Organic light-emitting devices

Abstract

To provide an organic light-emitting element with excellent light emission efficiency and an endurance characteristic.SOLUTION: An organic light-emitting element includes: a pair of electrodes; and a light emission layer arranged between the pair of electrodes. The light emission layer includes a gest molecule and a host molecule. The host molecule is an organic chemical compound expressed by the following general equation [1], and the gest molecule is an organometallic complex having a ligand.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an organic light-emitting device. [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 these electrodes. By injecting electrons and holes from this 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. Recent advances in organic light-emitting devices have been remarkable, including low driving voltage, diverse emission wavelengths, fast response, and the ability to reduce the thickness and weight of light-emitting devices. Incidentally, there has been active research into the creation of compounds suitable for organic light-emitting devices. This is because the creation of compounds with excellent device life characteristics is important for providing high-performance organic light-emitting devices. Among the compounds that have been created so far, fused polycyclic compound 1-a containing chalcogenophene is described in Patent Document 1.

[0003] [ka] [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2015 / 0034914 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses an example of a green light-emitting device using Compound 1-a, but further improvements in luminous efficiency and durability are desired. The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic light-emitting element that is excellent in luminous efficiency and durability. [Means for solving the problem]

[0006] The organic light-emitting element of the present invention has a pair of electrodes and a light-emitting layer disposed between the pair of electrodes, the light-emitting layer contains at least guest molecules and host molecules; The host molecule is an organic compound represented by the following general formula [1]: The guest molecule is an organometallic complex represented by the following general formula [2].

[0007] [ka] M(L)m(L')n(L")p [2] In formula [1], R1 to R 12 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, provided that R to R 12 At least one of the groups is selected from a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group. X is selected from an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. In formula [2], M is selected from iridium and platinum. L, L' and L" each represent a different bidentate ligand. m is selected from integers of 1 to 3, and n and p are each selected from integers of 0 to 2, with the proviso that m+n+p=3. The partial structure M(L)m is represented by the following general formula [2-1].

[0008] [ka] In formula [2-1], R 21 ~R 28are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group, provided that R 21 ~R 28 At least one of the adjacent R is selected from a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group. 21 ~R 28 may be bonded to each other to form a ring. The partial structure M(L')n is represented by the following general formula [2-2].

[0009] [ka] In formula [2-2], R 31 ~R 38 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group. 31 ~R 38 may be bonded to each other to form a ring. The partial structure M(L")p is represented by the following general formula [2-3].

[0010] [ka] In formula [2-3], R 39 ~R 41are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group. [Effects of the Invention]

[0011] According to the present invention, an organic light-emitting element having excellent luminous efficiency and durability can be provided by using an organic compound having a highly planar fused-ring chalcogenophene skeleton and an emitting layer having a highly planar organometallic complex. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating the effects brought about by host molecules and guest molecules. [Figure 2] 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 3] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 4] 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 an electronic device according to an embodiment of the present invention. [Figure 5] 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 6] 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 example of a moving body having a vehicle lamp according to an embodiment of the present invention. [Figure 7]1A is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. [Figure 8] 1A is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of an exposure light source of the image forming apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] (1) Organic light-emitting element The organic light-emitting element of this embodiment has a pair of electrodes and a light-emitting layer disposed between the pair of electrodes, and the light-emitting layer has at least a guest molecule and a host molecule. The host molecule is an organic compound represented by general formula [1], and the guest molecule is an organometallic complex represented by general formula [2].

[0014] Specific examples of the organic light-emitting device of this embodiment include a multilayer structure in which electrode layers and organic compound layers shown in (1) to (6) below are sequentially stacked on a substrate. In any of the structure, the organic compound layers always include 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 However, these device configuration examples are merely very basic device configurations, and the device configuration is not limited to these. For example, various layer configurations can be adopted, such as providing an insulating layer, adhesive layer, or interference layer at the interface between the electrode and the organic compound layer, forming an electron transport layer or hole transport layer from two layers with different ionization potentials, or forming an emitting layer from two layers made of different emitting materials.

[0015] The light-emitting layer may be a single layer or multiple layers. Multiple layers refer to a state in which a light-emitting layer is stacked with another light-emitting layer. For example, a light-emitting layer containing an organic compound represented by general formula [1] as a host molecule and an organometallic complex represented by general formula [2] as a guest molecule may be stacked with another light-emitting layer that emits a different color from the color of light emitted by the light-emitting layer. In this case, the emitted color may be white or a neutral color.

[0016] Among the device configurations (1) to (6), the configuration (6) is preferable because it has both an electron blocking layer and a hole blocking layer. In other words, the configuration (6) having an electron blocking layer and a hole blocking layer can reliably confine both hole and electron carriers within the light-emitting layer, resulting in an organic light-emitting device with no carrier leakage and high luminous efficiency.

[0017] The light output from the light-emitting layer can be extracted from the electrode on the substrate side (device configuration), either in a bottom emission mode, where light is extracted from the electrode on the substrate side, or in a top emission mode, where light is extracted from the opposite side of the substrate.A double-sided emission mode, where light is extracted from both the substrate side and the opposite side of the substrate, can also be used.

[0018] In the organic light-emitting device of this embodiment, the organic compound having a fused-ring chalcogenophene skeleton represented by general formula [1] is preferably contained in the light-emitting layer of the organic compound layer. In this case, the light-emitting layer contains at least an organometallic complex represented by general formula [2]. In this case, the compound contained in the light-emitting layer has different uses depending on its concentration in the light-emitting layer. Specifically, the compound is divided into a main component and a subcomponent depending on its concentration in the light-emitting layer.

[0019] The main compound is the compound with the largest mass ratio (content concentration) among the compounds contained in the light-emitting layer, and is also called the host. The host is a compound that exists as a matrix around the light-emitting material in the light-emitting layer and is primarily responsible for transporting carriers to the light-emitting material and providing excitation energy to the light-emitting material.

[0020] Furthermore, the compounds that serve as minor components are compounds other than the main component, and can be called guests (dopants), emission assist materials, or charge injection materials depending on the function of the compound. A guest, which is one type of minor component, is a compound (light-emitting material) that is primarily responsible for emitting light in the light-emitting layer. A emission assist material, which is one type of minor component, is a compound that assists the guest in emitting light, and has a smaller mass ratio (content concentration) in the light-emitting layer than the host. A emission assist material is also called a second host based on its function.

[0021] The concentration of the guest relative to the host is 0.01% by mass or more and less than 50% by mass, and preferably 0.1% by mass or more and 20% by mass or less, based on the total amount of the constituent materials of the light-emitting layer. From the viewpoint of reducing concentration quenching, the concentration of the guest is particularly preferably 10% by mass or less.

[0022] The guest may be contained uniformly throughout the layer in which the host serves as a matrix, or may be contained with a concentration gradient. Alternatively, the guest may be contained partially in a specific region within the layer, so that the light-emitting layer has a region containing only the host and no guest.

[0023] In this embodiment, it is preferable that an organic compound having a condensed-ring chalcogenophene skeleton represented by General Formula [1] is included in the light-emitting layer as a host, and an organometallic complex represented by General Formula [2] is included as a guest. The light-emitting layer may further contain a third component. For example, for the purpose of assisting the transfer of excitons and carriers, another phosphorescent material may be further included in the light-emitting layer separately from the organometallic complex represented by General Formula [2]. Also, for the purpose of assisting the transfer of excitons and carriers, a compound different from the organic compound represented by General Formula [1] may be further included in the light-emitting layer as a second host.

[0024] (2) Host molecule The organic compound used as the host of the light-emitting layer will be described. The host molecule included in the organic light-emitting device of this embodiment is an organic compound represented by the following General Formula [1], and is a compound having a condensed-ring chalcogenophene skeleton. The mother skeleton (the skeleton where R1 to R 12 is a hydrogen atom) has no SP 3 carbon atoms and no amino group (X does not contain a nitrogen atom), so it has a high degree of planarity.

[0025]

Chemical formula

[0026] <R1 to R 12 > In Formula [1], R1 to R 12 are each independently selected from a hydrogen atom, a deuterium atom, an aryl group with or without a substituent, and a heterocyclic group with or without a substituent. However, at least one of R1 to R 12 is selected from an aryl group with or without a substituent and a heterocyclic group with or without a substituent. It is preferable that one or two of R1 to R 12 , preferably one, is selected from an aryl group with or without a substituent and a heterocyclic group with or without a substituent.

[0027] Examples of aryl groups include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, fluoranthenyl, and triphenylenyl groups, with phenyl being preferred.

[0028] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, triazolyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, phenanthrolyl, dibenzofuranyl, and dibenzothiophenyl groups. Of these, triazyl groups are preferred.

[0029] Examples of substituents that the aryl group and heterocyclic group may further have include, but are not limited to, a deuterium atom; aryl groups such as 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; and heterocyclic groups such as a pyridyl group, a pyrimidyl group, a pyrazyl group, a triazyl group, a triazolyl 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.

[0030] <x> X is selected from an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom, and X may be the same or different from each other.

[0031] The host molecule is preferably an organic compound represented by the following general formula [3].

[0032] [ka]

[0033] As described above, the host molecule is characterized by having a highly planar backbone. Therefore, it is preferable that the entire molecule has a highly planar structure. 12 The dihedral angle was calculated when either of the groups was a phenyl group. The results are shown in Table 1. The dihedral angle was calculated by molecular orbital calculation using Chem3D MM2.

[0034] [Table 1]

[0035] As shown in Table 1, R2, R3, R4, R5, R8, R9, R 10 , R 11 It was found that the substitution position of has a particularly small dihedral angle and high planarity. In other words, as will be described later, a high molecular planarity is preferable because triplet excitons can be efficiently diffused and exciton annihilation caused by triplet excitons is suppressed, thereby further improving driving durability.

[0036] (3) Guest molecules (organometallic complexes) The guest molecule is an organometallic complex represented by the following general formula [2].

[0037] M(L)m(L')n(L")p [2] <m> In formula [2], M is selected from iridium and platinum. Preferably, M is iridium.

[0038] <L, L’ and L”> L, L’ and L” each represent different bidentate ligands.

[0039] <m, n, p> m is selected from integers of 1 or more and 3 or less, and n and p are each selected from integers of 0 or more and 2 or less. However, m + n + p = 3.

[0040] <Substructure M(L)m> The substructure M(L)m is represented by the following general formula [2-1].

[0041]

Chemical formula

[0042] [R 21 to R 28 In formula [2-1], R 21 to R 28 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group with or without a substituent, an alkoxy group with or without a substituent, a silyl group with or without a substituent, an aryl group with or without a substituent, a heterocyclic group with or without a substituent, an amino group with or without a substituent, an aryloxy group with or without a substituent, a heteroaryloxy group with or without a substituent, and a cyano group. However, at least one of R 21 to R 28 is selected from an aryl group with or without a substituent and a heterocyclic group with or without a substituent.

[0043] Examples of the halogen atom include, but are not limited to, fluorine, chlorine, bromine, iodine, etc. Among these, a fluorine atom is preferred.

[0044] ​ Examples of the alkyl group 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] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy groups.

[0046] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0047] Examples of aryl groups include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, fluoranthenyl, and triphenylenyl groups.

[0048] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazolyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, phenanthrolyl, dibenzofuranyl, and dibenzothiophenyl groups.

[0049] Examples of the amino group 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, an N-piperidyl group, and a carbazolyl group.

[0050] Examples of the aryloxy group and heteroaryloxy group include, but are not limited to, a phenoxy group and a thienyloxy group.

[0051] Examples of substituents that may be further substituted by the alkyl group, alkoxy group, silyl group, aryl group, heterocyclic group, amino group, aryloxy group, and heteroaryloxy group include, but are not limited to, a deuterium atom; 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; cyano group, hydroxy group, and thiol group.

[0052] Also, adjacent R 21 ~R 28 , preferably adjacent R 21 ~R 24 or adjacent R 25 ~R 28 may be bonded to each other to form a ring. 21 ~R 28 are bonded to each other to form a ring, R 21 and R 22 , R 22 and R 23 , R 23 and R 24 and a ring formed by bonding R 21 ~R 24 The benzene ring to which R is attached forms a condensed ring, or 25 and R 26 , R 26 and R 27 , R 27 and R 28 and a ring formed by bonding R 25 ~R 28 This means that the pyridine ring to which the R is attached forms a fused ring. 21 ~R 28 The ring formed by bonding may be an aromatic ring.

[0053] <Substructure M(L')n> The partial structure M(L')n is represented by the following general formula [2-2].

[0054] [ka]

[0055] [R 31 ~R 38 ] In formula [2-2], R 31 ~R 38 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group.

[0056] Specific examples of the halogen atom, alkyl group, alkoxy group, silyl group, aryl group, heterocyclic group, amino group, aryloxy group, and heteroaryloxy group include R 31 ~R 38 Specific examples of the substituent that may be further substituted by the alkyl group, alkoxy group, silyl group, aryl group, heterocyclic group, amino group, aryloxy group, and heteroaryloxy group include, but are not limited to, those described above. 31 ~R 38 Examples of the above-described examples include, but are not limited to, those described above.

[0057] Also, adjacent R 31 ~R 38 , preferably adjacent R 31 ~R 34 or adjacent R 35 ~R 38 may be bonded to each other to form a ring. 31 ~R 38 are bonded to each other to form a ring, R 31 and R 32 , R 32 and R 33 , R 33 and R 34 and a ring formed by bonding R 31 ~R 34 The pyridine ring to which R is attached forms a condensed ring, or 35 and R 36 , R 36 and R 37 , R 37 and R 38 and a ring formed by bonding R 35 ~R 38 This means that the benzene ring to which the R is attached forms a condensed ring. 31 ~R 38 The ring formed by bonding may be an aromatic ring.

[0058] <Substructure M(L”)p> The partial structure M(L")p is represented by the following general formula [2-3].

[0059] [ka]

[0060] [R 39 ~R 41 ] In formula [2-3], R 39 ~R 41 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group.

[0061] Specific examples of the halogen atom, alkyl group, alkoxy group, silyl group, aryl group, heterocyclic group, amino group, aryloxy group, and heteroaryloxy group include R 31 ~R 38 Specific examples of the substituent that may be further substituted by the alkyl group, alkoxy group, silyl group, aryl group, heterocyclic group, amino group, aryloxy group, and heteroaryloxy group include, but are not limited to, those described above. 31 ~R 38 Examples of the above-described examples include, but are not limited to, those described above.

[0062] Among the organometallic complexes represented by the general formula [2], organometallic complexes in which the partial structure M(L)m has three or more fused rings are preferred. This is because the three or more fused ring skeleton improves planarity, promotes energy transfer from the host molecule, and leads to higher efficiency and improved durability. Examples of the three or more fused rings include a phenanthrene ring, a triphenylene ring, a benzofluorene ring, a dibenzofuran ring, a dibenzothiophene ring, a benzonaphthofuran ring, a benzonaphthothiophene ring, a benzoisoquinoline ring, and a naphthoisoquinoline ring.

[0063] (4) Effects of host and guest molecules In the organic light-emitting device of this embodiment, the light-emitting layer contains a guest molecule and a host molecule. The host molecule is an organic compound represented by general formula [1], and the guest molecule is an organometallic complex represented by general formula [2].

[0064] In order to more effectively use the host material of this embodiment, the inventors have investigated organic compounds having a fused chalcogenophene skeleton and guest materials suitable for use in the light-emitting layer. The inventors have found that the luminous efficiency and driving durability of organic light-emitting devices can be improved by designing the molecules of the host material and guest material while focusing on the following points. (I) Both the host material and the guest material have a highly planar skeleton. (II) The host material is SP 3 It has no carbon atoms or amino groups and has high bond stability.

[0065] In other words, two factors that are thought to be the cause of brightness degradation, (I) exciton annihilation due to triplet excitons, which leads to deterioration of the light-emitting layer material, and (II) host degradation due to bond dissociation, are suppressed, thereby extending the life of organic light-emitting devices.

[0066] (I) Both the host material and the guest material have a highly planar skeleton.

[0067] It is known that exciton annihilation due to triplet excitons generated by recombination in the light-emitting layer of a phosphorescent light-emitting device leads to a decrease in efficiency and driving durability. This is because triplet excitons have a longer excitation lifetime than singlet excitons, and are more likely to exist in the light-emitting layer, increasing the probability of triplet excitons colliding with each other. The present inventors have discovered a means for reducing the probability of triplet excitons colliding with each other. This involves improving the planarity of the host molecules and shortening the intermolecular distance, which makes triplet excitons more likely to diffuse.

[0068] Therefore, to shorten the distance between molecules, SP 3 We designed highly planar molecules that are not substituted with carbon atoms or sterically hindering groups such as amino groups. Furthermore, we found that by improving the planarity of the guest material, we could improve efficiency and durability. This is explained below.

[0069] The partial structure M(L)m of the organometallic complex represented by the general formula [2] is R 21 ~R 28 When at least one of the groups is an aryl group or a heterocyclic group, the conjugated plane of the π orbital is expanded. As a result, the guest material is more likely to interact with materials (especially the host material) in the vicinity thereof, which can promote energy transfer from the host material to the light-emitting material. On the other hand, in the case of the Ir(ppy)3 complex described in Patent Document 1, the molecule is spherical, and the conjugated plane of the π orbital is narrow. This limits energy transfer between the host material and the guest material, and triplet excitons accumulate in the host molecule, accelerating exciton annihilation between triplet excitons. This results in reduced efficiency and durability.

[0070] The present inventors have found that, in order to avoid exciton annihilation due to triplet excitons, the efficiency and driving durability of organic light-emitting devices can be improved by molecular design in which "both the host material and the guest material have highly planar skeletons."

[0071] FIG. 1 shows the molecular structures and intermolecular interactions of the host material, guest material, and comparative compound of the present invention, as well as the efficiency (EQE) and luminance degradation rate ratio described in each example.

[0072] In the case of the hosts having alkyl groups (comparative compound 1-a) of Comparative Examples 1 and 2, the planarity of the molecules is low, and triplet excitons cannot diffuse and accumulate, resulting in poor durability due to the annihilation of triplet excitons. In addition, the steric hindrance effect of the alkyl group increases the intermolecular distance between the host material and the guest material, regardless of whether the iridium complex is used, reducing the energy transfer efficiency, resulting in low efficiency and poor durability due to the annihilation of triplet excitons caused by the accumulation of triplet excitons.

[0073] Even when the highly planar host material of this embodiment is used as in Comparative Example 3, if the iridium complex has a spherical structure, although there is a diffusion effect of triplet excitons, the energy transfer efficiency decreases, and therefore the luminance degradation rate improves slightly, but at a low efficiency.

[0074] On the other hand, the combination of the host and the guest of this embodiment also promotes the diffusion of triplet excitons and improves the energy transfer efficiency, thereby improving both the efficiency and the luminance degradation.

[0075] (II) The host material is SP 3 It has no carbon atoms or amino groups and has high bond stability.

[0076] The organic layer of an organic light-emitting device, particularly the compound in the light-emitting layer, repeatedly transitions between the ground state and the excited state during the light-emitting process of the organic light-emitting device. During this transition, intense molecular movements such as stretching, contraction, and rotation occur. If a site where bonds are easily dissociated is present, the bond may be cleaved, resulting in the liberation of a portion of the compound. The liberation of a portion of the compound changes the structure, and if liberation is likely to occur, the durability of the compound decreases. Furthermore, when such a compound is used in an organic light-emitting device, the liberated portion acts as a quencher, reducing the durability of the device. Therefore, molecules with a structure that makes bonds less likely to dissociate and liberation less likely to occur will have better durability.

[0077] Comparative compound 1-a is C(SP 3 )-C(SP 3 ) bond and C-N bond. The bond dissociation energies are 88 kcal / mol and 87-104 kcal / mol, respectively. 2 )-C(SP 2 ) bond dissociation energy is 110 kcal / mol, so C(SP 3 )-C(SP 3 ) bonds and C-N bonds are more likely to dissociate.

[0078] Therefore, the organic compound according to this embodiment is less likely to be liberated due to bond cleavage than the comparative compound 1-a, and has higher durability. Therefore, when the organic compound according to this embodiment is used in the organic layer of an organic light-emitting device, liberation due to bond cleavage during device operation is less likely to occur, so that deterioration of the device is suppressed even when driven for a long time, and an organic light-emitting device with excellent durability can be obtained.

[0079] As described above, in this embodiment, the above (I) and (II) promote energy transfer from the host molecule to the guest molecule, suppress the annihilation of triplet excitons in the host molecule, and improve the binding stability of the host molecule, thereby improving the luminous efficiency and driving durability.

[0080] (5) Specific examples of host molecules Specific structural formulae of the host molecule are shown below.

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] Compounds belonging to Group A are organic compounds represented by formula [3], which contain R2 or R 11 is an aryl group or a heterocyclic group. Compounds belonging to group A have higher planarity and a high T1 among the compounds according to this embodiment. That is, group A is a compound group that has higher efficiency characteristics when used in an organic light-emitting device. Furthermore, A13 to A36 are a compound group having a heterocyclic group, and can adjust the HOMO level and LUMO level.

[0089] B1 to B9 and B19 to B27 are a group of organic compounds represented by formula [3] in which R4 or R9 is an aryl group or a heterocyclic group. B10 to B18 and B28 to B36 are a group of organic compounds represented by formula [3] in which R5 or R8 is an aryl group or a heterocyclic group. Compounds belonging to group B are more capable of achieving both film properties and a high T1 than the compounds according to this embodiment. That is, group B is a group of compounds that have longer life when used in organic light-emitting devices. Furthermore, B19 to B36 are a group of compounds having a heterocyclic group, and are capable of adjusting the HOMO level and LUMO level.

[0090] Compounds belonging to Group C are organic compounds represented by formula [3], which contain R3 or R 10 is an aryl group or a heterocyclic group. Compounds belonging to group C have a deeper LUMO level than the compounds according to this embodiment. That is, group C is a compound group that exhibits lower voltage driving characteristics when used in an organic light-emitting device. Furthermore, C10 to C18 are a compound group having a heterocyclic group, and the HOMO level and LUMO level can be adjusted.

[0091] D1 to D9 are R1 or R 12 is an aryl group or a heterocyclic group. D10 to D18 are organic compounds represented by formula [1], in which R6 or R7 is an aryl group or a heterocyclic group. Compounds belonging to group D exhibit higher film properties among the compounds according to this embodiment. That is, when used in an organic light-emitting device, group D is a compound group suitable for, for example, a coating process. Furthermore, D7 to D9 and D16 to D18 are compounds having a heterocyclic group, and the HOMO level and LUMO level can be adjusted.

[0092] (6) Specific examples of organometallic complexes Specific examples of the partial structure M(L) of the organometallic complex that serves as the guest are shown below, but the present invention is not limited to these. In the specific examples shown below, coordinate bonds are indicated by straight lines, dotted lines, or arrows.

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[0095] In the above general formulae [Ir-5] to [Ir-8], [Ir-15] to [Ir-16], X' is selected from an oxygen atom, a sulfur atom, a substituted or unsubstituted carbon atom, and a substituted or unsubstituted nitrogen atom.

[0096] The general formulas [Ir-2] to [Ir-8] are adjacent R 21 ~R 24 are bonded to each other to form a ring. 25 ~R 28 are bonded to each other to form a ring. In addition, the general formulas [Ir-3] to [Ir-8] are 21 ~R 24 At least one of R is a phenyl group or a naphthyl group, and forms a ring with the adjacent group. 25 ~R 28 At least one of the groups is a phenyl group or a naphthyl group, and forms a ring with the adjacent group. Therefore, the general formulae [Ir-3] to [Ir-8] and [Ir-11] to [Ir-16] may or may not further have an aryl group or a heterocyclic group.

[0097] Among the metal complexes in which the partial structure M(L)m is represented by the above general formulas [Ir-1] to [Ir-16], metal complexes having three or more fused rings in the ligand are more preferred. Specifically, the partial structure M(L)m is represented by the above general formulas [Ir-3] to [Ir-8], [Ir-11] to [Ir-16]. Specific examples thereof are shown below, but are not limited thereto.

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[0114] The exemplary compounds belonging to the AA group to the BB group are metal complexes in which the partial structure M(L)m is represented by the general formula [Ir-3], and which have at least a phenanthrene ring in the ligand. 2 Because it is made up of hybrid orbitals, it is a compound with particularly excellent stability.

[0115] The exemplary compounds belonging to the CC group are metal complexes in which the partial structure M(L)m is represented by the general formula [Ir-4], and which have at least a triphenylene ring in the ligand. These compounds are compounds in which the fused ring is SP 2 Because it is made up of hybrid orbitals, it is a compound with particularly excellent stability.

[0116] The exemplary compounds belonging to the DD group are metal complexes whose partial structure M(L)m is represented by the general formulas [Ir-5] to [Ir-8], and which have at least a dibenzofuran ring, a dibenzothiophene ring, a benzonaphthofuran ring, or a benzonaphthothiophene ring in the ligand. These compounds contain oxygen atoms and sulfur atoms in the fused ring, and the abundant lone electron pairs possessed by these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0117] The exemplary compounds belonging to the EE to GG groups are metal complexes in which the partial structure M(L)m is represented by the general formulas [Ir-6] to [Ir-8], and which have at least a benzofluorene ring in the ligand. These compounds have a substituent at the 9-position of the fluorene ring, in the direction perpendicular to the in-plane direction of the fluorene ring, which can particularly prevent the fused rings from overlapping with each other. Therefore, these compounds have particularly excellent sublimation properties.

[0118] The exemplary compounds belonging to the HH group are metal complexes in which the partial structure M(L)m is represented by the general formulas [Ir-11] to [Ir-13] and which have at least a benzoisoquinoline ring in the ligand. These compounds contain N atoms in the fused ring, and the unshared electron pairs and high electronegativity of these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0119] The exemplary compounds belonging to Group II are metal complexes in which the partial structure M(L)m is represented by the general formula [Ir-14] and which have at least a naphthoisoquinoline ring in the ligand. These compounds contain N atoms in the fused ring, and the unshared electron pairs and high electronegativity of these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0120] (7) Other compounds In the organic light-emitting device according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may be used together as needed. Examples of these compounds are listed below.

[0121] As the hole injection and transport material, a material with high hole mobility is preferred so that holes can be easily injected from the anode and the injected holes can be transported 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 organic light-emitting devices. Examples of low-molecular-weight and high-molecular-weight materials with hole injection and 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 and transport materials are also suitable for use in electron blocking layers. Specific examples of compounds that can be used as hole injection and transport materials are listed below, but the present invention is not limited to these.

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[0123] Examples of luminescent materials primarily involved in luminescence include organometallic complexes represented by general formula [2], 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. Specific examples of compounds used as luminescent materials are listed below, but of course, are not limited to these.

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[0126] The light-emitting layer host or light-emitting assist material contained in the light-emitting layer may contain a compound other than the organic compound of this embodiment as a third component. Examples of the third component include aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, azine derivatives, xanthone derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes.

[0127] In particular, materials having a carbazole skeleton, materials having an azine ring such as a diazine ring or a triazine ring in the skeleton, and materials having a xanthone skeleton are preferred as assist materials. This is because these materials have high electron donating and electron withdrawing properties, making it easy to adjust the HOMO and LUMO levels. The organic compound of this embodiment has a fused chalcogenophene skeleton, which widens the band gap to some extent. Therefore, materials having the above skeletons that can adjust the HOMO and LUMO levels are particularly preferred as assist materials. When these assist materials are combined with the organic compound of this embodiment, a good carrier balance can be achieved.

[0128] Specific examples of compounds used as the light-emitting layer host or light-emitting assist material in the light-emitting layer are shown below, but of course, the present invention is not limited to these. Among the specific examples below, materials having a carbazole skeleton that are preferred as assist materials are EM32 to EM38. Furthermore, materials having an azine ring in the skeleton that are preferred as assist materials are EM35 to EM40. Furthermore, materials having a xanthone skeleton that are preferred as assist materials are EM28 and EM30.

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[0130] The electron transport material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected taking into consideration the balance with the hole mobility of the hole transport material. Examples of materials having electron transport 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 transport materials are also suitable for use in hole-blocking layers. Specific examples of compounds used as electron transport materials are shown below, but of course, the present invention is not limited to these.

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[0132] (8) Structure of organic light-emitting element The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of an acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0133] [substrate] Examples of the substrate include quartz, glass, a silicon wafer, a resin, and a metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. Any material can be used for the insulating layer, as long as it allows for the formation of a contact hole so that wiring can be formed between the first electrode and the insulating layer, and ensures insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0134] [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0135] The anode material should have as high a work function as possible. Examples include simple 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.

[0136] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0137] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. The above materials can also function as a reflective film without functioning as an electrode. 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 techniques can be used to form the electrode.

[0138] 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 reduce silver aggregation. The alloy ratio is not critical as long as silver aggregation can be reduced. For example, the silver:other metal ratio can be 1:1, 3:1, or the like.

[0139] 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.

[0140] [Organic compound layer] The organic compound layer may be formed as a single layer or as multiple layers. When multiple layers are included, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, or electron injection layer depending on their functions. The organic compound layer is mainly composed of organic compounds but may also contain inorganic atoms or inorganic compounds. For example, the organic compound layer may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, or the like. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0141] 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 one embodiment of the present invention are formed by the method shown below.

[0142] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to 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 (for example, spin coating, dipping, casting, LB method, inkjet method, etc.).

[0143] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining with an appropriate binder resin.

[0144] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0145] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0146] [Protective layer] A protective layer may be provided on the second electrode. For example, by adhering glass with a moisture absorbent on the second electrode, the infiltration of water and other contaminants into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the second electrode to reduce the infiltration of water and other contaminants into the organic compound layer. For example, after forming the second electrode, the second electrode may be transferred to another chamber without breaking the vacuum, and a 2 μm-thick silicon nitride film may be formed by CVD to serve as a protective layer. A protective layer may be provided using atomic layer deposition (ALD) after the CVD film formation. The material of the film formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed on the film formed by ALD by CVD. The film formed by ALD may have a thickness smaller than that of the film formed by CVD. Specifically, the thickness may be 50% or less, or even 10% or less.

[0147] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element 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 the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[0148] [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the underlying layer. It may also be called a material resin layer without limiting its purpose. The planarization layer may be composed of an organic compound, and may be either a low molecular weight or a high molecular weight, but a high molecular weight is preferred.

[0149] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0150] [Microlens] The organic light-emitting element or organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting element or organic light-emitting device or to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the hemisphere. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the semicircle.

[0151] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0152] [Counter substrate] An opposing substrate may be provided on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the opposing substrate may be a second substrate.

[0153] [Pixel circuit] An organic light-emitting device having an organic light-emitting element may have a pixel circuit connected to the organic light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0154] The light-emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of a transistor constituting the pixel circuit may be smaller than the mobility of a transistor constituting the display control circuit. The slope of the current-voltage characteristics of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistor constituting the display control circuit. The slope of the current-voltage characteristics can be measured by the so-called Vg-Ig characteristics. The transistor constituting the pixel circuit is a transistor connected to a light-emitting element, such as a first light-emitting element.

[0155] [Pixels] An organic light emitting device having an organic light emitting element may have a plurality of pixels, each of which has sub-pixels that emit different colors, for example, RGB colors.

[0156] A pixel emits light from an area called a pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between subpixels may be 10 μm or less, more specifically, it may be 8 μm, 7.4 μm, or 6.4 μm.

[0157] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0158] (9) Devices using organic light-emitting elements 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.

[0159] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has 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.

[0160] 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.

[0161] Next, a display device according to this embodiment will be described with reference to the drawings. Fig. 2 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).

[0162] FIG. 2(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel includes sub-pixels 10. The sub-pixels 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 sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel 10 includes a reflective electrode serving as a first electrode 2 on an interlayer insulating layer 1, an insulating layer 3 covering the edge of the first electrode 2, an organic compound layer 4 covering the first electrode 2 and the insulating layer 3, a transparent electrode serving as a second electrode 5, a protective layer 6, and a color filter 7.

[0163] A transistor and a capacitor element may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode 2 may be electrically connected via a contact hole or the like (not shown).

[0164] The insulating layer 3 is also called a bank or a pixel separation film. It covers the edges of the first electrode 2 and is disposed to surround the first electrode 2. The portion where the insulating layer 3 is not disposed is in contact with the organic compound layer 4 and becomes a light-emitting region.

[0165] 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 .

[0166] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0167] The protective layer 6 reduces the penetration of moisture into the organic compound layer 4. Although the protective layer 6 is illustrated as being one layer, it may be multiple layers, and each layer may be an inorganic compound layer and an organic compound layer.

[0168] The color filters 7 are divided into 7R, 7G, and 7B depending on their colors. The color filters 7 may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters 7. The color filters 7 may be formed on a protective layer 6. Alternatively, the color filters 7 may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0169] The display device 100 in FIG. 2(b) has an organic light-emitting element 26 and a TFT 18 as 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, a gate insulating film 14, and a semiconductor layer 15 of the active element are disposed on top of it. The TFT 18 also includes a drain electrode 16 and a source electrode 17. An insulating film 19 is provided on top of the TFT 18. An anode 21 constituting the organic light-emitting element 26 and the source electrode 17 are connected via a contact hole 20 provided in the insulating film 19.

[0170] The electrical connection method 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 18 is not limited to the embodiment shown in Fig. 2(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. TFT stands for thin film transistor.

[0171] 2(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 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element 26.

[0172] In the display device 100 of FIG. 2(b), transistors are used as switching elements, but other switching elements may be used instead.

[0173] The transistors used in the display device 100 of Fig. 2(b) are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on an insulating surface of a substrate. 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.

[0174] The transistors included in the display device 100 of Fig. 2(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 formed integrally.

[0175] 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.

[0176] 3 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.

[0177] 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.

[0178] The display device according to the present embodiment may be used as a display unit of 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.

[0179] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with a plurality of 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 disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0180] 4A 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.

[0181] 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.

[0182] 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. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0183] FIG. 4(b) is a schematic diagram illustrating 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 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit 1201. Examples of the electronic device 1200 include a smartphone and a laptop computer.

[0184] FIG. 5 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 5(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 use a light-emitting element according to this embodiment. The display device 1300 has the frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in FIG. 5(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0185] FIG. 5(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 5(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 light-emitting elements 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.

[0186] FIG. 6(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 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost surface.

[0187] 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 that dims these colors. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage 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.

[0188] 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.

[0189] 6(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.

[0190] 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 light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0191] 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.

[0192] 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.

[0193] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 7. 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. The image capturing and display device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0194] Fig. 7(a) is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention. Using Fig. 7(a), glasses 1600 (smart glasses) according to one application example will be described. 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. In addition, a display device according to each of the above-mentioned embodiments is provided on the back side of the lens 1601.

[0195] 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. 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.

[0196] FIG. 7(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 7(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in FIG. 7(a) and a display device. A lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and also controls the operation of the imaging device and the display device.

[0197] The control device 1612 may include a gaze detection unit that detects the wearer's gaze. The gaze detection may use infrared light. The infrared light emitter emits infrared light toward the eyeball of the user gazing at the display image. An imaging unit with a light-receiving element detects the reflected infrared light from the eyeball, thereby obtaining a captured image of the eyeball. A reduction unit that reduces light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality. The user's gaze toward the displayed image is detected from the captured image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the captured image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used. More specifically, gaze detection processing based on the pupil-corneal reflex method is performed. Using the pupil-corneal reflex method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the image of the pupil and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0198] A display device according to one embodiment of the present invention may include an imaging device having a light receiving element, and may control the display image of the display device based on user line-of-sight information from the imaging device. 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 8(a) is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. The image forming apparatus 40 is an electrophotographic image forming apparatus and includes a photoconductor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transfer unit 32, a transport roller 33, and a fixing unit 35. Light 29 is irradiated from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoconductor 27. The exposure light source 28 includes 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 roller 33 transports the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0203] 8(b) and 8(c) 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 direction parallel to the axis of the photoconductor, 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(b) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(c) shows a configuration different from FIG. 8(b), 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(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0204] 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]

[0205] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0206] [Example 1 (Synthesis of Exemplary Compound A1)] Exemplary Compound A1 was synthesized by the synthesis method described in Patent Document 1 through the following synthesis route. [ka]

[0207] Exemplified Compound A1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=577 Calculated value: C 42 H 24 B2N4=577

[0208] [Examples 2 to 25 (Synthesis of Exemplary Compounds)] As shown in Tables 2 to 7, the exemplary compounds shown in Examples 2 to 25 were synthesized in the same manner as in Example 1, except that raw material J1 in Example 1 was replaced with raw material 1, raw material J2 with raw material 2, raw material J3 with raw material 3, and raw material J4 with raw material 4. The actual measured values (m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0209] [Table 2]

[0210] [Table 3]

[0211] [Table 4]

[0212] [Table 5]

[0213] [Table 6]

[0214] [Table 7]

[0215] [Example 26] 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.

[0216] 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 Vacuum deposition was performed by resistance heating in a vacuum chamber at 100 Pa to successively form the organic compound layer and electrode layer shown in Table 8 on the ITO substrate. 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.

[0217] [Table 8]

[0218] The device characteristics were measured and evaluated. The maximum external quantum efficiency (EQE) of the light-emitting device was 15%. Furthermore, at a current density of 100 mA / cm 2 A continuous driving test was carried out at 100°C, and the time when the luminance degradation rate reached 5% was measured. When the time when the luminance degradation rate of Comparative Example 1 reached 5% was set to 1.0, the luminance degradation rate ratio of this example was 1.3.

[0219] 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.

[0220] [Examples 27 to 45, Comparative Examples 1 to 3] Organic light-emitting devices were produced in the same manner as in Example 26, except for appropriately changing the compounds shown in Table 9. The characteristics of the obtained devices were measured and evaluated in the same manner as in Example 26. The measurement results are shown in Table 9. The host material used in Comparative Examples 1 and 2 was Compound 1-a described in Patent Document 1.

[0221] [Table 9]

[0222] As can be seen from Table 9, the maximum external quantum efficiencies (EQE) of Comparative Examples 1 to 3 were 8%, 9%, and 9%, respectively, and the light-emitting devices according to Examples had higher luminous efficiency, which is due to the fact that both the host material and the guest material have highly planar skeletons.

[0223] Furthermore, the light-emitting device according to the example had a longer life. This is because both the host material and the guest material have a highly planar skeleton, and the host material has a structure similar to that of the SP 3 This is because it does not have carbon atoms or amino groups and has high bond stability.

[0224] Furthermore, by selecting a phosphorescent material having a ligand with a fused ring consisting of three or more rings that is suitable for combination with the organic compound of this embodiment, a light-emitting device with particularly high efficiency and long life can be obtained.

[0225] As described above, by using the organic compound according to this embodiment, it is possible to provide a highly efficient element with excellent durability.

[0226] [Example 46] An organic light-emitting device was produced in the same manner as in Example 26, except that the organic compound layer and the electrode layer shown in Table 10 were successively formed.

[0227] [Table 10]

[0228] The device characteristics were measured and evaluated. The light-emitting device emitted green light and had a maximum external quantum efficiency (EQE) of 19%.

[0229] [Examples 47 to 65] An organic light-emitting device was produced in the same manner as in Example 46, except that the compounds were appropriately changed to those shown in Table 11. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 46. The measurement results are shown in Table 11.

[0230] [Table 11] [Explanation of symbols]

[0231] 1: interlayer insulating layer, 2: first electrode, 3: insulating layer, 4: organic compound layer, 5: second electrode, 6: protective layer, 7: color filter, 10: subpixel, 11: substrate, 12: insulating layer, 13: gate electrode, 14: gate insulating film, 15: semiconductor layer, 16: drain electrode, 17: source electrode, 18: TFT, 19: insulating film, 20: contact hole, 21: anode, 22: organic compound layer, 23: cathode, 24: first protective layer, 25: second protective layer, 26: organic light-emitting element, 100: display device< / m> < / x>

Claims

1. a pair of electrodes and a light-emitting layer disposed between the pair of electrodes; the light-emitting layer contains at least guest molecules and host molecules; The host molecule is an organic compound represented by the following general formula [1]: The organic light-emitting element is characterized in that the guest molecule is an organometallic complex represented by the following general formula [2]: 【Chemical 1】 M(L)m(L')n(L”)p [2] In formula [1], R 1 ~R 12 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, provided that R 1 ~R 12 At least one of the groups is selected from a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group. X is selected from the group consisting of an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. In the formula [2], M is selected from iridium and platinum. L, L' and L" each represent a different bidentate ligand. m is selected from an integer of 1 to 3, and n and p are each selected from an integer of 0 to 2, provided that m+n+p=3. The partial structure M(L)m is represented by the following general formula [2-1]. 【Chemistry 2】 In formula [2-1], R 21 ~R 28 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group, provided that R 21 ~R 28 At least one of the adjacent R is selected from a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group. 21 ~R 28 may be bonded to each other to form a ring. The partial structure M(L')n is represented by the following general formula [2-2]. 【Chemistry 3】 In formula [2-2], R 31 ~R 38 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group. 31 ~R 38 may be bonded to each other to form a ring. The partial structure M(L″)p is represented by the following general formula [2-3]. 【Chemistry 4】 In formula [2-3], R 39 ~R 41 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a cyano group.

2. 2. The organic light-emitting device according to claim 1, wherein the host molecule is an organic compound represented by the following general formula [3]: 【Chemistry 5】

3. The R 1 ~R 12 3. The organic light-emitting device according to claim 1, wherein one or two of the groups are selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted heterocyclic group.

4. The R 1 ~R 12 3. The organic light-emitting device according to claim 1, wherein at least one of the groups is selected from the group consisting of a substituted or unsubstituted phenyl group and a substituted or unsubstituted triazyl group.

5. 5. The organic light-emitting element according to claim 1, wherein M is iridium.

6. 6. The organic light-emitting element according to claim 1, wherein the partial structure M(L)m has three or more fused rings.

7. 7. The organic light-emitting element according to claim 6, wherein the three or more fused rings are any one of a phenanthrene ring, a triphenylene ring, a benzofluorene ring, a dibenzofuran ring, a dibenzothiophene ring, a benzonaphthofuran ring, a benzonaphthothiophene ring, a benzoisoquinoline ring, and a naphthoisoquinoline ring.

8. The organic light-emitting device according to claim 1 , wherein the light-emitting layer further contains a third component.

9. The organic light-emitting element according to claim 8 , wherein the third component has at least a carbazole skeleton.

10. The organic light-emitting element according to claim 8 , wherein the third component has at least an azine ring in its skeleton.

11. The organic light-emitting device according to claim 8 , wherein the third component has at least xanthone in its skeleton.

12. 12. The organic light-emitting element according to claim 1, further comprising another light-emitting layer disposed in a stacked state with the light-emitting layer, the another light-emitting layer emitting light of a color different from the color of light emitted by the light-emitting layer.

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

14. A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising the organic light-emitting element according to claim 1 and a transistor connected to the organic light-emitting element.

15. 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; The photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to claim 1 .

16. 14. An electronic device comprising: a display unit having the organic light-emitting element according to claim 1; a housing in which the display unit is provided; and a communication unit provided in the housing and communicating with an external device.

17. 14. A lighting device comprising: a light source having the organic light-emitting element according to claim 1; and a light diffusion section or an optical filter that transmits light emitted by the light source.

18. A moving body comprising: a lamp having the organic light-emitting element according to claim 1; and a vehicle on which the lamp is provided.

19. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to claim 1 .

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