Organic compounds, organic light-emitting devices, display devices, photoelectric conversion devices, electronic devices, lighting devices, moving objects, and exposure light sources

Abstract

To provide an organic compound excellent in light-emitting properties and sublimability.SOLUTION: An organic compound is represented by the general formula [1], IrLmL'n, where L and L' are specific bidentate ligands different from each other, and a partial structure IrLm is a partial structure represented by the general formula [2].SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] An organic light-emitting element (hereinafter sometimes referred to as an "organic electroluminescence element" or "organic EL element") is an electronic element having a pair of electrodes and an organic compound layer disposed between the electrodes. By injecting electrons and holes from the pair of electrodes, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting element emits light.

[0003] Recent progress in organic light-emitting devices has been remarkable, and some of their features include low driving voltage, diverse emission wavelengths, high-speed response, and the ability to make light-emitting devices thinner and lighter.

[0004] Incidentally, light-emitting organic compounds have been actively developed up to now, because the development of compounds with excellent light-emitting properties is important for providing high-performance organic light-emitting devices.

[0005] As a compound that has been created so far, Non-Patent Document 1 describes the following compound 1-a.

[0006] [ka] [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Inorganic Chemistry, 2013, Vol.52, No.17, pp.9842-9860 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have examined compound 1-a described in Non-Patent Document 1 and found that there is room for improvement in the luminescence characteristics. By improving the luminescence characteristics of the compound, it is possible to provide an organic light-emitting device with even higher luminous efficiency.

[0009] In view of the above problems, an object of the present invention is to provide an organic compound having excellent light-emitting properties. Another object of the present invention is to provide an organic light-emitting device having excellent light-emitting properties. [Means for solving the problem]

[0010] The organic compound according to one aspect of the present invention is represented by the following general formula [1]:

[0011] [ka]

[0012] (In the general formula [1], Ir is iridium. L and L' each represent a different bidentate ligand. m is an integer of 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. The partial structure IrL m is a partial structure represented by the following general formula [2], and the partial structure IrL' n is a partial structure represented by the following general formula [3-1] or general formula [3-2]. When m is 2 or more, the multiple L's may be the same or different. When n is 2, the multiple L's may be the same or different.

[0013] [ka]

[0014] [ka]

[0015] In the general formula [2], ring A is selected from the following general formulae [A-1] to [A-5].

[0016] [ka]

[0017] In the general formulas [A-1] to [A-5], * represents a bonding position.

[0018] In the general formulas [2], [3-1], and [A-1] to [A-5], R1 to R 49 are each 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.

[0019] In the general formula [3-2], X1 to X8 are each independently selected from carbon atoms or nitrogen atoms. When X1 to X8 are carbon atoms, the carbon atoms have hydrogen atoms, deuterium atoms, or substituents, and the substituents are each independently selected from halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted amino groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted silyl groups, cyano groups, substituted or unsubstituted aromatic hydrocarbon groups, and substituted or unsubstituted heterocyclic groups. Effect of the Invention

[0020] According to the present invention, an organic compound having excellent light-emitting properties can be provided. [Brief description of the drawings]

[0021] [Figure 1]1A is a schematic cross-sectional view showing an example of a pixel of a display device according to one embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing an example of a display device using an organic light-emitting element according to one embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Diagram 3] 1A is a schematic diagram illustrating an example of an imaging device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of a portable device according to an embodiment of the present invention. [Figure 4] 1A is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of a foldable display device. [Diagram 5] 1A is a schematic diagram showing an example of a lighting device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an automobile, which is an example of a moving body according to an embodiment of the present invention. [Figure 6] 1A is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, the wearable device having an imaging device. [Figure 7] 1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram illustrating an example of an exposure light source of the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] ≪Organic compounds≫ First, the organic compound according to this embodiment will be described.

[0023] The organic compound according to this embodiment is an organometallic complex represented by the following general formula [1].

[0024] [ka]

[0025] In the general formula [1], Ir is iridium. L and L' each represent a different bidentate ligand. m is an integer of 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 the following general formula [2], and the partial structure IrL' n is a partial structure represented by the following general formula [3-1] or general formula [3-2]. When m is 2 or more, the multiple L's may be the same or different. Multiple types of L may be included. When n is 2, the multiple L's may be the same or different.

[0026] [ka]

[0027] [ka]

[0028] In the general formula [2], ring A is selected from the following general formulae [A-1] to [A-5].

[0029] [ka]

[0030] In the general formulas [A-1] to [A-5], * represents a bonding position.

[0031] In the general formulas [2], [3-1], and [A-1] to [A-5], R1 to R 49 are each 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.

[0032] In the general formula [3-2], X1 to X8 are each independently selected from a carbon atom or a nitrogen atom. When X1 to X8 are carbon atoms, the carbon atoms have a hydrogen atom, a deuterium atom, or a substituent, and the substituent is each 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.

[0033] In the general formulas [2], [3-1], and [A-1] to [A-5], R1 to R 49 are preferably each 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.

[0034] In the general formula [2], R1 to R4, R8 to R 11 are preferably each independently selected from a hydrogen atom and an alkyl group, and more preferably each 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 later, the organic compound represented by general formula [1] has a partial structure represented by general formula [2] and has a tetrahydropyrene skeleton. The tetrahydropyrene skeleton has high planarity, although not as high as the pyrene skeleton, and this planarity promotes interaction with other organic compounds, for example, a host, in the light-emitting layer of the organic light-emitting device. Therefore, in general formula [2], R1 to R4, R8 to R 11 are each independently selected from a hydrogen atom and an alkyl group, the planarity becomes higher than when other substituents are used, and therefore it is preferable.

[0035] In the general formula [3-2], when X1 to X8 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.

[0036] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 may have a halogen atom as a substituent, and R1 to R 49 Examples of the halogen atom represented by the formula (I) include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0037] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 may each be an alkyl group which may have a substituent, and R1 to R 49 Examples of the alkyl group represented by the formula (I) include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group, but are not limited to these.

[0038] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 each represent an alkoxy group which may be substituted, and R1 to R 49 Examples of the alkoxy group represented by the formula (I) include a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, a benzyloxy group, and the like, but are not limited thereto.

[0039] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 each represent an amino group which may be substituted, and R1 to R 49Examples of the amino group represented by the formula (I) include an N-methylamino group, an N-ethylamino group, an N,N-dimethylamino group, an N,N-diethylamino group, an N-methyl-N-ethylamino group, an N-benzylamino group, an N-methyl-N-benzylamino group, an N,N-dibenzylamino group, an anilino group, an N,N-diphenylamino group, an N,N-dinaphthylamino group, an N,N-difluorenylamino group, an N-phenyl-N-tolylamino group, an N,N-ditolylamino group, an N-methyl-N-phenylamino group, an N,N-dianisolylamino group, an N-mesityl-N-phenylamino group, an N,N-dimesitylamino group, an N-phenyl-N-(4-tert-butylphenyl)amino group, an N-phenyl-N-(4-trifluoromethylphenyl)amino group, and an N-piperidyl group, but are not limited thereto.

[0040] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 may have an aryloxy group, a heteroaryloxy group, or R1 to R 49 Examples of the aryloxy group and heteroaryloxy group represented by the following formula include, but are not limited to, a phenoxy group and a thienyloxy group.

[0041] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 each represent a silyl group which may be substituted, and R1 to R 49 Examples of the silyl group represented by the formula (I) include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0042] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 may have an aromatic hydrocarbon group as a substituent, and R1 to R 49 Examples of the aromatic hydrocarbon group represented by the formula (I) include, but are not limited to, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a fluoranthenyl group, and a triphenylenyl group.

[0043] In the general formulae [2], [3-2], [3-1], and [A-1] to [A-5], the carbon atoms of X1 to X8 may have a heterocyclic group as a substituent, and R1 to R 49 Examples of the heterocyclic group represented by the formula (I) include, but are not limited to, a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinyl group, a phenanthrolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group.

[0044] Examples of the substituent that the above alkyl group, alkoxy group, amino group, aryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group may further have include halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tertiary butyl group; alkoxy groups such as methoxy group, ethoxy group, and propoxy group; amino groups such as dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, and ditolylamino group; aryloxy groups such as phenoxy group; aromatic hydrocarbon groups such as phenyl group and biphenyl group; heterocyclic groups such as pyridyl group and pyrrolyl group; and cyano group, but are not limited to these.

[0045] (Features of the organic compound according to this embodiment) Next, the characteristics of the organic compound according to the present embodiment will be described. The organic compound according to the present embodiment has the following characteristics, and therefore has a high quantum yield and excellent sublimation properties. Furthermore, by using this organic compound, an organic light-emitting device having excellent luminous efficiency and element durability can be provided. (1) The quantum yield is high because it has a tetrahydropyrene skeleton. (2) It has excellent sublimation properties due to its tetrahydropyrene structure.

[0046] These features will be described below with reference to comparative compound 1-a, which is a compound described in Non-Patent Document 1.

[0047] (1) The tetrahydropyrene structure gives it a high quantum yield.

[0048] In developing the organic compound of the present invention, the present inventors focused on the structure of the ligand of the organic compound. Specifically, they attempted to improve the quantum yield by using a tetrahydropyrene skeleton in the aromatic ring of the aromatic ring and the heterocyclic ring that constitute the ligand of the Ir complex.

[0049] Here, the results of comparing the emission characteristics of the exemplary compound A25, which is an organic compound according to this embodiment, and the comparative compound 1-a are shown in Table 1. The emission wavelength was measured by photoluminescence (PL) measurement of a diluted toluene solution at room temperature and an excitation wavelength of 350 nm using a Hitachi F-4500. The quantum yield was measured by measuring the absolute quantum yield in a diluted toluene solution using an absolute PL quantum yield measurement device (C9920-02) manufactured by Hamamatsu Photonics KK The quantum yield is expressed as a relative value with the quantum yield of the exemplary compound A25 taken as 1.0.

[0050] [Table 1]

[0051] It is clear from Table 1 that the exemplary compound A25 has a significantly higher quantum yield and is more excellent in luminescence characteristics than the comparative compound 1-a. The present inventors have considered this as follows.

[0052] The structural difference between the two compounds is the aromatic ring coordinated to the Ir metal: the aromatic ring of Comparative Compound 1-a has a pyrene skeleton, whereas that of Exemplary Compound A25 has a tetrahydropyrene skeleton.

[0053] Here, the pyrene skeleton is a condensed polycyclic structure in which four benzene rings are condensed, and the π electrons are delocalized throughout the pyrene skeleton, resulting in an expanded π-conjugated system. Therefore, a ligand having a pyrene skeleton is a ligand with an expanded π-conjugated system. Therefore, the luminescence properties of an Ir complex having a pyrene skeleton ligand are such that the π-π* property is strengthened, while the MLCT (Metal to Ligand Charge Transfer) property, which is an interaction with the Ir metal, is weakened. As a result, it is considered that the quantum yield of phosphorescence emission is reduced in the comparative compound 1-a because sufficient luminescence associated with the MLCT transition cannot be obtained.

[0054] On the other hand, the ligand of the exemplary compound A25 is a ligand having a tetrahydropyrene skeleton. The tetrahydropyrene skeleton has a structure in which two ethylene chains are crosslinked to a biphenyl skeleton, so that the π electrons are not delocalized throughout the tetrahydropyrene skeleton, unlike the pyrene skeleton, and the π conjugated system does not extend to the entire tetrahydropyrene skeleton. As a result, it is considered that a sufficient MLCT transition can be maintained, and therefore a high quantum yield was shown.

[0055] In addition, the emission wavelength (λmax) of the comparative compound 1-a was 626 nm, and the comparative compound 1-a emitted light in the red region, whereas the emission wavelength (λmax) of the exemplary compound A25 was 530 nm, and emitted light in the green region. As described above, this is also due to the difference in the structure of the aromatic ring coordinated to the Ir metal. That is, in the case of the pyrene skeleton, the π-conjugated system spreads over the entire pyrene skeleton, so the emission wavelength shifts to longer wavelengths, resulting in emission in the red region. On the other hand, in the case of the tetrahydropyrene skeleton, the π-conjugated system does not spread over the entire tetrahydropyrene skeleton, so the emission wavelength does not shift to longer wavelengths, resulting in emission in the green region.

[0056] Therefore, in the case of the organic compound according to this embodiment, even if the heterocycle represented by ring A in general formula [1] is a fused heterocycle with two or more rings whose conjugation extends beyond the pyridine ring of example compound A25, it can have an emission wavelength in the visible light region. On the other hand, in the case of a pyrene skeleton such as comparative compound 1-a, if a fused heterocycle with two or more rings whose conjugation extends beyond the pyridine ring is used as the heterocycle, the emission wavelength shifts further to a longer wavelength and the emission becomes in the near infrared region. If the emission wavelength is in the near infrared region or infrared region, the emission cannot reproduce the color of the visible light region that can be seen by humans, and is therefore not suitable for use in image display devices such as displays. In other words, in the case of the organic compound according to this embodiment, even if the heterocycle represented by ring A in general formula [1] is a fused heterocycle with two or more rings, it still emits visible light, and is therefore suitable for use in image display devices such as displays.

[0057] (2) It has excellent sublimation properties due to its tetrahydropyrene structure.

[0058] In developing the organic compound according to the present embodiment, the present inventors focused on the three-dimensional structure of the ligand of the organic compound. Specifically, they attempted a molecular design that reduces the planarity of the ligand.

[0059] Here, Table 2 shows the results of a comparison between Example Compound A25, which is an organic compound according to this embodiment, and Comparative Compound 1-a, focusing on the planarity of the aromatic ring moiety in the ligand.

[0060] [Table 2]

[0061] From Table 2, it can be seen that the pyrene skeleton, which is the aromatic ring of the comparative compound 1-a, has a high planarity. Here, when the planarity of the ligand is high, the π-π interaction between the ligands is increased, and the Ir complex becomes a compound that is prone to aggregation. As a result, the sublimability of the Ir complex is reduced, which is undesirable.

[0062] In contrast, it can be seen that the tetrahydropyrene skeleton, which is the aromatic ring of the exemplary compound A25, has a flexible ethylene chain, and thus the planarity is reduced. More specifically, the two benzene rings contained in the aromatic ring portion are not completely parallel, but have a slightly twisted structure. For this reason, it is possible to suppress the interaction between the ligands, and it is possible to suppress the aggregation of the Ir complex. As a result, the exemplary compound A25 is a compound with excellent sublimation properties.

[0063] Therefore, the compound according to the present embodiment has high sublimability, that is, it can be sublimated at a lower temperature. In addition, the low sublimation temperature suppresses thermal decomposition during sublimation, and allows stable sublimation purification. This also means that the deposition stability is high when an organic light-emitting device is produced using the compound according to the present embodiment. In other words, according to the present embodiment, a deposition film can be produced without decomposition during deposition, and an organic light-emitting device with a long life can be provided.

[0064] The light emitting properties and sublimation properties of the compounds listed in the characteristics (1) and (2) of the organic compound according to this embodiment will be described in more detail in the examples described later.

[0065] (Examples of organic compounds according to this embodiment) Specific examples of the organic compound according to this embodiment are shown below. However, the present invention is not limited to these. In the following structural formulae, the dashed lines represent coordinate bonds.

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] Among the above exemplary compounds, the exemplary compounds (A1 to A40) belonging to group A are organic compounds in which ring A in general formula [2] is a pyridine ring. That is, the organic compounds are those in which ring A in general formula [2] is represented by general formula [A-1]. The exemplary compounds belonging to group A have emission wavelengths in the green to yellow range. By using these compounds, it is possible to provide a light-emitting device in the green to yellow range. Therefore, when ring A in general formula [2] has a structure represented by general formula [A-1], it is suitable as an organic compound for a green light-emitting device.

[0074] Among the above exemplary compounds, the exemplary compounds (B1 to B20) belonging to group B are organic compounds in which ring A in general formula [2] is a quinoline ring. That is, they are organic compounds in which ring A in general formula [2] is represented by general formula [A-2]. The exemplary compounds belonging to group B emit light in the orange to red wavelength range. By using these compounds, it is possible to provide a light-emitting device in the yellow to orange wavelength range.

[0075] Among the above exemplary compounds, the exemplary compounds (C1 to C20) belonging to group C are organic compounds in which ring A in general formula [2] is an isoquinoline ring. That is, they are organic compounds in which ring A in general formula [2] is represented by general formula [A-3]. The exemplary compounds belonging to group C emit light in the orange to red wavelength range. By using these compounds, it is possible to provide a light-emitting device emitting light in the orange to red wavelength range.

[0076] Among the above exemplary compounds, the exemplary compounds (D1 to D40) belonging to group D are organic compounds in which ring A in general formula [2] is a benzoisoquinoline ring. That is, they are organic compounds in which ring A in general formula [2] is represented by general formula [A-4]. The exemplary compounds belonging to group D emit light in the orange to red wavelength range. By using these compounds, it is possible to provide a light-emitting device in the orange to red wavelength range.

[0077] Among the above exemplary compounds, the exemplary compounds (E1 to E20) belonging to group E are organic compounds in which ring A in general formula [2] is a naphthoisoquinoline ring. That is, they are organic compounds in which ring A in general formula [2] is represented by general formula [A-5]. The exemplary compounds belonging to group D have an emission wavelength in the orange to red range. By using these compounds, it is possible to provide a light-emitting device with an emission wavelength in the orange to red range.

[0078] In the general formula [2], when the ring A has a structure represented by the general formulas [A-2] to [A-5], the organic compound is suitable for a red light emitting device, and among these, it is preferable that the ring A has a structure represented by the general formula [A-4]. This is because the emission wavelength is suitable for a red light emitting device and the compound shows excellent characteristics in terms of balance with sublimation property.

[0079] <Organic light-emitting element> Next, the organic light-emitting device according to this embodiment will be described.

[0080] A specific device configuration of the organic light-emitting device according to this embodiment includes a multi-layer device configuration in which the electrode layers and organic compound layers shown in (1) to (6) below are sequentially laminated on a substrate. That is, the organic light-emitting device according to this embodiment at least has a pair of electrodes, an anode and a cathode, and an organic compound layer disposed between these electrodes. In any device configuration, the organic compound layer necessarily includes a light-emitting layer having a light-emitting material. (1) Anode / light-emitting layer / cathode (2) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (4) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode (5) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) Anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode

[0081] However, these device configuration examples are merely very basic device configurations, and the device configuration of the organic light-emitting device of the present invention is not limited to these. 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. Also, the electron transport layer or the hole transport layer may have a multilayer structure having two layers with different ionization potentials. The light-emitting layer may have a multilayer structure having two layers each containing a different light-emitting material. 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 the anode and the cathode. The first light and the second light may be different colors, for example, light that becomes white when mixed, to provide an organic light-emitting device that emits white light. In addition to this, various layer configurations can be adopted.

[0082] In this embodiment, the extraction mode (element form) of the light output from the light emitting layer may be a so-called bottom emission type in which light is extracted from the electrode on the substrate side, or a so-called top emission type in which light is extracted from the opposite side of the substrate. Also, a double-sided extraction type in which light is extracted from the substrate side and the opposite side of the substrate may be adopted.

[0083] Among the device configurations shown in (1) to (6) above, the configuration (6) is preferable because it has both an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). In other words, in the configuration (6) having an electron blocking layer and a hole blocking layer, both hole and electron carriers can be reliably confined within the light-emitting layer, resulting in an organic light-emitting device with no carrier leakage and high light-emitting efficiency.

[0084] The organic light-emitting element according to this embodiment contains an organic compound represented by the above-mentioned general formula [1] in the organic compound layer. The organic light-emitting element according to this embodiment preferably contains an organic compound represented by the above-mentioned general formula [1] in the light-emitting layer. However, the present invention is not limited thereto, and the organic compound may be used as a constituent material of an organic compound layer other than the light-emitting layer constituting the organic light-emitting element according to this embodiment. Specifically, the organic compound may be used as a constituent material of an electron transport layer, an electron injection layer, an electron blocking layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc.

[0085] In the organic light-emitting device 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 consisting of only the organic compound represented by the general formula [1]. Alternatively, the light-emitting layer may be a layer consisting of the organic compound represented by the general formula [1] and a second compound which is another compound. Here, when the light-emitting layer is a layer consisting of the organic compound represented by the general formula [1] and another compound, the organic compound according to this embodiment may be used as a host (also called a host material) of the light-emitting layer or as a guest (also called a guest material). It may also be used as an assist material which may be contained in the light-emitting layer.

[0086] Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. The guest is the compound with a smaller mass ratio than the host among the compounds constituting the light-emitting layer, and is the compound that is mainly responsible for emitting light. The assist material is the compound with a smaller mass ratio than the host among the compounds constituting the light-emitting layer, and assists the light emission of the guest. The assist material is also called the second host.

[0087] In addition, the host is preferably a material having a higher LUMO than the guest (a material having a LUMO closer to the vacuum level). This allows electrons supplied to the host in the light-emitting layer to be efficiently transferred to the guest, improving the light-emitting efficiency. Furthermore, when an assist material is used in addition to the host and guest, the host is preferably a material having a higher LUMO than the assist material (a material having a LUMO closer to the vacuum level). This allows electrons supplied to the host in the light-emitting layer to be efficiently transferred to the assist material, allowing the assist material to take on exciton recombination. As a result, it becomes possible to efficiently transfer energy to the guest.

[0088] The energy of the excited singlet state (S1) of the host (singlet energy) is S h1 , the energy of the excited triplet state (T1) (triplet energy) is T h1 Let guest S1's energy be S g1 , the energy of T1 is T g1 In this case, S h1 >S g1 It is preferable that T h1 >T g1 It is more preferable to satisfy the following. Furthermore, the energy of S1 of the assist material is S a1 , the energy of T1 is T a1 Then, S a1 >S g1 It is preferable to satisfy T a1 >T g1 It is more preferable that S h1 >S a1 >S g1It is more preferable to satisfy T h1 >T a1 >T g1 It is more preferable that the following condition is satisfied.

[0089] 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% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, based on the total mass of the light-emitting layer.

[0090] The present inventors have conducted various investigations and found that when an organic compound represented by general formula [1] is used as a host or guest in an emission layer, particularly as a guest in an emission layer, an organic light-emitting element having excellent luminous efficiency and durability can be obtained.

[0091] When the organic light-emitting element according to this embodiment contains an organic compound represented by general formula [1] in the light-emitting layer, it is preferable that the compound contained in the light-emitting layer satisfies the following conditions. Note that a plurality of the following conditions may be satisfied simultaneously. As described above, the organic compound represented by general formula [1] is preferably used as a guest in the light-emitting layer, and therefore, in each of the following conditions, it is preferable that the second organic compound is a host in the light-emitting layer. (3) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having an azine skeleton. (4) The light-emitting layer contains an organic compound represented by general formula [1] and a second organic compound having at least one structure selected from the group consisting of a triphenylene structure, a phenanthrene structure, a chrysene structure, and a fluoranthene structure. (5) The light-emitting layer contains an 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. (6) The light-emitting layer contains an organic compound represented by general formula [1] and a second organic compound having no sp3 carbon.

[0092] Each of the above conditions will now be described.

[0093] (3) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having an azine skeleton.

[0094] The organic compound represented by the general formula [1] is an organic compound with a tetrahydropyrene skeleton. This organic compound has a structure in which two electron-donating alkyl groups are introduced to the benzene ring coordinated to the Ir metal. Therefore, the HOMO is shallower (closer to the vacuum level) than when no electron-donating alkyl groups are introduced to the benzene ring coordinated to the Ir metal.

[0095] Therefore, a compound with a deep LUMO is preferable as the second organic compound that forms the light-emitting layer together with the organic compound represented by the general formula [1]. This is because, by using such a second organic compound, the organic compound represented by the general formula [1] is responsible for the transfer of holes injected from the hole transport layer to the light-emitting layer, and the second organic compound is responsible for the transfer of electrons injected from the electron transport layer. As a result, carrier injection from the surrounding layer to the light-emitting layer becomes smooth, and unnecessary charge accumulation can be prevented. This can be expected to improve low-voltage operation and device durability.

[0096] Here, the inventors have found that compounds with azine rings in the skeleton are preferable as materials with deep LUMO. Azine rings such as pyridine, pyrazine, pyrimidine, and triazine are electron-deficient heterocycles. In other words, by having these structures, it is expected that the compound will have a deep LUMO.

[0097] On the other hand, compounds having an azine ring tend to have not only a deep LUMO but also a deep HOMO. If the HOMO is too deep, the hole injection from the hole transport layer to the light emitting layer may be reduced. Therefore, it is particularly preferable that the second organic compound further has a carbazole skeleton, which is expected to suppress the HOMO from becoming deep enough to maintain the hole injection characteristics. That is, it is particularly preferable that the second organic compound has a carbazole skeleton and an azine skeleton. As a result, by combining with an organic compound represented by the general formula [1], it is possible to realize an emission layer that has a suitable HOMO-LUMO gap and has good carrier injection from the hole transport layer and the electron transport layer to the emission layer.

[0098] In addition, an organic compound having only an arylamine or carbazole skeleton without an azine ring is an organic compound having a shallow HOMO and a shallow LUMO. When such an organic compound is combined with an organic compound represented by general formula [1] as a second organic compound, the entire light-emitting layer has a shallow HOMO and a shallow LUMO. Therefore, there is a concern that the electron injection from the electron transport layer to the light-emitting layer will be reduced. Specifically, CBP (4,4'-bis(9H-carbazol-9-yl)biphenyl) and the like are not preferable as a second compound to be used with an organic compound represented by general formula [1].

[0099] (4) The light-emitting layer contains an organic compound represented by general formula [1] and a second organic compound having at least one structure selected from the group consisting of a triphenylene structure, a phenanthrene structure, a chrysene structure, and a fluoranthene structure.

[0100] The organic compound represented by the general formula [1] is an organic compound having a tetrahydropyrene skeleton. As shown in Table 2, in the tetrahydropyrene skeleton, the two benzene rings are bonded in a direction away from the Ir metal, and although not as planar as the pyrene skeleton, it has a high degree of planarity.

[0101] For this reason, it is preferable that the second organic compound used in combination with the organic compound represented by the general formula [1] has an aromatic ring and a highly planar structure. This is because the second organic compound has a highly planar structure, and the highly planar portions of the second organic compound interact with the organic compound represented by the general formula [1] to approach each other. More specifically, the planar portion of the second organic compound is more likely to approach the tetrahydropyrene portion of the organic compound represented by the general formula [1]. For this reason, it is expected that the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound will be shortened.

[0102] It is known that triplet energy used for phosphorescence emission in organic light-emitting devices undergoes energy transfer via the Dexter mechanism. The Dexter mechanism is a mechanism in which energy transfer occurs through contact between molecules. In other words, by shortening the intermolecular distance between the host and the guest, energy transfer from the host to the guest is efficiently performed.

[0103] By using a highly planar organic compound as the second organic compound, the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound is shortened, and energy transfer by the Dexter mechanism between the two compounds occurs more efficiently. More specifically, when the second organic compound is used as a 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.

[0104] Here, the highly planar structure specifically refers to a triphenylene structure, a phenanthrene structure, a chrysene structure, or a fluoranthene structure. Among them, it is preferable to have a triphenylene structure from the viewpoint of planarity. By using a compound having at least one of these structures as the second organic compound and combining it with the organic compound represented by the general formula [1], a more efficient light-emitting element can be provided.

[0105] (5) The light-emitting layer contains an 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.

[0106] The organic compound represented by the general formula [1] is an organic compound having a tetrahydropyrene skeleton in the ligand. Therefore, as shown in Table 3 below, the HOMO site formed by the ligand and Ir metal has a characteristic molecular orbital in which the conjugation does not extend to the end of the tetrahydropyrene site.

[0107] For this reason, in the HOMO molecular orbital, the terminal portion of the tetrahydropyrene skeleton becomes an empty orbital, and the hole transport ability is reduced compared to when the conjugation extends to the terminal portion of the tetrahydropyrene skeleton.

[0108] In order to compensate for this hole transporting ability, the second organic compound used in combination with the organic compound represented by the general formula [1] is preferably a compound having a skeleton with excellent hole transporting ability. A skeleton with excellent hole transporting ability is a skeleton having a large number of unshared electron pairs and high electron donating ability. Specifically, skeletons having electron donating nitrogen atoms such as carbazole as described in (3) above, and skeletons having chalcogen atoms having a large number of unshared electron pairs such as dibenzothiophene structure and dibenzofuran structure can be mentioned.

[0109] Of these, the second organic compound that can be suitably used together with the organic compound represented by the general formula [1] preferably has at least one skeleton of a dibenzothiophene structure or a dibenzofuran structure. The skeletons of the dibenzothiophene structure and the dibenzofuran structure rarely have an extremely shallow HOMO, so they can adjust the carrier balance of holes and electrons and are suitable as skeletons that support the hole transport ability of the organic compound represented by the general formula [1]. Among these, it is particularly preferable that the second organic compound has a dibenzothiophene structure that is rich in unshared electron pairs.

[0110] [Table 3]

[0111] (6) The light-emitting layer contains an organic compound represented by general formula [1] and a second organic compound having no sp3 carbon.

[0112] As described in (4) above, the light-emitting properties of the organic light-emitting element can be improved by shortening the intermolecular distance between the organic compound represented by the general formula [1] and the second organic compound. By using a material that does not have sp3 carbon as the second organic compound, the intermolecular distance with the organic compound represented by the general formula [1] can be further shortened.

[0113] When sp3 carbon is present, the intermolecular distance between the organic compound represented by general formula [1] and the second organic compound is increased due to the hydrophobic interaction and steric hindrance of the alkyl group. On the other hand, when sp3 carbon is not present, the hydrophobic interaction and steric hindrance caused by the alkyl group are eliminated, so that the increase in the separation distance due to these is not generated, and the intermolecular distance with the organic compound represented by general formula [1] can be shortened. As a result, the light-emitting properties of the organic light-emitting device can be improved.

[0114] Specific examples of the second compound according to this embodiment, more specifically, specific examples of compounds suitable as a host material are shown below, but the present invention is not limited thereto.

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] Among the above compounds, the exemplary compounds (AA1 to AA21) belonging to the AA group are compounds having an azine ring in the skeleton. Therefore, these compounds have a deep HOMO and a small gap between the HOMO and the LUMO of the organic compound represented by the general formula [1]. As a result, a good light-emitting layer can be formed with the organic compound represented by the general formula [1], and an organic light-emitting device with low driving voltage and high durability can be obtained.

[0120] Among the above compounds, the exemplary compounds (BB1 to BB42) belonging to the BB group have at least one structure selected from the group consisting of a triphenylene structure, a phenanthrene structure, a chrysene structure, and a fluoranthene structure in the skeleton, and do not have sp3 carbon. Therefore, when these compounds are combined with an organic compound represented by general formula [1] to form a layer, the intermolecular distance between the two can be shortened. As a result, energy transfer between molecules, more specifically, energy transfer from the second organic compound to the compound represented by general formula [1] can be performed with high efficiency, and the luminous efficiency can be improved. Among these compounds, compounds having a triphenylene structure, specifically, BB6 to BB8, BB10 to BB29, and BB34 to BB42, are particularly preferred because they have particularly high planarity.

[0121] Among the above compounds, the exemplary compounds (CC1 to CC21) belonging to the CC group have either a dibenzothiophene structure or a dibenzofuran structure in the skeleton, and do not have sp3 carbon. Therefore, when these compounds are combined with the organic compound represented by the general formula [1] to form a light-emitting layer, the balance between the HOMO and the LUMO is improved. 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, compounds having a dibenzothiophene structure, specifically, CC2 to CC5, CC7, CC9, CC13 to CC16, and CC18 to CC21, are particularly preferred from the viewpoint of carrier balance.

[0122] (Other compounds) Other examples of compounds that can be used in the organic light-emitting device of this embodiment are given below.

[0123] As the hole injection transport material suitably used for the hole injection layer or the hole transport layer, a material having a high hole mobility is preferred so as to facilitate the injection of holes from the anode and transport the injected holes to the light emitting layer. In addition, a material having a high glass transition temperature is preferred so as to suppress deterioration of the film quality such as crystallization in the organic light emitting device. Examples of low molecular weight and polymeric materials having hole injection and transport performance include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above-mentioned hole injection transport material is also suitably used for the electron blocking layer.

[0124] Specific examples of compounds usable as the hole injection transport material are shown below, but the invention is not limited to these.

[0125] [ka]

[0126] Examples of luminescent materials mainly involved in luminescence 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, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives.

[0127] Specific examples of compounds that can be used as the light-emitting material are shown below, but the present invention is not limited to these.

[0128] [ka]

[0129] [ka]

[0130] Examples of the emission layer host or assist material contained in the emission layer include, in addition to the above-mentioned AA group, BB group, and CC group materials, aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organic aluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes.

[0131] As the assist material, a compound having a xanthone skeleton, a thioxanthone skeleton, or a benzophenone skeleton, which has a deep LUMO (far from the vacuum level) like an azine skeleton, is preferable. Specifically, the following EM28 to EM31 are particularly preferable.

[0132] Specific examples of compounds that can be used as the host or assist material in the light-emitting layer are shown below, but the present invention is not limited to these.

[0133] [ka]

[0134] The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected in consideration of the balance with the hole mobility of the hole transporting material. Examples of materials having electron transporting properties include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organic aluminum complexes, and condensed ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above-mentioned electron transporting materials are also suitable for use in the hole blocking layer.

[0135] Specific examples of compounds usable as the electron transporting material are shown below, but the present invention is not limited to these.

[0136] [ka]

[0137] Hereinafter, the constituent members other than the organic compound layer that constitute the organic light-emitting device of this embodiment will be described. The organic light-emitting device may be provided by forming a first electrode, an organic compound layer, and a second electrode on a substrate. One of the first electrode and the second electrode is an anode and the other is a cathode. A protective layer, a color filter, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of acrylic resin, etc.

[0138] The substrate may be made of quartz, glass, silicon, resin, metal, or the like. In addition, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. The insulating layer may be made of any material as long as it can form a contact hole to ensure electrical continuity between the anode and the wiring, and can ensure insulation from unconnected wiring. For example, resin such as polyimide, silicon oxide, silicon nitride, or the like may be used.

[0139] The material for the anode should have a work function as large as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, or alloys combining these metals, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used. These electrode materials may be used alone or in combination of two or more types. The anode may be composed of a single layer or multiple layers. When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. When used as a transparent electrode, transparent conductive oxide layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited to these. Photolithography technology can be used to form the anode.

[0140] On the other hand, the material for the cathode should have a small work function. Examples of the material include alkali metals such as lithium, alkaline earth metals such as calcium, aluminum, titanium, manganese, silver, lead, chromium, and other metals or mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, and the like can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more types. The cathode may have a single layer structure or a multi-layer structure. Among these, it is preferable to use silver, and it is even more preferable to use a silver alloy in order to suppress the aggregation of silver. As long as the aggregation of silver can be suppressed, the ratio of the alloy is not important. For example, it may be 1:1.

[0141] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but it is more preferable to use a direct current or alternating current sputtering method, etc., since the film coverage is good and the resistance can be easily reduced.

[0142] A protective layer may be provided after the cathode is formed. For example, by bonding glass provided with a moisture absorbent on the cathode, it is possible to suppress the intrusion of water and the like into the organic compound layer and suppress the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to suppress the intrusion of water and the like into the organic compound layer. For example, after the cathode is formed, the device may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may be provided using the atomic deposition method (ALD method) after the film formation by the CVD method.

[0143] A color filter may be provided for each pixel. For example, a color filter that matches the size of the pixel may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on a protective layer such as silicon oxide using a photolithography technique.

[0144] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting device according to this embodiment are formed by the following method. That is, the organic compound layers can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. In addition, instead of the dry process, a wet process can be used in which the organic compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (for example, spin coating, dipping, casting, LB method, inkjet method, etc.). Here, when a layer is formed by vacuum deposition or solution coating method, crystallization is unlikely to occur and the stability over time is excellent. In addition, when a film is formed by a coating method, a film can be formed by combining with an appropriate binder resin. Examples of binder resins include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, etc., but are not limited thereto. The binder resin may be a homopolymer or a copolymer, and may be used alone or in combination of two or more kinds. If necessary, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination.

[0145] <Device using organic light-emitting element> The organic light-emitting device according to the present embodiment can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, a light-emitting device having a white light source and a color filter, etc.

[0146] The display device may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, or the like, an information processing unit that processes the input information, and displays the input image on a display unit. The display device may have a plurality of pixels, at least one of which may have the organic light-emitting element of this embodiment and a transistor connected to the organic light-emitting element. In this case, the substrate may be a semiconductor substrate such as silicon, and the transistor may be a MOSFET formed on the substrate.

[0147] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may be used in the display unit of a multifunction printer.

[0148] Next, the display device according to the present embodiment will be described with reference to the drawings.

[0149] 1 is a schematic cross-sectional view showing an example of a display device having 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).

[0150] FIG. 1(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel has sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B according to their light emission. The emitted light color may be distinguished by the wavelength emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel has a reflective electrode 2, which is 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.

[0151] A transistor and a capacitor may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode may be electrically connected via a contact hole or the like (not shown).

[0152] The insulating layer 3 is also called a bank or a pixel separation film. It covers the edge of the first electrode and is disposed so as to surround the first electrode. The part where the insulating layer is not disposed contacts the organic compound layer 4 and becomes a light-emitting region.

[0153] The organic compound layer 4 has 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 .

[0154] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0155] The protective layer 6 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as being a single layer, it may be a multi-layer. Each layer may be an inorganic compound layer and an organic compound layer.

[0156] The color filters 7 are divided into 7R, 7G, and 7B according to their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters. The color filters may be formed on a protective layer 6. Alternatively, the color filters may be provided on an opposing substrate such as a glass substrate and then bonded to each other.

[0157] The display device 100 in Fig. 1(b) has an organic light-emitting element 26 and a TFT 18, which is an example of a transistor. A substrate 11 made of glass, silicon, or the like is provided on top of the substrate 11, and an insulating layer 12 is provided on the substrate 11. An active element such as the TFT 18 is disposed on the insulating layer 12, and a gate electrode 13 of the active element, a gate insulating film 14, and a semiconductor layer 15 are provided on the substrate 11.

[0158] The TFT 18 has a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on the upper part of the TFT 18. An anode 21 constituting an organic light emitting element 26 and the source electrode 17 are connected via a contact hole 20.

[0159] The electrical connection between the electrodes (anode 21, cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the TFT is not limited to the embodiment shown in Fig. 1(b). In other words, it is sufficient that either the anode 21 or the cathode 23 is electrically connected to either the source electrode 17 or the drain electrode 16 of the TFT 18.

[0160] 1(b), the organic compound layer 22 is illustrated as a single layer, but the organic compound layer 22 may be a multi-layer. A first protective layer 25 and a second protective layer 24 are provided on the cathode 23 to suppress deterioration of the organic light-emitting element.

[0161] In the display device 100 of FIG. 1(b), transistors are used as switching elements, but other switching elements such as MIM elements may be used instead.

[0162] The transistor used in the display device 100 of Fig. 1(b) is not limited to a thin film transistor having an active layer on an insulating surface of a substrate, but may be a transistor using a single crystal silicon wafer. Examples of the active layer include single crystal silicon, amorphous silicon, non-single crystal silicon such as microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin film transistors are also called TFT elements.

[0163] The transistors included in the display device 100 of Fig. 1(b) may be formed in a substrate such as a Si substrate. Here, "formed in a substrate" means that the substrate itself such as a Si substrate is processed to produce the transistors. In other words, having a transistor in a substrate can be seen as the substrate and the transistor being integrally formed.

[0164] The organic light-emitting element according to this embodiment has its light emission brightness controlled by a TFT, which is an example of a switching element, and by providing the organic light-emitting element on a plurality of surfaces, an image can be displayed based on the respective light emission brightnesses. The switching element according to this embodiment is not limited to 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. On the substrate may also be within the substrate. Whether to provide a transistor within the substrate or to use a TFT is selected according to the size of the display unit. For example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0165] 2 is a schematic diagram showing an example of a display device according to the present embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A transistor is printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position if the display device is a portable device.

[0166] The display device according to the present embodiment may be used in a display section of an imaging device having an optical section with a plurality of lenses and an imaging element that receives light that has passed through the optical section. The imaging device may have a display section that displays information acquired by the imaging element. The display section may be a display section exposed to the outside of the imaging device, or may be a display section disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera. The imaging device may also be referred to as a photoelectric conversion device.

[0167] 3(a) is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0168] Since the timing suitable for imaging is short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of this embodiment. This is because the organic light-emitting element has a fast response speed. A display device using an organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0169] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, and forms an image on an imaging element housed in a housing 1104. The focal points of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0170] The display device according to this embodiment may have color filters having red, green, and blue colors, the red, green, and blue colors being arranged in a delta arrangement.

[0171] The display device according to the present embodiment may be used as a display unit of an electronic device such as a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include mobile phones such as smartphones, tablets, and head-mounted displays.

[0172] 3(b) is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform unlocking or the like. An electronic device having a communication unit may be called a communication device.

[0173] FIG. 4 is a schematic diagram showing an example of a display device according to the present embodiment. FIG. 4(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device according to the present embodiment may be used for the display unit 1302. The display device 1300 has a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in FIG. 4(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved so that the display surface of the display unit 1302 is curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0174] FIG. 4(b) is a schematic diagram showing another example of the display device according to the present embodiment. The display device 1310 in FIG. 4(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has 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 have the light-emitting device according to the present embodiment. The first display unit 1311 and the second display unit 1312 may be one display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first and second display units may display one image.

[0175] FIG. 5(a) is a schematic diagram showing an example of a lighting device according to the present embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404 that transmits light emitted by the light source 1402, and a light diffusion section 1405. The light source 1402 may have an organic light-emitting element according to the present embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion section can effectively diffuse the light of the light source, such as for lighting up, and deliver the light over a wide range. The optical filter and the light diffusion section may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0176] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white, neutral white, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity and a color adjusting circuit that adjusts the emitted color. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage into DC voltage. Moreover, white has a color temperature of 4200K, and neutral white has a color temperature of 5000K. The lighting device may have a color filter.

[0177] The lighting device according to the present embodiment may also include a heat dissipation section that dissipates heat from within the device to the outside, and examples of the heat dissipation section include metals with high specific heat, liquid silicon, and the like.

[0178] 5B is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of a lamp. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0179] The tail lamp 1501 may have an organic light-emitting element according to this embodiment. The tail lamp 1501 may have a protective member for protecting the organic EL element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0180] The automobile 1500 may have a 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 automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent members.

[0181] The moving body according to the present embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lamp provided on the body. The lamp may emit light to indicate the position of the body. The lamp has the organic light-emitting element according to the present embodiment.

[0182] An application example of the display device of each of the above-mentioned embodiments will be described with reference to Fig. 6. The display device can be applied to a system that can be worn as a wearable device such as smart glasses, HMD, and smart contacts. An image capturing and display device used in such an application example has an image capturing device capable of photoelectrically converting visible light, and a display device capable of emitting visible light.

[0183] 6(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, a display device according to each of the above-mentioned embodiments is provided on the back side of the lens 1601.

[0184] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light on the image capture device 1602.

[0185] FIG. 6(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, and the control device 1612 is equipped with an imaging device equivalent to the imaging device 1602 and a display device. The lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device, and controls the operation of the imaging device and the display device. The control device may have a line-of-sight detection unit that detects the line of sight of the wearer. Infrared light may be used for detecting the line of sight. The infrared light emitting unit emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. By having a reduction means for reducing light from the infrared light emitting unit to the display unit in a planar view, deterioration of image quality is reduced.

[0186] The gaze of the user with respect to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0187] More specifically, the gaze detection process is performed based on the pupil-corneal reflex method. Using the pupil-corneal reflex method, a gaze vector that indicates the direction (rotation angle) of the eyeball is calculated based on the pupil image and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0188] A display device according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control a display image on the display device based on information about a user's line of sight from the imaging device.

[0189] Specifically, the display device determines a first field of view area to which the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be received from an external control device. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0190] The display area includes a first display area and a second display area different from the first display area, and an area having a high priority is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the area having a high priority may be controlled to be higher than the resolution of areas other than the area having a high priority. In other words, the resolution of an area having a relatively low priority may be lowered.

[0191] AI may be used to determine the first field of view area and the area with high priority. The AI ​​may be a model configured to estimate the angle of the line of sight and the distance to an object at the end of the line of sight from the image of the eyeball, using the image of the eyeball and the direction in which the eyeball in the image was actually looking as teacher data. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0192] When display control is performed based on visual recognition detection, the present invention is preferably applicable to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0193] FIG. 7 is a schematic diagram showing an example of an image forming apparatus according to the present embodiment. The image forming apparatus 40 is an electrophotographic image forming apparatus, and includes a photoconductor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transfer unit 32, a transport roller 33, and a fixing unit 35. Light 29 is emitted from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoconductor 27. The exposure light source 28 includes an organic light-emitting element according to the present embodiment. The developing unit 31 includes a toner and the like. The charging unit 30 charges the photoconductor 27. The transfer unit 32 transfers the developed image to a recording medium 34. The transport roller 33 transports the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0194] 8(a) and 8(b) are diagrams showing the exposure light source 28, and are schematic diagrams showing a state in which a plurality of light-emitting sections 36 are arranged on a long substrate. Arrow 37 indicates the column direction in which the organic light-emitting elements are arranged. This column direction is the same as the direction of the axis about which the photoconductor 27 rotates. This direction can also be called the long axis direction of the photoconductor 27. FIG. 8(a) shows a form in which the light-emitting sections 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(b) shows a form different from FIG. 8(a), in which the light-emitting sections 36 are alternately arranged in the column direction in each of the first column and the second column. The first column and the second column are arranged at different positions in the row direction. In the first column, a plurality of light-emitting sections 36 are arranged at intervals. In the second column, the light-emitting sections 36 are located at positions corresponding to the intervals between the light-emitting sections 36 in the first column. That is, a plurality of light-emitting sections 36 are also arranged at intervals in the row direction. The arrangement in FIG. 8(b) can also be described as, for example, a grid-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0195] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve a display with good image quality and stability even over a long period of time. EXAMPLES

[0196] The present invention will be described below with reference to examples, but the present invention is not limited to these.

[0197] [Example 1 (Synthesis of Exemplary Compounds A25 and A33)] Exemplary compounds A25 and A33 were synthesized according to the following synthesis scheme.

[0198] [ka]

[0199] (1) Synthesis of compound m-2 The following reagents and solvents were placed in a 2000 ml recovery flask. Compound m-1: 10.0g (0.05mol) Bromine: 6.9g (0.04mol) Chloroform: 500 ml

[0200] 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 a liquid separation operation. 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 (yield: 82%) of m-2 as a light brown solid.

[0201] (2) Synthesis of compound m-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-2: 10.0g (35.1mmol) Bispinacoldiborolane: 13.4g (52.6mmol) Pd(PPh3)2Cl2: 0.3g (0.04mmol) Potassium acetate: 8.6 g (87.7 mmol) Dioxane: 200ml

[0202] Next, the reaction solution was heated and stirred under a nitrogen stream. After the reaction was completed, pure water was added at room temperature. The reaction solution was extracted with toluene and concentrated, and the resulting residue was purified by column chromatography (toluene / heptane = 1:4), and then dispersed and washed with heptane to obtain 8.1 g (yield: 70%) of m-3 as a light brown solid.

[0203] (3) Synthesis of compound m-5 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-3: 5.0g (15.0mmol) Compound m-4: 2.85g (18.1mmol) Pd(PPh3)4: 0.17g Toluene: 50 ml Ethanol: 25ml 2M sodium carbonate solution: 25ml

[0204] Next, the reaction solution was heated and stirred under a nitrogen stream at 80° C. for 6 hours. After the reaction was completed, water was added to separate the solution, and the solution was dissolved in chloroform. The solution was purified by column chromatography (chloroform), and then recrystallized from chloroform / methanol to obtain 2.2 g (yield: 52%) of compound m-5 as a pale yellow solid.

[0205] (4) Synthesis of compound m-6 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 30ml Ion exchange water: 10ml Iridium(III) chloride hydrate: 0.45g Compound m-5: 1.0g (3.5mmol)

[0206] Next, the reaction solution was heated to 120° C. and stirred for 6 hours. After cooling, water was added, filtered, and washed with water. This was dried to obtain 1.2 g (yield 87%) of compound m-6 as a yellow solid.

[0207] (5) Synthesis of Example Compound A25 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 30ml Compound m-6: 1.0g (0.6mmol) Compound m-7: 0.25g (2.5mmol) Sodium carbonate: 0.7 g (6.3 mmol)

[0208] Next, the reaction solution was heated to 100° C. and stirred for 6 hours. After cooling, methanol was added, filtered, and washed with methanol. This was dried to obtain 0.7 g (yield 64%) of exemplary compound A25 as a yellow solid.

[0209] Exemplary Compound A25 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker).

[0210] [MALDI-TOF-MS] Measured value: m / z=857 Calculated value: C 47 H 40 IrN2O2=857

[0211] (6) Synthesis of Example Compound A33 The following reagents and solvents were placed in a 50 ml recovery flask. Exemplary compound A25: 0.5 g (0.6 mmol) Compound m-5: 1.7g (5.8mmol) Glycerol: 15ml

[0212] 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 stirred until the temperature reached room temperature. Heptane was then added and filtered. The filtrate was purified by silica gel column chromatography (ethyl acetate) to obtain 0.1 g (yield 20%) of a dark yellow solid A35.

[0213] Exemplary Compound A25 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker).

[0214] [MALDI-TOF-MS] Measured value: m / z=1040 Calculated value: C 63 H 49 IrN3=1040

[0215] [Examples 2 to 7 (Synthesis of Exemplary Compounds)] Table 4 shows the exemplary compounds shown in Examples 2 to 7, which were synthesized in the same manner as in Example 1, except that the raw materials m-2, m-4, and m-7 in Example 1 were changed. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0216] [Table 4]

[0217] [Examples 8 to 9 (Synthesis of Exemplary Compounds)] Table 5 shows the exemplary compounds shown in Examples 8 to 9. The exemplary compounds were synthesized in the same manner as in Example 1, except that the raw materials m-2, m-4, and m-5 in Example 1 were changed. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0218] [Table 5]

[0219] [Example 10 (Synthesis of Exemplary Compound A1)] Exemplary compound A1 was synthesized according to the following synthesis scheme.

[0220] [ka]

[0221] (1) Synthesis of compound k-2 The synthesis of compound k-2 from compound k-1 is similar to the synthesis of compound m-6 in Example 1 (4), and therefore the explanation is omitted.

[0222] (2) Synthesis of Example Compound A1 The following reagents and solvents were placed in a 200 ml recovery flask. Compound k-2: 1.0g (0.9mmol) AgOTf: 0.5g (1.9mmol) Dichloromethane: 50 ml Methanol: 2 ml

[0223] The reaction solution was then stirred at room temperature for 6 hours, after which the solvent was removed under reduced pressure to obtain a yellow solid.

[0224] 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 the procedures (1) to (3) of Example 1. Ethanol: 30ml Compound k-3: 0.4g (1.4mmol)

[0225] Next, the reaction solution was heated to 85° C. and stirred for 3 hours. After cooling, filtration was performed. The filtrate was purified by silica gel column chromatography (chloroform:heptane=1:1) to obtain 0.9 g (yield 59%) of a deep yellow solid A1.

[0226] The exemplary compound A1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker).

[0227] [MALDI-TOF-MS] Measured value: m / z=783 Calculated value: C 43 H 32 IrN3=783

[0228] [Examples 11 to 20 (Synthesis of Exemplary Compounds)] Table 6 shows the exemplary compounds shown in Examples 11 to 20, which were synthesized in the same manner as in Example 10, except that the raw materials k-1 and k-3 in Example 10 were changed. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 10 are also shown.

[0229] [Table 6]

[0230] [Comparative Examples 1-2 (Synthesis of Comparative Compounds)] Comparative compounds 1-a and 1-b shown in Table 7 were synthesized in the same manner as in Example 1, except that raw materials m-2 and m-4 in Example 1 were changed. The actual measured values: m / z of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0231] [Table 7]

[0232] When comparative compound 1-a was subjected to sublimation purification, a decrease in purity was confirmed. In addition, when the emission wavelengths of comparative compound 1-a and comparative compound 1-b were measured, it was found that both had a maximum emission wavelength λmax exceeding 680 nm and did not have a maximum emission wavelength in the visible light region. For this reason, comparative compound 1-a and comparative compound 1-b are not suitable for organic light-emitting elements for image display devices such as displays. In addition, when comparative compound 1-b was subjected to sublimation purification, it was not possible to perform sublimation purification, and decomposition was confirmed. This is thought to be because, as described above, the sublimation temperature was high due to the ligand having a pyrene skeleton with extremely high planarity, and thermal decomposition occurred before sublimation.

[0233] [Example 21] An organic light-emitting device of bottom emission type structure was produced by sequentially forming 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 on a substrate.

[0234] First, an ITO film was formed on a glass substrate, and the desired patterning process was performed to form an ITO electrode (anode). At this time, the film thickness of the ITO electrode was set to 100 nm. The substrate on which the ITO electrode was formed was used as an ITO substrate in the following process. Next, a 1.33×10 -4The organic compound layer and the electrode layer shown in Table 8 were successively formed on the ITO substrate by vacuum deposition using resistance heating in a vacuum chamber at 1000 Pa. Note that at this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm 2 It was made so that:

[0235] [Table 8]

[0236] The characteristics of the obtained device were measured and evaluated. The maximum emission wavelength of the light-emitting device was 532 nm, and the maximum external quantum efficiency (EQE) was 11%. Furthermore, at a current density of 100 mA / cm 2 A continuous driving test was performed at 100° C., and the time (LT95) when the luminance degradation rate reached 5% was measured. When the time (LT95) when the luminance degradation rate reached 5% in Comparative Example 3 was taken as 1.0, the LT95 in this example was 1.4.

[0237] In this example, the measuring device was a microammeter 4140B manufactured by Hewlett-Packard Company to measure the current-voltage characteristics, and a BM7 manufactured by Topcon Corporation to measure the luminance.

[0238] [Examples 22 to 31, Comparative Example 3] An organic light-emitting device was produced in the same manner as in Example 21, except that the materials forming each layer in Example 21 were appropriately changed to the compounds shown in Table 9. Note that layers not shown in Table 9 had the same configuration as in Example 21. The characteristics of the obtained element were measured and evaluated in the same manner as in Example 21. The measurement results are shown in Table 9 together with the results of Example 21.

[0239] [Table 9]

[0240] From Table 9, the maximum external quantum efficiency (EQE) of Comparative Example 3 was 2%, whereas the maximum external quantum efficiency of Examples 21 to 31 was 8 to 12%, resulting in a higher luminous efficiency for the organic light-emitting devices of Examples 21 to 31. This is believed to be because the organic compounds contained as guests in the luminescent layers of the organic light-emitting devices of Examples 21 to 31 have higher quantum yields than the comparative compound 1-a contained as a guest in the luminescent layer of Comparative Example 3. The reason for this is believed to be that the organic compounds contained as guests in the luminescent layers of the organic light-emitting devices of Examples 21 to 31 have a tetrahydropyrene skeleton, so that the π-conjugated system does not spread too much as described above, and sufficient MLCT transition can be exhibited.

[0241] Furthermore, from Table 9, each of the organic light-emitting devices in Examples 21 to 31 had a longer life than the organic light-emitting device in 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 device in Comparative Example 3 is a material with low sublimability, and therefore decomposition occurred during vacuum deposition, causing impurities to be mixed into the device, resulting in a decrease in the durability of the device. On the other hand, each of the organic compounds contained as a guest in the light-emitting layer of the organic light-emitting devices in Examples 21 to 31 has a tetrahydropyrene skeleton, and therefore has good sublimability as described above, and can be stably deposited without decomposition, which is thought to have suppressed a decrease in the durability of the device.

[0242] [Example 32] An organic light-emitting device was produced in the same manner as in Example 21, except that the organic compound layer and the electrode layer shown in Table 10 were successively formed.

[0243] [Table 10]

[0244] The characteristics of the obtained element were measured and evaluated in the same manner as in Example 21. The light-emitting element emitted green light, and the maximum external quantum efficiency (EQE) was 19%. In addition, when a continuous driving test was carried out in the same manner as in Example 21, the LT95 was 2.6, assuming that the LT95 of Comparative Example 3 was 1.0.

[0245] [Examples 33 to 42] An organic light-emitting device was produced in the same manner as in Example 32, except that the materials forming each layer in Example 32 were appropriately changed to the compounds shown in Table 11. Note that layers not shown in Table 11 had the same configuration as in Example 32. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 34. The measurement results are shown in Table 11, together with the results of Example 32.

[0246] [Table 11]

[0247] As described above, by using an organic compound having a tetrahydropyrene skeleton as a guest in the light-emitting layer, an organic light-emitting element having high maximum external quantum efficiency and high luminous efficiency can be realized. [Explanation of symbols]

[0248] 1. Organic light-emitting device 11 Substrate 21 Anode 22 Organic compound layer 23 Cathode

Claims

1. An organic compound represented by the following general formula [1]: 【Chemistry 1】 (In the general formula [1], Ir is iridium. L and L' each represent a bidentate ligand different from each other. m is an integer of 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 the following general formula [2], and the partial structure IrL′ ｎ is a partial structure represented by the following general formula [3-1] or general formula [3-2]. When m is 2 or more, the multiple L's may be the same or different. When n is 2, the multiple L's may be the same or different. 【Chemistry 2】 【Chemistry 3】 In the general formula [2], ring A is selected from the following general formulae [A-1] to [A-5]. 【Chemistry 4】 In the general formulae [A-1] to [A-5], * represents a bonding position. In the general formulae [2], [3-1], and [A-1] to [A-5], R １ ~R ４９ are each 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. In the general formula [3-2], X １ ~X ８ are each independently selected from a carbon atom or a nitrogen atom. １ ~X ８ is a carbon atom, the carbon atom has a hydrogen atom, a deuterium atom or a substituent, and the 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.

2. In the general formula [2], R １ ~R ４ , R ８ ~R １１ 2. The organic compound according to claim 1, wherein each of is independently selected from a hydrogen atom and an alkyl group.

3. 3. The organic compound according to claim 1, wherein in the general formula [2], ring A is represented by the general formula [A-1] or [A-4].

4. An organic light-emitting device having an anode, a cathode, and an organic compound layer having at least a light-emitting layer, the organic compound layer being disposed between the anode and the cathode, The organic compound layer comprises the organic compound according to any one of claims 1 to 3.

5. The organic light-emitting device according to claim 4 , wherein the light-emitting layer comprises the organic compound.

6. The organic light-emitting device according to claim 5 , wherein the light-emitting layer further comprises a host material.

7. The organic light-emitting device according to claim 6 , wherein the host material has an azine ring in its skeleton.

8. 8. The organic light-emitting device according to claim 6, wherein the host material has at least one structure selected from the group consisting of a triphenylene structure, a phenanthrene structure, a chrysene structure, and a fluoranthene structure.

9. 9. The organic light-emitting device according to claim 6, wherein the host material has at least one structure selected from the group consisting of a dibenzothiophene structure and a dibenzofuran structure.

10. 10. The organic light-emitting device according to claim 6, wherein the host material does not have sp3 carbon.

11. 11. The organic light-emitting device according to claim 6, wherein the light-emitting layer further contains a compound different from the organic compound and the host material.

12. the light-emitting layer is a first light-emitting layer, a second light-emitting layer different from the first light-emitting layer is provided between the first light-emitting layer and the anode or between the first light-emitting layer and the cathode; 12. The organic light-emitting element according to claim 4, wherein the second light-emitting layer emits light of a color different from that of the light emitted by the light-emitting layer.

13. The organic light-emitting device according to claim 12, which emits white light.

14. A plurality of pixels are included. A display device, wherein at least one of the plurality of pixels comprises the organic light-emitting element according to any one of claims 4 to 13, and an active element connected to the organic light-emitting element.

15. 15. The display device according to claim 14, further comprising a color filter.

16. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image captured by the image sensor; A photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to any one of claims 4 to 13.

17. The device has a housing, a communication unit that communicates with the outside, and a display unit, 14. An electronic device, wherein the display section comprises the organic light-emitting element according to claim 4.

18. A lighting device having a light source and a light diffusion unit or an optical filter, 14. An illumination device, wherein the light source comprises the organic light-emitting element according to claim 4.

19. The drone has a body and a lighting device provided on the body, The vehicle, wherein the lighting device comprises the organic light-emitting element according to any one of claims 4 to 13.

20. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light emitting device according to any one of claims 4 to 13.

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