Patent Application
20250154405
This application priority to and the benefit of Korean Patent Application No. 10-2023-0150291, filed on Nov. 2, 2023, 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.
One or more aspects relate to an organometallic compound, an organic light-emitting device including the same, and an electronic apparatus including the organic light-emitting device.
Organic light-emitting devices (OLEDs) are self-emissive devices that have excellent characteristics in terms of viewing angles, response time, brightness, driving voltage, and response speed. In addition, OLEDs can produce full-color images.
An organic light-emitting device typically includes an anode, a cathode, and an organic layer disposed between the anode and the cathode and including an emission layer. A hole transport region may be disposed between the anode and the emission layer, and an electron transport region may be disposed 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 recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thereby generating light.
One or more aspects relate to an organometallic compound, an organic light-emitting device including the same, 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 herein.
According to an aspect, provided is an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein, in Formula 1,
wherein, in Formulae 1A and 1B,
According to another aspect, an organic light-emitting device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one organometallic compound represented by Formula 1.
At least one of the organometallic compounds represented by Formula 1 may be included in the emission layer of the organic layer, and the at least one organometallic compound represented by Formula 1 included in the emission layer may serve as a dopant.
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 accompanying drawing, in which:
The FIGURE is 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, by referring to the FIGURE, to explain certain aspects and features of the present detailed description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b, or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.
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.
According to an aspect, an organometallic compound is represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein M1 in Formula 1 is a transition metal.
For example, M1 may be a first-row transition metal of the Periodic Table of Elements, a second-row transition metal of the Periodic Table of Elements, or a third-row transition metal of the Periodic Table of Elements.
In one or more embodiments, M1 may be iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), or rhodium (Rh).
In one or more embodiments, M1 may be iridium (Ir), platinum (Pt), osmium (Os), or rhodium (Rh).
In one or more embodiments, M1 may be iridium (Ir).
In Formula 1, n1 is 1 or 2, and n2 is 1 or 2.
In one or more embodiments, a sum of n1 and n2 may be 2 or 3.
In one or more embodiments, M1 may be iridium (Ir), and the sum of n1 and n2 may be 3.
In one or more embodiments, M1 may be platinum (Pt), and the sum of n1 and n2 may be 2.
L1 in Formula 1 is a ligand represented by Formula 1A:
wherein, in Formula 1A, X1 is C or N, and X2 is C or N.
In one or more embodiments, X1 may be N, and X2 may be C.
Ring CY1 in Formula 1A is a 5-membered heterocyclic group, a 5-membered heterocyclic group condensed with a C5-C30 carbocyclic group, or a 5-membered heterocyclic group condensed with a C1-C30 heterocyclic group.
In one or more embodiments, ring CY1 may be a pyrrole group, an imidazole group, a pyrazole group, an oxazole group, an indole group, an azaindole group, a benzopyrazole group, a benzimidazole group, or a benzoxazole group.
Ring CY2 in Formula 1A is a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, ring CY2 may be a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a phenanthrene 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 benzofuran group, a benzothiophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.
In one or more embodiments, in Formula 1A,
In one or more embodiments, a moiety represented by
in Formula 1A may be a group represented by one of Formulae CY(1)-1 to CY(1)-3:
wherein, in Formulae CY(1)-1 to CY(1)-3,
In one or more embodiments, ring CY10 in Formulae CY(1)-2 and CY(1)-3 may be a benzene group, a naphthalene group, a pyrimidine group, a pyrazine group, or a pyridazine group.
In one or more embodiments, a moiety represented by
in Formula 1A may be a group represented by one of Formulae CY(2)-1 to CY(2)-16:
wherein, in Formulae CY(2)-1 to CY(2)-16,
In one or more embodiments, L1 may be a ligand represented by Formula 1A-1 or Formula 1A-2:
wherein, in Formulae 1A-1 and 1A-2,
In one or more embodiments, R11 in Formulae 1A-1 and 1A-2 may be a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, or a substituted or unsubstituted C6-C60 aryl group.
L2 in Formula 1 is a ligand represented by Formula 1B:
wherein, in Formula 1B, X3 is C or N, and X4 is C or N.
In one or more embodiments, X3 may be N, and X4 may be C.
Y1 in Formula 1B is O, S, or Se.
Ring CY3 in Formula 1B is a 5-membered heterocyclic group, a 5-membered heterocyclic group condensed with a C5-C30 carbocyclic group, or a 5-membered heterocyclic group condensed with a C1-C30 heterocyclic group.
In one or more embodiments, ring CY3 may be a pyrrole group, an imidazole group, a pyrazole group, an oxazole group, an indole group, an azaindole group, a benzopyrazole group, a benzimidazole group, or a benzoxazole group.
Ring CY4 and ring CY5 in Formula 1B are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, ring CY4 and ring CY5 may each independently be a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a phenanthrene 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 benzofuran group, a benzothiophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.
In one or more embodiments, in Formula 1B,
In one or more embodiments, a moiety represented by
in Formula 1B may be a group represented by one of Formulae CY(3)-1 to CY(3)-3:
wherein, in Formulae CY(3)-1 to CY(3)-3,
In one or more embodiments, a moiety represented by
in Formula 1B may be a group represented by one of Formulae CY(4)-1 to CY(4)-6:
wherein, in Formulae CY(4)-1 to CY(4)-6,
In one or more embodiments, L2 may be a ligand represented by Formula 1B-1 or Formula 1B-2:
wherein, in Formulae 1B-1 and 1B-2,
In one or more embodiments, R31 in Formulae 1B-1 and 1B-2 may be a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, or a substituted or unsubstituted C6-C60 aryl group.
R1 to R4 in Formulae 1A and 1B are each independently 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-C1 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, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q1)(Q2)(Q3), —Ge(Q1)(Q2)(Q3), —N(Q4)(Q5), —B(Q6)(Q7), —P(Q8)(Q9), or —P(═O)(Q8)(Q9).
In one or more embodiments, R1 to R4 may each independently be:
R5 in Formula 1B is:
In one or more embodiments, R5 may be:
In one or more embodiments, R1 to R4 may each independently be:
In Formulae 9-1 to 9-39, 9-44 to 9-61, 9-201 to 9-240, 10-1 to 10-129, and 10-201 to 10-350, * indicates a binding site to a neighboring atom, “Ph” is a phenyl group, “TMS” is a trimethylsilyl group, and “TMG” is a trimethylgermyl group.
T1 in Formula 1B is:
In one or more embodiments, T1 may be:
* in Formulae 8-1 to 8-14 indicates a binding site to a neighboring atom.
b1 to b5 and c1 in Formulae 1A and 1B are each independently an integer from 1 to 10.
In one or more embodiments, c1 in Formula 1B may be 1 or 2.
In one or more embodiments, the organometallic compound represented by Formula 1 may be represented by one of Compounds 1 to 60:
In one or more embodiments, the organometallic compound represented by Formula 1 may be electrically neutral.
The organometallic compound represented by Formula 1 satisfies the structure of Formula 1 described above, and includes ligands represented by Formulae 1A and 1B, and Formula 1B includes a substituent (T1) including deuterium. Due to this structure, the organometallic compound represented by Formula 1 has excellent luminescence characteristics, and has characteristics suitable for use as a luminescent material with high color purity by controlling the emission wavelength range.
The organometallic compound represented by Formula 1 may have excellent electrical mobility, and thus, electronic devices, for example, organic light-emitting devices, including at least one of the organometallic compounds represented by Formula 1 may exhibit a low driving voltage, high external quantum efficiency, and/or long lifespan.
The highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, singlet (Si) energy level, and triplet (T1) energy level of selected organometallic compounds represented by Formula 1 were calculated using a density functional theory (DFT) method of the Gaussian 09 program with the molecular structure optimized at the B3LYP level, and results thereof are shown in Table 1. The energy levels are expressed in electron volts (eV).
From Table 1, it was confirmed that the organometallic compound represented by Formula 1 has such electric characteristics that are suitable for use as a dopant for an electronic device, for example, an organic light-emitting device.
In one or more embodiments, the maximum emission wavelength (emission peak wavelength maximum, λmax) of the emission peak of the emission spectrum or electroluminescence (EL) spectrum of the organometallic compound represented by Formula 1 may be about 490 nanometers (nm) to about 550 nm, about 500 nm to about 540 nm, or about 510 nm to about 530 nm.
Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art and by referring to Synthesis Examples provided below.
The organometallic compound represented by Formula 1 may be suitable for use in an organic layer of an organic light-emitting device, for example, for use as a dopant in an emission layer of the organic layer. Therefore, according to one or more embodiments, an organic light-emitting device includes a first electrode; a second electrode; and an organic layer that is disposed between the first electrode and the second electrode, wherein the emission layer includes an organic layer, and wherein the organic layer further includes an emission layer comprising at least one organometallic compound represented by Formula 1.
The organic light-emitting device may have an excellent driving voltage, excellent maximum external quantum efficiency, and excellent lifespan characteristics by including an organic layer including at least one of the organometallic compounds represented by Formula 1 as described above.
The organometallic compound represented by Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound represented by Formula 1 may serve as a dopant, and the emission layer may further include a host. When the emission layer further includes a host, the amount of the host in the emission layer may be greater than an amount of the at least one organometallic compound represented by Formula 1 in the emission layer, on a weight basis.
In one or more embodiments, the emission layer may emit a green light. For example, the emission layer may emit a green light having a maximum emission wavelength of about 490 nm to about 550 nm, about 500 nm to about 540 nm, or about 510 nm to about 530 nm.
The expression “(an organic layer) includes at least one organometallic compound” as used herein may be interpreted as “(an organic layer) may include one organometallic compound represented by Formula 1 or at least two different organometallic compounds represented by Formula 1”.
For example, the organic layer may include, as the at least one organometallic compound represented by Formula 1, only Compound 1. In this regard, Compound 1 may be included in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the at least one organometallic compound represented by Formula 1, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may exist in the same layer (for example, both Compound 1 and Compound 2 may exist in an emission layer).
The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode, or the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.
For example, in the organic light-emitting device, the first electrode may be an anode, the second electrode may be a cathode, the organic layer may further include a hole transport region disposed between the first electrode and the emission layer, and an electron transport region disposed between the emission layer and the second electrode, wherein the hole transport region may include a hole injection layer (HIL), a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer (EIL), or a combination thereof.
The term “organic layer” as used herein refers to a single layer and/or a plurality of layers disposed between the first electrode and the second electrode of the organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including a metal, or the like.
The FIGURE is a schematic cross-sectional view of an organic light-emitting device 10 according to one or more embodiments. Hereinafter, the structure and manufacturing method of the organic light-emitting device 10 according to one or more embodiments will be described with reference to the FIGURE. The organic light-emitting device 10 may have a structure in which a first electrode 11, an organic layer 15, and a second electrode 19 are sequentially stacked in the stated order.
A substrate may be further disposed under the first electrode 11 or on the second electrode 19. The substrate may be a substrate used in general organic light-emitting devices, e.g., 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 formed by, for example, 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 one or more 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 at least two 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 disposed 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 disposed between the first electrode 11 and the emission layer.
The hole transport region may include an 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 an hole injection layer or a hole transport layer. In one or more embodiments, the hole transport region may be a hole injection layer/hole transport layer structure or a hole injection layer/hole transport layer/electron blocking layer structure, in which respective layers of each structure are sequentially stacked in the 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 various 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 depending on a compound that is used as a material for forming the hole injection layer, and the structure and thermal characteristics of an hole injection layer to be formed, and may include a deposition temperature of about 100° C. to about 500° C., a vacuum degree 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 compound that is used as a material for forming the hole injection layer, and the structure and thermal characteristics of the hole injection layer, and 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 of 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 referred to the description provided for the conditions for forming the hole injection layer.
The hole transport region may include, for example, 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), β-NPB, N,N′-bis(3-methylph enyl)-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, but are not limited to, at least one of Compounds HT1 to HT20:
The thickness of the hole transport region may be about 100 angstroms (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 an hole injection layer and a hole transport layer, the thickness of the hole injection layer may be about 50 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and the 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. 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 the above-described materials, a charge-generation material for improving conductivity. 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, such as 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, such as a tungsten oxide, a molybdenum oxide, or the like; or a cyano group-containing compound, such as Compounds HT-D1 or F12, but embodiments are not limited thereto:
The hole transport region may further include a buffer layer.
The buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, thus increasing efficiency.
An emission layer (EML) 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 generally 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.
In some embodiments, when the hole transport region includes an electron blocking layer, a material for forming the electron blocking layer may be selected from, but is not limited to, the above-described materials that may be used in the hole transport region and a host material described below. 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 described below.
The emission layer may include a host and a dopant, and the dopant may include at least one of the organometallic compounds 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 one or more embodiments, the host may include a compound represented by Formula 301, but embodiments are not limited thereto:
wherein Ar111 and Ar112 in Formula 301 may each independently be:
Ar113 to Ar116 in Formula 301 may each independently be:
Ar113 to Ar116 in Formula 301 may each independently be:
In Formula 301, g, h, i, and j may each independently be an integer from 0 to 4, and may be, for example, g, h, i, and j may each independently be 0, 1, or 2.
In one or more embodiments, the host may include a compound represented by Formula 302:
Ar122 to Ar125 in Formula 302 may each be defined the same as 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).
In Formula 302, k and l may each independently be an integer from 0 to 4. For example, k and l may each independently be 0, 1, or 2.
When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In one or more embodiments, the emission layer may have a structure in which a red emission layer, a green emission layer, and/or a blue emission layer are stacked, and thus, various modifications such as emission of white light are possible.
When the emission layer includes a host and a dopant, the amount of the dopant in the emission layer generally may be about 0.01 parts by weight to about 15 parts by weight, with respect to about 100 parts by weight of the host in the emission layer, but embodiments are not limited thereto.
The thickness of the emission layer may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
Next, 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, a 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, and 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 referred to the description provided for 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:
The 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. 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 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 one or more embodiments, the electron transport layer may include at least one of ET1 to ET25, but embodiments are not limited thereto:
The 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. When the thickness of the electron transport layer is within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may further include a metal-containing material, in addition to the material as described above.
The metal-containing material may include a L1 complex. The L1 complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2:
The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 19.
The electron injection layer may include LiF, NaCl, CsF, Li2O, BaO, or a combination thereof.
The thickness of the electron injection layer may be about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 may be disposed 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, an 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 one or more embodiments, to manufacture a top-emission type light-emitting device, various modifications, such as formation of a transmissive second electrode using ITO or IZO, is possible.
The organic light-emitting device has been described with reference to the FIGURE, but embodiments are not limited thereto.
According to one or more embodiments, a diagnostic composition includes at least one organometallic compound represented by Formula 1.
The organometallic compound represented by Formula 1 may provide high luminous efficiency, and thus, a diagnostic composition including at least one of the organometallic compounds represented by Formula 1 may have high diagnostic efficiency.
The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, a biomarker, or the like, but embodiments are not limited thereto.
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, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, a hexyl group, or the like. The term “C1-C60 alkylene group” as used herein refers to a divalent group having the same structure as the C1-C60 alkyl group.
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), and non-limiting examples thereof include a methoxy group, an ethoxy group, an isopropyloxy 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 structure containing at least one carbon-carbon double bond in the middle or at the end 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 group containing at least one carbon-carbon triple bond in the middle or at the end 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 ring group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, or the like. The term “C3-C10 cycloalkylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as used herein refers to a monovalent ring group having at least one heteroatom selected from B, N, O, P, Si, S, Se, or Ge as a ring-forming atom and 1 to 10 carbon atoms as ring-forming atoms(s), and non-limiting examples thereof include a tetrahydrofuranyl group, a tetrahydrothiophenyl group, or the like. The term “C1-C10 heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein refers to a monovalent ring group that has 3 to 10 carbon atoms, and at least one carbon-carbon double bond in the ring thereof and has 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 ring group that has at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom, 1 to 10 carbon atoms as ring-forming atom(s), and at least one double bond in the ring thereof. 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 “C1-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 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 with 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 having at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge 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 system that contains at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as a ring-forming atom and has 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 with 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 the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein indicates —SA103 (wherein A103 is the C6-C60 aryl group).
The term “C1-C60 heteroaryloxy group” as used herein indicates —OA104 (wherein A104 is the 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 with 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.
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, a heteroatom selected from B, N, O, P, Si, S, Se, and Ge 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.
The term “C5-C30 carbocyclic group” as used herein refers to a saturated or unsaturated ring group having, as a ring-forming atom, 5 to 30 carbon atoms only. The C5-C30 carbocyclic group may be a monocyclic group or a polycyclic group.
The term “C1-C30 heterocyclic group” as used herein refers to a saturated or unsaturated ring group having 1 to 30 carbon atoms as ring-forming atom(s) and at least one heteroatom selected from B, N, O, P, Si, S, Se, and Ge as ring-forming atoms. The C1-C30 heterocyclic group may be a monocyclic group or a polycyclic group.
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 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:
For example, 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 C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C1-C60 alkylthio group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C7-C60 alkyl aryl group, a C7-C60 aryl alkyl group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C1-C60 heteroaryl group, a C2-C60 alkyl heteroaryl group, a C2-C60 heteroaryl alkyl group, a C1-C60 heteroaryloxy group, a C1-C60 heteroarylthio group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with at least one of deuterium, a C1-C60 alkyl group, a C3-C10 cycloalkyl group, a C6-C60 aryl group, or a combination thereof.
Hereinafter, organometallic compounds represented by Formula 1 and organic light-emitting devices including the same, according to one or more exemplary embodiments, will be described in further detail with reference to Synthesis Example and Examples. However, the following examples are not intended to limit the scope of the disclosure. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of A used was identical to an amount of B used, in terms of a molar equivalent.
3.0 grams (g) (8.46 millimoles (mmol)) of 1-(2,6-diisopropylphenyl)-2-phenyl-1H-benzo[d]imidazole and 1.42 g (4.03 mmol) of iridium chloride trihydrate were mixed with 90 milliliters (mL) of 2-ethoxyethanol and 30 mL of deionized (DI) water, followed by stirring while heating at reflux for 24 hours. The temperature was then lowered to room temperature. The generated solid was separated by filtration, and washed sufficiently with water, methanol, and hexane in the stated order to obtain a solid. The obtained solid was dried in a vacuum oven to thereby obtain 3.1 g (yield of 82%) of Compound 1A.
3.1 g (1.66 mmol) of Compound 1A and 120 mL of dichloromethane were combined. A separate solution of 0.9 g (3.52 mmol) of silver trifluoromethanesulfonate (AgOTf) was prepared with 40 mL of methanol, and the separate solution was added to the solution of Compound 1A. Then, the resultant mixture was stirred for 18 hours at room temperature while blocking light with aluminum foil. The mixture was filtered through Celite to remove the generated solid, and the solvent was removed under a reduced pressure to obtain a solid (Compound 1B), which was used in the next reaction without any further purification.
2.7 g (2.43 mmol) of Compound 1B and 1.31 g (2.43 mmol) of 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole were mixed with 25 mL of 2-ethoxyethanol and 25 mL of dimethylformamide, followed by stirring at 120° C. for 24 hours. Then, the temperature was lowered to room temperature. The solvent was removed from the resultant mixture under a reduced pressure to obtain a solid, which was purified by column chromatography (eluents: hexane and ethyl acetate), to thereby obtain 1.01 g (yield of 29%) of Compound 1. The obtained compound was identified by high resolution mass spectrometry using matrix assisted laser desorption ionization (HRMS (MALDI)) and high-performance liquid chromatography (HPLC) analysis.
HRMS (MALDI) calculated for C88H80D3IrN6O: m/z 1435.6446; found: 1435.6443.
0.97 g (yield of 27%) of Compound 5 was obtained in a similar manner as in Synthesis Example 1, except that 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-(phenyl-d5)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole was used instead of 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C93H80D5IrN6O: m/z 1499.6728; found: 1499.6726.
0.94 g (yield of 28%) of Compound 11 was obtained in a similar manner as in Synthesis Example 1, except that 1-(2,6-diisopropylphenyl)-2-(7-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole was used instead of 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C82H76D3IrN6O: m/z 1359.6133; found: 1359.6135.
0.89 g (yield of 27%) of Compound 13 was obtained in a similar manner as in Synthesis Example 1, except that 1-(2,6-diisopropylphenyl)-2-(6-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole was used instead of 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-(methyl-d3)dibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C82H76D3IrN6O: m/z 1359.6133; found: 1359.6131.
As an anode, an ITO-patterned glass substrate was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated in isopropyl alcohol and DI water for 5 minutes each, cleaned by irradiation of ultraviolet rays and exposure to ozone for 30 minutes, and then mounted on a vacuum deposition apparatus.
Compounds HT3 and F12-P-Dopant were vacuum co-deposited in a weight ratio of 98:2 on the anode to form a hole injection layer having a thickness of 100 Å, and Compound HT3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,650 Å.
Then, Compound GH3 (host) and Compound 1 (dopant) were co-deposited in a weight ratio of 92:8 on the hole transport layer to form an emission layer having a thickness of 400 Å.
Next, Compound ET3 and Liq-N-Dopant were co-deposited in a volume ratio of 50:50 on the emission layer to form an electron transport layer having a thickness of 350 Å, Liq-N-Dopant was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, 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.
Organic light-emitting devices were manufactured in a similar manner as in Example 1, except that, in forming the emission layer, the compounds shown in Table 2 were used instead of Compound 4.
The driving voltage (Volts, V), maximum external quantum efficiency (Max EQE, %), maximum emission wavelength (nm), and lifespan (LT97, %) of each of the organic light-emitting devices of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated, and the results thereof are shown in Table 2. As evaluation apparatuses, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used. Lifespan (LT97) (at 6000 candela per square meter, cd/m2) was evaluated as the time taken for luminance to reach 97% relative to 100% of the initial luminance, and the lifespan value was expressed as a value relative to Comparative Example 1.
From Table 2, it was confirmed that each of the organic light-emitting devices of Examples 1 to 4 has a low driving voltage, an increased maximum external quantum efficiency, and a long lifespan.
From Table 2, it was confirmed that the organic light-emitting devices of Examples 1 to 4 have similar or lower driving voltages, similar or higher maximum external quantum efficiencies, and improved lifespans, compared to the organic light-emitting devices of Comparative Examples 1 to 3.
According to one or more exemplary embodiments, an organometallic compound represented by Formula (1) has excellent electrical characteristics, and thus, an electronic device, e.g., an organic light-emitting device, including at least one of the organometallic compounds represented by Formula (1) may have a low driving voltage, a maximum external quantum efficiency, and a long lifespan. Thus, by using the organometallic compound represented by Formula (1), a high-quality organic light-emitting device may be realized.
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 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 |
|---|---|---|---|
| 10-2023-0150291 | Nov 2023 | KR | national |
