the n-doped layer of the emission layer.
The maximum emission wavelength of the emission spectrum (λmax, nm), luminescence efficiency (relative %), and lifespan characteristics (LT97, relative %) of each of the organic light-emitting devices manufactured according to Examples 1 and 2 and Comparative Examples 1 to 6 were evaluated. Results thereof are shown in Table 2. A Keithley 2400 current voltmeter and a luminance meter (Topcon SR3) were used in the evaluations. Lifespan characteristics (LT97) indicates the time taken for the luminance to reach 97% of the initial luminance of 100%, and is expressed in Table 2 as a relative value to Example 1.
From Table 2, it was confirmed that the organic light-emitting device according to one or more embodiments had excellent luminescence efficiency and lifespan characteristics.
In addition, the organic light-emitting devices of Examples 1 and 2 were found to be significantly better in lifespan characteristics compared to the organic light-emitting devices of Comparative Examples 1 and 2, in which the n-doped layer was not formed.
According to the one or more embodiments, by including the n-doped layer between the emission layer and the first electrode, and including the at least one organometallic compound including the at least one silyl group and/or the at least one germyl group in the emission layer, the organic light-emitting device may have an excellent luminescence efficiency, a long lifespan, and a high color purity. Particularly, by including at least one silyl group or at least one germyl group in the at least one organometallic compound included in the organic light-emitting device, the organic light-emitting device may have a low deposition temperature, and the emission wavelength thereof may be easily controlled to have a target wavelength characteristic (for example, a shortening of the wavelength). In addition, the cation formed from the anode by the free electron formed from the n-doped layer of the organic light-emitting device may be effectively removed, thereby preventing the at least one silyl group and/or the at last one germyl group of the at least one organometallic compound from being decomposed. In addition, an excellent high-quality electronic apparatus including the organic light-emitting device may be provided.
It should be understood that exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each exemplary embodiment should typically be considered as available for other similar features or aspects in other exemplary embodiments. While one or more exemplary embodiments have been described if further detail and with reference to the FIGURE, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0187752 | Dec 2022 | KR | national |
