Organometallic compounds and organic light emitting diode comprising the same

Abstract

The present invention provides a novel organometallic compound represented by Chemical Formula 1, and by including it in the dopant material of the phosphorescent light-emitting layer of an organic light-emitting device, the performance of the organic light-emitting device, such as driving voltage, luminous efficiency, and lifespan, can be improved, and at the same time, the red-shift phenomenon can be suppressed. [Chemical Formula 1]

Description

Technology Field

[0001] The present invention relates to organometallic compounds, and more specifically, to organometallic compounds having phosphorescent properties and organic light-emitting diodes containing the same. Background Technology

[0003] Interest in display devices is growing as they are applied in various fields. As one of these display devices, the technology of organic light-emitting display devices, including organic light-emitting diodes (OLEDs), is developing rapidly.

[0004] Organic light-emitting diodes (OLEDs) are devices that emit light by injecting charges into a light-emitting layer formed between an anode and a cathode, causing electrons and holes to pair up to form excitons. Compared to conventional display technologies, OLEDs offer several advantages, including low-voltage operation, relatively low power consumption, and excellent color reproduction. Furthermore, they allow for the application of flexible substrates, enabling diverse applications and the ability to freely adjust the size of the display device. The problem to be solved

[0006] Organic light-emitting diodes (OLEDs) have superior viewing angles and contrast ratios compared to liquid crystal displays (LCDs), and because they do not require a backlight, they can be lightweight and ultra-thin. An organic light-emitting diode is formed by arranging a plurality of organic layers, such as a hole injection layer, a hole transport layer, a hole transport assist layer, an electron blocking layer, a light-emitting layer, and an electron transport layer, between a cathode (electron injection electrode) and an anode (hole injection electrode).

[0007] In this organic light-emitting diode structure, when a voltage is applied between the two electrodes, electrons and holes are injected from the cathode and anode, respectively, and excitons generated in the light-emitting layer fall to the ground state and emit light.

[0008] Organic materials used in organic light-emitting diodes (OLEDs) can be broadly classified into light-emitting materials and charge transport materials. Light-emitting materials are a critical factor in determining the luminous efficiency of OLEDs; they must possess high quantum efficiency, excellent electron and hole mobility, and exist uniformly and stably within the light-emitting layer. Light-emitting materials are classified into blue, red, and green types based on the color of the emitted light, and they are used as hosts or dopants to increase color purity and enhance luminous efficiency through energy transfer.

[0009] Recently, there has been a trend of using phosphorescent materials more than fluorescent materials in the emissive layer. This is because, in the case of fluorescent materials, only about 25% of the singlets among the excitons formed in the emissive layer are used to produce light, and 75% of the triplets are mostly lost as heat, whereas phosphorescent materials have a light emission mechanism that converts both singlets and triplets into light.

[0010] Conventionally, organometallic compounds have been used as phosphorescent materials in organic light-emitting diodes, and there is a continuous demand for research and development of phosphorescent materials to solve the problems of their low efficiency and lifespan.

[0011] Accordingly, the objective of the present invention is to provide an organometallic compound capable of improving driving voltage, efficiency, and lifespan, and an organic light-emitting diode in which the same is applied to an organic light-emitting layer.

[0013] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0015] In order to solve the above problem, according to one embodiment of the present invention, an organometallic compound having a novel structure represented by the following chemical formula 1, an organic light-emitting element including the same as a light-emitting layer dopant, and an organic light-emitting display device including the organic light-emitting element may be provided.

[0016] [Chemical Formula 1]

[0017] In the above chemical formula 1,

[0018] X can be one selected from the group consisting of O, S and Se;

[0019] X1, X2, and X3 are each independently N or CR a It could be;

[0020] R1, R2 and R3 can each independently represent a single substitution, a two-substitution, a three-substitution, a four-substitution, or no substitution;

[0021] R5, R 6, R 7, R a Each can independently represent a single substitution, a two-substitution, a three-substitution, or a non-substitution;

[0022] R4 and R8 can each independently represent a single substitution, a heterosubstitution, or a nonsubstitution;

[0023] R1, R2, R3, R4, R 7, R8 and R a Each can be independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0024] R5 and R6 can each be independently selected from the group consisting of halides, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0025] n can be 0, 1, or 2.

[0027] According to another aspect of the present invention, an organic light-emitting device may be provided comprising: a first electrode; a second electrode facing the first electrode; and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, the light-emitting layer comprises a dopant material, and the dopant material comprises an organometallic compound according to the above aspect of the present invention.

[0029] According to another aspect of the present invention, an organic light-emitting display device may be provided, comprising: a substrate; a driving element located on the substrate; and an organic light-emitting element according to the other aspect of the present invention, which is located on the substrate and connected to the driving element. Effects of the invention

[0031] By applying the organometallic compound according to the present invention to the phosphorescent light-emitting layer dopant of an organic light-emitting diode, the driving voltage, efficiency, and lifespan characteristics of the organic light-emitting diode can be improved, and at the same time, an excellent effect of suppressing the red-shift phenomenon can be achieved.

[0033] The effects of this specification are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0035] FIG. 1 is a cross-sectional view schematically illustrating an organic light-emitting device in which an organometallic compound according to an exemplary embodiment of the present invention is applied to a light-emitting layer. FIG. 2 is a cross-sectional view schematically illustrating an organic light-emitting diode having a tandem structure with two light-emitting parts according to an exemplary embodiment of the present invention, and comprising an organometallic compound represented by Formula 1 of the present invention. FIG. 3 is a cross-sectional view schematically illustrating an organic light-emitting diode having a tandem structure with three light-emitting parts according to an exemplary embodiment of the present invention, and comprising an organometallic compound represented by Formula 1 of the present invention. FIG. 4 is a cross-sectional view schematically illustrating an organic light-emitting display device to which an organic light-emitting element according to an exemplary embodiment of the present invention is applied. Specific details for implementing the invention

[0036] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0037] In describing this specification, specific descriptions of related prior art are omitted if it is determined that such descriptions would unnecessarily obscure the gist of this specification.

[0038] Where terms such as 'includes,' 'has,' 'consists of,' or 'arranges' are used for components below, other parts may be added unless 'only' is used. Where a component is expressed in the singular, it includes cases where it is in the plural unless specifically stated otherwise.

[0039] In interpreting the components below, they shall be interpreted to include a margin of error even without separate explicit notation.

[0040] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0042] Hereinafter, the structure and preparation examples of an organometallic compound according to the present invention and an organic light-emitting diode containing the same will be described.

[0044] Conventionally, organometallic compounds have been used as dopants for phosphorescent light-emitting layers, and for example, structures such as 2-phenylpyridine, 2-phenylquinoline, and 2-pyridine benzofuropyridine are known as main ligand structures of organometallic compounds. However, these conventional light-emitting dopants have limitations in improving the efficiency and lifespan of organic light-emitting devices, so it was necessary to develop novel light-emitting dopant materials. Accordingly, the inventors sought to derive a light-emitting dopant material capable of further improving the efficiency and lifespan of organic light-emitting devices.

[0046] As a result of the inventors' research, they confirmed that the objective of the present invention was achieved by using an organometallic compound represented by the following chemical formula 1 as a phosphorescent light-emitting dopant material, and completed the present invention.

[0047] [Chemical Formula 1]

[0048] In the above chemical formula 1,

[0049] X can be one selected from the group consisting of O, S and Se;

[0050] X1, X2, and X3 are each independently N or CR a It could be;

[0051] R1, R2 and R3 can each independently represent a single substitution, a two-substitution, a three-substitution, a four-substitution, or no substitution;

[0052] R5, R 6, R 7, R a Each can independently represent a single substitution, a two-substitution, a three-substitution, or a non-substitution;

[0053] R4 and R8 can each independently represent a single substitution, a heterosubstitution, or a nonsubstitution;

[0054] R1, R2, R3, R4, R 7, R8 and R a Each can be independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0055] R5 and R6 are each independently selected from the group consisting of halides, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0056] n can be 0, 1, or 2.

[0058] In particular, as can be seen in the main ligand structure of Chemical Formula 1 above, by increasing the long-short axis ratio of the carbon (C) connected ring portion among the two rings connected to the central coordination metal Ir (iridium), it was possible to increase the device performance, including the luminous efficiency, of an organic light-emitting diode using the organometallic compound of Chemical Formula 1 as a phosphorescent light-emitting dopant. The long-short axis ratio refers to the ratio of the long axis length of the optimized target material to the short axis length perpendicular thereto, calculated through B3LYP / LANL2DZ (6-31g,d) in the Gaussian16 program. In this case, the long axis length refers to the length of the longest part of the material with the central coordination metal Ir as the axis.

[0060] According to an exemplary embodiment of the present invention, in Formula 1, R5 and R6 may each be independently selected from the group consisting of a C1-C6 straight-chain alkyl group single-substituted with a deuterium or halogen element; a branched-chain alkyl group single-substituted with a deuterium or halogen element; and a cycloalkyl group single-substituted with a deuterium or halogen element.

[0062] For example, an organometallic compound was derived by combining a ‘bulky 6-membered aromatic ring structure having a substituent (excluding hydrogen)’ with a ‘benzofuropyridine group’ in which X of Chemical Formula 1 of the present invention is O (oxygen). In this way, the present invention was completed by experimentally confirming the excellent effect of increasing the luminous efficiency and lifespan of the organic light-emitting diode and lowering the driving voltage when the organometallic compound represented by Chemical Formula 1 is included in the dopant material of the phosphorescent light-emitting layer of the organic light-emitting diode.

[0063] Specifically, it was confirmed that the organometallic compound structure of Formula 1 of the present invention can i) increase the long-short axis ratio compared to conventional compounds that do not have an aromatic ring structure in the 'benzofuropyridine group', thereby improving the efficiency of an organic light-emitting diode using the organometallic compound of Formula 1 of the present invention, ii) increase the lifespan of the organic light-emitting diode using the organometallic compound of Formula 1 of the present invention as the stability of the main ligand structure is also increased, and iii) simultaneously exhibit excellent effects such as suppressing the red shift phenomenon of the organic light-emitting diode using the organometallic compound of Formula 1 of the present invention.

[0064] More specifically, when controlling an organic light-emitting diode using an organometallic compound, such as an iridium complex which is a phosphorescent light-emitting dopant, to improve efficiency and lifespan, it was common for the desired wavelength of emission to become somewhat longer. However, as can be seen in Table 1 below, the organometallic compound of Formula 1 of the present invention maintains the desired wavelength of emission (e.g., at the level of 520 nm to 540 nm in the case of a green phosphorescent light-emitting layer) and does not lengthen the wavelength of emission, thus having significant technical significance in that the efficiency and lifespan of organic light emission are improved while the color change phenomenon is suppressed.

[0066] As will be described in more detail below in the specific embodiments of the present invention and the performance evaluation of the organic light-emitting diode, the long-short axis ratio of ‘Ref 1’ and ‘Ref 3’, which are organometallic compounds according to one embodiment of the present invention, and ‘Target Comp.’, which falls under the definition of Chemical Formula 1 of the present invention, were applied as dopant materials to the organic light-emitting diode, and in order to accurately compare the long-short axis ratios, the auxiliary ligand portions were all applied identically.

[0067] The method of fabricating the organic light-emitting diode is the same as in <Example 1>, except that the dopant materials used are 'Ref 1', 'Ref 3', and 'Target Comp.' instead of Compound 1, and the measurement method for EQE and LT95 of the organic light-emitting diode is the same as the method described in <Performance Evaluation of Organic Light-Emitting Diode> below, and the results are shown in Table 1 below.

[0068] The 'long-short axis ratio' was measured and calculated by dividing the ratio of the long axis length of the material, optimized through the calculation of B3LYP / LANL2DZ (6-31g,d) in the Gaussian 16 program, by the short axis length perpendicular to it. In addition, as a result of measuring the emission wavelength of organic light-emitting diodes using 'Ref 3' and 'Target Comp.', it was confirmed that when using 'Ref 3', the wavelength increased by about 10–15 nm compared to when using 'Target Comp.', and both efficiency and characteristics were inferior.

[0070] dopant Long-short axis ratio EQE LT95 Ref 1 1.28 100 % 100 % Ref 3 1.61 110 % 127 % Target Comp. 1.61 127 % 151 %

[0072] The structures of Ref 1, Ref 3 and Compound 1 in Table 1 above are as follows.

[0073] Ref 1 :

[0074] Ref 3 :

[0075] Target Comp. :

[0077] In an embodiment of the present invention, an organometallic compound may have a bidentate ligand applied as an auxiliary ligand in addition to the main ligand described above to iridium, which is the central coordination metal, and may have a 2-phenylpyridine structure as shown in Formula 1 above, and R1 or R2 may be a single substitution, a disubstituted, a trisubstituted, a tetrasubstituted, or an unsubstituted.

[0079] An organometallic compound according to one embodiment of the present invention may have a homoleptic or heteroleptic structure, for example, a homoleptic structure in which n is 0 in Formula 1; a heteroleptic structure in which n is 1; or a heteroleptic structure in which n is 2.

[0081] According to one embodiment of the present invention, a specific example of the compound represented by Formula 1 of the present invention may be one selected from the group consisting of the following compounds 1 to 564, but is not necessarily limited to compounds 1 to 564 as long as it falls within the definition of Formula 1 of the present invention, such as the 'Target Comp.' above.

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0091] According to one embodiment of the present invention, the organometallic compound represented by Formula 1 of the present invention can be used as a red phosphorescent material or a green phosphorescent material, and preferably as a green phosphorescent material.

[0093] Referring to FIG. 1 according to one embodiment of the present invention, an organic light-emitting element (100) may be provided, comprising: a first electrode (110); a second electrode (120) facing the first electrode (110); and an organic layer (130) disposed between the first electrode (110) and the second electrode (120). The organic layer (130) comprises a light-emitting layer (160), the light-emitting layer (160) comprises a host (160') and a dopant (160"), and the dopant (160") may comprise an organometallic compound represented by Chemical Formula 1. Additionally, in the organic light-emitting diode (100), the organic layer (130) disposed between the first electrode (110) and the second electrode (120) may have a structure comprising, sequentially from the first electrode (110), a hole injection layer (140, hole injection layer; HIL), a hole transport layer (150, hole transfer layer; HTL), an emission material layer (160, emission material layer, EML), an electron transport layer (170, electron transfer layer; ETL), and an electron injection layer (180, electron injection layer, EIL). The second electrode (120) may be formed on the electron injection layer (180), and a protective film (not shown) may be formed thereon.

[0095] Additionally, although not illustrated in FIG. 1, a hole transport auxiliary layer may be further added between the hole transport layer (150) and the light-emitting layer (160). The hole transport auxiliary layer includes a compound with good hole transport characteristics and controls the hole injection characteristics by reducing the HOMO energy level difference between the hole transport layer (150) and the light-emitting layer (160), thereby reducing the accumulation of holes at the interface between the hole transport auxiliary layer and the light-emitting layer (160) and reducing the quenching phenomenon in which excitons are extinguished by polarons at the interface. Accordingly, the degradation of the device is reduced and the device is stabilized, thereby improving efficiency and lifespan.

[0097] The first electrode (110) may be an anode and may be made of a conductive material such as ITO, IZO, tin oxide, or zinc oxide, which has a relatively large work function value, but is not limited thereto.

[0098] The second electrode (120) may be a negative electrode and may include a conductive material such as Al, Mg, Ca, Ag, or an alloy or combination thereof that has a relatively low work function value, but is not limited thereto.

[0100] The hole injection layer (140) may be located between the first electrode (110) and the hole transport layer (150). The hole injection layer (140) has the function of improving the interface characteristics between the first electrode (110) and the hole transport layer (150) and may be selected from a material having appropriate conductivity. The hole injection layer (140) may include compounds such as MTDATA, CuPc, TCTA, HATCN, TDAPB, PEDOT / PSS, N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine), and preferably may include N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine), but is not limited thereto.

[0102] The hole transport layer (150) is located adjacent to the light-emitting layer between the first electrode (110) and the light-emitting layer (160). The hole transport layer (150) may include compounds such as TPD, NPB, CBP, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)biphenyl)-4-amine, and preferably may include NPB, but is not limited thereto.

[0104] According to the present invention, the light-emitting layer (160) may be formed by doping an organometallic compound represented by Formula 1 as a dopant (160) to improve the light-emitting efficiency of the host (160') and the device, and the dopant (160) may be used as a material that emits green or red light, and preferably as a green phosphorescent material.

[0105] The doping concentration of the dopant (160) of the present invention can be controlled within a range of 1 to 30 weight% based on the total weight of the host (160'), and is not limited thereto, for example, the doping concentration may be 2 to 20 weight%, for example, 3 to 15 weight%, for example, 5 to 10 weight%, for example, 3 to 8 weight%, for example, 2 to 7 weight%, for example, 5 to 7 weight%, for example, 5 to 6 weight%.

[0107] The light-emitting layer (160) of the present invention may include an organometallic compound represented by Chemical Formula 1 in the dopant (160") material, and may use a host (160') material used in the art field that can achieve the effects of the present invention. For example, in the present invention, a compound containing a carbazole group may be used as the host (160'), and preferably may include host materials such as CBP (carbazole biphenyl) and mCP (1,3-bis(carbazol-9-yl), but is not limited thereto.

[0109] Additionally, an electron transport layer (170) and an electron injection layer (180) may be sequentially stacked between the light-emitting layer (160) and the second electrode (120). The material of the electron transport layer (170) requires high electron mobility, and electrons can be stably supplied to the light-emitting layer through smooth electron transport.

[0111] For example, the material of the electron transport layer (170) is one used in the art, for example, Alq3 (tris(8-hydroxyquinolino)aluminum), Liq (8-hydroxyquinolinolatolithium), PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), TAZ (3-(4-biphenyl)4-phenyl-5-tert-butylphenyl-1,2,4-triazole), spiro-PBD, BAlq (bis(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminum), SAlq, TPBi (2,2',2-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole), oxadiazole, triazole, phenanthroline, benzoxazole, It may include compounds such as benzthiazole, 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, and preferably 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, but is not limited thereto.

[0113] The electron injection layer (180) serves to facilitate the injection of electrons, and the material of the electron injection layer is one used in the field of technology and may include, for example, compounds such as Alq3 (tris(8-hydroxyquinolino)aluminum), PBD, TAZ, spiro-PBD, BAlq, SAlq, but is not limited thereto. Alternatively, the electron injection layer (180) may be made of a metal compound, and the metal compound may include, for example, Liq, LiF, NaF, KF, RbF, CsF, FrF, BeF2, MgF2, CaF2, SrF2, BaF2, RaF2, but is not limited thereto.

[0114] The organic light-emitting device of the present invention may be a white organic light-emitting device having a tandem structure. In the case of a tandem organic light-emitting device according to one embodiment of the present invention, a single light-emitting stack (or light-emitting part) may be formed in a structure in which two or more are connected by a charge generation layer (CGL). The organic light-emitting device may include two or more plural light-emitting stacks (light-emitting parts) having a first electrode and a second electrode facing each other on a substrate, and a light-emitting layer stacked between the first and second electrodes that emits light of a specific wavelength range. The plural light-emitting stacks (light-emitting parts) may be applied to emit the same color or different colors. In addition, one light-emitting stack (light-emitting part) may also include one or more light-emitting layers, and the plural light-emitting layers may be light-emitting layers of the same or different colors.

[0115] At this time, one or more of the light-emitting layers included in the plurality of light-emitting parts may include an organometallic compound represented by Formula 1 according to the present invention as a dopant material. The plurality of light-emitting parts in the tandem structure may be connected to a charge generation layer (CGL) composed of an N-type charge generation layer and a P-type charge generation layer.

[0116] FIGS. 2 and FIGS. 3, exemplary embodiments of the present invention, are schematic cross-sectional views illustrating an organic light-emitting diode with a tandem structure having two light-emitting parts and three light-emitting parts, respectively.

[0117] As illustrated in FIG. 2, the organic light-emitting device (100) of the present invention comprises a first electrode (110) and a second electrode (120) facing each other, and an organic layer (230) located between the first electrode (110) and the second electrode (120). The organic layer (230) comprises a first light-emitting part (ST1) located between the first electrode (110) and the second electrode (120) and including a first light-emitting layer (261), a second light-emitting part (ST2) located between the first light-emitting part (ST1) and the second electrode (120) and including a second light-emitting layer (262), and a charge-generating layer (CGL) located between the first and second light-emitting parts (ST1 and ST2). The charge-generating layer (CGL) may include an N-type charge-generating layer (291) and a P-type charge-generating layer (292). One or more of the first light-emitting layer (261) and the second light-emitting layer (262) may include an organometallic compound represented by Formula 1 according to the present invention as a dopant. For example, as shown in FIG. 2, an organometallic compound represented by Formula 1 may be included as a dopant (262") together with the host (262') of the second light-emitting layer (262) of the second light-emitting part (ST2). Although not shown in FIG. 2, each of the first and second light-emitting parts (ST1 and ST2) may further include an additional light-emitting layer in addition to the first light-emitting layer (261) and the second light-emitting layer (262).

[0119] As illustrated in FIG. 3, the organic light-emitting element (100) of the present invention comprises a first electrode (110) and a second electrode (120) facing each other, and an organic layer (330) located between the first electrode (110) and the second electrode (120). The organic layer (330) includes a first light-emitting part (ST1) located between the first electrode (110) and the second electrode (120) and comprising a first light-emitting layer (261); a second light-emitting part (ST2) comprising a second light-emitting layer (262); a third light-emitting part (ST3) comprising a third light-emitting layer (263); a first charge-generating layer (CGL1) located between the first and second light-emitting parts (ST1 and ST2); and a second charge-generating layer (CGL2) located between the second and third light-emitting parts (ST2 and ST3). The first and second charge generating layers (CGL1 and CGL2) may each include an N-type charge generating layer (291, 293) and a P-type charge generating layer (292, 294). One or more of the first light-emitting layer (261), the second light-emitting layer (262), and the third light-emitting layer (263) may include an organometallic compound represented by Formula 1 according to the present invention as a dopant. For example, as illustrated in FIG. 3, an organometallic compound represented by Formula 1 may be included as a dopant (262") together with the host (262') of the second light-emitting layer (262) of the second light-emitting part (ST2). Although not illustrated in FIG. 3, each of the first, second, and third light-emitting parts (ST1, ST2, and ST3) may be formed with a plurality of light-emitting layers by including additional light-emitting layers in addition to the first light-emitting layer (261), the second light-emitting layer (262), and the third light-emitting layer (263).

[0121] Furthermore, an organic light-emitting device according to one embodiment of the present invention may include a tandem structure in which four or more light-emitting parts and three or more charge-generating layers are disposed between a first electrode and a second electrode.

[0123] The organic light-emitting element according to the present invention can be utilized in organic light-emitting display devices and lighting devices to which the organic light-emitting element is applied. In one embodiment, FIG. 4 is a cross-sectional view schematically illustrating an organic light-emitting display device to which an organic light-emitting element according to an exemplary embodiment of the present invention is applied.

[0124] As illustrated in FIG. 4, the organic light-emitting display device (3000) may include a substrate (3010), an organic light-emitting element (4000), and an encapsulation film (3900) covering the organic light-emitting element (4000). On the substrate (3010), a driving thin-film transistor (Td), which is a driving element, and an organic light-emitting element (4000) connected to the driving thin-film transistor (Td) are positioned.

[0125] Although not explicitly shown in FIG. 4, on the substrate (3010), gate wiring and data wiring that intersect each other to define pixel regions, power wiring that extends spaced apart parallel to either of the gate wiring and data wiring, switching thin-film transistors connected to the gate wiring and data wiring, and storage capacitors connected to one electrode of the power wiring and switching thin-film transistors are further formed.

[0126] The driving thin-film transistor (Td) is connected to the switching thin-film transistor and includes a semiconductor layer (3100), a gate electrode (3300), a source electrode (3520), and a drain electrode (3540).

[0127] The semiconductor layer (3100) is formed on the substrate (3010) and may be made of an oxide semiconductor material or polycrystalline silicon. If the semiconductor layer (3100) is made of an oxide semiconductor material, a light-blocking pattern (not shown) may be formed on the lower part of the semiconductor layer (3100), and the light-blocking pattern prevents light from being incident on the semiconductor layer (3100) to prevent the semiconductor layer (3100) from deteriorating due to light. Alternatively, the semiconductor layer (3100) may be made of polycrystalline silicon, in which case impurities may be doped on both edges of the semiconductor layer (3100).

[0128] A gate insulating film (3200) made of an insulating material is formed on the front surface of the substrate (3010) on the upper side of the semiconductor layer (3100). The gate insulating film (3200) may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

[0129] A gate electrode (3300) made of a conductive material such as metal is formed on the upper part of the gate insulating film (3200) in correspondence with the center of the semiconductor layer (3100). The gate electrode (3300) is connected to a switching thin-film transistor.

[0130] An interlayer insulating film (3400) made of an insulating material is formed on the front surface of the substrate (3010) above the gate electrode (3300). The interlayer insulating film (3400) may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or of an organic insulating material such as benzocyclobutene or photoacryl.

[0131] The interlayer insulating film (3400) has first and second semiconductor layer contact holes (3420, 3440) that expose both sides of the semiconductor layer (3100). The first and second semiconductor layer contact holes (3420, 3440) are located on both sides of the gate electrode (3300) and spaced apart from the gate electrode (3300).

[0132] A source electrode (3520) and a drain electrode (3540) made of a conductive material such as metal are formed on the interlayer insulating film (3400). The source electrode (3520) and the drain electrode (3540) are spaced apart from the gate electrode (3300) and contact both sides of the semiconductor layer (3100) through the first and second semiconductor layer contact holes (3420, 3440), respectively. The source electrode (3520) is connected to a power wire (not shown).

[0133] A semiconductor layer (3100), a gate electrode (3300), a source electrode (3520), and a drain electrode (3540) form a driving thin-film transistor (Td), and the driving thin-film transistor (Td) has a coplanar structure in which the gate electrode (3300), the source electrode (3520), and the drain electrode (3540) are located on the upper part of the semiconductor layer (3100).

[0134] In contrast, the driving thin-film transistor (Td) may have an inverted staggered structure in which the gate electrode is located at the bottom of the semiconductor layer and the source and drain electrodes are located at the top of the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon. Meanwhile, the switching thin-film transistor (not shown) may have a structure substantially identical to that of the driving thin-film transistor (Td).

[0135] Meanwhile, the organic light-emitting display device (3000) may include a color filter (3600) that absorbs light generated from an organic light-emitting element (4000). For example, the color filter (3600) may absorb red (R), green (G), blue (B), and white (W) light. In this case, the red, green, and blue color filter patterns that absorb light may be formed separately for each pixel area, and each of these color filter patterns may be arranged to overlap with the organic layer (4300) in the organic light-emitting element (4000) that emits light of the wavelength band to be absorbed. By adopting the color filter (3600), the organic light-emitting display device (3000) can achieve full color.

[0136] For example, if the organic light-emitting display device (3000) is of the bottom-emission type, a color filter (3600) that absorbs light may be located on the upper part of the interlayer insulating film (3400) corresponding to the organic light-emitting element (4000). In an exemplary embodiment, if the organic light-emitting display device (3000) is of the top-emission type, the color filter may be located on the upper part of the organic light-emitting element (4000), that is, on the upper part of the second electrode (4200). For example, the color filter (3600) may be formed with a thickness of 2 to 5 μm.

[0137] Meanwhile, a protective layer (3700) having a drain contact hole (3720) that exposes the drain electrode (3540) of the driving thin-film transistor (Td) is formed to cover the driving thin-film transistor (Td).

[0138] On the protective layer (3700), a first electrode (4100) connected to the drain electrode (3540) of the driving thin-film transistor (Td) through the drain contact hole (3720) is formed separately for each pixel area.

[0139] The first electrode (4100) may be an anode and may be made of a conductive material having a relatively large work function value. For example, the first electrode (4100) may be made of a transparent conductive material such as ITO, IZO, or ZnO.

[0140] Meanwhile, if the organic light-emitting display device (3000) is of the top-emission type, a reflective electrode or reflective layer may be further formed below the first electrode (4100). For example, the reflective electrode or reflective layer may be made of any one of aluminum (Al), silver (Ag), nickel (Ni), or aluminum-palladium-copper (APC) alloy.

[0141] A bank layer (3800) covering the edge of the first electrode (4100) is formed on the protective layer (3700). The bank layer (3800) exposes the center of the first electrode (4100) corresponding to the pixel area.

[0142] An organic layer (4300) is formed on the first electrode (4100), and if necessary, the organic light-emitting element (4000) may have a tandem structure, and for the tandem structure, refer to FIGS. 2 to 4 showing exemplary embodiments of the present invention and the above description thereof.

[0143] A second electrode (4200) is formed on the upper surface of a substrate (3010) on which an organic layer (4300) is formed. The second electrode (4200) is located on the front surface of the display area and is made of a conductive material with a relatively small work function value and can be used as a cathode. For example, the second electrode (4200) can be made of any one of aluminum (Al), magnesium (Mg), or an aluminum-magnesium alloy (Al-Mg).

[0144] The first electrode (4100), the organic layer (4300), and the second electrode (4200) form an organic light-emitting element (4000).

[0145] On the second electrode (4200), an encapsulation film (3900) is formed to prevent external moisture from penetrating into the organic light-emitting diode (4000). Although not explicitly shown in FIG. 4, the encapsulation film (3900) may have a triple-layer structure in which a first inorganic layer, an organic layer, and an inorganic layer are sequentially stacked, but is not limited thereto.

[0147] The following describes manufacturing examples and embodiments of the present invention. However, the following embodiments are merely examples of the present invention and are not limited thereto.

[0149] Preparation Example - Preparation of Ligand

[0150] (1) Preparation of ligand A

[0151] Step 1) Preparation of Ligand A-3

[0152]

[0153] A solution of SM_A (9.50 g, 25 mmol) and sodium ethoxide (3.39 g, 50 mmol) in DMSO-d6 (100 ml) was refluxed for 60 hours. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. After solvent evaporation, the residue was purified by column chromatography over silica gel using 40-50% hexane in dichloromethane, yielding 7.38 g (77%) of the desired compound A-3.

[0154] Step 2) Preparation of Ligand A-2

[0155]

[0156] A-3 (7.30 g, 19 mmol), 3-bromo-6-chloropyridin-2-amine (3.94 g, 19 mmol), sodium carbonate (4.03 g, 38 mmol), and Pd(PPh3)4 (0.46 g, 0.4 mmol) were added to tetrahydrofuran (100 ml), and the solution was refluxed and stirred for 6 hours. The crude mixture was filtered through Celite and silica gel, the solid was dissolved in dichloromethane, and the solid was precipitated while methanol was added little by little to obtain 5.98 g (82%) of the desired compound A-2.

[0157] Step 3) Preparation of Ligand A-1

[0158]

[0159] A-2 (5.95 g, 15.5 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (50 ml) and stirred for 2 hours at 0°C, after which the reaction mixture was heated to room temperature. The residue was partitioned with ethyl acetate and water, and the organic phase was isolated, washed with aqueous sodium bicarbonate and brine, and then dried under sodium sulfate. Upon evaporation of the solvent, 3.88 g (71%) of the desired compound A-1 was obtained by column chromatography on silica gel with 30% dichloromethane in hexane.

[0160] Step 4) Preparation of Ligand A

[0161]

[0162] A mixture of A-1 (3.88 g, 11 mmol), Pd2(dba)3 (0.20 g, 0.22 mmol), K3PO4 (4.67 g, 22 mmol), and (t-bu)3PBF4H (0.13 g, 0.44 mmol) in 1,4-dioxane (100 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 3.39 g (73%) of the desired compound A was obtained by column chromatography over silica gel with 30-40% dichloromethane in hexane.

[0164] (2) Preparation of ligand B

[0165] Step 1) Preparation of Ligand B-3

[0166]

[0167] A solution of SM_B (8.13 g, 25 mmol) and sodium ethoxide (3.39 g, 50 mmol) in DMSO-d6 (100 ml) was refluxed for 60 hours. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. After solvent evaporation, the residue was purified by column chromatography over silica gel using 40-50% hexane in dichloromethane, yielding 5.91 g (72%) of the desired compound B-3.

[0168] Step 2) Preparation of Ligand B-2

[0169]

[0170] B-3 (5.91 g, 18 mmol), 3-bromo-6-chloropyridin-2-amine (3.73 g, 18 mmol), sodium carbonate (3.82 g, 36 mmol), and Pd(PPh3)4 (0.46 g, 0.4 mmol) were added to tetrahydrofuran (100 ml), and the solution was refluxed and stirred for 6 hours. The crude mixture was filtered through Celite and silica gel, the solid was dissolved in dichloromethane, and the solid was precipitated while methanol was added little by little to obtain 4.91 g (83%) of the desired compound B-2.

[0171] Step 3) Preparation of Ligand B-1

[0172]

[0173] B-2 (4.91 g, 15 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (40 ml) and stirred for 2 hours at 0°C, after which the reaction mixture was heated to room temperature. The residue was partitioned with ethyl acetate and water, and the organic phase was isolated, washed with aqueous sodium bicarbonate and brine, and then dried under sodium sulfate. Upon evaporation of the solvent, 3.57 g (80%) of the desired compound B-1 was obtained by column chromatography on silica gel with 30% dichloromethane in hexane.

[0174] Step 4) Preparation of Ligand B

[0175]

[0176] A mixture of B-1 (3.57 g, 12 mmol), Pd2(dba)3 (0.22 g, 0.24 mmol), K3PO4 (5.09 g, 24 mmol) and (t-bu)3PBF4H (0.14 g, 0.48 mmol) in 1,4-dioxane (120 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 3.31 g (75%) of the desired compound B was obtained by column chromatography over silica gel with 30-40% dichloromethane in hexane.

[0178] (3) Preparation of ligand C

[0179] Step 1) Preparation of Ligand C-3

[0180]

[0181] A solution of SM_C (8.48 g, 25 mmol) and sodium ethoxide (3.39 g, 50 mmol) in DMSO-d6 (100 ml) was refluxed for 60 hours. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. After solvent evaporation, the residue was purified by column chromatography over silica gel using 40-50% hexane in dichloromethane, yielding 6.39 g (74%) of the desired compound C-3.

[0182] Step 2) Preparation of Ligand C-2

[0183]

[0184] C-3 (6.39 g, 18.5 mmol), 3-bromo-6-chloropyridin-2-amine (3.83 g, 18.5 mmol), sodium carbonate (3.32 g, 37 mmol), and Pd(PPh3)4 (0.46 g, 0.4 mmol) were added to tetrahydrofuran (100 ml), and the solution was refluxed and stirred for 6 hours. The crude mixture was filtered through Celite and silica gel, the solid was dissolved in dichloromethane, and the solid was precipitated while methanol was added little by little to obtain 5.05 g (79%) of the desired compound C-2.

[0185] Step 3) Preparation of Ligand C-1

[0186]

[0187] C-2 (5.05 g, 14.6 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (40 ml) and stirred for 2 hours at 0°C, after which the reaction mixture was heated to room temperature. The residue was partitioned with ethyl acetate and water, and the organic phase was isolated, washed with aqueous sodium bicarbonate and brine, and then dried under sodium sulfate. Upon evaporation of the solvent, 3.81 g (83%) of the desired compound C-1 was obtained by column chromatography on silica gel with 30% dichloromethane in hexane.

[0188] Step 4) Preparation of Ligand C

[0189]

[0190] A mixture of C-1 (3.81 g, 12.1 mmol), Pd2(dba)3 (0.22 g, 0.24 mmol), K3PO4 (5.09 g, 24 mmol) and (t-bu)3PBF4H (0.14 g, 0.48 mmol) in 1,4-dioxane (120 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 3.16 g (68%) of the desired compound C was obtained by column chromatography over silica gel with 30-40% dichloromethane in hexane.

[0192] (4) Preparation of ligand D

[0193]

[0194] A mixture of A-1 (5.79 g, 16.4 mmol), Pd2(dba)3 (0.30 g, 0.33 mmol), K3PO4 (7.01 g, 33 mmol) and (t-bu)3PBF4H (0.20 g, 0.67 mmol) in 1,4-dioxane (100 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 5.40 g (66%) of the desired compound D was obtained by column chromatography over silica gel with 20-30% dichloromethane in hexane.

[0196] (5) Preparation of ligand E

[0197]

[0198] A mixture of B-1 (5.48 g, 18.4 mmol), Pd2(dba)3 (0.34 g, 0.37 mmol), K3PO4 (7.85 g, 37 mmol) and (t-bu)3PBF4H (0.22 g, 0.75 mmol) in 1,4-dioxane (150 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 6.28 g (77%) of the desired compound E was obtained by column chromatography over silica gel with 25-30% dichloromethane in hexane.

[0200] (6) Preparation of ligand F

[0201] Step 1) Preparation of Ligand F-3

[0202]

[0203] SM_A (11.44 g, 30 mmol), 3-bromo-6-chloropyridin-2-amine (6.22 g, 30 mmol), sodium carbonate (6.36 g, 60 mmol), and Pd(PPh3)4 (0.69 g, 0.6 mmol) were added to tetrahydrofuran (150 ml), and the solution was refluxed and stirred for 6 hours. The crude mixture was filtered through Celite and silica gel, the solid was dissolved in dichloromethane, and the solid was precipitated while methanol was added little by little to obtain 9.74 g (85%) of the desired compound F-3.

[0204] Step 2) Preparation of Ligand F-2

[0205]

[0206] F-3 (9.74 g, 25.5 mmol) was added to acetic acid (120 ml) and tetrahydrofuran (60 ml) and stirred for 2 hours at 0°C, after which the reaction mixture was heated to room temperature. The residue was partitioned with ethyl acetate and water, and the organic phase was isolated, washed with aqueous sodium bicarbonate and brine, and then dried under sodium sulfate. Upon evaporation of the solvent, 6.26 g (70%) of the desired compound F-2 was obtained by column chromatography on silica gel with 30% dichloromethane in hexane.

[0207] Step 3) Preparation of Ligand F-1

[0208]

[0209] A mixture of A-1 (6.26 g, 17.8 mmol), Pd2(dba)3 (0.33 g, 0.36 mmol), K3PO4 (7.64 g, 36 mmol) and (t-bu)3PBF4H (0.21 g, 0.72 mmol) in 1,4-dioxane (120 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 5.17 g (69%) of the desired compound F-1 was obtained by column chromatography over silica gel with 30-40% dichloromethane in hexane.

[0210] Step 4) Preparation of Ligand F

[0211]

[0212] A solution of F-1 (5.05 g, 12 mmol) and sodium ethoxide (4.07 g, 60 mmol) in DMSO-d6 (120 ml) was refluxed for 60 hours. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. After solvent evaporation, the residue was purified by column chromatography over silica gel using 40-50% hexane in dichloromethane, yielding 3.65 g (71%) of the desired compound F.

[0214] (7) Preparation of ligand G

[0215] Step 1) Preparation of ligand G-3

[0216]

[0217] SM_B (9.76 g, 30 mmol), 3-bromo-6-chloropyridin-2-amine (6.22 g, 30 mmol), sodium carbonate (6.36 g, 60 mmol), and Pd(PPh3)4 (0.69 g, 0.6 mmol) were added to tetrahydrofuran (150 ml), and the solution was refluxed and stirred for 6 hours. The crude mixture was filtered through Celite and silica gel, the solid was dissolved in dichloromethane, and the solid was precipitated while methanol was added little by little to obtain 7.82 g (80%) of the desired compound F-3.

[0218] Step 2) Preparation of Ligand G-2

[0219]

[0220] G-3 (7.82 g, 24 mmol) was added in acetic acid (120 ml) and tetrahydrofuran (60 ml) and stirred for 2 hours at 0°C, after which the reaction mixture was heated to room temperature. The residue was partitioned with ethyl acetate and water, and the organic phase was isolated, washed with aqueous sodium bicarbonate and brine, and then dried under sodium sulfate. Upon evaporation of the solvent, 5.23 g (74%) of the desired compound G-2 was obtained by column chromatography on silica gel with 30% dichloromethane in hexane.

[0221] Step 3) Preparation of ligand G-1

[0222]

[0223] A mixture of A-1 (5.01 g, 17 mmol), Pd2(dba)3 (0.31 g, 0.34 mmol), K3PO4 (7.22 g, 34 mmol) and (t-bu)3PBF4H (0.20 g, 0.69 mmol) in 1,4-dioxane (120 ml) was refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. Subsequently, 4.46 g (72%) of the desired compound G-1 was obtained by column chromatography over silica gel with 30-40% dichloromethane in hexane.

[0224] Step 4) Preparation of Ligand G

[0225]

[0226] A solution of G-1 (4.37 g, 12 mmol) and sodium ethoxide (4.07 g, 60 mmol) in DMSO-d6 (120 ml) was refluxed for 60 hours. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was isolated, dried over sodium sulfate, and evaporated. After solvent evaporation, the residue was purified by column chromatography over silica gel using 40–50% hexane in dichloromethane, yielding 3.27 g (73%) of the desired compound G.

[0228] (8) Preparation of ligand H'

[0229] Step 1) Preparation of ligand HH

[0230]

[0231] A solution of H (6.77 g, 40 mmol) and IrCl3 (4.78 g, 16 mmol) in ethoxyethanol (100 ml) and distilled water (30 ml) was refluxed and stirred for 24 hours. Afterward, the temperature was lowered to room temperature, and the resulting solid was separated by vacuum filtration. The solid filtered through the filter was thoroughly washed with water and cold methanol, and the vacuum filtration process was repeated several times to obtain 8.39 g (93%) of the desired compound HH.

[0232] Step 2) Preparation of ligand H'

[0233]

[0234] A solution containing HH (6.77 g, 6 mmol) and Silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred overnight at room temperature. After the reaction was complete, the solid precipitate was removed by filtering through Celite. The filtered filtrate was subjected to vacuum filtration several times to obtain 8.46 g (95%) of the desired compound H'.

[0236] (9) Preparation of ligand I'

[0237] Step 1) Preparation of Ligand II

[0238]

[0239] A solution of I (7.89 g, 40 mmol) and IrCl3 (4.78 g, 16 mmol) in ethoxyethanol (100 ml) and distilled water (30 ml) was refluxed and stirred for 24 hours. Afterward, the temperature was lowered to room temperature, and the resulting solid was separated by vacuum filtration. The solid filtered through the filter was thoroughly washed with water and cold methanol, and the vacuum filtration process was repeated several times to obtain 8.93 g (90%) of the desired compound II.

[0240] Step 2) Preparation of Ligand I'

[0241]

[0242] A solution containing II (7.44 g, 6 mmol) and Silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred overnight at room temperature. After the reaction was complete, the solid precipitate was removed by filtering through Celite. The filtered filtrate was subjected to vacuum filtration several times to obtain 8.81 g (92%) of the desired compound I'.

[0244] (10) Preparation of ligand J'

[0245] Step 1) Preparation of Ligand JJ

[0246]

[0247] A solution of J (6.89 g, 40 mmol) and IrCl3 (4.78 g, 16 mmol) in ethoxyethanol (100 ml) and distilled water (30 ml) was refluxed and stirred for 24 hours. Afterward, the temperature was lowered to room temperature and the resulting solid was separated by vacuum filtration. The solid filtered through the filter was thoroughly washed with water and cold methanol, and the vacuum filtration process was repeated several times to obtain 8.48 g (93%) of the desired compound JJ.

[0248] Step 2) Preparation of Ligand J'

[0249]

[0250] A solution containing JJ (6.84 g, 6 mmol) and Silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred overnight at room temperature. After the reaction was complete, the solid precipitate was removed by filtering through Celite. The filtered filtrate was subjected to vacuum filtration several times to obtain 8.53 g (95%) of the desired compound J'.

[0252] (11) Preparation of ligand K'

[0253] Step 1) Preparation of ligand KK

[0254]

[0255] A solution of K (8.25 g, 40 mmol) and IrCl3 (4.78 g, 16 mmol) in ethoxyethanol (100 ml) and distilled water (30 ml) was refluxed and stirred for 24 hours. Afterward, the temperature was lowered to room temperature, and the resulting solid was separated by vacuum filtration. The solid filtered through the filter was thoroughly washed with water and cold methanol, and the vacuum filtration process was repeated several times to obtain 9.29 g (91%) of the desired compound KK.

[0256] Step 2) Preparation of ligand K'

[0257]

[0258] A solution containing KK (7.66 g, 6 mmol) and Silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred overnight at room temperature. After the reaction was complete, the solid precipitate was removed by filtering through Celite. The filtered filtrate was subjected to vacuum filtration several times to obtain 9.20 g (94%) of the desired compound K'.

[0260] Preparation Example - Preparation of Iridium Compounds

[0261] < Preparation of Iridium Compound 13 >

[0262]

[0263] A solution containing B (1.84 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 3.89 g (87%) of the desired iridium compound 13.

[0265] < Preparation of Iridium Compound 14 >

[0266]

[0267] A solution containing B (1.84 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 3.69 g (82%) of the desired iridium compound 14.

[0269] < Preparation of Iridium Compound 15 >

[0270]

[0271] A solution containing A (2.11 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 3.99 g (84%) of the desired iridium compound 15.

[0273] < Preparation of Iridium Compound 16 >

[0274]

[0275] A solution containing A (2.11 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.06 g (85%) of the desired iridium compound 16.

[0277] Preparation of Iridium Compound 17

[0278]

[0279] A solution containing B (1.84 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.00 g (84%) of the desired iridium compound 17.

[0281] < Preparation of Iridium Compound 18 >

[0282]

[0283] A solution containing B (1.84 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 3.93 g (81%) of the desired iridium compound 18.

[0285] Preparation of Iridium Compound 19

[0286]

[0287] A solution containing A (2.11 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.03 g (80%) of the desired iridium compound 19.

[0289] Preparation of Iridium Compound 20

[0290]

[0291] A solution containing A (2.11 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135 °C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.20 g (82%) of the desired iridium compound 20.

[0293] Preparation of Iridium Compound 21

[0294]

[0295] A solution containing G (1.87 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 3.69 g (82%) of the desired iridium compound 21.

[0297] Preparation of Iridium Compound 22

[0298]

[0299] A solution containing G (1.87 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 3.97 g (83%) of the desired iridium compound 22.

[0301] Preparation of Iridium Compound 23

[0302]

[0303] A solution containing F (2.14 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.11 g (86%) of the desired iridium compound 23.

[0305] < Preparation of Iridium Compound 24 >

[0306]

[0307] A solution containing F (2.14 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 3.80 g (75%) of the desired iridium compound 24.

[0309] Preparation of Iridium Compound 25

[0310]

[0311] A solution containing D (2.49 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.10 g (80%) of the desired iridium compound 25.

[0313] Preparation of Iridium Compound 26

[0314]

[0315] A solution containing D (2.49 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.34 g (84%) of the desired iridium compound 26.

[0317] Preparation of Iridium Compound 27

[0318]

[0319] A solution containing D (2.49 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.22 g (78%) of the desired iridium compound 27.

[0321] Preparation of Iridium Compound 28

[0322]

[0323] A solution containing D (2.49 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.46 g (81%) of the desired iridium compound 28.

[0325] < Preparation of Iridium Compound 29 >

[0326]

[0327] A solution containing E (2.22 g, 5 mmol) and H' (4.45 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.22 g (87%) of the desired iridium compound 29.

[0329] Preparation of Iridium Compound 30

[0330]

[0331] A solution containing E (2.22 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.20 g (86%) of the desired iridium compound 30.

[0333] Preparation of Iridium Compound 31

[0334]

[0335] A solution containing E (2.22 g, 5 mmol) and I' (4.79 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 4.11 g (80%) of the desired iridium compound 31.

[0337] Preparation of Iridium Compound 32

[0338]

[0339] A solution containing E (2.22 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.44 g (85%) of the desired iridium compound 32.

[0341] Preparation of Iridium Compound 33

[0342]

[0343] A solution containing G (1.87 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 3.63 g (80%) of the desired iridium compound 33.

[0345] Preparation of Iridium Compound 34

[0346]

[0347] A solution containing G (1.87 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.00 g (82%) of the desired iridium compound 34.

[0349] Preparation of Iridium Compound 35

[0350]

[0351] A solution containing F (2.14 g, 5 mmol) and J' (4.49 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was finished, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over a silica gel using 25% ethyl acetate in hexane, yielding 3.90 g (81%) of the desired iridium compound 35.

[0353] Preparation of Iridium Compound 36

[0354]

[0355] A solution containing F (2.14 g, 5 mmol) and K' (4.90 g, 6 mmol) in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic phase was isolated using dichloromethane and distilled water, and the water was removed by adding anhydrous magnesium sulfate. The residue obtained by filtration under reduced pressure was purified by column chromatography over silica gel using 25% ethyl acetate in hexane, yielding 4.07 g (79%) of the desired iridium compound 36.

[0357] Examples

[0358] < Example 1 >

[0359] After cleaning a glass substrate coated with a thin film of ITO (indium tin oxide) to a thickness of 1,000 Å, the substrate was ultrasonically cleaned with solvents such as isopropyl alcohol, acetone, and methanol, and then dried. On the prepared ITO transparent electrode, HI-1 was thermally vacuum deposited to a thickness of 60 nm as a hole injection material, followed by thermally vacuum depositing NPB to a thickness of 80 nm as a hole transport material. On the transport material, compound 1 was used as the dopant and CBP as the host for the emissive layer, and the layer was thermally vacuum deposited with a doping concentration of 5 wt% and a thickness of 30 nm. On the emissive layer, ET-1:Liq (1:1) (30 nm) was thermally vacuum deposited as the material for the electron transport layer and electron injection layer, and then a 100 nm thick aluminum layer was deposited to form a cathode, thereby fabricating an organic light-emitting diode that emits green light.

[0360]

[0361]

[0362] The above HI-1 refers to N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine).

[0363] The above ET-1 refers to 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole.

[0365] < Examples 2–25 and Comparative Examples 1–3 >

[0366] Organic light-emitting diodes of Examples 2 to 25 and Comparative Examples 1 to 3 were each fabricated in the same manner as in Example 1, except that the compounds shown in Tables 2 and 3 below were used instead of Compound 1 as the dopant in Example 1.

[0368] Performance Evaluation of Organic Light-Emitting Diodes >

[0369] For the organic light-emitting diodes prepared according to the above Examples 1 to 25 and Comparative Examples 1 to 3, 10 mA / cm 2 Driving voltage and efficiency characteristics when driven by current and 40mA / cm 2 The driving voltage (V), maximum luminous quantum efficiency (%), external quantum efficiency (EQE) (%), and LT95 (%) were measured by comparing lifetime characteristics accelerated under 40°C temperature conditions. The maximum luminous quantum efficiency, EQE, and LT95 were converted into relative values ​​with respect to Comparative Example 1, and the results are shown in Tables 2 and 3 below. LT95 is a lifetime evaluation method that refers to the time required for an organic light-emitting diode to lose 5% of its initial brightness. Compound

[0371] dopant Driving voltage (V) Maximum luminous efficiency (%, relative value) EQE(%, relative value) LT95(%, relative value) Comparative Example 1 Ref 1 4.36 100 100 100 Comparative Example 2 Ref 2 4.35 104 108 111 Comparative Example 3 Ref 3 4.36 108 110 127 Example 1 Compound 1 4.32 111 125 153 Example 2 Compound 13 4.35 114 130 179 Example 3 Compound 14 4.34 115 132 185 Example 4 Compound 15 4.36 116 133 183 Example 5 Compound 16 4.33 117 134 189 Example 6 Compound 17 4.34 116 134 183 Example 7 Compound 18 4.32 117 135 186 Example 8 Compound 19 4.36 118 137 188 Example 9 Compound 20 4.33 119 138 191 Example 10 Compound 21 4.32 114 132 184 Example 11 Compound 22 4.35 116 135 189 Example 12 Compound 23 4.35 116 134 189 Example 13 Compound 24 4.34 118 138 194

[0373] dopant Driving voltage (V) Maximum luminous efficiency (%, relative value) EQE(%, relative value) LT95(%, relative value) Example 14 Compound 25 4.33 115 138 177 Example 15 Compound 26 4.32 116 139 183 Example 16 Compound 27 4.32 117 141 181 Example 17 Compound 28 4.34 118 143 184 Example 18 Compound 29 4.32 112 135 173 Example 19 Compound 30 4.34 114 136 179 Example 20 Compound 31 4.35 115 139 177 Example 21 Compound 32 4.32 116 140 180 Example 22 Compound 33 4.34 115 133 191 Example 23 Compound 34 4.35 117 137 192 Example 24 Compound 35 4.32 117 135 195 Example 25 Compound 36 4.34 119 139 197

[0375] The structures of Ref 1 to Ref 3, which are the dopant materials of Comparative Examples 1 to 3 in Table 2 above, are as follows.

[0376] Ref 1 :

[0377] Ref 2 :

[0378] Ref 3 :

[0380] As can be seen from the results of Tables 2 and 3 above, the organic light-emitting diodes in which the organometallic compounds used in Examples 1 to 25 of the present invention are applied as dopants in the light-emitting layer have a lower driving voltage and improved maximum luminous efficiency, external quantum efficiency (EQE), and lifespan (LT95) compared to Comparative Examples 1 to 3.

[0382] Although the embodiments of this specification have been described in more detail with reference to the attached drawings, this specification is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of this specification. Accordingly, the embodiments disclosed in this specification are intended to explain, not limit, the technical spirit of this specification, and the scope of the technical spirit of this specification is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of this specification shall be interpreted by the claims, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of this specification. Explanation of the symbols

[0384] 100, 4000 : Organic light-emitting diode 110, 4100: First electrode 120, 4200 : Second electrode 130, 230, 330, 4300 : Organic layer 140 : Hole injection layer 150: Precision Transport Layer, 251: 1st Precision Transport Layer, 252: 2nd Precision Transport Layer, 253: 3rd Precision Transport Layer 160: Emitting layer, 261: First emitting layer, 262: Second emitting layer, 263: Third emitting layer 160', 262' : Host 160", 262" : Dopant 170: Electron transport layer, 271: First hole transport layer, 272: Second hole transport layer, 273: Third hole transport layer 180 : Electron injection layer 3000 : Organic light-emitting display 3010 : Substrate 3100 : Semiconductor layer 3200 : Gate insulating film 3300 : Gate electrode 3400 : Interlayer insulation film 3420, 3440: 1st and 2nd semiconductor layer contact holes 3520 : Source electrode 3540 : Drain electrode 3600 : Color filter 3700 : Protective layer 3720 : Drain contact hole 3800 : Bank layer 3900 : Encapsulation film

Claims

Claim 1 Organometallic compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X is one selected from the group consisting of O and S; X1, X2 and X3 are CR a and; R1 indicates non-substitution or uniform substitution; R2 indicates non-substitution, uniform substitution, or dissubstitution; R3 indicates non-substitution or uniform substitution; R7 indicates non-substitution; R a represents unsubstituted or monosubstituted; R4 and R8 represent unsubstituted; R1 and R2 are each independently selected from the group consisting of deuterium, alkyl, and combinations thereof; R3 is selected from the group consisting of deuterium, alkyl, and combinations thereof; R a is selected from the group consisting of hydrogen, deuterium, aryl, and combinations thereof; R5 and R6 are selected from the group consisting of alkyl groups, C1-C6 straight-chain alkyl groups single-substituted with deuterium, and branched-chain alkyl groups single-substituted with deuterium; and n is 2. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 In claim 1, the above X is an organometallic compound in which O (oxygen). Claim 6 In claim 1, the above X is an organometallic compound in which S (sulfur) is the organometallic compound. Claim 7 In claim 1, the compound represented by the above chemical formula 1 is an organometallic compound selected from the group consisting of the following compounds. Claim 8 An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, the light-emitting layer comprises a dopant material, and the dopant material comprises an organometallic compound according to claim 1. Claim 9 In claim 8, the above-mentioned light-emitting layer is a green phosphorescent light-emitting layer, an organic light-emitting device. Claim 10 An organic light-emitting device according to claim 8, wherein the organic layer further comprises one or more selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Claim 11 An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and a first light-emitting part and a second light-emitting part located between the first electrode and the second electrode, wherein the first light-emitting part and the second light-emitting part each comprise one or more light-emitting layers, at least one of the light-emitting layers is a green phosphorescent light-emitting layer, wherein the green phosphorescent light-emitting layer comprises a dopant material, and the dopant material comprises an organometallic compound according to claim 1. Claim 12 An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and a first light-emitting part, a second light-emitting part, and a third light-emitting part located between the first electrode and the second electrode, wherein the first light-emitting part, the second light-emitting part, and the third light-emitting part each comprise one or more light-emitting layers, and at least one of the light-emitting layers is a green phosphorescent light-emitting layer, wherein the green phosphorescent light-emitting layer comprises a dopant material, and the dopant material comprises an organometallic compound according to claim 1. Claim 13 An organic light-emitting display device comprising: a substrate; a driving element located on the substrate; and an organic light-emitting element according to any one of claims 8 to 12 located on the substrate and connected to the driving element.

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