Organic compound, organic light-emitting element, display device, photoelectric conversion device, electronic device, lighting device, and exposure light source

Abstract

The present invention relates to an organic compound, an organic light-emitting element, a display device, a photoelectric conversion device, an electronic device, a lighting device, and an exposure light source. An organic compound represented by formula [1]. In formula [1], L and L' are bidentate ligands different from each other, and the partial structure IrL m is a partial structure represented by formula [2], and a partial structure IrL' n It is a partial structure represented by formula [3-1] or formula [3-2].

Description

Technical Field

[0001] The present disclosure relates to an organic compound, an organic light-emitting element, a display device, a photoelectric conversion device, an electronic device, a lighting device, a moving object, and an exposure light source. Background Art

[0002] An organic light-emitting element (hereinafter also referred to as an "organic electroluminescent element" or "organic EL element") is an electronic device comprising a pair of electrodes and an organic compound layer disposed between the electrodes. Electrons and holes are injected through the pair of electrodes to generate excitons in the light-emitting organic compound in the organic compound layer. When the excitons return to their ground state, the organic light-emitting element emits light.

[0003] Recent advances in organic light-emitting devices have been remarkable, with low driving voltage, various emission wavelengths, high-speed response, and thinner and lighter light-emitting devices now possible.

[0004] To date, efforts have been actively made to create light-emitting organic compounds. This is because the creation of compounds with good light-emitting properties is important for providing high-performance organic light-emitting elements.

[0005] One of the compounds created so far is the following compound 1-a disclosed in Inorganic Chemistry, 2013, Vol. 52, No. 17, pp. 9842-9860 (Non-Patent Document 1).

[0006]

[0007] The present inventors have conducted research and found that the luminescence characteristics of Compound 1-a disclosed in Non-Patent Document 1 can be improved. Improving the luminescence characteristics of the compound can provide an organic light-emitting element with higher luminescence efficiency. Summary of the Invention

[0008] In view of the above, the present disclosure provides an organic compound having good luminescence properties. The present disclosure also provides an organic light-emitting element having good luminescence properties.

[0009] The organic compound according to one aspect of the present disclosure is represented by the following formula [1].

[0010] Ir L m L' n [1]

[0011] In formula [1], Ir represents iridium. L and L' represent bidentate ligands different from each other. m is an integer from 1 to 3, and when m is 1, n is 2, when m is 2, n is 1, and when m is 3, n is 0. Partial structure IrL mis a partial structure represented by formula [2], and a partial structure IrL' n is a partial structure represented by formula [3-1] or formula [3-2]. When m is 2 or more, the multiple L sites may be the same or different. When n is 2 or more, the multiple L' sites may be the same or different.

[0012]

[0013]

[0014] In formula [2], ring A is selected from the following formulae [A-1] to [A-5].

[0015]

[0016] In formulae [A-1] to [A-5], * represents a binding position.

[0017] In formulae [2], [3-1], and [A-1] to [A-5], R1 to R 49 Each is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group and a substituted or unsubstituted heterocyclic group.

[0018] In formula [3-2], X1 to X8 are each independently selected from a carbon atom and a nitrogen atom. When X1 to X8 are carbon atoms, each carbon atom has a hydrogen atom, a deuterium atom or a substituent, and each substituent is independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0019] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The results of comparison between the example compounds and the comparative compounds with respect to the planarity of the aromatic ring portion of the ligand are shown.

[0021] Figure 2 The structures, HOMO, and LUMO of example compounds are shown.

[0022] Figure 3A is a schematic cross-sectional view illustrating an example of a pixel of a display device according to an embodiment of the present disclosure. Figure 3Bis a schematic cross-sectional view of an example of a display device including an organic light emitting element according to an embodiment of the present disclosure.

[0023] Figure 4 An example of a display device according to an embodiment of the present disclosure is schematically shown.

[0024] Figure 5A An example of an image pickup apparatus according to an embodiment of the present disclosure is schematically shown. Figure 5B An example of a moving object according to an embodiment of the present disclosure is schematically shown.

[0025] Figure 6A An example of a display device according to an embodiment of the present disclosure is schematically shown. Figure 6B An example of a foldable display device is schematically shown.

[0026] Figure 7A An example of a lighting device according to an embodiment of the present disclosure is schematically shown. Figure 7B An automobile is schematically shown as an example of a moving object according to an embodiment of the present disclosure.

[0027] Figure 8A An example of a wearable device according to an embodiment of the present disclosure is schematically shown. Figure 8B An example of a wearable device including an imaging apparatus according to an embodiment of the present disclosure is schematically shown.

[0028] Figure 9 An example of an image forming apparatus according to an embodiment of the present disclosure is schematically shown.

[0029] Figure 10A and Figure 10B Each schematically illustrates an example of an exposure light source of an image forming apparatus according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] organic compounds

[0031] First, the organic compound according to the embodiment will be described.

[0032] The organic compound according to the present embodiment is an organometallic complex represented by the following general formula [1].

[0033] Ir L m L' n [1]

[0034] In the general formula [1], Ir represents iridium. L and L' represent bidentate ligands different from each other. m is an integer from 1 to 3, and when m is 1, n is 2, when m is 2, n is 1, and when m is 3, n is 0. Partial structure IrL mis a partial structure represented by the general formula [2], and a partial structure IrL' n It is a partial structure represented by the general formula [3-1] or the general formula [3-2]. When m is 2 or more, the multiple L sites may be the same or different. It may include multiple L sites. When n is 2 or more, the multiple L' sites may be the same or different.

[0035]

[0036] In the general formula [2], ring A is selected from the following general formulae [A-1] to [A-5].

[0037]

[0038] In the general formulae [A-1] to [A-5], * represents a binding position.

[0039] In the general formulae [2], [3-1] and [A-1] to [A-5], R1 to R 49 Each is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group and a substituted or unsubstituted heterocyclic group.

[0040] In the general formula [3-2], X1 to X8 are each independently selected from a carbon atom and a nitrogen atom. When X1 to X8 are carbon atoms, each carbon atom has a hydrogen atom, a deuterium atom, or a substituent, and each substituent is independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0041] In the general formulae [2], [3-1] and [A-1] to [A-5], R1 to R 49 Preferably, each is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted amino group having 1 to 6 carbon atoms, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituted or unsubstituted heterocyclic group having 3 to 27 carbon atoms.

[0042] In the general formula [2], R1 to R4 and R8 to R 11Preferably, each is independently selected from a hydrogen atom and an alkyl group, and more preferably each is independently selected from a hydrogen atom and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. As will be described in detail below, the organic compound represented by the general formula [1] has a partial structure represented by the general formula [2] and has a tetrahydropyrene skeleton. Although the planarity of the tetrahydropyrene skeleton is not as high as that of the pyrene skeleton, it has high planarity, and this planarity promotes interaction with other organic compounds such as the host in the light-emitting layer of the organic light-emitting element. Therefore, when R1 to R4 and R8 to R 11 When each is independently selected from a hydrogen atom and an alkyl group, planarity can be higher than when other substituents are used.

[0043] When X1 to X8 in the general formula [3-2] are carbon atoms, the substituents on the carbon atoms are preferably each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted amino group having 1 to 6 carbon atoms, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituted or unsubstituted heterocyclic group having 3 to 27 carbon atoms.

[0044] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have a halogen atom as a substituent and the carbon atoms represented by R1 to R 49 Examples of the halogen atom represented by include fluorine, chlorine, bromine and iodine, but are not limited thereto.

[0045] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have an alkyl group as a substituent and R1 to R 49 Examples of the alkyl group represented include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, octyl, cyclohexyl, 1-adamantyl, and 2-adamantyl.

[0046] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have an alkoxy group as a substituent and R1 to R 49 Examples of the alkoxy group represented include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy.

[0047] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have an amino group as a substituent and R1 to R 49Examples of the amino group represented include N-methylamino, N-ethylamino, N,N-dimethylamino, N,N-diethylamino, N-methyl-N-ethylamino, N-benzylamino, N-methyl-N-benzylamino, N,N-dibenzylamino, anilino, N,N-diphenylamino, N,N-dinaphthylamino, N,N-difluorenylamino, N-phenyl-N-tolylamino, N,N-ditolylamino, N-methyl-N-phenylamino, N,N-dianisolylamino, N-mesityl-N-phenylamino, N,N-di-mesitylamino, N-phenyl-N-(4-tert-butylphenyl)amino, N-phenyl-N-(4-trifluoromethylphenyl)amino and N-piperidinyl, but are not limited thereto.

[0048] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have an aryloxy group and a heteroaryloxy group as substituents and R1 to R 49 Examples of the aryloxy and heteroaryloxy groups represented include, but are not limited to, phenoxy and thienyloxy.

[0049] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have a silyl group as a substituent and R1 to R 49 Examples of the silyl group represented by include, but are not limited to, trimethylsilyl and triphenylsilyl.

[0050] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have an aromatic hydrocarbon group as a substituent and the aromatic hydrocarbon groups represented by R1 to R 49 Examples of the aromatic hydrocarbon group represented by include phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, fluoranthenyl, and benzo[9,10]phenanthryl, but are not limited thereto.

[0051] In the general formulae [2], [3-2], [3-1] and [A-1] to [A-5], the carbon atoms represented by X1 to X8 may have a heterocyclic group as a substituent and the carbon atoms represented by R1 to R 49 Examples of the heterocyclic group represented by include a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinyl group, a phenanthrolinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, but are not limited thereto.

[0052] Examples of substituents that the above-mentioned alkyl, alkoxy, amino, aryloxy, silyl, aromatic hydrocarbon and heterocyclic groups may further have include halogen atoms such as fluorine, chlorine, bromine and iodine; alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl and tert-butyl; alkoxy groups such as methoxy, ethoxy and propoxy; amino groups such as dimethylamino, diethylamino, dibenzylamino, diphenylamino and ditolylamino; aryloxy groups such as phenoxy; aromatic hydrocarbon groups such as phenyl and biphenyl; heterocyclic groups such as pyridyl and pyrrolyl; and cyano, but are not limited thereto.

[0053] Characteristics of the organic compound according to the present embodiment

[0054] Next, the characteristics of the organic compound according to this embodiment will be described. The organic compound according to this embodiment has the characteristics described below, thereby having a high quantum yield and high sublimation properties. In addition, the use of this organic compound can also provide an organic light-emitting element with high luminous efficiency and high element durability.

[0055] (1) Organic compounds have high quantum yields due to their tetrahydropyrene skeleton.

[0056] (2) Organic compounds have high sublimability due to their tetrahydropyrene skeleton.

[0057] Hereinafter, these characteristics will be described using Comparative Compound 1-a as a comparative reference. Comparative Compound 1-a is a compound disclosed in Non-Patent Document 1.

[0058] (1) Organic compounds have high quantum yields due to their tetrahydropyrene skeleton.

[0059] When inventing the organic compound disclosed herein, the inventors focused on the structure of the ligand of the organic compound. Specifically, among the aromatic rings and heterocyclic rings constituting the ligand of the Ir complex, a tetrahydropyrene skeleton was used as the aromatic ring in order to improve the quantum yield.

[0060] Here, the results of the comparison of luminescence characteristics between Example Compound A25 and Comparative Compound 1-a, which are organic compounds according to this embodiment, are shown in Table 1. The luminescence wavelength was measured by photoluminescence (PL) measurement of a diluted toluene solution at room temperature at an excitation wavelength of 350 nm using an F-4500 manufactured by Hitachi, Ltd. For the measurement of quantum yield, the absolute quantum yield of the diluted toluene solution was measured using an absolute PL quantum yield spectrometer (C9920-02) manufactured by Hamamatsu Photonics KK. The quantum yield is expressed as a relative value, and the quantum yield of Example Compound A25 is 1.0.

[0061] Table 1

[0062]

[0063] Table 1 shows that the quantum yield of Example Compound A25 is higher and the luminescence characteristics are better than those of Comparative Compound 1-a. The present inventors considered this as follows.

[0064] The structural difference between the two compounds is the difference in the aromatic ring coordinated to the metal Ir. The aromatic ring of the comparative compound 1-a is a pyrene skeleton, while the aromatic ring of the exemplary compound A25 is a tetrahydropyrene skeleton.

[0065] Here, the pyrene skeleton is a fused polycyclic structure in which four benzene rings are fused together. In this structure, the π-electrons are delocalized throughout the pyrene skeleton to form an extended π-conjugated system. Therefore, the ligand having the pyrene skeleton is a ligand having an extended π-conjugated system. Therefore, the luminescence characteristics of the Ir complex with the ligand having the pyrene skeleton are strong in π-π* characteristics, while on the other hand, the metal-to-ligand charge transfer (MLCT) characteristics, which means the interaction with the metal Ir, are weak. As a result, Comparative Compound 1-a fails to exhibit luminescence accompanied by sufficient MLCT migration, and therefore has a low phosphorescence quantum yield.

[0066] In contrast, the ligand of Example Compound A25 is a ligand having a tetrahydropyrene skeleton.

[0067] The tetrahydropyrene skeleton has a structure in which two ethylene chains are cross-linked to a biphenyl skeleton. Therefore, in this structure, the π-electrons are not delocalized across the entire tetrahydropyrene skeleton to form an extended π-conjugated system, unlike the pyrene skeleton. As a result, sufficient MLCT migration can be maintained, resulting in a high quantum yield for Example Compound A25.

[0068] In addition, the emission wavelength (λmax) of the comparative compound 1-a is 626 nm and emits light in the red region, while the emission wavelength (λmax) of the exemplary compound A25 is 530 nm and emits light in the green region. As described above, this is also due to the structural difference between the aromatic rings coordinated to the metal Ir. Specifically, in the case of the pyrene skeleton, since the π-conjugated system extends over the entire pyrene skeleton, the emission wavelength shifts to a longer wavelength, resulting in emission in the red region. In the case of the tetrahydropyrene skeleton, since the π-conjugated system does not extend over the entire tetrahydropyrene skeleton, the emission wavelength does not shift to a longer wavelength, resulting in emission in the green region.

[0069] Therefore, even if the heterocyclic ring represented by ring A in the general formula [1] is a fused heterocyclic ring composed of two or more rings in which the conjugation is extended wider than the pyridine ring of the exemplary compound A25, the organic compound according to this embodiment can also have a light emission wavelength in the visible light region. In contrast, in the case of having a pyrene skeleton as in the comparative compound 1-a, if a fused heterocyclic ring composed of two or more rings in which the conjugation is extended wider than the pyridine ring is used as the heterocyclic ring, the light emission wavelength is further shifted to a longer wavelength, resulting in light emission in the near-infrared region. Light emission with a light emission wavelength in the near-infrared region or the infrared region cannot reproduce the color visible to the human eye in the visible light region and is therefore not suitable for use in image display devices such as displays. In other words, even if the heterocyclic ring represented by ring A in the general formula [1] is a fused heterocyclic ring composed of two or more rings, the organic compound according to this embodiment is suitable for use in image display devices such as displays because it exhibits light emission in the visible light region.

[0070] (2) Organic compounds have high sublimability due to their tetrahydropyrene skeleton.

[0071] When inventing the organic compound according to this embodiment, the present inventors focused on the steric structure of the ligand of the organic compound. Specifically, they designed the molecule so that the ligand has low planarity.

[0072] Here, the comparison results regarding the planarity of the aromatic ring portion of the ligand between the exemplary compound A25 as the organic compound according to the present embodiment and the comparative compound 1-a are shown in FIG. Figure 1 Shown in.

[0073] Figure 1 This indicates that the pyrene skeleton, the aromatic ring of Comparative Compound 1-a, is highly planar. Highly planar ligands promote π-π interactions between ligands, making the Ir complex prone to aggregation. Consequently, the sublimation properties of the Ir complex are disadvantageously reduced.

[0074] In contrast, the tetrahydropyrene skeleton of the aromatic ring of Example Compound A25 has a flexible ethylene chain and therefore exhibits low planarity. More specifically, the two benzene rings included in the aromatic ring portion are not completely parallel to each other and have a slightly twisted structure. Consequently, interactions between ligands are suppressed, and aggregation of Ir complexes is inhibited. Consequently, Example Compound A25 exhibits high sublimability.

[0075] Therefore, the compound according to this embodiment has high sublimability, that is, it can sublime at a relatively low temperature. Due to the low sublimation temperature, thermal decomposition during sublimation can be suppressed, thereby achieving stable sublimation purification. This also means that the deposition stability during the production of an organic light-emitting element using the compound according to this embodiment is high. That is, according to this embodiment, a deposited film can be formed without decomposition during deposition, and an organic light-emitting element with a long life can be provided.

[0076] Evaluation of the light emitting characteristics and sublimation properties of the compounds described in the characteristics (1) and (2) of the organic compound according to the present embodiment will be described in more detail in Examples given later.

[0077] Examples of the organic compound according to the present embodiment

[0078] Specific examples of the organic compound according to the present embodiment are shown below. However, the present disclosure is not limited thereto. In the following structural formula, the dotted line represents a coordination bond.

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] Among the above-mentioned example compounds, the example compounds (A1 to A40) belonging to Group A are organic compounds represented by the general formula [2] in which Ring A is a pyridine ring, that is, organic compounds represented by the general formula [2] in which Ring A is represented by the general formula [A-1]. The emission wavelength of the example compounds belonging to Group A is a wavelength in the green to yellow region. Use of these compounds can provide light-emitting elements in the green to yellow region. Therefore, compounds represented by the general formula [2] in which Ring A has a structure represented by the general formula [A-1] are suitable as organic compounds for green light-emitting elements.

[0087] Among the above-mentioned exemplary compounds, the exemplary compounds (B1 to B20) belonging to Group B are organic compounds represented by the general formula [2] in which Ring A is a quinoline ring, that is, organic compounds represented by the general formula [2] in which Ring A is represented by the general formula [A-2]. The exemplary compounds belonging to Group B emit light at wavelengths in the yellow to orange region. Use of these compounds can provide light-emitting elements in the yellow to orange region.

[0088] Among the above-mentioned exemplary compounds, the exemplary compounds (C1 to C20) belonging to Group C are organic compounds represented by the general formula [2] in which Ring A is an isoquinoline ring, that is, organic compounds represented by the general formula [2] in which Ring A is represented by the general formula [A-3]. The exemplary compounds belonging to Group C emit light at wavelengths in the orange to red region. Use of these compounds can provide light-emitting elements in the orange to red region.

[0089] Among the above-mentioned exemplary compounds, the exemplary compounds (D1 to D40) belonging to Group D are organic compounds represented by the general formula [2] in which Ring A is a benzoisoquinoline ring, that is, organic compounds represented by the general formula [2] in which Ring A is represented by the general formula [A-4]. The exemplary compounds belonging to Group D emit light at wavelengths in the orange to red region. Use of these compounds can provide light-emitting elements in the orange to red region.

[0090] Among the above-mentioned exemplary compounds, the exemplary compounds (E1 to E20) belonging to Group E are organic compounds represented by the general formula [2] in which Ring A is a naphthoisoquinoline ring, that is, organic compounds represented by the general formula [2] in which Ring A is represented by the general formula [A-5]. The emission wavelengths of the exemplary compounds belonging to Group E are in the orange to red region. Use of these compounds can provide light-emitting elements in the orange to red region.

[0091] Compounds represented by the general formula [2], wherein Ring A has a structure represented by any of the general formulas [A-2] to [A-5], are suitable as organic compounds for red light-emitting elements. In particular, Ring A may have a structure represented by the general formula [A-4]. This is because such compounds have an emission wavelength suitable for red light-emitting elements and exhibit excellent properties in terms of balance with sublimation properties.

[0092] organic light-emitting diodes

[0093] Next, an organic light emitting element according to the embodiment will be described.

[0094] Specific examples of the element structure of the organic light-emitting element according to this embodiment include a multilayer element structure in which the electrode layer and the organic compound layer shown in the following (1) to (6) are sequentially stacked on a substrate. That is, the organic light-emitting element of this embodiment includes at least a pair of electrodes, namely a first electrode and a second electrode, and an organic compound layer arranged between the electrodes. One of the first electrode and the second electrode can be an anode, and the other can be a cathode. In any element structure, the organic compound layer needs to include a light-emitting layer containing a light-emitting material.

[0095] (1) Anode / light-emitting layer / cathode

[0096] (2) Anode / Hole Transport Layer / Emitting Layer / Electron Transport Layer / Cathode

[0097] (3) Anode / Hole Transport Layer / Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0098] (4) Anode / Hole Injection Layer / Hole Transport Layer / Light Emitting Layer / Electron Transport Layer / Cathode

[0099] (5) Anode / Hole Injection Layer / Hole Transport Layer / Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0100] (6) Anode / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode

[0101] It should be noted that these example element structures are merely basic element structures, and the element structure of the organic light-emitting element disclosed herein is not limited thereto. For example, an insulating layer, an adhesive layer, or an interference layer may be provided at the interface between the electrode and the organic compound layer. Alternatively, the electron transport layer or the hole transport layer may have a multilayer structure including two layers with different ionization potentials. The light-emitting layer may have a multilayer structure including two layers containing different light-emitting materials. That is, a first light-emitting layer that emits a first light and a second light-emitting layer that emits a second light may be provided between a first electrode and a second electrode. If the first light and the second light have different colors and are converted into white light, for example, when they are combined, an organic light-emitting element that emits white light may be provided. Various other layer structures may be employed.

[0102] In this embodiment, the light extraction mode output from the light-emitting layer (element configuration) can be a so-called bottom emission mode in which light is extracted from the electrode on the substrate side, or a top emission mode in which light is extracted from the side opposite the substrate. Alternatively, a double-sided extraction mode in which light is extracted from both the substrate side and the side opposite the substrate can be adopted.

[0103] Among the element structures shown in (1) to (6) above, structure (6) can be adopted because it includes both an electron blocking layer and a hole blocking layer. That is, structure (6) including the electron blocking layer and the hole blocking layer can reliably capture two types of carriers, namely holes and electrons, in the light-emitting layer, thereby providing an organic light-emitting element that does not suffer from carrier leakage and has high luminous efficiency.

[0104] The organic light-emitting element according to this embodiment contains the organic compound represented by the general formula [1] in the organic compound layer. The organic light-emitting element according to this embodiment may contain the organic compound represented by the general formula [1] in the light-emitting layer. The present disclosure is not limited to this configuration, and the organic compound represented by the general formula [1] may be used as a constituent material of an organic compound layer other than the light-emitting layer of the organic light-emitting element according to this embodiment. Specifically, the organic compound may be used as a constituent material of, for example, an electron transport layer, an electron injection layer, an electron blocking layer, a hole transport layer, a hole injection layer, or a hole blocking layer.

[0105] In the organic light-emitting element according to this embodiment, when the organic compound represented by the general formula [1] is contained in the light-emitting layer, the light-emitting layer may be a layer formed only by the organic compound represented by the general formula [1]. Alternatively, the light-emitting layer may be a layer formed by the organic compound represented by the general formula [1] and other compounds, i.e., a second organic compound. Here, when the light-emitting layer is a layer formed by the organic compound represented by the general formula [1] and other compounds, the organic compound according to this embodiment may be used as a host (also referred to as a host material) or a guest (also referred to as a guest material) of the light-emitting layer. The organic compound may also be used as an auxiliary material that may be contained in the light-emitting layer.

[0106] As used herein, the term "host" refers to a compound that occupies the largest mass proportion among compounds constituting the light-emitting layer.

[0107] The term "guest" refers to a compound that occupies a lower mass fraction than the host in the compounds constituting the light-emitting layer and primarily emits light. The term "assistant material" refers to a compound that occupies a lower mass fraction than the host in the compounds constituting the light-emitting layer and assists the guest in emitting light. An assist material is also called a secondary host.

[0108] The host can be a material with a higher LUMO energy level than the guest (a material with a LUMO energy level closer to the vacuum energy level). This allows the electrons supplied to the host of the light-emitting layer to be efficiently transferred to the guest, thereby improving the luminous efficiency. In addition, when the auxiliary material is used as a compound different from the host and the guest, the host can be a material with a higher LUMO energy level than the auxiliary material (a material with a LUMO energy level closer to the vacuum energy level). This allows the electrons supplied to the host of the light-emitting layer to be efficiently transferred to the auxiliary material, thereby allowing the auxiliary material to undergo exciton recombination. This can effectively transfer energy to the guest.

[0109] When the energy (singlet energy) of the excited singlet state (S1) of the host is S h1 , the energy of the excited triplet state (T1) of the host (triplet energy) is T h1 , the energy of the object S1 is S g1 , and the energy of the object T1 is Tg1 When S h1 >S g1 , and can further satisfy T h1 >T g1 In addition, when the energy of auxiliary material S1 is S a1 , the energy of auxiliary material T1 is T a1 When S a1 >S g1 , and can further satisfy T a1 >T g1 In addition, S h1 >S a1 >S g1 , and can further satisfy T h1 >T a1 >T g1 .

[0110] Here, when the organic compound represented by the general formula [1] is used as a guest in the light-emitting layer, the concentration of the guest is preferably 1 mass % to 30 mass % inclusive, more preferably 5 mass % to 15 mass % inclusive, relative to the total mass of the light-emitting layer.

[0111] The present inventors conducted various studies and found that when the organic compound represented by the general formula [1] is used as a host or guest of a light-emitting layer, particularly as a guest of a light-emitting layer, an organic light-emitting element having high luminous efficiency and high durability can be obtained.

[0112] When the organic light-emitting element according to this embodiment contains the organic compound represented by the general formula [1] in the light-emitting layer, the following conditions may be satisfied regarding the compound contained in the light-emitting layer.

[0113] Two or more of the following conditions may be satisfied simultaneously: Since the organic compound represented by the general formula [1] can be used as a guest of the light-emitting layer as described above, the second organic compound can be a host of the light-emitting layer under the following conditions.

[0114] (3) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having an azine skeleton.

[0115] (4) The light-emitting layer contains an organic compound represented by the general formula [1] and a structure selected from the group consisting of a benzo[9,10]phenanthrene structure, a phenanthrene structure, A second organic compound of at least one selected from the group consisting of a fluoranthene structure and a fluoranthene structure.

[0116] (5) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having at least one of a dibenzothiophene structure and a dibenzofuran structure.

[0117] (6) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having no sp3 carbon.

[0118] The above conditions will be described below.

[0119] (3) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having an azine skeleton.

[0120] The organic compound represented by the general formula [1] is an organic compound having a tetrahydropyrene skeleton. This organic compound has a structure in which two electron-donating alkyl groups are introduced into the benzene ring coordinated to the metal Ir. Therefore, the HOMO energy level is shallower (closer to the vacuum level) than when the electron-donating alkyl group is not introduced into the benzene ring coordinated to the metal Ir.

[0121] Therefore, the second organic compound forming the light-emitting layer together with the organic compound represented by the general formula [1] can be a compound with a deep LUMO energy level. This is because when such a second organic compound is used, the organic compound represented by the general formula [1] can transfer holes injected from the hole transport layer to the light-emitting layer, and the second organic compound can transfer electrons injected from the electron transport layer. As a result, carrier injection from adjacent layers to the light-emitting layer can be smoothed to prevent unnecessary charge accumulation. This can achieve low-voltage driving and improve device durability.

[0122] The present inventors have discovered that compounds with an azine ring as their backbone are suitable as materials with deep LUMO energy levels. Azine rings, such as pyridine, pyrazine, pyrimidine, and triazine, are electron-deficient heterocycles. Therefore, compounds with such structures can exhibit deep LUMO energy levels.

[0123] On the other hand, compounds having an azine ring tend to have not only a deep LUMO energy level but also a deep HOMO energy level. If the HOMO energy level is too deep, the hole injection property from the hole transport layer to the light-emitting layer will be reduced. Therefore, in particular, the second organic compound can further have a carbazole skeleton that can suppress the deepening of the HOMO energy level to an extent that the hole injection property can be maintained. That is, in particular, the second organic compound can have a carbazole skeleton and an azine skeleton. By combining such a second organic compound with an organic compound represented by general formula [1], a light-emitting layer having good carrier injection property from the hole transport layer and the electron transport layer to the light-emitting layer while having a suitable HOMO-LUMO energy gap can be realized.

[0124] Organic compounds having only an aromatic amine or carbazole skeleton without an azine ring have shallow HOMO and LUMO levels. When such an organic compound is used as a second organic compound and combined with an organic compound represented by the general formula [1], the entire light-emitting layer has a shallow HOMO and LUMO level. Consequently, electron injection from the electron transport layer to the light-emitting layer is reduced. Specifically, for example, CBP (4,4'-bis(9H-carbazol-9-yl)biphenyl) is not suitable as a second compound for use with the organic compound represented by the general formula [1].

[0125] (4) The light-emitting layer contains an organic compound represented by the general formula [1] and a structure selected from the group consisting of a benzo[9,10]phenanthrene structure, a phenanthrene structure, A second organic compound of at least one selected from the group consisting of a fluoranthene structure and a fluoranthene structure.

[0126] The organic compound represented by the general formula [1] is an organic compound having a tetrahydropyrene skeleton. Figure 1 As shown, the tetrahydropyrene skeleton in which two benzene rings are bonded to each other in a direction away from the metal Ir is not as planar as the pyrene skeleton, but still has high planarity.

[0127] Therefore, the second organic compound used in combination with the organic compound represented by the general formula [1] can have a highly planar structure including an aromatic ring. This is because when the second organic compound has a highly planar structure, the second organic compound can approach the organic compound represented by the general formula [1] due to the interaction between the second organic compound and the highly planar site of the organic compound represented by the general formula [1]. More specifically, the planar site of the second organic compound easily approaches the tetrahydropyrene site of the organic compound represented by the general formula [1]. Therefore, the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound can be short.

[0128] It is known that triplet energy used for phosphorescent light emission in organic light-emitting devices undergoes energy transfer via the Dexter mechanism. The Dexter mechanism is a mechanism in which energy transfer occurs when molecules come into contact with each other. That is, when the intermolecular distance between the host and the guest is short, energy transfer from the host to the guest proceeds efficiently.

[0129] When a highly planar organic compound is used as the second organic compound, the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound is short, and energy transfer between the two compounds occurs more efficiently through the Dexter mechanism. More specifically, when the second organic compound is used as the host, the efficiency of energy transfer from the second organic compound to the organic compound represented by the general formula [1] is improved. As a result, an organic light-emitting element that exhibits highly efficient light emission can be provided.

[0130] Here, the highly planar structure specifically refers to a benzo[9,10]phenanthrene structure, a phenanthrene structure, The second organic compound may have a benzo[9,10]phenanthrene structure and a fluoranthene structure. In particular, from the viewpoint of planarity, the second organic compound may have a benzo[9,10]phenanthrene structure. When a compound having at least one of these structures is used as the second organic compound and combined with the organic compound represented by the general formula [1], a light-emitting element with higher efficiency can be provided.

[0131] (5) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having at least one of a dibenzothiophene structure and a dibenzofuran structure.

[0132] The organic compound represented by the general formula [1] is an organic compound including a ligand having a tetrahydropyrene skeleton. Figure 2 As shown, the HOMO region formed by the ligand and the metal Ir has a characteristic molecular orbital in which conjugation does not extend to the terminal of the tetrahydropyrene site.

[0133] In the case of this molecular orbital of HOMO, the terminal portion of the tetrahydropyrene skeleton remains as an empty orbital, and therefore, the hole transporting property is lower than that of the case in which the conjugation extends to the terminal portion of the tetrahydropyrene skeleton.

[0134] In order to compensate for this hole transporting property, the second organic compound used in combination with the organic compound represented by the general formula [1] may be a compound having a skeleton with high hole transporting property. A skeleton with high hole transporting property refers to a skeleton rich in unshared electron pairs and having strong electron donating properties. Specific examples include skeletons having electron donating nitrogen atoms, such as carbazole described in (3) above, and skeletons having sulfide atoms rich in unshared electron pairs, such as dibenzothiophene structures and dibenzofuran structures.

[0135] Among them, the second organic compound that can be suitably used together with the organic compound represented by the general formula [1] may have at least one skeleton selected from a dibenzothiophene structure and a dibenzofuran structure. The skeletons of the dibenzothiophene structure and the dibenzofuran structure are less likely to have an extremely shallow HOMO, and therefore can control the hole-electron carrier balance, and are suitable as a skeleton for compensating for the hole transport property of the organic compound represented by the general formula [1]. In particular, the second organic compound may have a dibenzothiophene structure rich in unshared electron pairs.

[0136] (6) The light-emitting layer contains the organic compound represented by the general formula [1] and a second organic compound having no sp3 carbon.

[0137] As described in (4) above, when the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound is short, the luminescence characteristics of the organic light-emitting element can be improved. When the second organic compound is a material that does not have sp3 carbon, the intermolecular distance between the second organic compound and the organic compound represented by the general formula [1] can be even shorter.

[0138] When sp3 carbons are present, the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound becomes longer due to the hydrophobic interaction and steric hindrance caused by the alkyl group. In contrast, when sp3 carbons are absent, the hydrophobic interaction and steric hindrance caused by the alkyl group do not occur, and thus the intermolecular distance does not increase, thereby achieving a short intermolecular distance between the second organic compound and the organic compound represented by the general formula [1]. As a result, the luminescent properties of the organic light-emitting element can be improved.

[0139] Specific examples of the second organic compound according to the present embodiment, more specifically, specific examples of compounds suitable as a host material are shown below. However, the present disclosure is not limited thereto.

[0140]

[0141]

[0142]

[0143]

[0144] Among the above compounds, the exemplary compounds (AA1 to AA21) belonging to the AA group are compounds each having an azine ring as a skeleton. Therefore, when these compounds are combined with the organic compound represented by the general formula [1], they each have a deep HOMO energy level and provide a small HOMO-LUMO energy gap. Therefore, these compounds can each form a good light-emitting layer together with the organic compound represented by the general formula [1], and can each provide an organic light-emitting element with low driving voltage and high durability.

[0145] Among the above compounds, exemplary compounds (BB1 to BB42) belonging to the BB group are compounds each having a structure selected from the group consisting of a benzo[9,10]phenanthrene structure, a phenanthrene structure, A compound having at least one of the group consisting of a fluoranthene structure and a benzo[9,10]phenanthrene structure as a skeleton and having no sp3 carbon. Therefore, when each of these compounds is combined with an organic compound represented by the general formula [1] to form a layer, the intermolecular distance between the two compounds can be short. As a result, intermolecular energy transfer, more specifically, energy transfer from the second organic compound to the compound represented by the general formula [1] can be performed with high efficiency, and luminous efficiency can be improved. Among these compounds, in particular, compounds having a benzo[9,10]phenanthrene structure, specifically BB6 to BB8, BB10 to BB29, and BB34 to BB42, can be used because they have particularly high planarity.

[0146] Among the above compounds, the exemplary compounds (CC1 to CC21) belonging to the CC group are compounds each having a dibenzothiophene structure or a dibenzofuran structure as a skeleton and having no sp3 carbon. Therefore, when each of these compounds is combined with an organic compound represented by the general formula [1] to form a light-emitting layer, a good balance between the HOMO and LUMO is provided. As a result, a good carrier balance can be achieved, and an organic light-emitting element with high luminous efficiency can be provided. Among these compounds, in particular, compounds having a dibenzothiophene structure can be used from the perspective of carrier balance, specifically CC2 to CC5, CC7, CC9, CC13 to CC16, and CC18 to CC21.

[0147] Other compounds

[0148] Examples of other compounds that can be used in the organic light-emitting element of this embodiment will be given below.

[0149] As hole injection / transport materials suitable for hole injection layer and hole transport layer, materials that promote hole injection from the anode and have high hole mobility so that the injected holes can be transported to the light-emitting layer can be used. In order to prevent the degradation of film quality such as crystallization in the organic light-emitting element, materials with high glass transition temperature can be used. Examples of low molecular weight and high molecular weight materials with hole injection / transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly (vinylcarbazole), poly (thiophene) and other conductive polymers. These hole injection / transport materials are also suitable for electron blocking layers.

[0150] Non-limiting specific examples of compounds useful as hole injection / transport materials are shown below.

[0151]

[0152] Examples of luminescent materials that primarily contribute to the luminescent function include, in addition to the organic compounds represented by the general formula [1], fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, naphthacene derivatives, anthracene derivatives and rubrene), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organic aluminum complexes such as tris(8-hydroxyquinoline)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes and polymer derivatives such as poly(phenylene vinylene) derivatives, poly(fluorene) derivatives and poly(phenylene) derivatives.

[0153] Non-limiting specific examples of compounds that can be used as light-emitting materials are shown below.

[0154]

[0155]

[0156] Examples of the light-emitting layer main body or auxiliary materials contained in the light-emitting layer include, in addition to the materials belonging to the above-mentioned AA group, BB group and CC group, aromatic hydrocarbon compounds and their derivatives, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organic aluminum complexes such as tris(8-hydroxyquinoline)aluminum, and organic beryllium complexes.

[0157] As the auxiliary material, a compound having a xanthone skeleton, a thioxanthone skeleton, or a benzophenone skeleton that provides a deep LUMO level (far from a vacuum level) similar to an azine skeleton can be used. Specifically, EM28 to EM31 given below can be used.

[0158] Non-limiting specific examples of compounds that can be used as a host or an auxiliary material contained in the light-emitting layer are shown below.

[0159]

[0160] Any electron transport material capable of transporting electrons injected from the cathode to the light-emitting layer can be freely selected in consideration of, for example, the balance with the hole mobility of the hole transport material. Examples of materials capable of transporting electrons include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, These electron transporting materials are also suitable for the hole blocking layer.

[0161] Non-limiting specific examples of compounds that can be used as electron transport materials are shown below.

[0162]

[0163] The following describes the constituent components other than the organic compound layer that constitute the organic light-emitting element of this embodiment. The organic light-emitting element can be provided by forming a first electrode, an organic compound layer, and a second electrode on a substrate. One of the first and second electrodes is an anode, and the other is a cathode. A protective layer, a color filter, and the like can be provided on the second electrode. When a color filter is provided, a planarization layer can be provided between the protective layer and the color filter. The planarization layer can be formed of, for example, an acrylic resin.

[0164] The substrate can be made of quartz, glass, silicon, resin, or metal. Switching elements such as transistors and wiring can be arranged on the substrate, and an insulating layer can be provided thereon. The insulating layer can be made of any material as long as contact holes can be formed to provide electrical connection between the anode and the wiring and the anode can be insulated from the wiring not connected to the anode. For example, resins such as polyimide, silicon oxide, and silicon nitride can be used.

[0165] The material used for the anode is expected to have a work function as high as possible. For example, elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium and tungsten can be used, mixtures comprising these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide. Conductive polymers such as polyaniline, polypyrrole and polythiophene can also be used. These electrode materials can be used alone or in combination of two or more. The anode can be composed of a single layer or multiple layers. When the anode is used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, their alloys or their laminates can be used. When the anode is used as a transparent electrode, a transparent conductive layer made of oxides such as indium tin oxide (ITO) or indium zinc oxide can be used, but these materials are non-limiting examples. Photolithography can be used for anode formation.

[0166] The constituent material for the cathode is expected to have a low work function. Examples of such materials include alkali metals such as lithium; alkaline earth metals such as calcium; elemental metals such as aluminum, titanium, manganese, silver, lead and chromium; and mixtures containing these elemental metals. Alloys of these elemental metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combinations of two or more. The cathode can be composed of a single layer or multiple layers. In particular, silver is preferably used, and a silver alloy is more preferably used to suppress the aggregation of silver. As long as the aggregation of silver can be suppressed, the content ratio in the alloy is not limited, for example, it can be 1:1.

[0167] There is no particular limitation on the cathode, and it can be formed as a conductive oxide layer such as ITO to provide a top-emitting element, or it can be formed as a reflective electrode such as aluminum (Al) to provide a bottom-emitting element. The cathode can be formed by any method. For example, DC and AC sputtering methods can be used because these methods provide good film coverage and easily reduce resistance.

[0168] After the cathode is formed, a protective layer can be provided. For example, by bonding a glass plate provided with a moisture absorbent to the cathode, it is possible to suppress the penetration of water and the like into the organic compound layer, and the occurrence of poor display can be suppressed. In another embodiment, a passivation film made of silicon nitride and the like can be provided on the cathode to suppress the penetration of water and the like into the organic compound layer. For example, the protective layer can be formed as follows: after forming the cathode, the resultant is transported to another chamber without destroying the vacuum, and a silicon nitride film having a thickness of 2 μm is formed by chemical vapor deposition (CVD). After the film is formed by CVD, atomic layer deposition (ALD) can be performed to form a protective layer.

[0169] Color filters can be provided on the pixels. For example, color filters sized to fit the pixels can be provided on another substrate and attached to the substrate on which the organic light-emitting elements are provided. Alternatively, the color filters can be patterned by photolithography on a protective layer made of silicon oxide or the like.

[0170] Each organic compound layer (for example, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer) constituting the organic light-emitting element according to the present embodiment is formed by any one of the following methods. Specifically, dry methods such as vacuum deposition, ion plating, sputtering, or plasma deposition can be used to form each organic compound layer. Instead of the dry method, a wet method in which a solution in an appropriate solvent is applied by a known coating method (for example, spin coating, dipping, casting, LB technology, or inkjet method) to form a layer can also be used. When these layers are formed, for example, by vacuum deposition or solution coating, these layers are less likely to undergo crystallization, etc. and are highly stable over time. When the coating method is used for film formation, a suitable binder resin can be used in combination to form the film. Examples of binder resins include, but are not limited to, polyvinyl carbazole resins, polycarbonate resins, polyester resins, ABS resins, acrylic resins, polyimide resins, phenolic resins, epoxy resins, silicone resins, and urea-formaldehyde resins. The binder resin may be used alone as a homopolymer or a copolymer, or may be used as a mixture of two or more. In addition, known additives such as a plasticizer, an antioxidant, and an ultraviolet absorber may be optionally used in combination.

[0171] Device including organic light emitting element

[0172] The organic light emitting element according to this embodiment can be used as a component of a display device or a lighting device. Other uses include exposure light sources in electrophotographic image forming devices, backlights in liquid crystal display devices, and light emitting devices including white light sources with color filters.

[0173] The display device may be an image information processing device that includes an image input unit that receives image information from an area array CCD, a linear array CCD, or a memory card, an information processing unit that processes the input information, and a display unit that displays the input image. The display device includes a plurality of pixels, and at least one of the plurality of pixels may include an organic light-emitting element according to this embodiment and a transistor connected to the organic light-emitting element. In this case, the substrate may be a semiconductor substrate made of silicon or the like, and the transistor may be a MOSFET formed on the substrate.

[0174] The display unit of an imaging device or inkjet printer may have a touch panel function. The touch panel function may be activated by any system such as an infrared system, an electrostatic capacitance system, a resistive film system, or an electromagnetic induction system. The display device may also be used in the display unit of a multifunction printer.

[0175] Next, a display device according to the embodiment will be described with reference to the accompanying drawings.

[0176] Figure 3A and Figure 3B Schematic cross-sectional views each showing an example of a display device including an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin film transistor (TFT).

[0177] Figure 3A is an example of a pixel as a component of a display device according to the present embodiment. The pixel has a sub-pixel 10. The sub-pixels are divided into sub-pixels 10R, 10G, and 10B according to their luminescence. The luminescent color can be distinguished by the wavelength of the light emitted from the luminescent layer. Alternatively, the light emitted from the sub-pixel can be selectively transmitted through a color filter or the like, or color conversion can be performed by a color filter or the like. Each sub-pixel includes a reflective electrode 2 serving as a first electrode on an interlayer insulating layer 1, an insulating layer 3 covering the edge of the reflective electrode 2, an organic compound layer 4 covering the first electrode and the insulating layer, a transparent electrode 5, a protective layer 6, and a color filter 7.

[0178] The interlayer insulating layer 1 may include transistor and capacitor elements below or inside the interlayer insulating layer 1 .

[0179] The transistor and the first electrode may be electrically connected to each other through a contact hole (not shown) or the like.

[0180] The insulating layer 3 is also called a bank or a pixel separation film. The insulating layer 3 is arranged to cover the edge of the first electrode and surround the first electrode. The portion where the insulating layer is not provided is in contact with the organic compound layer 4 and serves as a light-emitting region.

[0181] The organic compound layer 4 includes a hole injection layer 41 , a hole transport layer 42 , a first light-emitting layer 43 , a second light-emitting layer 44 , and an electron transport layer 45 .

[0182] The second electrode 5 may be a transparent electrode, a reflective electrode or a semi-transparent electrode.

[0183] The protective layer 6 reduces the penetration of water into the organic compound layer. Although the protective layer is shown as a single layer, it can be composed of multiple layers. These layers can be composed of an inorganic compound layer and an organic compound layer.

[0184] Color filters 7 are divided into color filters 7R, 7G, and 7B according to their colors. The color filters can be formed on a planarization film (not shown). A resin protective layer (not shown) can be provided on the color filters. The color filters can be formed on the protective layer 6. The color filters can be formed on an opposing substrate such as a glass substrate and then attached.

[0185] Figure 3B The display device 100 includes an organic light-emitting element 26 and a TFT 18, which is an example of a transistor. An insulating layer 12 is provided on a substrate 11 made of glass, silicon, or the like. Active elements such as the TFT 18 are provided on the insulating layer 12 and are composed of a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15.

[0186] The TFT 18 includes a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided over the TFT 18. An anode 21 and the source electrode 17 constituting the organic light emitting element 26 are connected to each other through a contact hole 20.

[0187] The electrodes (anode 21 and cathode 23) included in the organic light emitting element 26 and the electrodes (source electrode 17 and drain electrode 16) included in the TFT do not necessarily have to be connected in a uniform manner. Figure 3B It is only necessary to electrically connect the anode 21 or the cathode 23 to the source electrode 17 or the drain electrode 16 of the TFT 18.

[0188] Although the organic compound layer 22 is Figure 3B The display device 100 in FIG. 1 is shown as a single layer, but the organic compound layer 22 may be composed of a plurality of layers. A first protective layer 25 and a second protective layer 24 for suppressing degradation of the organic light emitting element are provided above the cathode 23 .

[0189] Despite Figure 3BAlthough transistors are used as switching elements in the display device 100 in FIG. 1 , other switching elements such as metal-insulator-metal (MIM) elements may be used instead.

[0190] Figure 3B The transistors used in the display device 100 may be thin film transistors including an active layer on an insulating surface of a substrate, or may be transistors obtained using a single crystal silicon wafer. The active layer may be formed of, for example, single crystal silicon, non-single crystal silicon such as amorphous silicon or microcrystalline silicon, or non-single crystal oxide semiconductors such as indium zinc oxide or indium gallium zinc oxide. Thin film transistors are also called TFT elements.

[0191] exist Figure 3B The transistors included in the display device 100 may be formed in a substrate such as a Si substrate. The phrase "formed in a substrate" means that the transistors are produced by processing the substrate itself such as a Si substrate. In other words, having a transistor in a substrate may also mean that the substrate and the transistor are formed integrally.

[0192] The organic light emitting element according to the present embodiment has a light emitting brightness controlled by a TFT as an example of a switching element. When a plurality of organic light emitting elements are arranged in a plane, an image can be displayed with different light emitting brightness. The switching element according to the present embodiment does not necessarily have to be a TFT, and may be a transistor formed of low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. The phrase "on a substrate" can be replaced with "in a substrate". Whether to set a transistor in the substrate or use a TFT is selected depending on the size of the display unit. For example, when the size of the display unit is about 0.5 inches, the organic light emitting element can be arranged on a Si substrate.

[0193] Figure 4 An example of a display device according to this embodiment is schematically shown. The display device 1000 may include an upper cover 1001, a lower cover 1009, a touch panel 1003, a display panel 1005, a frame 1006, a circuit substrate 1007, and a battery 1008 disposed between the upper cover 1001 and the lower cover 1009. Flexible printed circuits (FPCs) 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005, respectively. Transistors are printed on the circuit substrate 1007. If the display device is not a mobile body, the battery 1008 can be omitted. When the display device is a mobile body, the battery 1008 can be disposed in other locations.

[0194] The display device according to this embodiment can be used as a display unit of an imaging device, which includes an optical unit having multiple lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may include a display unit that displays information acquired by the imaging element. The display unit may be exposed to the outside of the imaging device or provided in a viewfinder. The imaging device may be a digital camera or a digital video camera. The imaging device may be referred to as a photoelectric conversion device.

[0195] Figure 5A An example of an imaging device according to this embodiment is schematically shown. An imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operating unit 1103, and a housing 1104. The viewfinder 1101 may include a display device according to this embodiment. In this case, the display device may display not only the image to be captured but also environmental information, image capture instructions, and the like. Environmental information may include, for example, the intensity of external light, the direction of external light, the speed of movement of the subject, and the likelihood that the subject is obscured by an object.

[0196] Because the time available for capturing an image is only a fraction of a second, it is desirable to display information as quickly as possible. Therefore, a display device including an organic light-emitting element according to this embodiment can be used. This is because organic light-emitting elements have a high response speed. Display devices including such organic light-emitting elements are more suitable for use than such devices and liquid crystal display devices, which require high display speeds.

[0197] The imaging device 1100 includes an optical unit (not shown). The optical unit includes a plurality of lenses and focuses an image on an imaging element housed in a housing 1104. By adjusting the relative positions of the plurality of lenses, the focus can be adjusted. This operation can also be performed automatically.

[0198] The display device according to the present embodiment may include a red color filter, a green color filter, and a blue color filter. The red color filter, the green color filter, and the blue color filter may be arranged in a delta arrangement.

[0199] The display device according to this embodiment can be used in a display unit of an electronic device such as a mobile terminal. In this case, the display device can have both a display function and an operation function. Examples of mobile terminals include mobile phones such as smartphones, tablet computers, and head-mounted displays.

[0200] Figure 5BAn example of an electronic device according to this embodiment is schematically shown. Electronic device 1200 includes a display unit 1201, an operating unit 1202, and a housing 1203. Housing 1203 may include a circuit, a printed circuit board including the circuit, a battery, and a communication unit. Operating unit 1202 may be a button or a touch response unit. The operating unit may be, for example, a biometric unit for unlocking via fingerprint recognition. An electronic device including a communication unit may also be referred to as a communication device.

[0201] Figure 6A and Figure 6B An example of the display device according to the present embodiment is schematically shown. Figure 6A 13 shows a display device such as a TV monitor or a PC monitor. The display device 1300 includes a frame 1301 and a display unit 1302. The light emitting device according to this embodiment can be used for the display unit 1302. The display device 1300 includes a base 1303 supporting the frame 1301 and the display unit 1302. The base 1303 does not necessarily have to be Figure 6A The lower side of the frame 1301 can be used as a base. The frame 1301 and the display unit 1302 can be curved so that the display surface of the display unit 1302 is curved. The curvature radius can be 5,000 mm or more and 6,000 mm or less.

[0202] Figure 6B Another example of the display device according to the present embodiment is schematically shown. Figure 6B The display device 1310 in the embodiment is configured to be foldable and is a so-called foldable display device. The display device 1310 includes a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may include a light-emitting device according to the present embodiment. The first display unit 1311 and the second display unit 1312 may be seamless, monolithic display devices. The first display unit 1311 and the second display unit 1312 may be divided by a bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit may display a single image together.

[0203] Figure 7AAn example of a lighting device according to this embodiment is schematically shown. Lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404 that transmits light emitted from light source 1402, and a light diffusion unit 1405. Light source 1402 may include an organic light-emitting element according to this embodiment. The filter may be a filter for improving the color rendering characteristics of the light source. The light diffusion unit effectively diffuses the light from the light source and helps the light reach a wide area for example, to be illuminated. The optical filter and the light diffusion unit may be arranged on the light-emitting side of the lighting device. Optionally, a cover may be arranged on the outermost portion.

[0204] The lighting device is, for example, an indoor lighting device. The lighting device can emit cool white light, daylight white light, or any other color of light ranging from blue to red. The lighting device can include a light modulation circuit that modulates the light or a color modulation circuit that modulates the color of the emitted light. The lighting device can include an organic light-emitting element according to this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage into DC voltage. Cool white has a color temperature of 4200K, while daylight white has a color temperature of 5000K. The lighting device can include a color filter.

[0205] The lighting device according to the present embodiment may further include a heat dissipation unit. The heat dissipation unit is configured to dissipate heat inside the device to the outside of the device and may be formed of, for example, a high specific heat metal or liquid silicone.

[0206] Figure 7B A car is schematically shown as an example of a mobile body according to this embodiment. The car includes taillights as an example of lighting fixtures. The car 1500 includes taillights 1501, and the taillights can be configured to turn on in response to, for example, a braking operation.

[0207] Taillight 1501 may include an organic light-emitting element according to this embodiment. Taillight 1501 may include a protective member to protect the organic light-emitting element. The protective member may be made of any material that has a certain degree of strength and is transparent, and may be made of, for example, polycarbonate. Polycarbonate may be mixed with, for example, a furandicarboxylic acid derivative or an acrylonitrile derivative.

[0208] The car 1500 may include a vehicle body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display unless it is a window for checking the front and rear of the car. The transparent display may include the organic light emitting element according to this embodiment.

[0209] In this case, components such as electrodes of the organic light emitting element are formed of a transparent material.

[0210] The mobile object according to this embodiment may be, for example, a ship, an aircraft, or an unmanned aerial vehicle. The mobile object may include a main body and a lighting fixture provided on the main body. The lighting fixture may emit light for identifying the position of the main body. The lighting fixture includes the organic light-emitting element according to this embodiment.

[0211] Will refer to Figure 8A and Figure 8B The following describes application examples of the display device according to the above embodiment. The display device can be applied to systems that can be worn as wearable devices such as smart glasses, head-mounted displays (HMDs), and smart contact lenses. The imaging and display devices used in these application examples include imaging devices that can photoelectrically convert visible light and display devices that can emit visible light.

[0212] Figure 8A Glasses 1600 (smart glasses) according to one application example are shown. An imaging device 1602, such as a complementary metal oxide semiconductor (CMOS) sensor or a single photon avalanche diode (SPAD), is provided on the front side of a lens 1601 of the glasses 1600. A display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0213] The glasses 1600 further include a controller 1603. The controller 1603 serves as a power source for supplying power to the camera 1602 and the display device according to any embodiment. The controller 1603 controls the operation of the camera 1602 and the display device. The lens 1601 is provided with an optical system for focusing light on the camera 1602.

[0214] Figure 8B Glasses 1610 (smart glasses) according to an application example are shown. Glasses 1610 include a controller 1612, which is equipped with a camera and a display device comparable to camera 1602. Lens 1611 is provided with an optical system for focusing light on the camera in controller 1612 and projecting light emitted from the display device, and an image is projected onto lens 1611. Controller 1612 serves as a power supply to supply power to the camera and display devices, and also controls the operation of the camera and display devices. The controller may include a line of sight detection unit for detecting the wearer's line of sight. Line of sight may be detected using infrared radiation. An infrared light emitting unit emits infrared light toward the eye of a user who is looking at a displayed image. Reflection of the infrared light emitted from the eye is detected by the camera unit including a light receiving element, thereby obtaining a captured image of the eye. Due to the presence of a reduction unit that reduces light from the infrared light emitting unit to the display unit in a plan view, degradation of image quality is reduced.

[0215] The user's gaze toward the displayed image is detected from a captured image of the eyeball obtained by infrared imaging. Any known method can be used for gaze detection using a captured image of the eyeball. For example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0216] More specifically, a gaze detection method based on the pupil-corneal reflection method is performed. Using the pupil-corneal reflection method, a gaze vector representing the direction (rotation angle) of the eyeball is calculated based on the pupil image and Purkinje image contained in the captured image of the eyeball, thereby detecting the user's gaze.

[0217] A display device according to an embodiment of the present disclosure may include an imaging device having a light receiving element, and may control a display image on the display device based on visual line information of a user from the imaging device.

[0218] Specifically, the display device determines a first field of view at which the user is looking and a second field of view outside the first field of view based on the line of sight information. The first field of view and the second field of view may be determined by a controller of the display device, or may be determined by and transmitted from an external controller. In the display area of ​​the display device, the display resolution of the first field of view may be controlled to be higher than the display resolution of the second field of view. In other words, the resolution in the second field of view may be set to be lower than the resolution in the first field of view.

[0219] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on the line of sight information. The first field of view and the second field of view can be determined by a controller of the display device, or can be determined by an external controller and sent therefrom. The resolution of the high-priority area can be controlled to be higher than the resolution of areas other than the high-priority area. That is, the resolution in the relatively low-priority area can be set to be lower.

[0220] Artificial intelligence (AI) can be used to determine the first field of view or a high-priority area. The AI ​​can be a model configured to estimate the sight angle and distance to the gazed object from the eye image by using the eye image and the actual sight direction of the eye in the image as training data. The AI ​​program can be included in a display device, a camera device, or an external device. When the AI ​​program is included in an external device, the acquired data is transmitted to the display device via communication.

[0221] When display control is performed based on visual recognition, smart glasses that further include a camera device for capturing external images are suitable for use. Smart glasses can display the captured external information in real time.

[0222] Figure 9An example of an image forming apparatus according to the present embodiment is schematically shown. Image forming apparatus 40 is an electrophotographic image forming apparatus and includes a photoreceptor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transfer unit 32, a conveying roller 33, and a fixing unit 35. Exposure light source 28 emits light 29 to form an electrostatic latent image on the surface of photoreceptor 27. Exposure light source 28 includes an organic light emitting element according to the present embodiment. Developing unit 31 contains toner, etc. Charging unit 30 charges photoreceptor 27. Transfer unit 32 transfers the developed image to recording medium 34. Conveying roller 33 conveys recording medium 34. Recording medium 34 is, for example, paper. Fixing unit 35 fixes the image formed on recording medium 34.

[0223] Figure 10A and Figure 10B Each shows an exposure light source 28, and each schematically shows how a plurality of light emitting units 36 are arranged on a long substrate. Arrow 37 indicates the row direction of the organic light emitting elements. The row direction is the same as the rotation axis direction of the photoreceptor 27. This direction can also be called the main axis direction of the photoreceptor 27. Figure 10A In FIG, the light emitting portion 36 is arranged along the main axis direction of the photoreceptor 27. Figure 10B In, with Figure 10A Unlike the conventional arrangement, light-emitting sections 36 are arranged alternately in the row direction between the first and second rows. The first and second rows are located at different positions in the column direction. In the first row, multiple light-emitting sections 36 are arranged at intervals. In the second row, light-emitting sections 36 are arranged at positions corresponding to the spaces between light-emitting sections 36 in the first row. In other words, multiple light-emitting sections 36 are also arranged at intervals in the column direction. Figure 10B The arrangement in may be referred to as, for example, a lattice arrangement, a staggered arrangement, or a checkered pattern.

[0224] As described above, use of a device including the organic light emitting element according to the present embodiment can achieve stable display with good image quality over a long period of time.

[0225] Example

[0226] Now, the present disclosure will be described with reference to embodiments. It should be noted that the present disclosure is not limited to these embodiments.

[0227] Example 1 (Synthesis of Exemplary Compounds A25 and A33)

[0228] Exemplary compounds A25 and A33 were synthesized by the following synthetic scheme.

[0229]

[0230] (1) Synthesis of compound m-2

[0231] Place the following reagents and solvent into a 2000 mL recovery flask.

[0232] Compound m-1: 10.0 g (0.05 mol)

[0233] Bromine: 6.9 g (0.04 mol)

[0234] Chloroform: 500ml

[0235] Next, the reaction solution was stirred at room temperature under a nitrogen stream. After the reaction was completed, water was added at room temperature and the reaction solution was subjected to liquid-liquid extraction. The organic layer was concentrated and the resulting residue was purified by column chromatography (chloroform / heptane=1:4) and then recrystallized from chloroform / methanol to obtain 11.3 g of light brown solid m-2 (yield: 82%).

[0236] (2) Synthesis of compound m-3

[0237] Place the following reagents and solvent into a 200 mL recovery flask.

[0238] Compound m-2: 10.0 g (35.1 mmol)

[0239] Bis-pinacol diborane: 13.4 g (52.6 mmol)

[0240] Pd(PPh3)2Cl2: 0.3 g (0.04 mmol)

[0241] Potassium acetate: 8.6 g (87.7 mmol)

[0242] Dioxane: 200ml

[0243] Next, the reaction solution was heated under stirring under a nitrogen stream. After the reaction was completed, pure water was added at room temperature. The reaction solution was extracted with toluene, and the extract was concentrated. The resulting residue was then purified by column chromatography (toluene / heptane = 1:4) and then washed by dispersion with heptane to obtain 8.1 g of light brown solid m-3 (yield: 70%).

[0244] (3) Synthesis of Compound m-5

[0245] Place the following reagents and solvent into a 200 ml recovery flask.

[0246] Compound m-3: 5.0 g (15.0 mmol)

[0247] Compound m-4: 2.85 g (18.1 mmol)

[0248] Pd(PPh3)4:0.17g

[0249] Toluene: 50ml

[0250] Ethanol: 25ml

[0251] 2M sodium carbonate aqueous solution: 25ml

[0252] Next, the reaction solution was heated at 80 ° C for 6 hours under a stream of nitrogen with stirring. After the reaction was completed, water was added and liquid-liquid extraction was performed. The resulting product was dissolved in chloroform, purified by column chromatography (chloroform), and then recrystallized from chloroform / methanol to obtain 2.2 g of light yellow solid compound m-5 (yield: 52%).

[0253] (4) Synthesis of Compound m-6

[0254] Place the following reagents and solvent into a 200 ml recovery flask.

[0255] 2-Ethoxyethanol: 30ml

[0256] Ion exchange water: 10ml

[0257] Iridium (III) chloride hydrate: 0.45 g

[0258] Compound m-5: 1.0 g (3.5 mmol)

[0259] Next, the reaction solution was heated to 120° C. and stirred for 6 hours. After cooling, water was added, and the resulting product was filtered and washed with water. The resulting product was dried to obtain 1.2 g of yellow solid compound m-6 (yield: 87%).

[0260] (5) Synthesis of Example Compound A25

[0261] Place the following reagents and solvent into a 200 mL recovery flask.

[0262] 2-Ethoxyethanol: 30ml

[0263] Compound m-6: 1.0 g (0.6 mmol)

[0264] Compound m-7: 0.25 g (2.5 mmol)

[0265] Sodium carbonate: 0.7 g (6.3 mmol)

[0266] Next, the reaction solution was heated to 100° C. and stirred for 6 hours. After cooling, methanol was added, and the resulting product was filtered and washed with methanol. The resulting product was dried to obtain 0.7 g of yellow solid Example Compound A25 (yield: 64%).

[0267] Mass spectrometry analysis of Exemplified Compound A25 was performed using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker Corporation).

[0268] MALDI-TOF-MS

[0269] Measured value: m / z = 857, calculated value: C 47 H 40 IrN2O2=857

[0270] (6) Synthesis of Example Compound A33

[0271] Place the following reagents and solvent into a 50 ml recovery flask.

[0272] Example compound A25: 0.5 g (0.6 mmol)

[0273] Compound m-5: 1.7 g (5.8 mmol)

[0274] Glycerin: 15ml

[0275] Next, the reaction solution was heated to 230° C. and stirred for 3 hours. After cooling to 100° C., 2 mL of toluene was added and the resulting product was stirred to room temperature. Subsequently, heptane was added and the resulting product was filtered. The residue was purified by silica gel column chromatography (ethyl acetate) to obtain 0.1 g of dark yellow solid A33 (yield: 20%).

[0276] Mass spectrometry analysis of Exemplified Compound A25 was performed using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker Corporation).

[0277] MALDI-TOF-MS

[0278] Measured value: m / z = 1040, calculated value: C 63 H 49 IrN3=1040

[0279] Examples 2 to 7 (Synthesis of Exemplary Compounds)

[0280] The exemplary compounds of Examples 2 to 7 shown in Table 2 were synthesized in the same manner as in Example 1, except that the starting materials m-2, m-4, and m-7 were changed. The measured values ​​(m / z) of the mass spectrum measured in the same manner as in Example 1 are also shown.

[0281] Table 2

[0282]

[0283] Examples 8 and 9 (Synthesis of Exemplary Compounds)

[0284] The exemplary compounds of Examples 8 and 9 shown in Table 3 were synthesized in the same manner as in Example 1, except that the starting materials m-2, m-4, and m-5 were changed. The measured values ​​(m / z) of the mass spectrum measured in the same manner as in Example 1 are also shown.

[0285] Table 3

[0286]

[0287] Example 10 (Synthesis of Example Compound A1)

[0288] Exemplified Compound A1 was synthesized by the following synthesis scheme.

[0289]

[0290] (1) Synthesis of compound k-2

[0291] The synthesis of compound k-2 from compound k-1 is the same as the synthesis of compound m-6 (4) in Example 1, and thus the description thereof is omitted.

[0292] (2) Synthesis of Example Compound A1

[0293] Place the following reagents and solvent into a 200 ml recovery flask.

[0294] Compound k-2: 1.0 g (0.9 mmol)

[0295] AgOTf: 0.5 g (1.9 mmol)

[0296] Dichloromethane: 50ml

[0297] Methanol: 2ml

[0298] Next, the reaction solution was stirred at room temperature for 6 hours, and then the solvent was distilled off under reduced pressure to obtain a yellow solid.

[0299] Next, the obtained yellow solid and the following reagents and solvents were placed in a 200 ml recovery flask. Compound k-3 was synthesized according to steps (1) to (3) in Example 1.

[0300] Ethanol: 30ml

[0301] Compound k-3: 0.4 g (1.4 mmol)

[0302] The reaction solution was then heated to 85° C. and stirred for 3 hours. After cooling, the mixture was filtered. The residue was purified by silica gel column chromatography (chloroform:heptane=1:1) to obtain 0.9 g of dark yellow solid A1 (yield: 59%).

[0303] Mass spectrometry analysis of Exemplified Compound A1 was performed using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker Corporation).

[0304] MALDI-TOF-MS

[0305] Measured value: m / z = 783, calculated value: C 43 H 32 IrN3=783

[0306] Examples 11 to 20 (Synthesis of Exemplary Compounds)

[0307] The exemplary compounds of Examples 11 to 20 shown in Table 4 were synthesized in the same manner as in Example 10, except that the starting materials k-1 and k-3 were changed. The measured values ​​(m / z) of the mass spectrum measured in the same manner as in Example 10 are also shown.

[0308] Table 4

[0309]

[0310] Comparative Examples 1 and 2 (Synthesis of Comparative Compounds)

[0311] Comparative Compound 1-a and Comparative Compound 1-b shown in Table 5 were synthesized in the same manner as in Example 1 except that the starting materials m-2 and m-4 were changed. Measured values ​​(m / z) of the mass spectrum measured in the same manner as in Example 1 are also shown.

[0312] Table 5

[0313]

[0314] During attempts to sublimate and purify Comparative Compound 1-a, a decrease in purity was observed. Measurement of the emission wavelengths of Comparative Compounds 1-a and 1-b revealed that each had a maximum emission wavelength, λmax, greater than 680 nm and outside the visible light region. Therefore, Comparative Compounds 1-a and 1-b are not suitable for use in organic light-emitting elements for image display devices such as monitors. Furthermore, during attempts to sublimate and purify Comparative Compound 1-b, sublimation purification was unsuccessful, and decomposition was observed. This is likely due to the high sublimation temperature of the pyrene skeleton, which has very high ligand planarity, and the occurrence of thermal decomposition before sublimation, as described above.

[0315] Example 21

[0316] An organic light-emitting element having a bottom emission structure is produced in which an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode are sequentially formed on a substrate.

[0317] First, an ITO film was formed on a glass substrate and patterned as desired to form an ITO electrode (anode). At this time, an ITO electrode with a thickness of 100 nm was formed. The substrate on which the ITO electrode was formed in this manner was used as an ITO substrate in the following method. Next, a 1.33×10 -4 The organic compound layer and electrode layer shown in Table 6 were continuously formed on the ITO substrate by vacuum deposition with resistance heating in a vacuum chamber at 100 Pa. At this time, the electrode area of ​​the counter electrode (metal electrode layer, cathode) was set to 3 mm 2 .

[0318] Table 6

[0319]

[0320] The characteristics of the obtained element were measured and evaluated. The maximum emission wavelength of the light-emitting element was 532 nm and the maximum external quantum efficiency (EQE) was 11%. In addition, the light-emitting element was tested at 100 mA / cm 2 The LT95 test was conducted to measure the time required for the luminance degradation rate to reach 5%. When the time required for the luminance degradation rate to reach 5% (LT95) of Comparative Example 3 was taken as 1.0, the LT95 of this embodiment was 1.4.

[0321] In this embodiment, the following measuring equipment was used: Specifically, the current-voltage characteristics were measured with a microammeter 4140B manufactured by Hewlett-Packard Company, and the luminous brightness was measured with a BM7 manufactured by TOPCON Corporation.

[0322] Examples 22 to 31 and Comparative Example 3

[0323] An organic light-emitting element was produced in the same manner as in Example 21, except that the materials used to form each layer were appropriately changed to the compounds shown in Table 7. For layers not listed in Table 7, the same configuration as in Example 21 was used. The characteristics of the resulting element were measured and evaluated in the same manner as in Example 21. The measurement results are shown in Table 7 together with the results of Example 21.

[0324] Table 7

[0325]

[0326] Table 7 shows that the maximum external quantum efficiency (EQE) of Comparative Example 3 is 2%, while the maximum external quantum efficiency of Examples 21 to 31 is 8% to 12%, indicating that the organic light-emitting elements of Examples 21 to 31 have higher luminous efficiency. This is probably because the quantum yield of the organic compound contained as a guest in the light-emitting layer of the organic light-emitting elements of Examples 21 to 31 is higher than that of Comparative Compound 1-a contained as a guest in the light-emitting layer of Comparative Example 3. This may be due to the following: Since the organic compound contained as a guest in the light-emitting layer of the organic light-emitting elements of Examples 21 to 31 each has a tetrahydropyrene skeleton, the π-conjugated system is not excessively extended as described above, and a sufficient MLCT transition can be exhibited.

[0327] Table 7 also shows that the organic light-emitting elements of Examples 21 to 31 have longer lifetimes than the organic light-emitting element of Comparative Example 3. This is presumably because the Ir complex (Comparative Compound 1-a) contained as a guest in the light-emitting layer of the organic light-emitting element of Comparative Example 3 is a material with low sublimability and, as a result, decomposes during vacuum deposition, contaminating the element with impurities, resulting in low element durability. In contrast, the organic compounds contained as guests in the light-emitting layers of the organic light-emitting elements of Examples 21 to 31 each have a tetrahydropyrene skeleton and, as described above, have good sublimability and are stably deposited without decomposition, thereby suppressing degradation of element durability.

[0328] Example 32

[0329] An organic light-emitting element was produced in the same manner as in Example 21, except that the organic compound layer and the electrode layer shown in Table 8 were formed successively.

[0330] Table 8

[0331]

[0332] The characteristics of the resulting element were measured and evaluated in the same manner as in Example 21. The light-emitting element emitted green light and had a maximum external quantum efficiency (EQE) of 19%. A continuous drive test was conducted in the same manner as in Example 21; the LT95 value was 2.6, compared to the LT95 value of 1.0 in Comparative Example 3.

[0333] Examples 33 to 42

[0334] An organic light-emitting element was produced in the same manner as in Example 32, except that the materials used to form each layer were appropriately changed to the compounds shown in Table 9. For each layer not listed in Table 9, the same configuration as in Example 32 was used. The characteristics of the resulting element were measured and evaluated in the same manner as in Example 34. The measurement results are shown in Table 9 together with the results of Example 32.

[0335] Table 9

[0336]

[0337] As described above, by using an organic compound having a tetrahydropyrene skeleton as a guest in a light-emitting layer, an organic light-emitting element having high maximum external quantum efficiency and high light-emitting efficiency is achieved.

[0338] According to the present disclosure, an organic compound having excellent light-emitting properties can be provided.

[0339] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An organic compound represented by formula [1], Ir L m L' n [1] It is characterized by: In formula [1], Ir represents iridium; L and L' represent bidentate ligands different from each other; m is an integer from 1 to 3, and when m is 1, n is 2, when m is 2, n is 1, and when m is 3, n is 0; partial structure IrL m is a partial structure represented by formula [2], and a partial structure IrL' n is a partial structure represented by formula [3-1] or formula [3-2]; when m is 2 or more, the plurality of L sites may be the same or different; and when n is 2 or more, the plurality of L' sites may be the same or different, In formula [2], ring A is selected from formulas [A-1] to [A-4], In formulas [A-1] to [A-4], * represents a binding position, In formulae [2], [3-1], and [A-1] to [A-4], R1 to R4 and R8 to R 11 R5 to R7 and R 12 to R 39 are each independently selected from a hydrogen atom, a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthrenyl group, and a fluoranthenyl group, and In formula [3-2], X1 to X8 are each independently selected from a carbon atom and a nitrogen atom, wherein X1 to X8 are carbon atoms, or wherein X1 to X4 are carbon atoms and one of X5 to X8 is a nitrogen atom, and when X1 to X8 are carbon atoms, each of the carbon atoms has a hydrogen atom or a substituent, and each substituent is independently selected from a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthrenyl group and a fluoranthene group.

2. An organic light-emitting element, comprising: a first electrode; a second electrode; and an organic compound layer disposed between the first electrode and the second electrode and including at least a light-emitting layer, Characterized in that the light-emitting layer comprises the organic compound according to claim 1.

3. The organic light-emitting element according to claim 2, wherein the light-emitting layer further comprises a second organic compound; and The second organic compound has an azine ring as a skeleton; or The second organic compound has a structure selected from benzo[9,10]phenanthrene, phenanthrene, At least one structure of a structure and a fluoranthene structure; or The second organic compound has at least one structure selected from a dibenzothiophene structure and a dibenzofuran structure; or The second organic compound does not have sp3 carbon.

4. The organic light-emitting element according to claim 3, wherein the light-emitting layer further comprises a compound different from the organic compound and the second organic compound, and the compound different from the organic compound and the second organic compound is a compound having a xanthone skeleton, a thioxanthone skeleton or a benzophenone skeleton.

5. The organic light-emitting element according to claim 2, wherein the light-emitting layer is a first light-emitting layer, A second light-emitting layer different from the first light-emitting layer is further provided between the first light-emitting layer and the first electrode or between the first light-emitting layer and the second electrode, and The second light-emitting layer emits light of a color different from the color of light emitted by the light-emitting layer. The organic light-emitting element according to claim 5 , wherein the organic light-emitting element emits white light.

7. A display device comprising a plurality of pixels, It is characterized by: At least one of the plurality of pixels includes the organic light emitting element according to any one of claims 2 to 6 and an active element connected to the organic light emitting element. The display apparatus according to claim 7 , further comprising a color filter.

9. A photoelectric conversion device comprising: an optical unit comprising a plurality of lenses; an imaging element that receives the light that has passed through the optical unit; and a display unit that displays an image captured by the imaging element, It is characterized in that the display unit includes the organic light emitting element according to any one of claims 2 to 6.

10. An electronic device comprising: case; a communication unit for communicating with an external unit; and Display unit, It is characterized in that the display unit includes the organic light emitting element according to any one of claims 2 to 6.

11. A lighting device comprising: light source; and light diffusion unit or optical filter, It is characterized in that the light source includes the organic light emitting element according to any one of claims 2 to 6.

12. A mobile object, comprising: main body; and A lighting fixture is provided on the main body, It is characterized in that the lighting fixture includes the organic light emitting element according to any one of claims 2 to 6.

13. An exposure light source for an electrophotographic image forming apparatus, characterized in that: It includes the organic light-emitting element according to any one of claims 2 to 6.

Images