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

Abstract

To provide an organic compound excellent in light-emitting properties.SOLUTION: The organic compound is represented by general formula [1] defined by IrLmL'n [where the partial structure IrL is the general formula [A-1] or general formula [A-2] in the figure; the partial structure IrL' is acetylacetonato or the like; Y1 to Y16 are C or N; and Z1 and Z2 are O, S, or the like.]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 mobile object, and an exposure light source. [Background technology]

[0002] An organic light-emitting device (hereinafter sometimes referred to as an "organic electroluminescence device" or "organic EL device") is an electronic device 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 device emits light.

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

[0004] Incidentally, the creation of light-emitting organic compounds has been actively pursued up to now, because the creation of compounds with excellent light-emitting properties is important in providing high-performance organic light-emitting devices.

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

[0006] [ka] [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2010 / 0327736 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have investigated Compound 1-a described in Patent Document 1 and found that there is room for improvement in the luminescence properties. By improving the luminescence properties 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 general formula [1], Ir represents iridium. L and L' represent different bidentate ligands. m represents 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 is a partial structure represented by the following general formula [A-1] or general formula [A-2], and the partial structure IrL' is a partial structure represented by the following general formula [B-1] or general formula [B-2]. When m is 2 or more, multiple L's may be the same or different. When n is 2, multiple L's may be the same or different.

[0013] [ka]

[0014] [ka]

[0015] In the general formulae [A-1], [A-2] and [B-2], Y1 to Y 24 are each independently selected from carbon atoms or nitrogen atoms. 24 When Y1 to Y2 are carbon atoms, the carbon atoms have a hydrogen atom, a deuterium atom, or a substituent R. 24 When a plurality of the carbon atoms among the groups are carbon atoms having a substituent R, the respective substituents R may have the same structure or different structures.

[0016] The substituents R are 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.

[0017] In the general formulae [A-1], [A-2], and [B-2], adjacent Y1 to Y 24 are both carbon atoms and have a substituent R, the substituents R may be bonded to each other to form a ring. The ring structure formed may be a benzene ring, a naphthalene ring, an azine ring, a thiophene ring, or a furan ring.

[0018] In general formulas [A-1] and [A-2], Z1 and Z2 are each independently selected from an oxygen atom, a sulfur atom, SiR1R2, CR1R2, GeR1R2, NR1, and CR1=CR2. R1 and R2 may be bonded to each other to form a ring.

[0019] In the general formulae [A-1], [A-2], and [B-1], R1 to R5 are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group. [Effects of the Invention]

[0020] According to the present invention, an organic compound having excellent light-emitting properties can be provided. [Brief explanation 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. [Figure 2] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 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. [Figure 5] 1A is a schematic diagram showing an example of an illumination device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an automobile as an example of a moving body according to an embodiment of the present invention. [Figure 6] 1A and 1B are schematic diagrams illustrating an example of a wearable device according to an embodiment of the present invention, each of which has 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 one embodiment of the present invention. [Figure 9] FIG. 1 is a schematic diagram showing the structures of exemplary compounds and comparative compounds, and the symmetry of the ligands. [Figure 10] FIG. 1 is a schematic diagram showing the structures of exemplary compounds and comparative compounds, and the symmetry of the ligands. [Figure 11] 1 is a schematic diagram showing the structures of exemplary compounds and comparative compounds, and the three-dimensional structures of ligands. FIG. DETAILED DESCRIPTION OF THE INVENTION

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

[0023] The organic compound according to this embodiment is an organic compound represented by the following general formula [1]: Since an organic ligand is coordinated to a metal, it can also be called an organometallic complex.

[0024] [ka]

[0025] In general formula [1], Ir represents iridium. L and L' represent different bidentate ligands. m represents 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 is a partial structure represented by the following general formula [A-1] or [A-2], and the partial structure IrL' is a partial structure represented by the following general formula [B-1] or [B-2]. When m is 2 or more, multiple L's may be the same or different. When n is 2, multiple L's may be the same or different.

[0026] [ka]

[0027] [ka]

[0028] In the general formulae [A-1], [A-2] and [B-2], Y1 to Y 24 are each independently selected from carbon atoms or nitrogen atoms. 24 When Y1 to Y2 are carbon atoms, the carbon atoms have a hydrogen atom, a deuterium atom, or a substituent R. 24 When a plurality of the carbon atoms among the groups are carbon atoms having a substituent R, the respective substituents R may have the same structure or different structures.

[0029] The substituents R are 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.

[0030] In the general formulae [A-1], [A-2], and [B-2], adjacent Y1 to Y 24 are both carbon atoms and have a substituent R, the substituents R may be bonded to each other to form a ring. The ring structure formed may be a benzene ring, a naphthalene ring, an azine ring, a thiophene ring, or a furan ring.

[0031] In general formulas [A-1] and [A-2], Z1 and Z2 are each independently selected from an oxygen atom, a sulfur atom, SiR1R2, CR1R2, GeR1R2, NR1, and CR1=CR2. R1 and R2 may be bonded to each other to form a ring.

[0032] In the general formulae [A-1], [A-2], and [B-1], R1 to R5 are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0033] In the organic compound according to this embodiment, in the general formula [1], the partial structure IrL is preferably a partial structure represented by the following general formulas [A-11] to [A-14] and [A-21] to [A-24].

[0034] [ka]

[0035] [ka]

[0036] In the general formulae [A-11] to [A-14] and [A-21] to [A-24], X1 to X 68 are each independently selected from carbon atoms or nitrogen atoms. 68 When X1 to X2 are carbon atoms, the carbon atoms have a hydrogen atom, a deuterium atom, or a substituent R. 68 When a plurality of the carbon atoms among the groups are carbon atoms having a substituent R, the respective substituents R may have the same structure or different structures.

[0037] The substituents R are 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.

[0038] In the general formulae [A-11] to [A-14] and [A-21] to [A-24], adjacent X1 to X 68 are both carbon atoms and have a substituent R, the substituents R may be bonded to each other to form a ring. The ring structure formed may be a benzene ring, a naphthalene ring, an azine ring, a thiophene ring, or a furan ring.

[0039] In general formulas [A-11] and [A-21], R6 to R9 are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0040] Y1~Y 24 is a carbon atom, the substituent R that the carbon atom may have, and X1 to X 68is a carbon atom, the substituents R that the carbon atom may have are preferably substituents 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.

[0041] In the general formulae [A-1], [A-2], and [B-1], R1 to R5 are preferably each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0042] In general formulas [A-11] and [A-21], R6 to R9 are preferably each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

[0043] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When R is a carbon atom, examples of the halogen atom that may be present as the substituent R that the carbon atom may have, and the halogen atoms represented by R1 to R5, include fluorine, chlorine, bromine, iodine, etc., but are not limited to these.

[0044] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68When R is a carbon atom, examples of the alkyl group that may be present as the substituent R that the carbon atom may have, and the alkyl groups represented by R1 to R5, include, but are not limited to, 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.

[0045] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When is a carbon atom, examples of the alkoxy group that may be present as the substituent R that the carbon atom may have include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, a benzyloxy group, and the like.

[0046] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When R is a carbon atom, examples of the amino group that may be possessed as the substituent R that the carbon atom may have include, but are not limited to, 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.

[0047] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68When is a carbon atom, examples of the aryloxy group and heteroaryloxy group that may be possessed as the substituent R that the carbon atom may have include, but are not limited to, a phenoxy group and a thienyloxy group.

[0048] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When is a carbon atom, examples of the silyl group that may be present as the substituent R that the carbon atom may have include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0049] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When R is a carbon atom, examples of the aromatic hydrocarbon group that may be present as the substituent R that the carbon atom may have, and the aromatic hydrocarbon groups represented by R1 to R5, 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.

[0050] Y1~Y 24 is a carbon atom, the carbon atom is a substituent R, and X1 to X 68 When R is a carbon atom, examples of the heterocyclic group that may be present as the substituent R that the carbon atom may have, and the heterocyclic groups represented by R1 to R5, 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.

[0051] Examples of substituents that may be further substituted by the alkyl group, alkoxy group, amino group, aryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group include, but are not limited to, 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.

[0052] (Method for synthesizing organic compounds) Next, a method for synthesizing the organic compound according to this embodiment will be described. The organic compound according to this embodiment can be synthesized, for example, according to the reaction scheme shown below.

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] Here, various compounds can be obtained by appropriately changing the compounds shown in (a), (b), (f), (h), (j), (k), (n), (p), (q), and (r) above. The present invention is not limited to the above synthesis scheme and the compounds synthesized by the above synthesis scheme, and various synthesis schemes and reagents can be used. The synthesis method will be described in detail in the Examples.

[0057] (Characteristics of the organic compound according to this embodiment) Next, the characteristics of the organic compound according to this embodiment will be described. In the organic compound according to this embodiment, the partial structure IrL is a partial structure represented by the above-mentioned general formula [A-1] or general formula [A-2]. In other words, it can be said that the ligand L has a dibenzo[f,h]quinoline skeleton.

[0058] The organic compound according to this embodiment has the following characteristics, and is therefore characterized by a high quantum yield. It also has excellent sublimation properties. Furthermore, by using this organic compound, an organic light-emitting device with excellent luminous efficiency can be provided. Furthermore, by using this organic compound, an organic light-emitting device with excellent device durability can be provided. (1) The ligand has a ring structure in which the dibenzo[f,h]quinoline skeleton is bridged by Z1 or Z2, resulting in a high quantum yield. (2) The ligand has a ring structure in which the dibenzo[f,h]quinoline skeleton is bridged by Z1 or Z2, and therefore the symmetry of the ligand is reduced, resulting in high sublimation properties.

[0059] These features will be explained below with reference to comparative compound 1-b, which is a compound in which the auxiliary ligand of compound 1-a described in Patent Document 1 is changed from acetylacetone to phenylpyridine.

[0060] (1) The ligand has a ring structure in which the dibenzo[f,h]quinoline skeleton is bridged by Z1 or Z2, resulting in a high quantum yield.

[0061] In developing the organic compound of the present invention, the inventors focused on the structure of the ligand of the organic compound. Specifically, in an Ir complex having a ligand with a dibenzo[f,h]quinoline skeleton, they attempted to improve the quantum yield by bridging the dibenzo[f,h]quinoline skeleton of the ligand with Z1 or Z2 to form a ring structure.

[0062] Table 1 shows the results of a comparison of the emission characteristics of Example Compound A21, an organic compound according to this embodiment, and Comparative Compound 1-b. 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 system (C9920-02) manufactured by Hamamatsu Photonics KK. The quantum yield is expressed as a relative value, with the quantum yield of Example Compound A21 set to 1.0.

[0063] [Table 1]

[0064] It can be seen from Table 1 that exemplary compound A21 has a higher quantum yield and more excellent light-emitting properties than comparative compound 1-b. The present inventors have considered this as follows.

[0065] The structural difference between the two compounds is whether the dibenzo[f,h]quinoline structure in the ligand forms a bridged ring structure. That is, in Comparative Compound 1-b, the ligand does not form a ring structure in which two carbon atoms in the dibenzo[f,h]quinoline skeleton are bridged. In contrast, in Exemplified Compound A21, a ring structure is formed in which two carbon atoms in the dibenzo[f,h]quinoline skeleton contained in the ligand are bridged by a dimethylmethylene group.

[0066] Here, the photoluminescence quantum yield (PLQY) is calculated from the rate constants of the radiative transition (emission) and non-radiative transition (non-emission) when returning from the excited state to the ground state, as expressed by the following formula: where kr is the rate constant of the radiative transition (radiative decay rate), and knr is the rate constant of the non-radiative transition (non-radiative decay rate). Furthermore, the radiative decay rate (kr) is proportional to the square of the transition dipole moment (TDM), as expressed by the following formula (see Phys. Chem. Chem. Phys. 16, 1719-1758 (2014)).

[0067]

number

[0068] From the above equation, it can be seen that increasing the radiative decay rate (kr) is effective for increasing the photoluminescence quantum yield (PLQY). As mentioned above, the radiative decay rate (kr) is proportional to the square of the transition dipole moment, so increasing the transition dipole moment is effective.

[0069] Here, the transition dipole moment in an Ir complex is proportional to the magnitude of the CT (Charge Transfer) between the HOMO (Highest Occupied Molar Molecular Orbital) and the LUMO (Lowest Unoccupied Molecular Orbital) (see J. Phys. Chem. 94, 239-243 (1990)). The HOMO in an Ir complex is distributed in the aromatic ring that forms a σ-bond with the Ir metal, and the LUMO is distributed in the heterocycle that forms a coordinate bond with the Ir metal. For example, it is known that in Ir(ppy)3, a representative Ir complex, the HOMO is distributed in the benzene ring and the LUMO is distributed in the pyridine ring.

[0070] The present inventors have discovered that in an Ir complex having a ligand having a dibenzo[f,h]quinoline skeleton, CT properties between the aromatic and heterocyclic moieties can be improved by forming a ring structure by bridging atoms in the dibenzo[f,h]quinoline skeleton. Specifically, they found that CT properties can be improved by providing a bridge structure at the para-position to the Ir metal in the aromatic or heterocyclic ring of the dibenzo[f,h]quinoline skeleton, which consists of six atoms including the atom that bonds to the Ir metal. More specifically, they found that CT properties can be improved by providing a bridge structure at the 9th or 4th position of the dibenzo[f,h]quinoline skeleton. As a result, the transition dipole moment increases, leading to an increase in the photoluminescence quantum yield (PLQY).

[0071] 9, in the case of Example Compound A21, an aromatic ring consisting of six atoms including a carbon atom that forms a σ-bond with Ir metal has a bridge structure with a methylene chain (dimethylmethylene group) at the position corresponding to the para position with respect to Ir metal. When the aromatic ring in which the HOMO is distributed has an electron-donating alkyl group, the electron-donating property is increased, causing a bias in the charge, and improving the CT property.

[0072] In the case of Example Compound G1, a heterocycle consisting of six atoms, including a nitrogen atom that forms a coordinate bond with the Ir metal, has a bridge structure with an oxygen atom at the position corresponding to the para position to the Ir metal. The heterocycle, in which the LUMO is distributed, has a highly electronegative oxygen atom, which increases electron-withdrawing properties, resulting in a charge imbalance and improved CT properties.

[0073] Although the examples given here are a structure in which an aromatic ring is bridged by an electron-donating substituent and a structure in which a heterocycle is bridged by an electron-withdrawing substituent, the present invention is not limited thereto. That is, if the partial structure IrL is a structure represented by the above general formula [A-1] or general formula [A-2], regardless of whether the substituents constituting the bridged structure are electron-donating or electron-withdrawing, symmetry can be broken to cause charge imbalance in the aromatic ring or heterocycle. This enhances the CT property, increases the transition dipole moment, and increases the radiative decay rate (kr). This is thought to result in an improved photoluminescence quantum yield (PLQY).

[0074] On the other hand, in the case of comparative compound 1-b, the symmetry of the ligand having the dibenzo[f,h]quinoline skeleton is higher than that of the organic compound according to the present embodiment, and the charge imbalance in the ligand is less likely to occur, which is thought to be the reason for the low CT property, low transition dipole moment, and low quantum yield.

[0075] Furthermore, from the above formula, it can be seen that decreasing the non-radiative decay rate (knr) is also effective in increasing the photoluminescence quantum yield (PLQY).

[0076] Non-radiative transition (non-radiative deactivation) is a deactivation process that occurs when the energy of a molecule's excited state is converted into a molecular vibrational mode. Non-radiative transitions can be reduced by suppressing molecular vibrations, but an effective way to suppress molecular vibrations is to increase the molecular rigidity. This is because a molecule with high rigidity has a state in which the stretching vibration, rotational vibration, and bending vibration of the bonds that form the molecule are more suppressed.

[0077] Here, in the organic compound according to this embodiment, the ligand has a structure in which atoms in the dibenzo[f,h]quinoline skeleton are bridged. Therefore, the vibration of the ligand is more suppressed than in a simple dibenzo[f,h]quinoline ligand without a bridged structure, and rigidity is improved. This is thought to result in a smaller non-radiative decay rate (knr) and a higher photoluminescence quantum yield (PLQY) compared to a case without the bridged structure.

[0078] (2) The ligand has a ring structure in which the dibenzo[f,h]quinoline skeleton is bridged by Z1 or Z2, and therefore the symmetry of the ligand is reduced, resulting in high sublimation properties.

[0079] In developing the organic compounds of the present invention, the present inventors focused on the symmetry of the ligand structure. To simplify the discussion of the symmetry of the ligand structure, as shown in FIG. 10, the molecular structures of the ligands are compared, with nitrogen atoms being likened to carbon atoms. The ligand of Comparative Compound 1-b has one three-fold rotation axis perpendicular to the molecular plane and three two-fold rotation axes parallel to the molecular plane (shown by dotted lines in FIG. 10), resulting in a high degree of symmetry. On the other hand, Exemplary Compound A21, due to the aforementioned crosslinked structure, has only one two-fold rotation axis parallel to the molecular plane (shown by dotted lines in FIG. 10), resulting in a structure with lower symmetry than Comparative Compound 1-b.

[0080] By decreasing the symmetry of the ligand, the sublimation temperature can be decreased. This is because when the symmetry of the ligand is low, the organic compounds are less likely to aggregate. On the other hand, when the symmetry is high, the organic compounds are more likely to aggregate, resulting in a higher sublimation temperature. When the sublimation temperature is low, the temperature difference between the sublimation temperature and the thermal decomposition temperature can be increased, which can suppress thermal decomposition during sublimation and increase the sublimability.

[0081] Here, the results of comparing the sublimation properties of Example Compound A21, which is an organic compound according to this embodiment, and Comparative Compound 1-b are shown in FIG. 10. The sublimation properties are evaluated by comparing the temperature difference between the sublimation temperature and the decomposition temperature. The larger this temperature difference, the higher the sublimation properties. The decomposition temperature was determined by TG / DTA measurement, and the temperature at which the weight loss reached 5% was taken as the decomposition temperature. The sublimation temperature was determined by 1×10 -1 The temperature was slowly raised under a vacuum of 0.1 Pa while flowing Ar, and sublimation purification was carried out. The temperature at which a sufficient sublimation rate was reached was taken as the sublimation temperature.

[0082] 10, it can be seen that exemplary compound A21, an organic compound according to this embodiment, has a large temperature difference between its sublimation temperature and decomposition temperature, making it a highly sublimable material. Furthermore, its high sublimability allows stable sublimation purification without decomposition during sublimation. This also indicates high vapor deposition stability when producing organic light-emitting devices. In other words, a highly pure vapor-deposited film can be produced without decomposition during vapor deposition, making it possible to provide an organic light-emitting device with a long life.

[0083] Low symmetry also brings about the following advantages. Comparative compound 1-b has a ligand with a dibenzo[f,h]quinoline structure with an extended π-conjugated system. Therefore, organic compounds are likely to aggregate due to π-π interactions, and concentration quenching is likely to occur when used in an organic light-emitting device. On the other hand, in the case of the organic compound according to this embodiment, although the ligand has a dibenzo[f,h]quinoline skeleton, the symmetry is reduced due to the presence of the above-mentioned bridged structure. Therefore, π-π interactions are suppressed compared to when there is no bridged structure, and aggregation of organic compounds can be suppressed. As a result, concentration quenching is less likely to occur, and a highly efficient organic light-emitting device can be provided.

[0084] The evaluation of the characteristics (1) and (2) of the organic compound according to this embodiment will be described in more detail in the examples described later.

[0085] Next, further characteristics of organic compounds in which the partial structure IrL is a partial structure represented by any one of the general formulae [A-11] to [A-14] and [A-21] to [A-24] will be described. These organic compounds have the following characteristics, making them suitable for use in organic light-emitting devices. (3) In the general formula [A-1] or [A-2], when Z1 or Z2 is SiR1R2, CR1R2, or GeR1R2, the dibenzo[f,h]quinoline structure has a substituent extending in a direction perpendicular to its in-plane direction, resulting in higher sublimation properties. (4) In the general formula [A-1] or [A-2], when Z1 or Z2 is either an oxygen atom or a sulfur atom, the unshared electron pair of the oxygen atom or sulfur atom enhances the CT property, resulting in a higher quantum yield. (5) When the partial structure IrL is represented by either of the general formulas [A-14] and [A-24], the carbon atoms constituting the basic skeleton of the ligand are composed only of sp2 carbons, resulting in higher chemical stability.

[0086] These features will be explained below.

[0087] (3) In the general formula [A-1] or [A-2], when Z1 or Z2 is SiR1R2, CR1R2, or GeR1R2, the dibenzo[f,h]quinoline structure has a substituent extending in a direction perpendicular to its in-plane direction, resulting in higher sublimation properties.

[0088] As shown in general formula [A-1] or [A-2], the organic compound according to this embodiment has a dibenzo[f,h]quinoline skeleton as a basic skeleton and a highly planar ligand with an extended π-conjugated system. The presence of the above-described crosslinked structure reduces the symmetry of the ligand, thereby suppressing stacking of the ligands. When Z1 or Z2 is SiR1R2, CR1R2, or GeR1R2, the substituents R1 and R2 can reduce the planarity of the ligand, further suppressing stacking of the ligands.

[0089] Here, the planarity of the ligands of Example Compound A21 and Comparative Compound 1-b is compared. As shown in FIG. 12, in the case of Example Compound A21, the ligand has a bridged structure consisting of dimethylmethylene groups, so that the substituents (methyl groups) bonded to the methylene chains extend in a direction perpendicular to the ligand plane. Therefore, the steric hindrance of these substituents makes it difficult for the ligands to aggregate, thereby further suppressing aggregation between organic compounds. This allows the sublimation temperature to be further lowered, the sublimation property to be further improved, and the organic compound to have higher resistance to concentration quenching.

[0090] Among them, in the general formula [A-1] or [A-2], Z1 or Z2 is preferably CR1R2. In other words, it is preferable that the partial structure IrL is represented by the general formula [A-11] or [A-21].

[0091] (4) In the general formula [A-1] or [A-2], when Z1 or Z2 is either an oxygen atom or a sulfur atom, the unshared electron pair of the oxygen atom or sulfur atom enhances the CT property, resulting in a higher quantum yield.

[0092] In general formula [A-1] or [A-2], when Z1 or Z2 is either an oxygen atom or a sulfur atom, the organic compound according to this embodiment has a structure in which carbon atoms in the dibenzo[f,h]quinoline skeleton are bridged by an oxygen atom or a sulfur atom. The oxygen atom has high electronegativity and an abundance of unshared electron pairs, while the sulfur atom has an abundance of unshared electron pairs. Therefore, when Z1 or Z2 is either an oxygen atom or a sulfur atom, polarization within the ligand increases, resulting in a large change in electron density, thereby further enhancing CT properties. As a result, as shown in Table 2, the organic compound has a superior quantum yield. The quantum yield was measured as described above and is expressed as a relative value, with the quantum yield of exemplary compound A21 set to 1.0.

[0093] [Table 2]

[0094] Therefore, from the viewpoint of quantum yield, it is preferable that Z1 or Z2 in general formula [A-1] or [A-2] is either an oxygen atom or a sulfur atom. In other words, it is preferable that the partial structure IrL is represented by any of general formulas [A-12], [A-13], [A-22], and [A-23].

[0095] (5) When the partial structure IrL is represented by either of the general formulas [A-14] and [A-24], the carbon atoms constituting the basic skeleton of the ligand are composed only of sp2 carbons, resulting in higher chemical stability.

[0096] When the partial structure IrL is represented by either of the general formulas [A-14] and [A-24], the organic compound according to this embodiment has a structure in which carbon atoms in the dibenzo[f,h]quinoline skeleton are crosslinked by an ethylene chain. Such a structure is preferable because it can improve the chemical stability of the ligand of the organic compound. This is because in this case, the carbon atoms constituting the basic skeleton of the ligand are composed of only sp2 carbons. In other words, it can be said that it is preferable that the carbon atoms constituting the basic skeleton of the ligand L are composed of only sp2 carbons. Note that the basic skeleton of the ligand in this specification refers to the structure in which Y1 to Y are bonded in the general formula [A-1] or [A-2]. 16 is a carbon atom having a hydrogen atom.

[0097] In organic light-emitting devices, oxidation and reduction are repeatedly carried out during device operation, and molecules with high energy in an excited state exist within the device. Therefore, it is preferable that the molecules forming the device are stable against oxidation and reduction and have a structure consisting only of high-energy bonds that do not break even in a high-energy state.

[0098] When the partial structure IrL is represented by either of the general formulas [A-14] and [A-24], the carbon atoms constituting the basic skeleton of the ligand are composed of only sp2 carbons. Therefore, when this organic compound is used in an organic light-emitting device, an organic light-emitting device having particularly excellent driving durability can be provided. Note that, X in the general formula [A-14] 25 ~X 34 and X in general formula [A-24] 59 ~X 68 When at least one of the atoms is a nitrogen atom, the bonds that make up the basic skeleton of the ligand are composed only of sp2 hybrid orbitals, just as when they are carbon atoms. Therefore, the bond energy of each bond that makes up the basic skeleton of the ligand is sufficiently high, resulting in a ligand with high chemical stability.

[0099] (Examples of organic compounds according to this embodiment) Specific examples of the organic compound according to this embodiment are shown below, but the present invention is not limited to these.

[0100]

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[0102]

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[0103]

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[0104]

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[0106]

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[0107]

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[0108]

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[0109]

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[0110]

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[0121] [ka]

[0122] Among the above exemplary compounds, the exemplary compounds (A1 to A40) belonging to group A are organic compounds in which Z1 is CR1R2 in the general formula [A-1]. In other words, they are organic compounds in which the partial structure IrL is represented by the general formula [A-11]. These compounds have the above characteristics (1), (2), and (3), and are compounds with superior sublimability among the above compounds.

[0123] Among the above exemplary compounds, the exemplary compounds (B1 to B40) belonging to group B are organic compounds in which Z1 in general formula [A-1] is a sulfur atom. In other words, they are organic compounds in which the partial structure IrL is represented by general formula [A-12]. These compounds have the above characteristics (1), (2), and (4), and are compounds with superior luminescence properties among the above exemplary compounds.

[0124] Among the above exemplary compounds, the exemplary compounds belonging to Group C are (C1 to C40) organic compounds in which Z1 in the general formula [A-1] is an oxygen atom. In other words, they are organic compounds in which the partial structure IrL is represented by the general formula [A-13]. These compounds have the above characteristics (1), (2), and (4), and are compounds with superior luminescence properties among the above exemplary compounds.

[0125] Among the above exemplary compounds, the exemplary compounds (D1 to D40) belonging to group D are organic compounds in which Z1 in general formula [A-1] is CR1=CR2. In other words, they are organic compounds in which the partial structure IrL is represented by general formula [A-14]. These compounds have the above characteristics (1), (2), and (5), and are compounds with superior chemical stability among the above exemplary compounds.

[0126] Among the above exemplary compounds, the exemplary compounds (E1 to E40) belonging to group E are organic compounds in which Z1 is CR1R2 in the general formula [A-2]. In other words, they are organic compounds in which the partial structure IrL is represented by the general formula [A-21]. These compounds have the above characteristics (1), (2), and (3), and are compounds with superior sublimability among the above compounds.

[0127] Among the above exemplary compounds, the exemplary compounds (F1 to F40) belonging to group F are organic compounds in which Z1 in general formula [A-2] is a sulfur atom. In other words, they are organic compounds in which the partial structure IrL is represented by general formula [A-22]. These compounds have the above characteristics (1), (2), and (4), and are compounds with superior luminescence properties among the above exemplary compounds.

[0128] Among the above exemplary compounds, the exemplary compounds (G1 to G40) belonging to group G are organic compounds in which Z1 in general formula [A-2] is an oxygen atom. In other words, they are organic compounds in which the partial structure IrL is represented by general formula [A-23]. These compounds have the above characteristics (1), (2), and (4), and are compounds with superior luminescence properties among the above exemplary compounds.

[0129] Among the above exemplary compounds, the exemplary compounds (H1 to H40) belonging to group H are organic compounds in which Z1 in general formula [A-2] is CR1=CR2. In other words, they are organic compounds in which the partial structure IrL is represented by general formula [A-24]. These compounds have the above characteristics (1), (2), and (5), and are compounds with superior chemical stability among the above exemplary compounds.

[0130] Among the above exemplary compounds, the exemplary compounds (I1 to I20) belonging to group I are organic compounds in which Z1 is SiR1R2 in the general formula [A-1]. The exemplary compounds (J1 to J20) belonging to group J are organic compounds in which Z1 is GeR1R2 in the general formula [A-1]. These compounds have the above characteristics (1), (2), and (3), and are compounds with superior sublimability among the above compounds.

[0131] Among the above exemplary compounds, the exemplary compounds (K1 to K20) belonging to group K are organic compounds in which Z2 is NR1 in the general formula [A-1]. These compounds have a structure in which carbon atoms in a dibenzo[f,h]quinoline skeleton are bridged by nitrogen atoms. Because the nitrogen atom has an unshared electron pair like the oxygen atom and sulfur atom, the compounds have the same properties as those in (4) above, and are high in CT properties and excellent in quantum yield. Furthermore, when the substituent (R1) of the nitrogen atom is a bulky substituent such as a benzene ring, the aggregation of ligands can be more effectively suppressed by steric hindrance, and therefore the compounds are excellent in sublimability.

[0132] Among the above exemplary compounds, the exemplary compounds (L1 to L20) belonging to the L group are organic compounds in which Z2 is SiR1R2 in the general formula [A-2]. The exemplary compounds (M1 to M20) belonging to the M group are organic compounds in which Z2 is GeR1R2 in the general formula [A-2]. These compounds have the above characteristics (1), (2), and (3), and are compounds with superior sublimability among the above compounds.

[0133] Among the above exemplary compounds, the exemplary compounds (N1 to N20) belonging to group N are organic compounds in which Z2 is NR1 in the general formula [A-2]. These compounds have a structure in which carbon atoms in a dibenzo[f,h]quinoline skeleton are bridged by nitrogen atoms. Because nitrogen atoms, like oxygen and sulfur atoms, have unshared electron pairs, they have the same properties as those in (4) above, and are compounds with high CT properties and excellent quantum yields. Furthermore, when the substituent (R1) of the nitrogen atom is a bulky substituent such as a benzene ring, the steric hindrance effect can more effectively suppress the aggregation of ligands, resulting in compounds with excellent sublimability.

[0134] Furthermore, in the general formula [1], m is preferably 1 or 2, and more preferably 2. That is, it is more preferably represented by Ir(L)(L')2. In this embodiment, the partial structure IrL is a partial structure represented by the general formula [A-1] or the general formula [A-2], and therefore the ligand L has a large molecular weight and a highly planar structure. Therefore, organic compounds having the ligand L tend to easily form associations due to interactions between organic compounds, and the molecular weight of the entire organic compound tends to increase. However, by setting m = 1, the molecular weight of the entire organic compound can be reduced, and the interactions between the organic compounds can be suppressed, thereby keeping the sublimation temperature low. As a result, it is preferable because device fabrication by sublimation purification or vacuum deposition can be performed at a lower temperature.

[0135] In addition, in the general formula [A-1] or [A-2], it is preferable that the carbon atom adjacent to the carbon atom forming a σ-bond with the Ir metal in the aromatic ring forming a σ-bond with the Ir metal has a methyl group. This is because it improves the balance between the MLCT (Metal to Ligand Charge Transfer) property, which is the interaction between the ligand and the Ir metal, and the π-π* property of the ligand. The same applies to the general formulas [A-11] to [A-14] and [A-21] to [A-24].

[0136] Therefore, in the general formula [1], the partial structure IrL is preferably a partial structure represented by the following general formula [C-1] or general formula [C-2].

[0137] [ka]

[0138] Furthermore, in the general formula [1], the partial structure IrL is more preferably a partial structure represented by any one of the following general formulae [C-11] to [C-14] and [C-21] to [C-24].

[0139] [ka]

[0140] [ka]

[0141] In addition, Y2 to Y2 in the above general formulas [C-1] and [C-2] 16 represents Y2 to Y2 in the general formulas [A-1] and [A-2]. 16 In addition, X2 to X in the general formulas [C-11] to [C-14] and [C-21] to [C-24] are the same as 68 represents X2 to X in the general formulas [A-11] to [A-14] and [A-21] to [A-24]. 68 is the same as:

[0142] Furthermore, in the general formula [1], it is preferable that all three ligands have different structures. This is because the symmetry of the Ir complex as a whole is reduced, which can improve sublimation properties and resistance to concentration quenching. In other words, it is preferable that the Ir complex is an organic compound represented by the following general formula [2].

[0143] [ka]

[0144] In the above general formula [2], Ir is iridium. L, L', and L" represent different bidentate ligands. The partial structure IrL is a partial structure represented by the above general formula [A-1] or general formula [A-2], and the partial structure IrL' is a partial structure represented by the above general formula [B-1] or general formula [B-2]. The partial structure IrL" is a partial structure represented by any of the above general formulas [A-1], [A-2], [B-1], and [B-2]. The partial structure IrL" is preferably a partial structure represented by the above general formula [B-1] or general formula [B-2].

[0145] <Organic light-emitting element> Next, the organic light-emitting device according to this embodiment will be described.

[0146] Specific examples of the organic light-emitting device according to this embodiment include a multilayer device configuration in which electrode layers and organic compound layers shown in (1) to (6) below are sequentially stacked on a substrate. That is, the organic light-emitting device according to this embodiment has at least 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 always includes a light-emitting layer containing a light-emitting material. (1) Anode / 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

[0147] 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, adhesive layer, or interference layer may be provided at the interface between the electrode and the organic compound layer. Furthermore, the electron transport layer or 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 emitting a first light and a second light-emitting layer emitting a second light may be provided between the anode and cathode. By making the first light and the second light different colors, for example, so that they become white when mixed, an organic light-emitting device that emits white light can be obtained. In addition to this, various layer configurations can be adopted.

[0148] In this embodiment, the extraction mode (device configuration) of 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 emission type in which light is extracted from the substrate side and the opposite side of the substrate may be adopted.

[0149] Among the device configurations shown in (1) to (6), the configuration (6) is preferable because it has both an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). That is, 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 luminous efficiency.

[0150] The organic light-emitting element according to this embodiment includes an organic compound represented by the general formula [1] in an organic compound layer. The organic light-emitting element according to this embodiment preferably includes an organic compound represented by the general formula [1] in an emitting layer. However, the present invention is not limited thereto, and the organic compound may be used as a constituent material for organic compound layers other than the emitting layer that constitute the organic light-emitting element according to this embodiment. Specifically, the organic compound may be used as a constituent material for 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.

[0151] In the organic light-emitting device according to this embodiment, when the organic compound represented by 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 general formula [1]. Alternatively, the light-emitting layer may be a layer consisting of the organic compound represented by general formula [1] and a second compound that is another compound. Here, when the light-emitting layer is a layer consisting of the organic compound represented by general formula [1] and another compound, the organic compound according to this embodiment may be used as a host (also referred to as a host material) or a guest (also referred to as a guest material) of the light-emitting layer. It may also be used as an assist material that can be contained in the light-emitting layer.

[0152] 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 mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and is the compound that is primarily responsible for emitting light. The assist material is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and assists the guest in emitting light. The assist material is also called the second host.

[0153] In addition, the host is preferably a material with a higher LUMO than the guest (a material with a LUMO closer to the vacuum level). This allows electrons supplied to the host in the emitting layer to be efficiently transferred to the guest, improving luminous efficiency. Furthermore, when an assist material is used in addition to the host and guest, the host is preferably a material with a higher LUMO than the assist material (a material with a LUMO closer to the vacuum level). This allows electrons supplied to the host in the emitting layer to be efficiently transferred to the assist material, allowing the assist material to take on exciton recombination. As a result, energy can be efficiently transferred to the guest.

[0154] 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 The energy of guest S1 is S g1 , the energy of T1 is T g1 In this case, S h1 >S g1 It is preferable to satisfy 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 to satisfy S h1 >S a1 >S g1It is more preferable to satisfy T h1 >T a1 >T g1 It is more preferable that the following be satisfied.

[0155] The present inventors have conducted various studies and found that when an organic compound represented by general formula [1] is used as a host or guest in an emitting layer, particularly as a guest in an emitting layer, an organic light-emitting element having excellent luminous efficiency and durability can be obtained.

[0156] 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 satisfy 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. (7) The light-emitting layer contains the organic compound represented by the general formula [1] in a concentration of 1% by mass or more and 30% by mass or less based on the entire light-emitting layer. (8) The light-emitting layer includes 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. (9) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having a carbazole structure. (10) 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. (11) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having no sp3 carbon.

[0157] Each of the above conditions will be explained below.

[0158] (7) The light-emitting layer contains the organic compound represented by the general formula [1] in a concentration of 1% by mass or more and 30% by mass or less based on the entire light-emitting layer.

[0159] When an organic compound represented by general formula [1] is used in the light-emitting layer, the content of the organic compound is preferably 1% by mass or more and 30% by mass or less with respect to the entire light-emitting layer. Furthermore, the content of the organic compound is more preferably 5% by mass or more and 15% by mass or less with respect to the entire light-emitting layer. When the organic compound represented by general formula [1] is used in the light-emitting layer, a lower concentration can exhibit better characteristics. Furthermore, a lower concentration can provide a light-emitting device with high efficiency and high color purity.

[0160] This is due to the structural characteristics of the organic compound represented by general formula [1]. The organic compound represented by general formula [1] has the above-mentioned ligand L, and the ligand L has a structure with an extended π-conjugated system. Therefore, if the organic compound represented by general formula [1] is mixed at an excessively high concentration in the light-emitting layer, the organic compounds may aggregate together, causing concentration quenching and reducing the luminous efficiency. On the other hand, by setting the content of the organic compound represented by general formula [1] at a relatively low concentration, between 1% and 30% by mass of the entire light-emitting layer, it is possible to suppress the aggregation of the organic compounds and increase the luminous efficiency.

[0161] (8) The light-emitting layer includes 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.

[0162] The organic compound represented by general formula [1] has a ligand having a dibenzo[f,h]quinoline skeleton and a highly planar structure with an extended π-conjugated system. Therefore, it is preferable that the second organic compound used in combination with the organic compound represented by general formula [1] has an aromatic ring and a highly planar structure. This is because the highly planar structure of the second organic compound allows the highly planar portions of the second organic compound to interact with each other and approach each other. More specifically, the ligand L of the organic compound represented by general formula [1] and the planar portion of the second organic compound are more likely to approach each other. Therefore, it is expected that the intermolecular distance between the organic compound represented by general formula [1] and the second organic compound will be shorter.

[0163] 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. That is, by shortening the intermolecular distance between the host and guest, energy transfer from the host to the guest is efficient.

[0164] By using a highly planar organic compound as the second organic compound, the intermolecular distance between the organic compound represented by general formula [1] and the second organic compound is shortened, resulting in more efficient energy transfer via the Dexter mechanism between the two compounds. 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 general formula [1] is improved. As a result, an organic light-emitting device that exhibits highly efficient light emission can be provided.

[0165] Here, the highly planar structure specifically refers to a triphenylene structure, a phenanthrene structure, a chrysene structure, or a fluoranthene structure. By combining a compound having at least one of these structures as a second organic compound with the organic compound represented by general formula [1], a light-emitting device with higher efficiency can be provided.

[0166] (9) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having a carbazole structure.

[0167] As shown in Table 3 below, the organic compound represented by general formula [1] has a HOMO moiety formed by an Ir metal and an aromatic ring, and a LUMO moiety formed by an Ir metal and a heterocyclic ring. In Table 3 below, the HOMO moiety and the LUMO moiety are indicated by dotted circles. The areas surrounded by dotted squares in Table 3 are vacant orbitals. As the HOMO moiety is localized near the Ir metal and the benzene ring bonded to the Ir metal, the organic compound represented by general formula [1] is prone to a decrease in hole transport ability due to the vacant orbitals.

[0168] Therefore, the present inventors have found that it is preferable to use an organic compound represented by general formula [1] in combination with an organic compound having a carbazole structure. The carbazole structure is a heterocyclic ring that has excellent hole transport ability. Therefore, organic compounds having a carbazole structure have excellent hole transport ability. Therefore, by using an organic compound having a carbazole structure in combination with an organic compound having a carbazole structure, the hole transport ability of the light-emitting layer can be improved by compensating for the hole transport ability that is reduced by the organic compound represented by general formula [1].

[0169] Furthermore, it is more preferable to use the organic compound represented by general formula [1] in combination with a second organic compound having a carbazole structure and an azine ring. Azine rings, such as pyridine, pyrazine, pyrimidine, and triazine, are heterocyclic rings with excellent electron transport properties. Therefore, by further introducing an azine ring into an organic compound having a carbazole structure, it is possible to improve both hole transport properties and electron transport properties. This is more preferable because it allows the formation of an emitting layer with improved electron transport properties and hole transport properties.

[0170] [Table 3]

[0171] (10) 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.

[0172] In general, Ir complexes are known to be hole-trapping compounds. In addition, as mentioned above, the organic compounds represented by the general formula [1] have vacant orbitals, which results in particularly low hole transport ability.

[0173] To compensate for this hole transport ability, the second organic compound used in combination with the organic compound represented by general formula [1] is preferably a material having a skeleton with excellent hole transport ability. A skeleton with excellent hole transport ability is one that has an abundance of unshared electron pairs and has high electron donating properties. Specifically, it is a skeleton having an electron donating nitrogen atom, such as carbazole, as explained in (9) above, or a skeleton having chalcogen atoms with an abundance of unshared electron pairs, such as a dibenzothiophene structure or a dibenzofuran structure.

[0174] Among these, the second organic compound that can be suitably used together with the organic compound represented by 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, and therefore can adjust the carrier balance between holes and electrons, and are suitable as skeletons that support the hole transport ability of the organic compound represented by general formula [1]. Among these, it is particularly preferred that the second organic compound has a dibenzothiophene structure that is rich in lone electron pairs.

[0175] (11) The light-emitting layer contains an organic compound represented by the general formula [1] and a second organic compound having no sp3 carbon.

[0176] As described in (8) above, the light-emitting properties of the organic light-emitting device can be improved by shortening the intermolecular distance between the organic compound represented by general formula [1] and the second organic compound. By using an organic compound that does not have an sp3 carbon as the second organic compound, the intermolecular distance between the organic compound represented by general formula [1] can be further shortened.

[0177] When sp3 carbon is present, the hydrophobic interaction and steric hindrance of the alkyl group increase the intermolecular distance between the organic compound represented by general formula [1] and the second organic compound. On the other hand, when sp3 carbon is absent, the hydrophobic interaction and steric hindrance caused by the alkyl group are eliminated, and the increase in the separation distance due to these factors does not occur, allowing the intermolecular distance with the organic compound represented by general formula [1] to be shortened. As a result, the light-emitting properties of the organic light-emitting device can be improved.

[0178] Specific examples of the second compound according to this embodiment, more specifically, specific examples of compounds suitable as host materials are shown below, but the present invention is not limited thereto.

[0179] [ka]

[0180] [ka]

[0181] [ka]

[0182] [ka]

[0183] Among the above compounds, the exemplary compounds (AA1 to AA21) belonging to the AA group have a carbazole structure. Therefore, these compounds have excellent hole transport ability due to the carbazole structure. As a result, it is possible to compensate for the relatively low hole transport ability of the organic compound represented by general formula [1], form a light-emitting layer with excellent hole transport ability, and obtain an organic light-emitting device with high luminous efficiency.

[0184] 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 their skeleton, and do not have an 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, intermolecular energy transfer, more specifically, energy transfer from the second organic compound to the compound represented by general formula [1], can be performed with high efficiency, thereby improving luminous efficiency. 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.

[0185] 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 their skeleton, and do not have an sp3 carbon. Therefore, when these compounds are combined with an organic compound represented by general formula [1] to form an emitting layer, the HOMO and LUMO are well balanced. As a result, a good carrier balance can be achieved, and an organic light-emitting device 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.

[0186] (Other compounds) Other examples of compounds that can be used in the organic light-emitting device of this embodiment are listed below.

[0187] As a hole injection / transport material suitable for use in the hole injection layer or hole transport layer, a material with 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. Furthermore, a material with a high glass transition temperature is preferred to suppress deterioration of film quality, such as crystallization, in the organic light-emitting device. Examples of low-molecular-weight and high-molecular-weight materials with hole injection / transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above-mentioned hole injection / transport materials are also suitable for use in the electron blocking layer.

[0188] Specific examples of compounds that can be used as hole injection and transport materials are shown below, but the present invention is not limited to these.

[0189] [ka]

[0190] Examples of luminescent materials mainly involved in luminescence function include organic compounds represented by general formula [1], as well as 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.

[0191] Specific examples of compounds that can be used as light-emitting materials are shown below, but the present invention is not limited to these.

[0192] [ka]

[0193] [ka]

[0194] Examples of the emitting layer host or assist material contained in the emitting layer include, in addition to the materials in the AA group, BB group, and CC group described above, aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes.

[0195] As the assist material, a compound having at least one structure selected from the group consisting of a xanthone structure, a thioxanthone structure, and a benzophenone structure, which have a deep LUMO (far from the vacuum level) similar to an azine ring, is preferred. Specifically, the following EM28 to EM31 are particularly preferred. As the assist material, a compound having an azine ring is also preferred.

[0196] Specific examples of compounds that can be used as the host or assist material contained in the light-emitting layer are shown below, but the present invention is not limited to these.

[0197] [ka]

[0198] 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, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting materials are also suitable for use in hole-blocking layers.

[0199] Specific examples of compounds that can be used as electron transporting materials are shown below, but the present invention is not limited to these.

[0200] [ka]

[0201] The following describes the components other than the organic compound layer that make up the organic light-emitting device of this embodiment. 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.

[0202] The substrate may be made of quartz, glass, silicon, resin, metal, or the like. Furthermore, 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, resins such as polyimide, silicon oxide, silicon nitride, or the like may be used.

[0203] The anode material should preferably have a high work function. Examples include metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used. These electrode materials can be used alone or in combination. The anode may be composed of a single layer or multiple layers. When used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates of these materials 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 can be used to form the anode.

[0204] On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combination. The cathode can have either a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to suppress silver aggregation. The alloy ratio is not critical as long as silver aggregation can be suppressed. For example, a 1:1 ratio is acceptable.

[0205] 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 DC and AC sputtering methods are more preferred because they provide good film coverage and make it easier to reduce resistance.

[0206] A protective layer may be provided after the cathode is formed. For example, by adhering glass provided with a moisture absorbent onto the cathode, it is possible to prevent water and other substances from penetrating the organic compound layer, thereby suppressing display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to prevent water and other substances from penetrating 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 with a thickness of 2 μm may be formed by CVD to serve as a protective layer. A protective layer may also be provided using atomic layer deposition (ALD) after the film is formed by CVD.

[0207] Alternatively, a color filter may be provided for each pixel. For example, a color filter matching 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 photolithography.

[0208] 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 can be formed by the following methods. That is, to form the organic compound layers, dry processes such as vacuum deposition, ionization deposition, sputtering, and plasma can be used. Alternatively, instead of the dry process, a wet process can be used in which the compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.). Here, when a layer is formed by a vacuum deposition method or solution coating method, crystallization and the like are unlikely to occur and the layer has excellent stability over time. Furthermore, when a film is formed by a coating method, a film can be formed by combining it with an appropriate binder resin. Examples of binder resins include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin. The binder resin may be a homopolymer or a copolymer, and may be used singly or in combination of two or more kinds. If necessary, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination.

[0209] <Device using organic light-emitting element> The organic light-emitting device according to this 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, or a light-emitting device having a white light source and a color filter.

[0210] 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, etc., 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.

[0211] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0212] Next, the display device according to this embodiment will be described with reference to the drawings.

[0213] 1 is a 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).

[0214] FIG. 1(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel includes subpixels 10. The subpixels are divided into 10R, 10G, and 10B based on their light emission. The emitted colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the subpixels may be selectively transmitted or color-converted using a color filter or the like. Each subpixel includes a reflective electrode 2, which serves as a first electrode, on an interlayer insulating layer 1; an insulating layer 3 covering the edges 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.

[0215] 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).

[0216] The insulating layer 3 is also called a bank or pixel separation film. It covers the edges of the first electrode and surrounds the first electrode. The part where the insulating layer is not provided contacts the organic compound layer 4 and becomes the light-emitting region.

[0217] The organic compound layer 4 includes a hole injection layer 41 , a hole transport layer 42 , a first light-emitting layer 43 , a second light-emitting layer 44 , and an electron transport layer 45 .

[0218] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0219] The protective layer 6 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as a single layer, it may be a multi-layer. Each layer may be an inorganic compound layer and an organic compound layer.

[0220] The color filters 7 are divided into 7R, 7G, and 7B depending on 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 thereto.

[0221] 1(b) includes 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 with an insulating layer 12 on top of it. 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 top of the substrate 11.

[0222] 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 top 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.

[0223] 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.

[0224] 1(b), the organic compound layer 22 is illustrated as a single layer, but may be a multi-layer organic compound layer 22. 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.

[0225] 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.

[0226] The transistors used in the display device 100 of Fig. 1(b) are not limited to thin-film transistors having an active layer on an insulating surface of a substrate, but may also be transistors using a single-crystal silicon wafer. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, as well as non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0227] The transistors included in the display device 100 of Fig. 1(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the substrate itself, such as a Si substrate, is processed to form the transistors. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being integrally formed.

[0228] The organic light-emitting element according to this embodiment has its emission brightness controlled by a TFT, which is an example of a switching element. By providing multiple organic light-emitting elements on a surface, an image can be displayed based on the emission brightness of each element. Note that the switching element according to this embodiment is not limited to a TFT, and may be a transistor formed from low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also be referred to as "inside the substrate." Whether to provide a transistor in the substrate or to use a TFT is determined by the size of the display unit. For example, for a display size of about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0229] 2 is a schematic diagram illustrating an example of a display device according to this embodiment. The display device 1000 may include 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. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are 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 even if the display device is a portable device.

[0230] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit located 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.

[0231] 3A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include a display device according to this embodiment. In this case, the display device may display not only 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 speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0232] Since the optimum timing for capturing an image is very 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 the organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0233] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0234] The display device according to this embodiment may have color filters having red, green, and blue colors, which may be arranged in a delta arrangement.

[0235] 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 a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0236] FIG. 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 operations such as unlocking. An electronic device having a communication unit can also be called a communication device.

[0237] FIG. 4 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 4(a) illustrates 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 display unit 1302 may include a light-emitting device according to this embodiment. 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 bottom 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.

[0238] FIG. 4(b) is a schematic diagram illustrating another example of a display device according to this 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 include a light-emitting device according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

[0239] FIG. 5(a) is a schematic diagram illustrating an example of a lighting device according to this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404 that transmits light emitted by the light source 1402, and a light diffusion unit 1405. The light source 1402 may include an organic light-emitting element according to this embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion unit can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter and the light diffusion unit may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0240] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit for dimming them or a color tuning circuit for tuning the emitted color. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected to it. The power supply circuit is a circuit that converts AC voltage to DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

[0241] The lighting device according to this embodiment may also include a heat dissipation unit, which dissipates heat from within the device to the outside, and may be made of a material such as a metal with a high specific heat capacity or liquid silicon.

[0242] 5(b) 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 lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0243] The tail lamp 1501 may include an organic light-emitting element according to this embodiment. The tail lamp 1501 may include 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 it is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0244] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display as long as it is not 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 materials.

[0245] The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light to indicate the position of the body. The lighting device has the organic light-emitting element according to this embodiment.

[0246] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 6. The display device can be applied to a system that can be attached as a wearable device, such as smart glasses, an HMD, or a smart contact lens. An image capturing and displaying device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a displaying device capable of emitting visible light.

[0247] 6(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0248] 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 onto the image capture device 1602.

[0249] FIG. 6(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device equivalent to the imaging device 1602 and a display device. A lens 1611 includes an optical system for projecting light emitted from the imaging device and the display device within the control device 1612, 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 also include a gaze detection unit for detecting the wearer's gaze. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit for reducing light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality.

[0250] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using an image of the eyeball. One example is a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea.

[0251] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0252] A display device according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control the image displayed on the display device based on information about the user's line of sight from the imaging device.

[0253] Specifically, the display device determines a first field of view area where 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 determined by an external control device and received. 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.

[0254] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on 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 high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0255] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication.

[0256] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0257] FIG. 7 is a schematic diagram illustrating an example of an image forming apparatus according to this 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, transport rollers 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. This exposure light source 28 includes the organic light-emitting element according to this embodiment. The developing unit 31 includes 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 rollers 33 transport 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.

[0258] 8(a) and 8(b) are diagrams showing an exposure light source 28 and are schematic diagrams illustrating a state in which multiple light-emitting units 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 axis direction about which the photoconductor 27 rotates. This direction can also be referred to as the long axis direction of the photoconductor 27. FIG. 8(a) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(b) shows a different configuration from FIG. 8(a), in which the light-emitting units 36 are arranged alternately in the column direction in the first and second columns. The first and second columns are arranged at different positions in the row direction. In the first column, multiple light-emitting units 36 are arranged at intervals. In the second column, light-emitting units 36 are located at positions corresponding to the intervals between the light-emitting units 36 in the first column. In other words, multiple light-emitting units 36 are also arranged at intervals in the row direction. The arrangement in FIG. 8(b) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0259] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time. [Example]

[0260] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0261] Example 1 (Synthesis of Exemplary Compounds A25 and A35) Exemplary compounds A25 and A35 were synthesized according to the following synthesis scheme.

[0262] [ka]

[0263] (1) Synthesis of compound m-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-1: 4.0g (16.8mmol) Compound m-2: 3.2g (18.5mmol) Pd(PPh3)4: 0.19g Toluene: 20 ml Ethanol: 10ml 2M sodium carbonate solution: 20 ml

[0264] Next, the reaction solution was heated under reflux under a nitrogen stream and stirred for 6 hours. After the reaction was completed, water was added and the mixture was separated. The mixture was then dissolved in chloroform and purified by column chromatography (chloroform). Recrystallization from chloroform / methanol gave 3.7 g (yield: 76%) of compound m-3 as a pale yellow solid.

[0265] (2) Synthesis of compound m-4 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-3: 3.5g (12.2mmol) Phosphorus oxychloride: 105 ml

[0266] Next, the reaction solution was heated to 130°C under a nitrogen stream and stirred for 3 days. After the reaction was completed, water was added and the mixture was separated. The mixture was then dissolved in chloroform and purified by column chromatography (chloroform). Recrystallization from chloroform / methanol gave 2.0 g (yield: 55%) of compound m-4 as a pale yellow solid.

[0267] (3) Synthesis of compound m-5 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-4: 2.0g (6.5mmol) Pd(dba)2: 0.23g P(Cy)3‐HBF4: 0.29g DMAc: 20ml Potassium carbonate: 2.7g (19.6mmol)

[0268] Next, the reaction solution was heated to 150°C under a nitrogen stream and stirred for 6 hours. After the reaction was completed, water was added to separate the solution. The solution was then dissolved in chloroform and purified by column chromatography (chloroform). Recrystallization from chloroform / methanol yielded 0.49 g (yield: 28%) of compound m-5 as a pale yellow solid.

[0269] (4) Synthesis of compound m-6 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 12 ml Iridium(III) chloride hydrate: 0.19g Compound m-5: 0.4g (1.5mmol)

[0270] 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 0.5 g (yield 90%) of compound m-6 as a yellow solid.

[0271] (5) Synthesis of Example Compound A25 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 30 ml Compound m-6: 0.5g (0.3mmol) Compound m-7: 0.13g (1.3mmol) Sodium carbonate: 0.3 g (3.3 mmol)

[0272] Next, the reaction solution was heated to 100°C and stirred for 6 hours. After cooling, methanol was added, and the mixture was filtered and washed with methanol. By drying, 0.3 g (yield 63%) of exemplary compound A25 was obtained as a yellow solid.

[0273] The exemplary compound A25 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=828 Calculated value: C 45 H 35 IrN2O2=828

[0274] (6) Synthesis of exemplary compound A35 The following reagents and solvents were placed in a 50 ml recovery flask. Exemplary compound A25: 0.2 g (0.2 mmol) Compound m-5: 0.7g (2.4mmol) Glycerol: 15ml

[0275] Next, the reaction solution was heated to 230°C and stirred for 3 hours. After cooling to 100°C, 2 mL of toluene was added and the mixture was stirred until it reached room temperature. Heptane was then added and the mixture was filtered. The residue was purified by silica gel column chromatography (ethyl acetate) to obtain 0.06 g (yield 24%) of exemplary compound A35 as a dark yellow solid.

[0276] The exemplary compound A35 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=997 Calculated value: C 60 H 42 IrN3=997

[0277] [Examples 2 to 7 (Synthesis of Exemplary Compounds)] As shown in Table 4, the exemplary compounds of Examples 2 to 7 were synthesized in the same manner as in Example 1, except that the raw materials m-1, m-2, 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.

[0278] [Table 4]

[0279] Example 8 (Synthesis of Exemplary Compounds E29 and E33) Exemplary compounds E29 and E33 were synthesized according to the following synthesis scheme.

[0280] [ka]

[0281] (1) Synthesis of compound n-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound n-1: 4.0g (16.7mmol) Compound n-2: 3.5g (18.4mmol) Pd(PPh3)4: 0.19g Toluene: 20 ml Ethanol: 10ml 2M sodium carbonate solution: 20 ml

[0282] Next, the reaction solution was heated under reflux and stirred under a nitrogen stream for 6 hours. After the reaction was completed, water was added and the mixture was separated. The mixture was then dissolved in chloroform and purified by column chromatography (chloroform). Recrystallization from chloroform / methanol yielded 3.3 g (yield: 64%) of compound n-3 as a pale yellow solid.

[0283] (3) Synthesis of compound m-4 The following reagents and solvents were placed in a 200 ml recovery flask. Compound n-3: 3.0g (9.8mmol) P(dba)2: 0.34g P(Cy)3‐HBF4: 0.43g DMAc: 30ml Potassium carbonate: 4.1g (29.4mmol)

[0284] Next, the reaction solution was heated to 150°C under a nitrogen stream and stirred for 6 hours. After the reaction was completed, water was added to separate the solution. The solution was then dissolved in chloroform and purified by column chromatography (chloroform). Recrystallization from chloroform / methanol yielded 0.8 g (yield: 29%) of compound n-4 as a pale yellow solid.

[0285] (4) Synthesis of compound n-5 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 24 ml Iridium(III) chloride hydrate: 0.32g Compound n-4: 0.7g (2.6mmol)

[0286] 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 0.9 g (yield 89%) of compound n-5 as a yellow solid.

[0287] (5) Synthesis of Example Compound E29 The following reagents and solvents were placed in a 200 ml recovery flask. 2-ethoxyethanol: 30 ml Compound n-5: 0.8g (0.6mmol) Compound n-6: 0.2g (2.5mmol) Sodium carbonate: 0.6g (6.3mmol)

[0288] Next, the reaction solution was heated to 100°C and stirred for 6 hours. After cooling, methanol was added, and the mixture was filtered and washed with methanol. This was dried to obtain 0.5 g (yield 61%) of exemplary compound E29 as a yellow solid.

[0289] The exemplary compound E29 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=828 Calculated value: C 45 H 35 IrN2O2=828

[0290] (6) Synthesis of Example Compound E33 The following reagents and solvents were placed in a 50 ml recovery flask. Exemplary compound E29: 0.5 g (0.5 mmol) Compound n-4: 1.6g (6.0mmol) Glycerol: 15ml

[0291] Next, the reaction solution was heated to 230°C and stirred for 3 hours. After cooling to 100°C, 2 mL of toluene was added and the mixture was stirred until it reached room temperature. Heptane was then added and the mixture was filtered. The residue was purified by silica gel column chromatography (ethyl acetate) to obtain 0.1 g of a dark yellow solid, E33 (yield 22%).

[0292] The exemplary compound E33 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=997 Calculated value: C 60 H 42 IrN3=997

[0293] [Examples 9 to 16 (Synthesis of Exemplary Compounds)] As shown in Table 5, the exemplary compounds of Examples 9 to 16 were synthesized in the same manner as in Example 8, except that raw materials n-1, n-2, and n-6 ​​were changed from those of Example 8. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 8 are also shown.

[0294] [Table 5]

[0295] [Examples 17 to 25 (Synthesis of Exemplary Compounds)] As shown in Table 6, the exemplary compounds of Examples 17 to 21 were synthesized in the same manner as in Example 1, except that raw materials m-1, m-2, and m-5 in Example 1 were changed. Also, as shown in Table 6, the exemplary compounds of Examples 22 to 25 were synthesized in the same manner as in Example 8, except that raw materials n-1, n-2, and n-4 in Example 8 were changed. Also shown are the measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Examples 1 and 8.

[0296] [Table 6]

[0297] Example 26 (Synthesis of Exemplary Compound A1) Exemplary compound A1 was synthesized according to the following synthesis scheme.

[0298] [ka]

[0299] The synthesis of compound k-2 is similar to the synthesis of compound m-6 in Example 1 (4), and therefore the explanation is omitted.

[0300] (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: 0.5 g (1.9 mmol) Dichloromethane: 50 ml Methanol: 2 ml

[0301] The reaction solution was then stirred at room temperature for 6 hours, after which the solvent was evaporated under reduced pressure to give a yellow solid.

[0302] Next, the obtained yellow solid and the following reagents and solvents were placed in a 200 ml recovery flask. Ethanol: 30ml Compound k-3: 0.4g (1.9mmol)

[0303] Next, the reaction solution was heated to 85°C and stirred for 3 hours. After cooling, the solution was filtered. The residue was purified by silica gel column chromatography (chloroform:heptane=1:1) to obtain 0.7 g (yield 52%) of a dark yellow solid A1.

[0304] The exemplary compound A1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=769 Calculated value: 542 H 30 IrN3=769

[0305] [Examples 27 to 43 (Synthesis of exemplified compounds)] As shown in Tables 7 and 8, the exemplary compounds shown in Examples 27 to 43 were synthesized in the same manner as in Example 26, except that raw materials k-1 and k-3 in Example 26 were changed. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 26 are also shown.

[0306] [Table 7]

[0307] [Table 8]

[0308] [Example 44] An organic light-emitting device with a bottom emission structure was fabricated 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.

[0309] First, an ITO film was formed on a glass substrate and then patterned as desired 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 the ITO substrate in the following process. Next, a 1.33 × 10 -4 The organic compound layer and electrode layer shown in Table 9 were successively formed on the ITO substrate by vacuum deposition using resistance heating in a vacuum chamber at 1000 Pa. At this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm 2 It was made to be like this.

[0310] [Table 9]

[0311] The characteristics of the obtained device were measured and evaluated. The maximum emission wavelength of the light-emitting device was 522 nm, and the maximum external quantum efficiency (EQE) was 12%. Furthermore, at a current density of 100 mA / cm 2 A continuous driving test was carried out 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 1 was taken as 1.0, the LT95 of this example was 1.4 (relative value).

[0312] In this example, the measuring device was specifically a microcurrent meter 4140B manufactured by Hewlett-Packard Company to measure the current-voltage characteristics, and a BM7 manufactured by Topcon Corporation to measure the luminance.

[0313] [Examples 45 to 68, Comparative Examples 1 and 2] An organic light-emitting device was produced in the same manner as in Example 44, except that the materials forming each layer in Example 44 were appropriately changed to the compounds shown in Table 10. Layers not shown in Table 10 had the same configuration as in Example 44. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 44. The measurement results are shown in Table 10, along with the results of Example 44.

[0314] [Table 10]

[0315] As shown in Table 10, the maximum external quantum efficiency (EQE) of Comparative Examples 1 and 2 was 8 to 9%, while the maximum external quantum efficiency of Examples 44 to 68 was 10 to 15%, resulting in higher luminous efficiency for the organic light-emitting devices of Examples 21 to 31. This is thought to be because the organic compounds contained as guests in the emitting layers of the organic light-emitting devices of Examples 44 to 68 have higher quantum yields than the organic compound (comparative compound 1) contained as guests in the emitting layers of the organic light-emitting devices of Comparative Examples 1 and 2. Here, comparative compound 1 is a compound in which the auxiliary ligand of compound 1-b described in Patent Document 1 is replaced with phenylpyridine instead of acetylacetone. Each of the organic compounds contained as guests in the emitting layers of the organic light-emitting devices of Examples 44 to 68 has a ring structure in which the carbon atoms constituting the dibenzo[f,h]quinoline skeleton are bridged. Therefore, the radiative decay rate is high due to the high CT property and transition dipole moment, and the non-radiative decay rate is low due to the high rigidity. As a result, it is believed that the quantum yield of each organic compound was high, which is why the organic light-emitting devices of Examples 44 to 68 exhibited high luminous efficiency.

[0316] As can be seen from Table 10, the examples (Examples 45, 51 to 53, 58, 60, 64, and 65) in which the light-emitting layer contained an organic compound as a guest, in which the partial structure IrL is a partial structure represented by the general formula [C-1] or [C-2], showed even higher maximum external quantum efficiency. This is thought to be because, in the aromatic ring that is σ-bonded to the Ir metal, the carbon atom adjacent to the carbon atom that is σ-bonded to the Ir metal has a methyl group, which improves the balance between the MLCT property and the π-π* property of the ligand.

[0317] Furthermore, Table 10 shows that the LT95 of Examples 44 to 68 was greater than that of the organic light-emitting devices of Comparative Examples 1 and 2, resulting in a longer life (excellent durability). This is thought to be because each of the organic compounds contained as guests in the light-emitting layers of Examples 44 to 68 has a ring structure in which the carbon atoms constituting the dibenzo[f,h]quinoline skeleton are bridged, reducing the symmetry of the ligands and making them highly sublimable. Therefore, each organic compound was highly stable during sublimation purification or vapor deposition, allowing the production of a highly pure vapor-deposited film, resulting in organic light-emitting devices with a long life.

[0318] [Example 69] An organic light-emitting device was produced in the same manner as in Example 44, except that the organic compound layer and the electrode layer shown in Table 11 were successively formed.

[0319] [Table 11]

[0320] The device characteristics were measured and evaluated. The light-emitting device emitted green light and had a maximum external quantum efficiency (EQE) of 19%.

[0321] [Examples 70 to 100] An organic light-emitting device was produced in the same manner as in Example 69, except that the materials forming each layer in Example 69 were appropriately changed to the compounds shown in Table 12. Layers not listed in Table 12 had the same configuration as in Example 69. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 69. The measurement results, along with the results of Example 69, are shown in Table 12.

[0322] [Table 12]

[0323] As described above, by using the organic compound represented by the general formula [1] as a guest in the light-emitting layer, an organic light-emitting device with high maximum external quantum efficiency and high luminous efficiency was realized. [Explanation of symbols]

[0324] 1. Organic light-emitting device 11 Circuit Board 21 Anode 22 Organic compound layer 23 Cathode

Claims

1. An organic compound represented by the following general formula [1]: 【Chemical 1】 (In general formula [1], Ir represents iridium. L and L' represent different bidentate ligands. m represents 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 is a partial structure represented by the following general formula [A-1] or general formula [A-2], and the partial structure IrL' is a partial structure represented by the following general formula [B-1] or general formula [B-2]. When m is 2 or more, the multiple Ls present may be the same or different. When n is 2, the multiple Ls present may be the same or different. 【Chemistry 2】 【Chemistry 3】 In the general formulae [A-1], [A-2] and [B-2], Y １ ~Y ２４ is a carbon atom. The carbon atom has a hydrogen atom, a deuterium atom, or a substituent R. Y １ ~Y ２４ When a plurality of the carbon atoms among the groups are carbon atoms having a substituent R, the respective substituents R may have the same structure or different structures. The substituents R are 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. In the general formulae [A-1], [A-2], and [B-2], adjacent Y １ ~Y ２４ are both carbon atoms and have a substituent R, the substituents R may be bonded to each other to form a ring. The ring structure formed may be a benzene ring, a naphthalene ring, an azine ring, a thiophene ring, or a furan ring. In the general formulae [A-1] and [A-2], Z １ and Z ２ represents an oxygen atom, a sulfur atom, SiR １ R ２ , C.R. １ R ２ , C.R. １ =CR ２ are independently selected from the following: １ and R ２ may be bonded to each other to form a ring. In the general formulae [A-1], [A-2], and [B-1], R １ ~R ５ are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

2. The organic compound according to claim 1, wherein the general formula [A-1] is independently selected from the following general formulas [A-11] to [A-14], and the general formula [A-2] is independently selected from the following general formulas [A-21] to [A-24]. 【Chemistry 4】 【Chemistry 5】 In the general formulae [A-11] to [A-14] and [A-21] to [A-24], X １ ~X ６８ is a carbon atom. The carbon atom has a hydrogen atom, a deuterium atom, or a substituent R. X １ ~X ６８ When a plurality of the carbon atoms among the groups are carbon atoms having a substituent R, the respective substituents R may have the same structure or different structures. The substituents R are 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. In the general formulae [A-11] to [A-14] and [A-21] to [A-24], adjacent X １ ~X ６８ are both carbon atoms and have a substituent R, the substituents R may be bonded to each other to form a ring. The ring structure formed may be a benzene ring, a naphthalene ring, an azine ring, a thiophene ring, or a furan ring. In the general formulae [A-11] and [A-21], R ６ ~R ９ are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heterocyclic group.

3. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-11].

4. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-12].

5. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-13].

6. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-14].

7. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-21].

8. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-22].

9. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-23].

10. 3. The organic compound according to claim 2, wherein in the general formula [1], the partial structure IrL is the general formula [A-24].

11. An organic light-emitting device having an anode, a cathode, and an organic compound layer disposed between the anode and the cathode and having at least a light-emitting layer, The organic compound layer comprises the organic compound according to any one of claims 1 to 10.

12. The organic light-emitting device according to claim 11 , wherein the light-emitting layer comprises the organic compound.

13. The organic light-emitting device according to claim 12 , wherein the light-emitting layer comprises a first material that is a compound different from the organic compound.

14. 14. The organic light-emitting element according to claim 13, wherein the content of the organic compound in the light-emitting layer is 1% by mass or more and 30% by mass or less.

15. The organic light-emitting element according to claim 13 or 14, wherein the first material has a carbazole structure.

16. The organic light-emitting element according to claim 15 , wherein the first material further comprises an azine ring.

17. 17. The organic light-emitting device according to claim 13, wherein the first material has at least one structure selected from a triphenylene structure, a phenanthrene structure, a chrysene structure, and a fluoranthene structure.

18. 18. The organic light-emitting element according to claim 13, wherein the first material has at least one structure selected from the group consisting of a dibenzothiophene structure and a dibenzofuran structure.

19. 19. The organic light-emitting element according to claim 13, wherein the first material does not have sp3 carbon.

20. 20. The organic light-emitting device according to claim 13, wherein the light-emitting layer further contains a second compound different from the organic compound and the first material.

21. The organic light-emitting device according to claim 20 , wherein the second compound has an azine ring.

22. 22. The organic light-emitting device according to claim 20, wherein the second compound has at least one structure selected from the group consisting of a xanthone structure, a thioxanthone structure, and a benzophenone structure.

23. the light-emitting layer is a first light-emitting layer, a second light-emitting layer different from the first light-emitting layer is further provided between the first light-emitting layer and the anode or between the first light-emitting layer and the cathode; 23. The organic light-emitting element according to claim 11, wherein the second light-emitting layer emits light of a color different from that of the light emitted by the first light-emitting layer.

24. The organic light-emitting device according to claim 23, which emits white light.

25. having a plurality of pixels, A display device, wherein at least one of the plurality of pixels comprises the organic light-emitting element according to any one of claims 11 to 24, and an active element connected to the organic light-emitting element.

26. 26. The display device according to claim 25, further comprising a color filter.

27. an optical unit having a plurality of lenses, an image pickup element that receives light that has passed through the optical unit, and a display unit that displays an image picked up by the image pickup element; A photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to any one of claims 11 to 24.

28. The device has a housing, a communication unit that communicates with the outside, and a display unit, 25. An electronic device, wherein the display unit comprises the organic light-emitting element according to claim 11.

29. An illumination device having a light source and a light diffusion unit or an optical filter, 25. A lighting device, wherein the light source comprises the organic light-emitting element according to claim 11.

30. A drone includes a body and a lighting fixture provided on the body, A moving body, wherein the lighting device comprises the organic light-emitting element according to any one of claims 11 to 24.

31. An electrophotographic image forming apparatus having an exposure light source, 25. An electrophotographic image forming apparatus, wherein the exposure light source comprises the organic light-emitting element according to claim 11.

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