Patent Application
20240327441
This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0039251, filed on Mar. 24, 2023, and 10-2023-0065232, filed on May 19, 2023, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the entire contents of which are incorporated by reference herein.
The present subject matter relates 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, which have improved characteristics in terms of viewing angles, response time, luminance, driving voltage, and response speed. OLEDs also produce full-color images.
In an example, an organic light-emitting device includes an anode, a cathode, and an organic layer that is arranged between the anode and the cathode, wherein the organic layer includes 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 recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thereby generating light.
Provided are 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 described 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, 1B, and 2,
According to another 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, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one of the organometallic compounds 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 act as a dopant.
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 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. 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. 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.
An aspect provides an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein M1 in Formula 1 is a transition metal.
In one or more embodiments, 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), osmium (Os), palladium (Pd), gold (Au), 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.
In Formula 1, L1 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.
In Formula 1A, ring CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, ring CY1 and ring CY2 may each independently be i) a first ring, ii) a second ring, iii) a condensed ring group wherein two or more first rings are condensed with each other, iv) a condensed ring group wherein two or more second rings are condensed with each other, or v) a condensed ring group wherein one or more first rings are condensed with one or more second rings, wherein the first ring may be a cyclopentane group, a cyclopentadiene group, a furan group, a thiophene group, a pyrrole group, a silole group, an indene group, a benzofuran group, a benzothiophene group, an indole group, a benzosilole group, an oxazole group, an isoxazole group, an oxadiazole group, an isoxadiazole group, an oxatriazole group, an isoxatriazole group, a thiazole group, an isothiazole group, a thiadiazole group, an isothiadiazole group, a thiatriazole group, an isothiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, an azasilole group, a diazasilole group, or a triazasilole group, and the second ring may be an adamantane group, a norbornane group, a norbornene group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.
In one or more embodiments, ring CY1 and ring CY2 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, ring CY1 may be a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group, and ring CY2 may be a benzene group or a naphthalene group.
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)-16:
wherein, in Formulae CY(1)-1 to CY(1)-16,
R11 to R14 may each independently be as described in connection with R1, provided that R11 to R14 are not hydrogen,
For example, in Formulae CY(1)-1 to CY(1)-16, R11 to R14 may be a C1-C10 alkyl group substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like).
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,
For example, in Formulae CY(2)-1 to CY(2)-16, R21 to R24 may be a C1-C10 alkyl group substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like).
In Formula 1, L2 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.
In Formula 1B, ring CY3 is (i) a 6-membered carbocyclic group, (ii) a 6-membered heterocyclic group, (iii) a 6-membered carbocyclic group condensed with a C5-C30 carbocyclic group or a 6-membered carbocyclic group condensed with a C1-C30 heterocyclic group, or (iv) a 6-membered heterocyclic group condensed with a C5-C30 carbocyclic group or a 6-membered heterocyclic group condensed with a C1-C30 heterocyclic group.
In one or more embodiments, ring CY3 may be i) a second ring, ii) a condensed ring group wherein two or more second rings are condensed with each other, or iii) a condensed ring group wherein one or more first rings are condensed with one or more second rings,
In one or more embodiments, ring CY3 may be a pyridine group, a pyrimidine group, a pyrazine group, a triazine group, a quinoline group, or an isoquinoline group.
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)-16:
wherein, in Formulae CY(3)-1 to CY(3)-16,
For example, in Formulae CY(3)-1 to CY(3)-16, R31 to R34 may each independently be:
In Formula 1B, X41 is C(R41) or N, X42 is C(R42) or N, X43 is C(R43) or N, X44 is C(R44) or N, X45 is C(R45) or N, X46 is C(R46) or N, X47 is C(R47) or N, and X48 is C(R48) or N, with the proviso that i) X45 is C(R45) and X46 is C(R46), wherein R45 and R46 are bonded together to form a group represented by Formula 2, ii) X46 is C(R46) and X47 is C(R47), wherein R46 and R47 are bonded together to form a group represented by Formula 2, or iii) X47 is C(R47) and X48 is C(R48), wherein R47 and R48 are bonded together to form a group represented by Formula 2:
Ring CY4 in Formula 1B and ring CY5 in Formula 2 are condensed with each other.
In Formula 2, indicates a single bond or a double bond.
In Formula 1B, Y1 is O, S, Se, C(R61) (R62), or N(R63).
In Formula 2, Y2 is O, S, Se, C(R64) (R65), or N(R66).
In one or more embodiments, Y1 and Y2 may be identical to each other.
In one or more embodiments, Y1 and Y2 may be different from each other.
In one or more embodiments, Y1 and Y2 may each independently be O or S. In one or more embodiments, Y1 and Y2 may each be O. In one or more embodiments, Y1 may be O and Y2 may be S. In one or more embodiments, Y1 and Y2 may each be S. In one or more embodiments, Y1 may be S and Y2 may be O.
In Formula 2, X51 is C(R51) or N, X52 is C(R52) or N, Xss is C(R53) or N, and X54 is C(R54) or N.
In one or more embodiments, L2 may be a ligand represented by one of Formulae 1B-1 to 1B-6:
wherein, in Formulae 1B-1 to 1B-6,
In one or more embodiments, L2 may be a ligand represented by one of Formulae 1B(1)-6 to 1B(1)-6:
wherein, in Formulae 1B(1)-1 to 1B(1)-6,
In one or more embodiments, in Formulae 1B(1)-1 to 1B(1)-6, X31 may be C(R31), X32 may be C(R32), X33 may be C(R33), and X34 may be C(R34), wherein R31 to R34 may each independently be:
In Formulae 1A, 1B, and 2, R1 to R3, R41 to R48, R51 to R54, and R61 to R66 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-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, 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 R3, R41 to R48, R51 to R54, and R61 to R66 may each independently be:
In one or more embodiments, R1 to R3, R41 to R48, R51 to R54, and R61 to R66 may each independently be:
wherein, 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 an adjacent atom, “Ph” represents a phenyl group, “TMS” represents a trimethylsilyl group, and “TMG” represents a trimethylgermyl group.
In one or more embodiments, in Formula 1A, at least one of R1 or R2 may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like). In one or more embodiments, in Formula 1A, at least one of R1 or R2 may be a C1-C10 alkyl group substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like).
For example, i) one or two of R1 in Formula 1A may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium, ii) one of R2 in Formula 1A may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium, or iii) one of R1 and one of R2 in Formula 1A may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium. For example, i) one or two of R1 in Formula 1A may be a C1-C10 alkyl group substituted with at least one deuterium, ii) one of R2 in Formula 1A may be a C1-C10 alkyl group substituted with at least one deuterium, or iii) one of R1 and one of R2 in Formula 1A may be a C1-C10 alkyl group substituted with at least one deuterium.
Neighboring two or more of R1 in Formula 1A are optionally bonded together to form a substituted or unsubstituted C5-C30 carbocyclic group or a substituted or unsubstituted C1-C30 heterocyclic group,
In Formulae 1A and 1B, * and *′ each indicate a binding site to M1 in Formula 1.
In one or more embodiments, the organometallic compound may be represented by at least one of Formulae 5-1 to 5-6:
wherein, in Formulae 5-1 to 5-6,
In one or more embodiments, in Formulae 5-1 to 5-6, at least one of R1 to R14 and R21 to R24 may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like). In one or more embodiments, in Formulae 5-1 to 5-6, at least one of R11 to R14 and R21 to R24 may be a C1-C10 alkyl group substituted with at least one deuterium (e.g., —CD3, —CD2H, —CDH2, or the like).
For example, i) one or two of R11 to R14 may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium, ii) one of R21 to R24 may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium, or iii) one of R11 to R14 and one of R21 to R24 may be a C1-C10 alkyl group unsubstituted or substituted with at least one deuterium. For example, i) one or two of R11 to R14 may be a C1-C10 alkyl group substituted with at least one deuterium, ii) one of R21 to R24 may be a C1-C10 alkyl group substituted with at least one deuterium, or iii) one of R1 to R14 and one of R21 to R24 may be a C1-C10 alkyl group substituted with at least one deuterium.
In one or more embodiments, the organometallic compound may be represented by at least one of Compounds 1 to 50:
In one or more embodiments, the organometallic compound may be electrically neutral.
The organometallic compound represented by Formula 1 satisfies the aforementioned structure of Formula 1 and includes a ligand having the structure represented by Formula 1B. Due to this structure, the organometallic compound represented by Formula 1 has excellent luminescence characteristics, and thus may have characteristics suitable for use as a luminescent material with high color purity by controlling the emission wavelength range.
In addition, the organometallic compound represented by Formula 1 has excellent electrical mobility, 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, high efficiency, and long lifespan.
A highest occupied molecular orbital (HOMO) energy level, a lowest unoccupied molecular orbital (LUMO) energy level, a singlet (S1) energy level, and a triplet (T1) energy level of some compounds of the organometallic compound 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).
1
6
11
From Table 1, it was confirmed that the organometallic compound represented by Formula 1 has electrical characteristics suitable for use as a dopant for an electronic device, e.g., an organic light-emitting device.
In one or more embodiments, emission peaks of an emission spectrum or an electroluminescence spectrum of the organometallic compound may have a maximum emission wavelength (emission peak wavelength, Amax) of about 490 nanometers (nm) to about 550 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 herein.
The organometallic compound represented by Formula 1 is 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. Thus, another aspect provides an organic light-emitting device that includes a first electrode; a second electrode; and an organic layer that is arranged 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.
The organic light-emitting device may have, by including at least one of the aforementioned organometallic compounds represented by Formula 1, excellent driving voltage, excellent maximum external quantum efficiency, and excellent lifespan characteristics.
The organometallic compound represented by Formula 1 may be used between a pair of electrodes of the organic light-emitting device. For example, at least one of the organometallic compounds represented by Formula 1 may be included in the emission layer. Here, the organometallic compound may serve as a dopant, and the emission layer may further include a host. When the emission layer further includes a host, 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 represented by Formula 1 in the emission layer.
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.
The expression “(an organic layer) includes at least one of organometallic compounds represented by Formula 1” as used herein may include a case in which “(an organic layer) includes identical organometallic compounds represented by Formula 1” and a case in which “(an organic layer) includes two or more 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 embodiment, 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. Here, Compound 1 and Compound 2 may exist in an identical layer (for example, Compound 1 and Compound 2 all 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.
In one or more embodiments, in the organic light-emitting device, the first electrode may be an anode, the second electrode may be a cathode, and the organic layer may further include a hole transport region arranged between the first electrode and the emission layer; and an electron transport region arranged between the emission layer and the second electrode, wherein 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, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
The term “organic layer” as used herein refers to a single layer and/or a plurality of layers arranged 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.
The
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, 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 (AI), 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-layer structure or a multi-layer structure including a plurality of layers. For example, the first electrode 11 may have a three-layer structure of ITO/Ag/ITO, but embodiments are not limited thereto.
The organic layer 15 may be arranged on the first electrode 11.
The organic layer 15 may include a hole transport region, an emission layer, an electron transport region, or a combination thereof.
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 one or more 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 the constituent layers 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 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 a 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 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 a spin coating method, coating conditions may vary depending on a compound used as a material for forming the hole injection layer, a structure and thermal characteristics of the desired hole injection layer, and the like. For example, a coating rate may be about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be about 80° C. to about 200° C., but embodiments 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 at least one of m-MTDATA, TDATA, 2-TNATA, NPB, B-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, 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, and a compound represented by Formula 202:
In Formula 201, Ar101 and Ar102 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:
In Formula 201, R109 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:
wherein, in Formula 201A, R101, R109, R111, and R112 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 HT20, but embodiments are not limited thereto:
A thickness of the hole transport region 140 may be about 100 angstroms (Å) to about 5,000 Å, for example, about 160 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or a combination thereof, a thickness of the hole injection layer may be about 50 Å to about 9,000 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. For example, 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 one of Compounds HT-D1, F12, or the like, but embodiments are not limited thereto:
The hole transport region may 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 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, but embodiments are not limited thereto. 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 herein 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 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, in Formula 301, Ar111 and Ar112 may each independently be:
In Formula 301, Ar113 to Ar116 may each independently be:
In Formula 301, Ar113 to Ar116 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, 0, 1, or 2.
In one or more embodiments, the host may include a compound represented by Formula 302:
wherein, in Formula 302, Ar122 to Ar125 may be as described herein in connection with Ar113 in Formula 301.
In Formula 302, Ar126 and Ar127 may each independently be a C1-C10 alkyl group (e.g., a methyl group, an ethyl group, a propyl group, or the like).
In Formula 302, k and i 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 one or more 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.
When the emission layer includes a host and a dopant, an amount of the dopant in the emission layer may be about 0.01 parts by weight to about 15 parts by weight, based on 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. Without wishing to be bound to theory, when the thickness of the emission layer is within these ranges, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
An electron transport region may be arranged 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, 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 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-N1,08)-(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 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-N1,08)-(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:
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 these ranges, satisfactory electron transporting characteristics may be obtained 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, Compound ET-D1 (lithium quinolate, 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 these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 may be arranged on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be 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 (AI), 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, 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 with reference to the FIGURE, but embodiments are not limited thereto.
Another aspect provides a diagnostic composition including at least one organometallic compound represented by Formula 1.
The organometallic compound represented by Formula 1 provides high luminescent efficiency. Accordingly, 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 isoamyl 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 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 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, an adamantanyl group, a norbornanyl 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, and Ge as a ring-forming atom and 1 to 10 carbon atoms as ring-forming atoms, 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 having 3 to 10 carbon atoms, 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, a norbornenyl 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 having 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 atoms, and at least one double bond in the ring structure 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 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 cyclic 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 atoms, and the term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a carbocyclic aromatic ring system having at least one heteroatom selected from B, N, O, P, Si, S, Se, an Ge as a ring-forming atom and 1 to 60 carbon atoms as ring-forming atoms. 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 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 to each other, only carbon atoms as ring-forming atoms, and no aromaticity in the 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, 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 the entire molecular structure thereof. 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 as described herein.
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, as a ring-forming atom, at least one heteroatom selected from B, N, O, Si, P, S, Se, and Ge other than 1 to 30 carbon atoms 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 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:
For example, Q1 to Q9, Q11 to Q19, Q21 to Q29, and Q31 to Q39 may each independently be:
Hereinafter, an organometallic compound represented by Formula 1 and an organic light-emitting device according to exemplary embodiments are described in further detail with reference to Synthesis Examples and Examples. However, embodiments are not limited thereto. 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.
5-(methyl-d3)-2-phenylpyridine (5.50 grams (g), 31.93 millimoles (mmol)) and iridium chloride trihydrate (5.00 g, 14.18 mmol) were mixed with 150 milliliters (mL) of ethoxyethanol and 50 mL of deionized (DI) water. After the mixed solution was stirred and heated under reflux for 24 hours, the reaction temperature was lowered to room temperature. Solids produced therefrom were separated by filtration and thoroughly washed with water/methanol/hexane in the stated order, and the resultant solid product was dried in a vacuum oven to obtain 7.35 g (yield of 81%) of Compound 6A(1).
Compound 6A(1) (1.70 g, 1.49 mmol) was mixed with 75 mL of methylene chloride, and a mixture of silver trifluoromethanesulfonate (AgOTf) (0.80 g, 3.11 mmol) and 25 mL of methanol was added thereto. Then, after stirring the mixed solution at room temperature for 18 hours under the condition where light was blocked with aluminum foil, solids thus produced were removed by Celite filtration, and the solid (Compound 6A) obtained by removing solvent from the filtrate was then used in the next reaction without further purification.
Under a nitrogen environment, 2-chloro-4-(methyl-d3)pyridine (1.00 g, 7.66 mmol) and 2-(benzo[4′,5′]furo[2′,3′:5,6]naphtho[1,2-b]benzofuran-6-yl)-4,4,5,5-tetramethyl-1,3,2-dioxoborolane (3.66 g, 8.42 mmol) were dissolved in 165 mL of 1,4-dioxane, and a mixture in which potassium carbonate (K2CO3) (2.43 g, 17.58 mmol) was dissolved in 55 mL of DI water was added to the reaction mixture. A palladium catalyst (tetrakis(triphenylphosphine)palladium(0), Pd(PPh3)4) (0.44 g, 0.38 mmol) was then also added thereto. Then, the resultant reaction mixture was stirred and heated under reflux at 100° C. After an extraction process was performed thereon, the solids thus obtained were purified by column chromatography (eluents: ethyl acetate (EA) and n-hexane) to obtain 2.35 g of Compound 6B (yield of 76%). 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 C28H14D3NO2: m/z: 402.47; found: 403.39.
Compound 6A (1.8 g, 2.41 mmol) and Compound 6B (1.12 g, 2.78 mmol) were mixed with 16 mL of 2-ethoxyethanol and 16 mL of N,N-dimethylformamide, and the mixed solution was stirred and heated under reflux for 24 hours. Then, the reaction temperature was lowered to room temperature. The solid obtained by removing the solvent from the resultant mixture under a reduced pressure was purified by column chromatography (eluents: MC and n-hexane) to obtain 1.05 g of Compound 6 (yield of 40%). The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C52H27DgIrN3O2: m/z: 936.15; found: 937.03.
1.15 g (yield of 43%) of Compound 7 was obtained by using a similar method as in the synthesis of compound 6, except that, in the synthesis of compound 6B, 2-chloro-4-(propan-2-yl-2-d)pyridine (1.00 g, 6.38 mmol) was used instead of 2-chloro-4-(methyl-d3)pyridine. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C54H33D7IrN3O2: m/z: 962.19; found: 963.08.
1.03 g (yield of 39%) of Compound 12 was obtained by using a similar method as in the synthesis of compound 7, except that, In the synthesis of compound 6A(1), 4,5-bis(methyl-d3)-2-phenylpyridine (6.04 g, 31.90 mmol) was used instead of 5-(methyl-d3)-2-phenylpyridine. The obtained compound was identified by HRMS (MALDI) and HPLC analysis. HRMS (MALDI) calculated for C56H31D13IrN3O2: m/z: 996.28; found: 997.15.
1.06 g (yield of 40%) of Compound 17 was obtained by using a similar method as in the synthesis of compound 7, except that, In the synthesis of compound 6A(1), 5-(methyl-d3)-2-(4-(methyl-d3)phenyl)pyridine (6.04g, 31.90 mmol) was used instead of 5-(methyl-d3)-2-phenylpyridine. The obtained compound was identified by HRMS (MALDI) and HPLC analysis. HRMS (MALDI) calculated for C56H31D13IrN3O2: m/z: 996.28; found: 996.98.
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 DI water, each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.
Compound HT3 and F12-P-dopant were vacuum-deposited in a weight ratio of 98:2 on the anode to form a hole injection layer having a thickness of 100 A, and Compound HT3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,650 Å.
Subsequently, Compound GH3 (host) and Compound 6 (dopant) were co-deposited on the hole transport layer in a weight ratio of 92:8 to form an emission layer having a thickness of 400 Å.
Then, Compound ET3 and Liq-N-dopant were co-deposited on the emission layer in a volume ratio of 50:50 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 1000 Å, thereby completing the manufacture of an organic light-emitting device. The structures of HT3, F12-P-dopant, GH3, ETL, and Liq-N-dopant as provided below.
Organic light-emitting devices were manufactured in a similar manner as in Example 1, except that compounds shown in Table 2 were each used instead of Compound 6 in forming an emission layer.
Evaluation Example 1: Characterization of organic light-emitting devices (OLEDs)
For the OLEDs of Examples 1 to 4 and Comparative Examples 1 and 2, driving voltage (Volts, V), maximum external quantum efficiency (Max EQE, %), maximum emission wavelength (nm), and lifespan (LT97, relative %) were evaluated, and the results are shown in Table 2. As evaluation apparatuses, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used. The lifespan (LT97)(at 6,000 nit) was evaluated for the time required to reach 97% of initial luminance, and the lifespan value was expressed as a relative value with respect to Comparative Example 1.
6
7
12
17
CE1
CE2
Referring to Table 2, it was confirmed that the organic light-emitting devices of Examples 1 to 4 had characteristics of a low driving voltage, increased maximum external quantum efficiency, and a long lifespan.
Referring to Table 2, it was confirmed that the organic light-emitting devices of Examples 1 to 4 had a lower driving voltage, higher maximum external quantum efficiency, and an improved lifespan, compared to the organic light-emitting devices of Comparative Examples 1 and 2.
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, high maximum external quantum efficiency, and long lifespan characteristics. Thus, due to the use of the organometallic compounds represented by Formula 1 in an organic layer, a high-quality organic light-emitting device may be embodied.
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 |
|---|---|---|---|
| 10-2023-0039251 | Mar 2023 | KR | national |
| 10-2023-0065232 | May 2023 | KR | national |
