Organometallic compound and organic light-emitting diode comprising the same

Abstract

A novel organometallic compound represented by the following chemical formula 1 is disclosed. This organometallic compound acts as a dopant for the phosphorescent light-emitting layer of an organic light-emitting diode (OLED). Consequently, the diode's operating voltage is reduced, its luminous efficiency and lifetime are improved, and red shift is suppressed: [Chemical Formula 1]#imgabs0#

Description

Technical Field

[0001] The present disclosure relates to an organometallic compound, and more particularly, to an organometallic compound having phosphorescent properties, and an organic light emitting diode and a display device including the same. Background Art

[0002] As display devices are applied to various fields, interest in display devices is increasing. One of these display devices is an organic light emitting display device including an organic light emitting diode (OLED), which is being rapidly developed.

[0003] In an organic light-emitting diode (OLED), when charge is injected into the light-emitting layer formed between the positive and negative electrodes, electrons and holes recombine in the light-emitting layer to form excitons. The energy of the excitons is converted into light. Consequently, OLEDs emit light. Compared to conventional display devices, OLEDs can operate at low voltages, consume relatively little power, exhibit excellent color, and, because flexible substrates can be applied to OLEDs, they can be used in a variety of ways. Furthermore, the size of OLEDs can be freely adjusted. Summary of the Invention

[0004] Compared to liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs) offer superior viewing angles and contrast. Because OLEDs do not require a backlight, they are lightweight and ultra-thin. OLEDs consist of multiple organic layers between a negative electrode (electron injection electrode, cathode) and a positive electrode (hole injection electrode, anode). These layers can include a hole injection layer, a hole transport layer, a hole transport-assisting layer, an electron blocking layer, a light-emitting layer, and an electron transport layer.

[0005] In this organic light-emitting diode structure, when voltage is applied to the two electrodes, electrons and holes are injected into the light-emitting layer from the negative electrode and the positive electrode, respectively, thereby generating excitons in the light-emitting layer, which then drop to the ground state to emit light.

[0006] The organic materials used in organic light-emitting diodes can be broadly divided into luminescent materials and charge transport materials. The luminescent material is a key factor in determining the luminous efficiency of organic light-emitting diodes. Luminescent materials exhibit high quantum efficiency, excellent electron and hole mobility, and are uniformly and stably present in the luminescent layer. Luminescent materials can be categorized based on the color of the light emitted, emitting blue, red, or green light. Chromogenic materials can include a host and a dopant to enhance color purity and luminous efficiency through energy transfer.

[0007] In recent years, there has been a trend toward using phosphorescent materials in light-emitting layers instead of fluorescent materials. When fluorescent materials are used, singlet states, which represent approximately 25% of the excitons generated in the light-emitting layer, contribute to light emission, while triplets, which represent the majority of the 75% of excitons generated in the light-emitting layer, are dissipated as heat. However, when phosphorescent materials are used, both singlet and triplet states contribute to light emission.

[0008] Conventionally, organometallic compounds are used as phosphorescent materials used in organic light-emitting diodes. Research and development of phosphorescent materials are constantly needed to solve the problems of low efficiency and lifespan.

[0009] Therefore, an object of the present invention is to provide an organic metal compound capable of reducing operating voltage, improving efficiency, and lifetime, and an organic light emitting diode including an organic light emitting layer containing the same.

[0010] The purpose of the present disclosure is not limited to the above-mentioned purpose. Other unmentioned purposes and advantages of the present disclosure can be understood from the following description and can be more clearly understood from the embodiments of the present disclosure. In addition, it is easy to understand that the purposes and advantages of the present disclosure can be achieved using the means shown in the claims and their combinations.

[0011] In order to achieve the above-mentioned objectives, one aspect of the present disclosure provides an organic metal compound having a novel structure represented by the following Chemical Formula I, an organic light-emitting diode in which the light-emitting layer contains the organic metal compound as its dopant, and an organic light-emitting display device including the organic light-emitting diode.

[0012] [Chemical Formula 1]

[0013]

[0014] Wherein in Chemical Formula 1,

[0015] X may represent one selected from the group consisting of O, S, and Se;

[0016] X1, X2 and X3 can each independently represent N or CR a ;

[0017] R1, R2 and R3 may each independently represent monosubstituted, disubstituted, trisubstituted, tetrasubstituted, or unsubstituted;

[0018] R5, R6, R7 and R a may each independently represent monosubstituted, disubstituted, trisubstituted, or unsubstituted;

[0019] R4 and R8 may each independently represent monosubstituted, disubstituted, or unsubstituted;

[0020] R1, R2, R3, R4, R7, R8 and R a each independently represents one selected from the group consisting of hydrogen, deuterium, halogen, deuterated or undeuterated alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

[0021] R5 and R6 may each independently represent one selected from the group consisting of halogen, deuterated or undeuterated alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

[0022] n can be 0, 1, or 2.

[0023] Another aspect of the present disclosure provides 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, wherein the light-emitting layer comprises a dopant material, and wherein the dopant material comprises an organic metal compound as defined above.

[0024] Yet another aspect of the present disclosure provides an organic light-emitting device, comprising: a first electrode and a second electrode facing each other; and a first light-emitting stack and a second light-emitting stack located between the first electrode and the second electrode, wherein each of the first light-emitting stack and the second light-emitting stack includes at least one light-emitting layer, wherein at least one of the light-emitting layers is a green phosphorescent light-emitting layer, wherein the green phosphorescent light-emitting layer includes a dopant material, and wherein the dopant material includes an organic metal compound as defined above.

[0025] Yet another aspect of the present disclosure provides an organic light-emitting device, comprising: a first electrode and a second electrode facing each other; and a first light-emitting stack, a second light-emitting stack, and a third light-emitting stack located between the first electrode and the second electrode, wherein each of the first light-emitting stack, the second light-emitting stack, and the third light-emitting stack includes at least one light-emitting layer, wherein at least one of the light-emitting layers is a green phosphorescent light-emitting layer, wherein the green phosphorescent light-emitting layer includes a dopant material, and wherein the dopant material includes an organic metal compound as defined above.

[0026] Yet another aspect of the present disclosure provides an organic light-emitting display device, comprising: a substrate; a driving element disposed on the substrate; and an organic light-emitting element disposed on the substrate and connected to the driving element, wherein the organic light-emitting element comprises the organic light-emitting device defined above.

[0027] The organometallic compound according to the present disclosure can be used as a dopant for a phosphorescent light-emitting layer of an organic light-emitting diode, so that the operating voltage of the diode can be reduced, its efficiency and lifespan characteristics can be improved, and at the same time, red shift can be suppressed.

[0028] The effects of the present disclosure are not limited to the above-mentioned effects, and other unmentioned effects will be clearly understood by those skilled in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a cross-sectional view schematically illustrating an organic light emitting diode in which a light emitting layer includes an organometallic compound according to an illustrative embodiment of the present disclosure.

[0030] Figure 2 is a cross-sectional view schematically illustrating an organic light emitting diode having a tandem structure including two light emitting stacks and including the organometallic compound represented by Chemical Formula 1 according to an illustrative embodiment of the present disclosure.

[0031] Figure 3 is a cross-sectional view schematically illustrating an organic light emitting diode having a tandem structure including three light emitting stacks and including the organometallic compound represented by Chemical Formula 1 according to an illustrative embodiment of the present disclosure.

[0032] Figure 4 is a cross-sectional view schematically illustrating an organic light emitting display device including an organic light emitting diode according to an illustrative embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] The advantages and features of the present disclosure, as well as the methods for achieving these advantages and features, will be described in detail below and in the accompanying drawings. Figure 1 The following detailed description of the embodiments will become apparent. However, the content of the present disclosure is not limited to the embodiments disclosed below, but can be implemented in a variety of different forms. Therefore, these embodiments are only provided to make the present disclosure complete and to fully inform those of ordinary skill in the art to which the present disclosure belongs of the scope of the present disclosure, and the scope of the present disclosure is limited only by the scope of the claims.

[0034] The shapes, sizes, proportions, angles, numbers, etc. disclosed in the accompanying drawings for describing the embodiments of the present disclosure are illustrative, and the present disclosure is not limited thereto. The same reference numerals refer to the same elements here. In addition, in order to simplify the description, descriptions and details of well-known steps and elements are omitted. In addition, in the following detailed description of the present disclosure, many specific details are set forth to provide a comprehensive understanding of the present disclosure. However, it is understood that the invention can be implemented without these specific details. In other cases, well-known methods, procedures, elements and circuits are not described in detail so as not to unnecessarily obscure various aspects of the present disclosure.

[0035] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular formations "a" and "an" are intended to also include plural formations, unless the context clearly indicates otherwise. It should be further understood that the terms "comprise," "include," "contain," and "contain" used in this specification refer to the presence of the described features, integers, operations, elements, and / or components, but do not exclude the presence or increase of one or more other features, integers, operations, elements, components, and / or parts thereof. As used herein, the term "and / or" includes any and all combinations of one or more related listed items. For example, an expression such as "at least one," when placed in front of a list of elements, can modify the entire list of elements without modifying a single element in the list. When interpreting numerical values, errors or tolerances may occur even without a clear description.

[0036] Furthermore, it is to be understood that when a first element or layer is referred to as being present on a second element or layer, the first element may be directly disposed on the second element, or may be indirectly disposed on the second element, with a third element or layer disposed between the first and second elements or layers. It is to be understood that when an element or layer is referred to as being "connected to" or "coupled to" another element or layer, it may be directly on, connected to, or coupled to the other element or layer, or one or more intervening elements or layers may be present. It is to be understood that when an element or layer is referred to as being "between" two elements or layers, it may be the only element or layer between the two elements or layers, or one or more intervening elements or layers may be present.

[0037] Further, as used herein, when a layer, film, region, plate, etc. is set on the "up" or "top" of another layer, film, region, plate, etc., the former can directly contact the latter or still another layer, film, region, plate, etc. can be set between the former and the latter. As used herein, when a layer, film, region, plate, etc. is directly set on the "up" or "top" of another layer, film, region, plate, etc., the former directly contacts the latter, and another layer, film, region, plate, etc. is not set between the former and the latter. In addition, as used herein, when a layer, film, region, plate, etc. is set on the "bottom" or "below" of another layer, film, region, plate, etc., the former can directly contact the latter, or another layer, film, region, plate, etc. can be set between the former and the latter. As used herein, when a layer, film, region, plate, etc. is directly set on the "bottom" or "below" of another layer, film, region, plate, etc., the former directly contacts the latter, and another layer, film, region, plate, etc. is not set between the former and the latter.

[0038] In descriptions of temporal relationships, such as a temporal precedence relationship between two events, such as "after," "subsequently," "before," etc., unless "directly after," "directly subsequent," or "directly before" is not specified, another event may occur in between.

[0039] 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 portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Thus, a first element, component, region, layer, or portion described below could be referred to as a second element, component, region, layer, or portion without departing from the spirit and scope of the present disclosure.

[0040] The features of the various embodiments of the present disclosure may be partially or completely combined with each other, and may be technically related to or interoperable with each other. The various embodiments may be implemented independently of each other, or may be implemented together in an associated relationship.

[0041] When interpreting a numerical value, the numerical value is interpreted as including a range of error unless otherwise expressly stated.

[0042] It will be understood that when an element or layer is referred to as being “connected to” or “coupled to” another element or layer, it can be directly on, connected to or coupled to the other element or layer, or one or more intervening elements or layers may be present. Additionally, it will be understood that when an element or layer is referred to as being “between” two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

[0043] The features of the various embodiments of the present disclosure may be partially or completely combined with each other, and may be technically related or interoperable with each other. The various embodiments may be implemented independently of each other, or may be implemented together in an associated relationship.

[0044] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the concepts of the present disclosure belong. It will be further understood that the terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the relevant technical context and will not be interpreted in an idealized or overly formal sense unless so explicitly defined in the present disclosure.

[0045] The structure and preparation examples of the organometallic compound according to the present disclosure and the organic light emitting diode including the same will be described below.

[0046] Traditionally, organometallic compounds have been used as dopants in the phosphorescent light-emitting layer of organic light-emitting diodes. For example,

[0047] Traditionally, organometallic compounds have been used as dopants for phosphorescent light-emitting layers. For example, structures such as 2-phenylpyridine, 2-phenylquinoline, or 2-pyridylbenzofuropyridine are known as the primary ligand structures of organometallic compounds. However, conventional luminescent dopants have limitations in improving the efficiency and lifetime of organic light-emitting diodes (OLEDs). Therefore, there is a need to develop new luminescent dopant materials. Therefore, the applicants of the present disclosure have developed a luminescent dopant material that can further improve the efficiency and lifetime of organic light-emitting diodes (OLEDs).

[0048] Based on in-depth research, the applicant of the present disclosure has found that when the organometallic compound represented by the following Chemical Formula 1 is used as a phosphorescent light-emitting dopant material, the above-mentioned object of the present disclosure has been achieved, thereby completing the present disclosure:

[0049] [Chemical Formula 1]

[0050]

[0051] Wherein in Chemical Formula 1,

[0052] X may represent one selected from the group consisting of O, S, and Se;

[0053] X1, X2 and X3 can each independently represent N or CR a ;

[0054] R1, R2 and R3 may each independently represent monosubstituted, disubstituted, trisubstituted, tetrasubstituted, or unsubstituted;

[0055] R5, R6, R7 and R a may each independently represent monosubstituted, disubstituted, trisubstituted, or unsubstituted;

[0056] R4 and R8 may each independently represent monosubstituted, disubstituted, or unsubstituted;

[0057] R1, R2, R3, R4, R7, R8 and R a each independently represents one selected from the group consisting of hydrogen, deuterium, halogen, deuterated or undeuterated alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

[0058] R5 and R6 may each independently represent one selected from the group consisting of halogen, deuterated or undeuterated alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

[0059] n can be 0, 1, or 2.

[0060] In particular, as can be determined in the primary ligand structure of Chemical Formula 1, the length ratio of the major axis and minor axis of the ring connected to Ir (iridium), the central coordinating metal, is increased, thereby improving the luminous efficiency of an organic light-emitting diode (OLED) using the organometallic compound of Chemical Formula 1 as its phosphorescent dopant. The major axis-to-minor axis length ratio refers to the length ratio of the major axis and the minor axis perpendicular thereto of the optimized target substance calculated by B3LYP / LANL2DZ (6-31g, d) in the Gaussian 16 program. In this regard, the major axis length refers to the length of the longest portion of the substance having the central coordinating metal Ir as an axis.

[0061] According to one embodiment of the present disclosure, in Chemical Formula 1, R5 and R6 may each independently represent one selected from the group consisting of: a C1-C6 straight-chain alkyl group monosubstituted with deuterium or a halogen element; a branched-chain alkyl group monosubstituted with deuterium or a halogen element; and a cycloalkyl group monosubstituted with deuterium or a halogen element.

[0062] For example, when X in Chemical Formula 1 according to the present disclosure is O (oxygen), an organometallic compound is derived in which a large six-membered aromatic ring structure having a substituent (excluding hydrogen) is bonded to benzofuropyridine. Therefore, when the organometallic compound represented by Chemical Formula 1 is used as a dopant material for the phosphorescent light-emitting layer of an organic light-emitting diode, the luminous efficiency and lifespan of the organic light-emitting diode can be improved, and its operating voltage can be reduced. This result was confirmed experimentally. Therefore, the present disclosure has been completed.

[0063] Specifically, i) the organometallic compound structure according to Chemical Formula 1 of the present disclosure has a ratio of the lengths of the major axis to the minor axis that is greater than that of conventional compounds in which the aromatic ring structure is not bound to a benzofuranopyridine. Therefore, the luminous efficiency of an organic light-emitting diode using the organometallic compound according to Chemical Formula 1 of the present disclosure can be improved. At the same time, ii) the stability of the primary ligand structure can be increased, and the lifespan of the organic light-emitting diode using the organometallic compound according to Chemical Formula 1 of the present disclosure can be increased. At the same time, iii) the red shift of the organic light-emitting diode using the organometallic compound according to Chemical Formula 1 of the present disclosure can be suppressed.

[0064] More specifically, controlling the ratio of the major and minor axes of an organometallic compound to improve the efficiency and lifetime of an organic light-emitting diode (OLED) using an organometallic compound, such as an iridium complex, as a phosphorescent dopant can result in the wavelength of the emitted light being somewhat longer than the target wavelength. However, as can be seen from Table 1 below, when the organometallic compound of Chemical Formula 1 of the present disclosure is used as a dopant material for the phosphorescent light-emitting layer of an OLED, the wavelength can be maintained at the target wavelength (e.g., 520 nm to 540 nm for a green phosphorescent light-emitting layer). Consequently, the efficiency and lifetime of the OLED can be improved, while red shift can be suppressed. This has important technical significance.

[0065] As will be described in more detail later in the specific examples of the present disclosure and in the performance evaluation of organic light-emitting diodes, the length ratios of the major and minor axes of each of the organometallic compounds "Reference 1" and "Reference 3," which are comparative examples of the present disclosure, and the "target compound," which conforms to the definition of Chemical Formula 1 of the present disclosure, were measured. These "Reference 1," "Reference 3," and the "target compound" were used as dopants for the light-emitting layers of organic light-emitting diodes. Furthermore, to accurately compare the length ratios of their major and minor axes, the compounds had the same auxiliary ligand.

[0066] The method for manufacturing organic light-emitting diodes was the same as described in <Example 1>, except that "Reference 1," "Reference 3," and "Target Compound" were used as dopant materials instead of Compound 1. The EQE and LT95 of each organic light-emitting diode were measured in the same manner as described in <Performance Evaluation of Organic Light-Emitting Diodes> below. The results are presented in Table 1 below. The major axis / minor axis length ratio refers to the ratio of the major axis to the minor axis perpendicular thereto of the optimized target substance, calculated using B3LYP / LANL2DZ (6-31g,d) using the Gaussian 16 program. Furthermore, the emission wavelengths of the organic light-emitting diodes using "Reference 3" and "Target Compound" were as follows: The emission wavelength increased by 10 to 15 nanometers when using "Reference 3" compared to when using "Target Compound." Therefore, it was confirmed that the efficiency and characteristics of the organic light-emitting diodes using "Reference 3" were inferior to those using the target compound.

[0067] Table 1

[0068] dopant The ratio of the length of the major axis to the minor axis EQE LT95 Reference 1 1.28 100 % 100 % Reference 3 1.61 110 % 127 % Target compound 1.61 127 % 151 %

[0069] The structures of reference 1, reference 3 and the target compound in Table 1 are as follows:

[0070] Reference 1:

[0071] Reference 3:

[0072] Target compound:

[0073] The organometallic compound according to an embodiment of the present disclosure may include not only the primary ligand bound to the central coordinating metal (iridium) as described above, but also a bidentate ligand as an auxiliary ligand bound to the central coordinating metal (iridium). As shown in Chemical Formula 1, the auxiliary ligand may have a 2-phenylpyridine structure, wherein R1 and R2 each independently represent mono-, di-, tri-, tetra-, or unsubstituted.

[0074] The organometallic compound according to an embodiment of the present disclosure may have a heteroleptic structure or a homoleptic structure. For example, the organometallic compound according to an embodiment of the present disclosure may have a heteroleptic structure in which n is 1 in Chemical Formula 1; or a heteroleptic structure in which n is 2 in Chemical Formula 1; or a homoleptic structure in which n is 0 in Chemical Formula 1.

[0075] Specific examples of the compound represented by Chemical Formula 1 according to the present disclosure may include one selected from the group consisting of the following compounds 1 to 564. However, the specific examples of the compound represented by Chemical Formula 1 according to the present disclosure are not limited thereto, as long as the compound satisfies the definition of the above-mentioned Chemical Formula 1 as satisfied by the target compound:

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] According to one embodiment of the present disclosure, the organometallic compound represented by Chemical Formula 1 of the present disclosure may be used as a red phosphorescent or green phosphorescent material, preferably, as a green phosphorescent material.

[0085] Reference Figure 1According to one embodiment of the present disclosure, an organic light-emitting diode 100 may be provided, including 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 may include a light-emitting layer 160, and the light-emitting layer 160 may include a host material 160' and a dopant 160". The dopant 160" may be made of an organometallic compound represented by Chemical Formula 1. In addition, in the organic light-emitting diode 100, the organic layer 130 disposed between the first electrode 110 and the second electrode 120 may be formed by sequentially stacking a hole injection layer 140 (HIL), a hole transport layer 150 (HTL), an light-emitting layer 160 (EML), an electron transport layer 170 (ETL), and an electron injection layer 180 (EIL) on the first electrode 110. The second electrode 120 may be formed on the electron injection layer 180, and a protective layer (not shown) may be formed thereon.

[0086] Furthermore, despite Figure 1 Although not shown, 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 may contain a compound with good hole transport properties and may reduce the difference between the HOMO energy levels of the hole transport layer 150 and the light-emitting layer 160, thereby adjusting the hole injection characteristics. Therefore, the accumulation of holes at the interface between the hole transport auxiliary layer and the light-emitting layer 160 may be reduced, thereby reducing the quenching phenomenon in which excitons disappear at the interface due to polarization. As a result, component degradation may be reduced, and the component may be stabilized, thereby improving its efficiency and lifespan.

[0087] The first electrode 110 may serve as a positive electrode and may be made of ITO, IZO, tin oxide, or zinc oxide, which are conductive materials having a relatively large work function value. However, the present disclosure is not limited thereto.

[0088] The second electrode 120 may serve as a negative electrode and may include Al, Mg, Ca, or Ag, which is a conductive material having a relatively small work function value, or an alloy or combination thereof. However, the present disclosure is not limited thereto.

[0089] The hole injection layer 140 may be located between the first electrode 110 and the hole transport layer 150. The hole injection layer 140 may have a 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 one or more compounds selected from the group consisting of MTDATA, CuPc, TCTA, HATCN, TDAPB, PEDOT / PSS, and N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4)-triphenylbenzene-1,4-diamine). Preferably, the hole injection layer 140 may include N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine). However, the present disclosure is not limited thereto.

[0090] The hole transport layer 150 may be adjacent to the light emitting layer and located between the first electrode 110 and the light emitting layer 160. The material of the hole transport layer 150 may include a compound selected from the group consisting of TPD, NPB, CBP, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl)-4-amine, etc. Preferably, the material of the hole transport layer 150 may include NPB. However, the present disclosure is not limited thereto.

[0091] According to the present disclosure, in order to improve the luminous efficiency of the diode 100, the light-emitting layer 160 can be formed by doping the host material 160' with the organic metal compound represented by Chemical Formula 1 as a dopant 160". The dopant 160" can serve as a green or red light-emitting material, preferably as a green phosphorescent material.

[0092] The doping concentration of the dopant 160 ″ according to the present disclosure may be adjusted to be in the range of 1 to 30 wt % based on the total weight of the host material 160 ′. However, the present disclosure is not limited thereto. For example, the doping concentration may be in the range of 2 to 20 wt %, for example, 3 to 15 wt %, for example, 5 to 10 wt %, for example, 3 to 8 wt %, for example, 2 to 7 wt %, for example, 5 to 7 wt %, or for example, 5 to 6 wt %.

[0093] The light-emitting layer 160 according to the present disclosure includes a host material 160' known in the art that can achieve the effects of the present disclosure, and the layer 160 includes an organic metal compound represented by Chemical Formula 1 as a dopant 160". For example, according to the present disclosure, the host material 160' may include a compound containing a carbazole group, and may preferably include a host material selected from the group consisting of CBP (carbazole biphenyl), mCP (1,3-bis (carbazole-9-yl), etc. However, the present disclosure is not limited thereto.

[0094] Furthermore, 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 has high electron mobility so that electrons can be stably supplied to the light emitting layer under smooth electron transport.

[0095] For example, the material of the electron transport layer 170 may be known in the art, and may include, for example, a compound selected from the group consisting of: Alq3 (tris(8-hydroxyquinoline)aluminum), Liq (8-hydroxyquinoline lithium), PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxazole), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), spiro-PBD, BAlq (bis(2-methyl-8-hydroxyquinoline)-4-(phenylphenol)aluminum), SA lq, TPBi (2,2',2-(1,3,5-benzoyl)-tris(1-phenyl-1-H-benzimidazole), oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, and 2-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole. Preferably, the material of the electron transport layer 170 may include 2-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole. However, the present disclosure is not limited thereto.

[0096] The electron injection layer 180 is used to promote electron injection, and the material of the electron injection layer can be known in the art, and for example, can include a compound selected from the group consisting of Alq3 (tris (8-hydroxyquinoline) aluminum), PBD, TAZ, spiro-PBD, BAlq, SAlq, etc. However, the present disclosure is not limited thereto. Alternatively, the electron injection layer 180 can be made of a metal compound. For example, the metal compound can include one or more selected from the group consisting of Liq, LiF, NaF, KF, RbF, CsF, FrF, BeF2, MgF2, CaF2, SrF2, BaF2, and RaF2. However, the present disclosure is not limited thereto.

[0097] The organic light-emitting diode according to the present disclosure can be embodied as a white light-emitting diode having a tandem structure. The tandem organic light-emitting diode according to an illustrative embodiment of the present disclosure can be formed into a structure in which two or more adjacent light-emitting stacks are connected to each other via a charge generation layer (CGL). The organic light-emitting diode may include at least two light-emitting stacks disposed on a substrate, wherein each of the at least two light-emitting stacks includes first and second electrodes facing each other, and a light-emitting layer disposed between the first and second electrodes to emit light in a specific wavelength band. The multiple light-emitting stacks can emit light of the same color or different colors. In addition, one or more light-emitting layers can be included in a single light-emitting stack, and the multiple light-emitting layers can emit light of the same color or different colors.

[0098] In this case, the light-emitting layer included in at least one of the plurality of light-emitting stacks may include the organometallic compound represented by Chemical Formula I of the present disclosure as a dopant. Adjacent light-emitting stacks in the series structure may be connected to each other through a charge generation layer CGL including an N-type charge generation layer and a P-type charge generation layer.

[0099] Figure 2 and Figure 3 are cross-sectional views schematically illustrating an organic light emitting diode in a series structure having two light emitting stacks and an organic light emitting diode in a series structure having three light emitting stacks according to some embodiments of the present disclosure.

[0100] like Figure 2 As shown, the organic light emitting diode 100 according to the present disclosure includes 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 may be located between the first electrode 110 and the second electrode 120, and may include a first light emitting stack ST1 including a first light emitting layer 261, a second light emitting stack ST2 disposed between the first light emitting stack ST1 and the second electrode 120 and including a second light emitting layer 262, and a charge generation layer CGL disposed between the first and second light emitting stacks ST1 and ST2. The charge generation layer CGL may include an N-type charge generation layer 291 and a P-type charge generation layer 292. At least one of the first light emitting layer 261 and the second light emitting layer 262 may contain an organic metal compound represented by Chemical Formula I according to the present disclosure as a dopant. For example, as Figure 2 As shown, the second light emitting layer 262 of the second light emitting stack ST2 may include a host material 262' and a dopant 262" made of an organic metal compound represented by Chemical Formula I doped therein. Figure 2Although not shown, each of the first and second light emitting stacks ST1 and ST2 may further include an additional light emitting layer in addition to each of the first light emitting layer 261 and the second light emitting layer 262 .

[0101] like Figure 3 As shown, the organic light emitting diode 100 according to the present disclosure includes 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 may be located between the first electrode 110 and the second electrode 120, and may include a first light emitting stack ST1 including a first light emitting layer 261, a second light emitting stack ST2 including a second light emitting layer 262, a third light emitting stack ST3 including a third light emitting layer 263, a first charge generation layer CGL1 located between the first and second light emitting stacks ST1 and ST2, and a second charge generation layer CGL2 located between the second and third light emitting stacks ST2 and ST3. The first charge generation layer CGL1 may include an N-type charge generation layer 291 and a P-type charge generation layer 292. The second charge generation layer CGL2 may include an N-type charge generation layer 293 and a P-type charge generation layer 294. At least one of the first light emitting layer 261, the second light emitting layer 262, and the third light emitting layer 263 may contain an organic metal compound represented by Chemical Formula I according to the present disclosure as a dopant. For example, as Figure 3 As shown, the second light emitting layer 262 of the second light emitting stack ST2 may include a host material 262' and a dopant 262" made of an organic metal compound represented by Chemical Formula I doped therein. Figure 3 Although not shown, each of the first, second, and third light emitting stacks ST1, ST2, and ST3 may further include an additional light emitting layer in addition to each of the first, second, and third light emitting layers 261, 262, and 263.

[0102] Furthermore, the organic light emitting diode according to an embodiment of the present disclosure may include a tandem structure in which four or more light emitting stacks and three or more charge generation layers are disposed between a first electrode and a second electrode.

[0103] The organic light emitting diode according to the present disclosure can be used as a light emitting element in each of an organic light emitting display device and an illumination device. In an embodiment, Figure 4 is a cross-sectional view schematically illustrating an organic light emitting display device including an organic light emitting diode according to some embodiments of the present disclosure.

[0104] like Figure 4As shown, the organic light emitting display device 3000 includes a substrate 3010, an organic light emitting diode 4000, and an encapsulation film 3900 covering the organic light emitting diode 4000. A driving thin film transistor Td as a driving element and the organic light emitting diode 4000 connected to the driving thin film transistor Td are located on the substrate 3010.

[0105] Despite Figure 4 Although not explicitly shown, gate lines and data lines intersecting each other to define pixel areas, power lines extending parallel to and spaced apart from one of the gate lines and data lines, switching thin film transistors connected to the gate lines and data lines, and storage capacitors connected to one electrode of the thin film transistor and the power line are further formed on the substrate 3010.

[0106] 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 .

[0107] The semiconductor layer 3100 may be formed on the substrate 3010 and may be made of an oxide semiconductor material or polycrystalline silicon. When the semiconductor layer 3100 is made of an oxide semiconductor material, a light shielding pattern (not shown) may be formed below the semiconductor layer 3100. The light shielding pattern may prevent light from entering the semiconductor layer 3100, thereby preventing the semiconductor layer 3100 from being degraded by light. Alternatively, the semiconductor layer 3100 may be made of polycrystalline silicon. In this case, both edges of the semiconductor layer 3100 may be doped with impurities.

[0108] A gate insulating layer 3200 made of an insulating material is formed on the entire surface of the substrate 3010 and on the semiconductor layer 3100. The gate insulating layer 3200 may be made of an inorganic insulating material, such as silicon oxide or silicon nitride.

[0109] A gate electrode 3300 made of a conductive material such as metal is formed on the gate insulating layer 3200 and corresponds to the center of the semiconductor layer 3100. The gate electrode 3300 is connected to the switching thin film transistor.

[0110] An interlayer insulating layer 3400 made of an insulating material is formed on the entire surface of the substrate 3010 and the gate 3300. The interlayer insulating layer 3400 may be made of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

[0111] The interlayer insulating layer 3400 has first and second semiconductor layer contact holes 3420 and 3440 respectively exposing opposite sides of the semiconductor layer 3100 as defined herein. The first and second semiconductor layer contact holes 3420 and 3440 are respectively disposed on opposite sides of the gate 3300 and spaced apart from the gate 3300.

[0112] A source electrode 3520 and a drain electrode 3540 made of a conductive material such as metal are formed on the interlayer insulating layer 3400. The source electrode 3520 and the drain electrode 3540 are disposed around the gate electrode 3300 and are spaced apart from each other, and contact two opposite sides of the semiconductor layer 3100 through first and second semiconductor layer contact holes 3420 and 3440, respectively. The source electrode 3520 is connected to a power supply line (not shown).

[0113] The semiconductor layer 3100 , the gate electrode 3300 , the source electrode 3520 , and the drain electrode 3540 constitute a driving thin film transistor Td. The driving thin film transistor Td has a coplanar structure, wherein the gate electrode 3300 , the source electrode 3520 , and the drain electrode 3540 are disposed on top of the semiconductor layer 3100 .

[0114] Alternatively, the driving thin film transistor Td may have an inverted staggered structure, in which the gate is disposed below the semiconductor layer, while the source and drain are disposed above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon. In one example, the switching thin film transistor (not shown) may have a structure substantially the same as that of the driving thin film transistor (Td).

[0115] In one example, an organic light-emitting display device 3000 may include a color filter 3600 that absorbs light generated by an electroluminescent element (light-emitting diode) 4000. For example, the color filter 3600 may absorb red (R), green (G), blue (B), and white (W) light. In this case, red, green, and blue color filter patterns that absorb light may be formed in different pixel regions. Each of these color filter patterns may be arranged to overlap with each organic layer 4300 of the organic light-emitting diode 4000 to emit light in the wavelength band corresponding to each color filter. The use of the color filter 3600 enables the organic light-emitting display device 3000 to achieve full color.

[0116] For example, when the organic light-emitting display device 3000 is a bottom emission type, the light-absorbing color filter 3600 may be located on a portion of the interlayer insulating layer 3400 corresponding to the organic light-emitting diode 4000. In an alternative embodiment, when the organic light-emitting display device 3000 is a top emission type, the color filter may be located on top of the organic light-emitting diode 4000, that is, on top of the second electrode 4200. For example, the color filter 3600 may be formed to have a thickness of 2 to 5 micrometers.

[0117] In one example, the protection layer 3700 having the drain contact hole 3720 as defined herein exposing the drain electrode 3540 of the driving thin film transistor Td is formed to cover the driving thin film transistor Td.

[0118] On the protective layer 3700 , each first electrode 4100 connected to the drain electrode 3540 of the driving thin film transistor Td through the drain contact hole 3720 is individually formed in each pixel region.

[0119] The first electrode 4100 may serve as a positive electrode (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.

[0120] In one example, when the organic light-emitting display device 3000 is a top emission type, a reflective electrode or a reflective layer may be further formed under the first electrode 4100. For example, the reflective electrode or the reflective layer may be made of one of aluminum (Al), silver (Ag), nickel (Ni), and aluminum-palladium-copper (APC) alloy.

[0121] A bank layer 3800 is formed on the protective layer 3700 to cover the edge of the first electrode 4100. The bank layer 3800 exposes the center of the first electrode 4100 corresponding to the pixel area.

[0122] An organic layer 4300 is formed on the first electrode 4100. Optionally, the organic light emitting diode 4000 may have a series structure. Figures 2 to 4 and the above description thereof.

[0123] The second electrode 4200 is formed on the substrate 3010 on which the organic layer 4300 is already formed. The second electrode 4200 is arranged over the entire surface of the display area and is made of a conductive material with a relatively low work function value. It can function as a negative electrode (cathode). For example, the second electrode 4200 can be made of one of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (Al-Mg).

[0124] The first electrode 4100 , the organic layer 4300 , and the second electrode 4200 constitute an organic light emitting diode 4000 .

[0125] An encapsulation film 3900 is formed on the second electrode 4200 to prevent external moisture from penetrating into the organic light emitting diode 4000. Figure 4 Although not explicitly shown in the figure, the encapsulation film 3900 may have a three-layer structure in which a first inorganic layer, an organic layer, and an inorganic layer are sequentially stacked. However, the present disclosure is not limited thereto.

[0126] Hereinafter, the preparation examples and embodiments of the present disclosure will be described. However, the following embodiments are merely examples of the present disclosure. The present disclosure is not limited thereto.

[0127] Preparation Example - Preparation of Ligand

[0128] (1) Preparation of ligand A

[0129] Step 1) Preparation of ligand A-3

[0130]

[0131] 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 separated, dried over sodium sulfate, and evaporated. After evaporation of the solvent, the residue was purified by column chromatography on silica gel using 40-50% n-hexane in dichloromethane to yield 7.38 g (77%) of the target compound A-3.

[0132] Step 2) Preparation of ligand A-2

[0133]

[0134] 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 dissolved in tetrahydrofuran (100 ml). The mixture was refluxed and stirred for 6 hours. The crude mixture was filtered through celite and silica gel, and the solid was dissolved in dichloromethane. Methanol was added dropwise to precipitate a solid, yielding 5.98 g (82%) of the target compound A-2.

[0135] Step 3) Preparation of ligand A-1

[0136]

[0137] A-2 (5.95 g, 15.5 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (50 ml). The mixture was stirred at 0°C for 2 hours, and the reaction product was then allowed to warm to room temperature. The residue was partitioned between ethyl acetate and water, and the organic phase was separated, washed with aqueous sodium bicarbonate solution and brine, and dried over sodium sulfate. After evaporation of the solvent, the residue was chromatographed on a silica gel column using 30% dichloromethane in hexane to yield 3.88 g (71%) of the target compound A-1.

[0138] Step 4) Preparation of Ligand A

[0139]

[0140] A mixed solution of A-1 (3.88 g, 11 mmol), Pd(dba) (0.20 g, 0.22 mmol), KPO (4.67 g, 22 mmol), and (t-bu)PBFH (0.13 g, 0.44 mmol) was dissolved in 1,4-dioxane (100 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 30-40% dichloromethane in hexane to yield 3.39 g (73%) of the target compound A.

[0141] (2) Preparation of ligand B

[0142] Step 1) Preparation of ligand B-3

[0143]

[0144] A solution of SM-B (8.13 g, 25 mmol) and sodium ethoxide (3.39 g, 50 mmol) dissolved 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 separated, dried over sodium sulfate, and evaporated. After evaporation of the solvent, the residue was purified by column chromatography on a silica gel column using 40-50% n-hexane and dichloromethane to obtain 5.91 g (72%) of the target compound B-3.

[0145] Step 2) Preparation of ligand B-2

[0146]

[0147] A mixture of 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) in tetrahydrofuran (100 ml) was refluxed and stirred for 6 hours. The crude mixture was filtered through celite and silica gel, and the solid was dissolved in dichloromethane. Methanol was added dropwise to precipitate a solid, yielding 4.91 g (83%) of the target compound B-2.

[0148] Step 3) Preparation of ligand B-1

[0149]

[0150] Compound B-2 (4.91 g, 15 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (40 ml). The mixed solution was stirred at 0°C for 2 hours, and then the reaction mixture was allowed to warm to room temperature. The residue was partitioned between ethyl acetate and water, and the organic phase was separated, washed with aqueous sodium bicarbonate solution and brine, and dried over sodium sulfate. After evaporation of the solvent, the residue was chromatographed on a silica gel column using 30% dichloromethane in hexane to yield 3.57 g (80%) of the target compound B-1.

[0151] Step 4) Preparation of ligand B

[0152]

[0153] A mixed solution 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) was dissolved in 1,4-dioxane (120 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 30-40% dichloromethane in hexane to yield 3.31 g (75%) of the target compound B.

[0154] (3) Preparation of ligand C

[0155] Step 1) Preparation of ligand C-3

[0156]

[0157] 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 separated, dried over sodium sulfate, and evaporated. After evaporation of the solvent, the residue was purified by column chromatography on silica gel using 40-50% n-hexane in dichloromethane to yield 6.39 g (74%) of the target compound C-3.

[0158] Step 2) Preparation of ligand C-2

[0159]

[0160] 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 dissolved in tetrahydrofuran (100 ml). The mixture was refluxed and stirred for 6 hours. The crude mixture was filtered through celite and silica gel, and the solid was dissolved in dichloromethane. Methanol was added dropwise to precipitate a solid, yielding 5.05 g (79%) of the target compound C-2.

[0161] Step 3) Preparation of ligand C-1

[0162]

[0163] C-2 (5.05 g, 14.6 mmol) was added to acetic acid (100 ml) and tetrahydrofuran (40 ml). The mixture was stirred at 0°C for 2 hours, and the reaction product was then allowed to warm to room temperature. The residue was partitioned between ethyl acetate and water, and the organic phase was separated, washed with aqueous sodium bicarbonate solution and brine, and dried over sodium sulfate. After evaporation of the solvent, the residue was chromatographed on a silica gel column using 30% dichloromethane in hexane to obtain 3.81 g (83%) of the target compound C-1.

[0164] Step 4) Preparation of Ligand C

[0165]

[0166] A mixture of C-1 (3.81 g, 12.1 mmol), Pd(dba) (0.22 g, 0.24 mmol), KPO (5.09 g, 24 mmol), and (t-bu)PBFH (0.14 g, 0.48 mmol) was dissolved in 1,4-dioxane (120 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 30-40% dichloromethane in hexane to yield 3.16 g (68%) of target compound C.

[0167] (4) Preparation of ligand D

[0168]

[0169] A mixed solution of A-1 (5.79 g, 16.4 mmol), Pd(dba) (0.30 g, 0.33 mmol), KPO (7.01 g, 33 mmol), and (t-bu)PBFH (0.20 g, 0.67 mmol) was dissolved in 1,4-dioxane (100 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 20-30% dichloromethane in hexane to yield 5.40 g (66%) of the target compound D.

[0170] (5) Preparation of ligand E

[0171]

[0172] A mixed solution 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) was dissolved in 1,4-dioxane (150 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 25-30% dichloromethane in hexane to yield 6.28 g (77%) of the target compound E.

[0173] (6) Preparation of ligand F

[0174] Step 1) Preparation of ligand F-3

[0175]

[0176] 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 dissolved in tetrahydrofuran (150 ml). The mixture was refluxed and stirred for 6 hours. The crude mixture was filtered through celite and silica gel, and the solid was dissolved in dichloromethane. Methanol was added dropwise to precipitate a solid, yielding 9.74 g (85%) of the target compound F-3.

[0177] Step 2) Preparation of ligand F-2

[0178]

[0179] F-3 (9.74 g, 25.5 mmol) was added to acetic acid (120 ml) and tetrahydrofuran (60 ml). The mixed solution was stirred at 0°C for 2 hours, and then the reaction product was warmed to room temperature. The residue was partitioned between ethyl acetate and water, and the organic phase was separated, washed with aqueous sodium bicarbonate solution and brine, and dried over sodium sulfate. After evaporation of the solvent, the residue was chromatographed on a silica gel column using 30% dichloromethane in hexane to obtain 6.26 g (70%) of the target compound F-2.

[0180] Step 3) Preparation of ligand F-1

[0181]

[0182] A mixed solution 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) was dissolved in 1,4-dioxane (120 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 30-40% dichloromethane in hexane to yield 5.17 g (69%) of the target compound F-1.

[0183] Step 4) Preparation of ligand F

[0184]

[0185] 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 separated, dried over sodium sulfate, and evaporated. After evaporation of the solvent, the residue was purified by column chromatography on silica gel using 40-50% n-hexane and dichloromethane to yield 3.65 g (71%) of the target compound F.

[0186] (7) Preparation of ligand G

[0187] Step 1) Preparation of ligand G-3

[0188]

[0189] 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 dissolved in tetrahydrofuran (150 ml). The mixture was refluxed and stirred for 6 hours. The crude mixture was filtered through celite and silica gel, and the solid was dissolved in dichloromethane. Methanol was added dropwise to precipitate a solid, yielding 7.82 g (80%) of the target compound F-3.

[0190] Step 2) Preparation of ligand G-2

[0191]

[0192] G-3 (7.82 g, 24 mmol) was added to acetic acid (120 ml) and tetrahydrofuran (60 ml). The mixed solution was stirred at 0°C for 2 hours, and then the reaction mixture was warmed to room temperature. The residue was partitioned between ethyl acetate and water, and the organic phase was separated, washed with aqueous sodium bicarbonate solution and brine, and dried over sodium sulfate. After evaporation of the solvent, the residue was chromatographed on a silica gel column using 30% dichloromethane in hexane to obtain 5.23 g (74%) of the target compound G-2.

[0193] Step 3) Preparation of ligand G-1

[0194]

[0195] A mixed solution 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) was dissolved in 1,4-dioxane (120 ml) and refluxed overnight. The solution was evaporated, and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over sodium sulfate, and evaporated. The crude mixture was then chromatographed on a silica gel column using 30-40% dichloromethane in hexane to yield 4.46 g (72%) of the target compound G-1.

[0196] Step 4) Preparation of ligand G

[0197]

[0198] 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 separated, dried over sodium sulfate, and evaporated. After evaporation of the solvent, the residue was purified by column chromatography on silica gel using 40-50% n-hexane in dichloromethane to yield 3.27 g (73%) of the target compound G.

[0199] (8) Preparation of ligand H'

[0200] Step 1) Preparation of ligand HH

[0201]

[0202] 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. The temperature was then lowered to room temperature, and the resulting solid was isolated by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol. The filtration was repeated several times under reduced pressure to yield 8.39 g (93%) of the target compound HH.

[0203] Step 2) Preparation of ligand H'

[0204]

[0205] A solution of HH (6.77 g, 6 mmol) and silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred at room temperature overnight. After the reaction was complete, the solid precipitate was removed by filtration through Celite. The filtrate was filtered repeatedly under reduced pressure through a filter to yield 8.46 g (95%) of the target compound H'.

[0206] (9) Preparation of ligand I'

[0207] Step 1) Preparation of Ligand II

[0208]

[0209] 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. The temperature was then lowered to room temperature, and the resulting solid was isolated by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol. The filtration was repeated several times under reduced pressure to yield 8.93 g (90%) of the target compound II.

[0210] Step 2) Preparation of ligand I'

[0211]

[0212] A solution of II (7.44 g, 6 mmol) and silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred at room temperature overnight. After the reaction was complete, the solid precipitate was removed by filtration through Celite. The filtrate was filtered repeatedly under reduced pressure through a filter to obtain 8.81 g (92%) of the target compound I'.

[0213] (10) Preparation of ligand J'

[0214] Step 1) Preparation of ligand JJ

[0215]

[0216] 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. The temperature was then lowered to room temperature, and the resulting solid was isolated by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol. The filtration was repeated several times under reduced pressure to yield 8.48 g (93%) of the target compound JJ.

[0217] Step 2) Preparation of ligand J'

[0218]

[0219] A solution of JJ (6.84 g, 6 mmol) and silver trifluoromethanesulfonate (4.54 g, 18 mmol) in dichloromethane (100 ml) and methanol (100 ml) was stirred at room temperature overnight. After the reaction was complete, the solid precipitate was removed by filtration through Celite. The filtrate was filtered repeatedly under reduced pressure through a filter to yield 8.53 g (95%) of the target compound J'.

[0220] (11) Preparation of ligand K'

[0221] Step 1) Preparation of ligand KK

[0222]

[0223] 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. The temperature was then lowered to room temperature, and the resulting solid was isolated by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol. The filtration was repeated several times under reduced pressure to yield 9.29 g (91%) of the target compound KK.

[0224] Step 2) Preparation of ligand K'

[0225]

[0226] A solution of 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 filtration through Celite. The filtrate was filtered repeatedly under reduced pressure through a filter to yield 9.20 g (94%) of the target compound K'.

[0227] Preparation Example - Preparation of Iridium Compounds

[0228] <Preparation of Iridium Compound 13>

[0229]

[0230] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.89 g (87%) of the target iridium compound 13.

[0231] <Preparation of Iridium Compound 14>

[0232]

[0233] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.69 g (82%) of the target iridium compound 14.

[0234] <Preparation of Iridium Compound 15>

[0235]

[0236] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.99 g (84%) of the target iridium compound 15.

[0237] <Preparation of Iridium Compound 16>

[0238]

[0239] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.06 g (85%) of the target iridium compound 16.

[0240] <Preparation of Iridium Compound 17>

[0241]

[0242] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.00 g (84%) of the target iridium compound 17.

[0243] <Preparation of Iridium Compound 18>

[0244]

[0245] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.93 g (81%) of the target iridium compound 18.

[0246] <Preparation of Iridium Compound 19>

[0247]

[0248] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.03 g (80%) of the target iridium compound 19.

[0249] <Preparation of Iridium Compound 20>

[0250]

[0251] A solution of 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 complete, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.20 g (82%) of the target iridium compound 20.

[0252] <Preparation of Iridium Compound 21>

[0253]

[0254] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.69 g (82%) of the target iridium compound 21.

[0255] <Preparation of Iridium Compound 22>

[0256]

[0257] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.97 g (83%) of the target iridium compound 22.

[0258] <Preparation of Iridium Compound 23>

[0259]

[0260] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.11 g (86%) of the target iridium compound 23.

[0261] <Preparation of Iridium Compound 24>

[0262]

[0263] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.80 g (75%) of the target iridium compound 24.

[0264] <Preparation of Iridium Compound 25>

[0265]

[0266] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.10 g (80%) of the target iridium compound 25.

[0267] <Preparation of Iridium Compound 26>

[0268]

[0269] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.34 g (84%) of the target iridium compound 26.

[0270] <Preparation of Iridium Compound 27>

[0271]

[0272] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.22 g (78%) of the target iridium compound 27.

[0273] <Preparation of Iridium Compound 28>

[0274]

[0275] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.46 g (81%) of the target iridium compound 28.

[0276] <Preparation of Iridium Compound 29>

[0277]

[0278] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on silica gel using 25% ethyl acetate in hexane to obtain 4.22 g (87%) of the target iridium compound 29.

[0279] <Preparation of Iridium Compound 30>

[0280]

[0281] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.20 g (86%) of the target iridium compound 30.

[0282] <Preparation of Iridium Compound 31>

[0283]

[0284] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.11 g (80%) of the target iridium compound 31.

[0285] <Preparation of Iridium Compound 32>

[0286]

[0287] A solution of E (2.22 g, 5 mmol) and K' (4.90 g, 6 mmol) dissolved in 2-ethoxyethanol (100 ml) and DMF (100 ml) was stirred at 135°C for 24 hours. After the reaction was completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.44 g (85%) of the target iridium compound 32.

[0288] <Preparation of Iridium Compound 33>

[0289]

[0290] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.63 g (80%) of the target iridium compound 33.

[0291] <Preparation of Iridium Compound 34>

[0292]

[0293] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.00 g (82%) of the target iridium compound 34.

[0294] <Preparation of Iridium Compound 35>

[0295]

[0296] A solution of 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 completed, the temperature was lowered to room temperature, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 3.90 g (81%) of the target iridium compound 35.

[0297] <Preparation of Iridium Compound 36>

[0298]

[0299] A solution of 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, and the organic phase was separated with dichloromethane and distilled water. The water was then removed by adding anhydrous magnesium sulfate. The solution obtained by filtration was decompressed to obtain a residue. The residue was then purified by column chromatography on a silica gel column using 25% ethyl acetate in hexane to obtain 4.07 g (79%) of the target iridium compound 36.

[0300] <Example 1>

[0301] A glass substrate coated with a 1,000 Å thick ITO (indium tin oxide) film was cleaned and then ultrasonically cleaned with a solvent such as isopropyl alcohol, acetone, or methanol. The glass substrate was then dried. Thus, an ITO transparent electrode was formed. HI-1, a hole injection material, was deposited on the ITO transparent electrode by thermal vacuum deposition. This formed a 60 nm thick hole injection layer. NPB, a hole transport material, was then deposited on the hole injection layer by thermal vacuum deposition. This formed an 80 nm thick hole transport layer. CBP, a host material for the light-emitting layer, was then deposited on the hole transport layer by thermal vacuum deposition. Compound 1, a dopant, was incorporated into the host material at a 5% doping concentration. This formed a 30 nm thick light-emitting layer. A 30 nm thick mixture of ET-1:Liq (1:1) was deposited on the light-emitting layer as materials for the electron transport and injection layers. A 100 nm thick layer of aluminum was then deposited on top to form the negative electrode. In this way, an organic light emitting diode is manufactured.

[0302] , , ,

[0303] , .

[0304] HI-1 refers to N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine).

[0305] ET-1 refers to 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole.

[0306] <Examples 2 to 25 and Comparative Examples 1 to 3>

[0307] Organic light emitting diodes of Examples 2 to 25 and Comparative Examples 1 to 3 were manufactured in the same manner as Example 1, except that the compounds shown in Tables 2 and 3 below were used as dopants instead of Compound 1 in Example 1.

[0308] <Performance Evaluation of Organic Light-Emitting Diodes>

[0309] Regarding the organic light emitting diodes prepared according to Examples 1 to 25 and Comparative Examples 1 to 3 of the present disclosure, the measured 2 The operating voltage and efficiency characteristics at currents as well as at 40 mA / cm 2 The lifespan characteristics when accelerated at 40°C and 40°C were analyzed. The operating voltage (V), EQE (%), and LT95 (%) were measured and converted to numerical values ​​relative to Comparative Example 1. The results are shown in Tables 2 and 3 below. LT95 refers to a lifetime evaluation protocol and means the time required for an organic light-emitting diode to lose 5% of its initial luminance.

[0310] Table 2

[0311] Example dopant Operating voltage (%) Maximum luminous efficiency (%, relative value) EQE (%, relative value) LT95 (%, relative value) Comparative Example 1 Reference 1 4.36 100 100 100 Comparative Example 2 Reference 2 4.35 104 108 111 Comparative Example 3 Reference 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

[0312] Table 3

[0313] Example dopant Operating voltage (%) 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

[0314] The structures of Reference 1 to Reference 3 used as dopant materials in Comparative Examples 1 to 3 of Table 2 are as follows:

[0315] Reference 1:

[0316] Reference 2:

[0317] Reference 3:

[0318] As can be seen from the results in Tables 2 to 3 above, in the organic light-emitting diodes in which the organometallic compounds of Examples 1 to 25 according to the present disclosure are used as dopants for the light-emitting layers of the diodes, the operating voltage of the diodes is reduced, and the maximum luminous efficiency, external quantum efficiency (EQE), and lifespan (LT95) of the diodes are improved compared to those in Comparative Examples 1 to 3.

[0319] The scope of protection of the present disclosure should be interpreted by the scope of the claims, and all technical concepts within the scope equivalent thereto should be interpreted as included within the scope of the present disclosure. Although the embodiments of the present disclosure have been described in more detail with reference to the accompanying drawings, the present disclosure is not necessarily limited to these embodiments. The present disclosure can be implemented in various modified ways without departing from the scope of the technical concept of the present disclosure. Therefore, the embodiments of the present disclosure are not intended to limit the technical concept of the present disclosure, but to describe the present disclosure. The scope of the technical concept of the present disclosure is not limited by the embodiments. Therefore, it should be understood that the above-mentioned embodiments are illustrative and non-restrictive in all aspects. The scope of protection of the present disclosure should be interpreted by the claims, and all technical concepts within the scope of the present disclosure should be interpreted as included within the scope of the present disclosure.

Claims

1. An organometallic compound selected from the group consisting of:

2. An organic light-emitting device, comprising: a first electrode; a second electrode facing the first electrode; as well as an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, wherein the light emitting layer comprises a dopant material, and Wherein the dopant material comprises the organometallic compound according to claim 1 . The device of claim 2 , wherein the light-emitting layer comprises a green phosphorescent light-emitting layer. 4 . The device of claim 2 , wherein the organic layer further comprises at least one selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

5. An organic light-emitting device, comprising: a first electrode and a second electrode facing each other; as well as a first light emitting stack and a second light emitting stack located between the first electrode and the second electrode, wherein each of the first light-emitting stack and the second light-emitting stack comprises at least one light-emitting layer, wherein 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 Wherein the dopant material comprises the organometallic compound according to claim 1 .

6. An organic light-emitting device, comprising: a first electrode and a second electrode facing each other; as well as a first light emitting stack, a second light emitting stack, and a third light emitting stack located between the first electrode and the second electrode, wherein each of the first light-emitting stack, the second light-emitting stack, and the third light-emitting stack includes at least one light-emitting layer, wherein 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 Wherein the dopant material comprises the organometallic compound according to claim 1 .

7. An organic light-emitting display device, comprising: substrate; a driving element disposed on the substrate; as well as An organic light emitting element provided on the substrate and connected to the driving element, The organic light-emitting element comprises the organic light-emitting device according to claim 2.

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