Organic light-emitting element

Abstract

A light-emitting layer includes a thermally activated delayed fluorescent material and a fluorescent light-emitting material, and the present invention includes, in contact with the light-emitting layer, a fluorescent material and a compound represented by general formula (1a) or (1b).

Description

Organic light-emitting diodes

[0001] This invention relates to an organic light-emitting element and an electronic device using the same.

[0002] An organic light-emitting element (also called an "organic electroluminescent element" or "organic EL element") is an electronic element having a first electrode, a second electrode, and an organic compound layer placed between these electrodes. By injecting electrons and holes from this pair of electrodes, the holes and electrons recombine in the luminescent organic compound within the organic compound layer to generate excitons, and the organic light-emitting element emits light when these excitons return to the ground state. Recent advances in organic light-emitting elements have been remarkable, and their excellent characteristics, such as low driving voltage, diverse emission wavelengths, high responsiveness, and the ability to make light-emitting devices thinner and lighter, are expected to lead to their application in various electronic devices.

[0003] Currently, as an attempt to improve the luminescence efficiency and color purity of organic light-emitting devices, for example, TAF (TADF-assisted Fluorescence) type organic light-emitting devices are being developed, which combine a thermally activated delayed fluorescence (TADF) material with a fluorescent emission material. TADF material is a luminescent organic compound that can convert triplet excitons, which normally do not contribute to luminescence due to spin forbiddenness, back to singlet excitons via reverse intersystem crossing using thermal energy. In TAF type organic light-emitting devices, it is possible to improve luminescence efficiency and color purity by transferring the returned singlet energy to the fluorescent emission material to cause luminescence. Patent Document 1 describes an organic light-emitting device having a triplet exciton deactivator in the light-emitting layer. Patent Document 2 describes an organic light-emitting device having an exciton management layer adjacent to the light-emitting layer.

[0004] Japanese Patent Publication No. 2022-14426, Japanese Patent Publication No. 2023-543421

[0005] However, in the organic light-emitting devices described in Patent Documents 1 and 2, the control of excess triplet excitons in the light-emitting layer is insufficient, leaving room for improvement in the operating life of the organic light-emitting devices.

[0006] Therefore, the present invention has been made in view of the above problems, and its purpose is to provide an organic light-emitting element with excellent operating life.

[0007] The first aspect of this disclosure is an organic light-emitting element comprising, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, and the first and second organic layers each independently comprise a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material. The second aspect of this disclosure is an organic light-emitting element comprising, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer comprises a third organic compound represented by the following general formula (5) and a fluorescent light-emitting material, and the first and second organic layers each independently comprise a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material.A third aspect of the present disclosure is an organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, and the first organic layer comprises a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material, and the first electrode is an anode. The fourth aspect of this disclosure is an organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises a third organic compound represented by the following general formula (5) and a fluorescent light-emitting material, the first organic layer comprises a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first organic layer is provided between the first electrode and the light-emitting layer if the relationship between the hole mobility μh and electron mobility μe of the light-emitting layer is μh / μe < 1, and the first organic layer is provided between the first electrode and the light-emitting layer if μh / μe > 1.

[0008]

[0009] [In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. Ra and Rb each represent a substituent for a carbon atom of the benzene ring, and are each independently selected from the group consisting of a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group; a plurality of Ra and a plurality of Rb may each be the same or different, and adjacent substituents among Ra and among Rb may form a ring. When forming a ring, the ring may contain a carbon atom or a heteroatom. n and m are each an integer of 1 to 5.]

[0010]

[0011] [In General Formula (5), R １１ to R １８ are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. When forming a ring, the ring may contain a carbon atom or a heteroatom. Cy Ａ is a ring structure having 6 to 13 carbon atoms, or a heterocyclic structure having 5 to 12 carbon atoms containing a heteroatom. n is an integer of 1 to 5. R ａ is Cy ＡRepresenting substituents on ring-forming atoms, each independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, with a plurality of R ａ n' may be the same or different. n' is an integer from 1 to 9. １１ ~R １８ , and R ａ At least one of them has the structure of one of the following general formulas (5a) to (5d).

[0012]

[0013] In general formulas (5a) to (5d), X １ ~X ３ , Y １ Y ４ Each of these is independently either a carbon atom or a nitrogen atom. １ R is one of the following atoms: nitrogen, oxygen, sulfur, selenium, or tellurium. ２１ ~R ２５ , R ３１ ~R ３６ , R ４１ and R ４２ , R ５１ ~R ５３ R represents substituents on the atoms forming each ring structure, and is independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, carbon atoms or heteroatoms may be included. ４１ and R ４２ , R ５１ ~R ５３If there are multiple values, they may be the same or different. m and m' are integers from 0 to 4, and l, l', and l'' are integers from 0 to 5. Z １ If R is a nitrogen atom, ４３ Z is selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. １ If R is not a nitrogen atom, ４３ * is a hydrogen atom. * represents R in general formula (5). １１ ~R １８ and R ａ The bond position in is represented, and the general formulas (5a) to (5d) are determined by the bond position of *. Ａ It may be directly bonded to the ring.

[0014] According to this disclosure, it is possible to provide an organic light-emitting element with excellent operating life.

[0015] This is a schematic cross-sectional view showing an example of a pixel in a display device according to one embodiment of the present disclosure. This is a schematic cross-sectional view of an example of a display device using an organic EL element according to one embodiment of the present disclosure. This is a schematic diagram showing an example of a display device according to one embodiment of the present disclosure. This is a schematic diagram showing an example of an imaging device according to one embodiment of the present disclosure. This is a schematic diagram showing an example of an electronic device according to one embodiment of the present disclosure. This is a schematic diagram showing an example of a display device according to one embodiment of the present disclosure. This is a schematic diagram showing an example of a foldable display device. This is a schematic diagram showing an example of an illumination device according to one embodiment of the present disclosure. This is a schematic diagram showing an example of an automobile having a vehicle light fixture according to one embodiment of the present disclosure. This is a schematic diagram showing an example of a wearable device according to one embodiment of the present disclosure, showing a form having an imaging device. This is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present disclosure. This is a schematic diagram showing an example of an exposure light source in an image forming apparatus according to one embodiment of the present disclosure. This is a schematic diagram showing an example of an exposure light source in an image forming apparatus according to one embodiment of the present disclosure.

[0016] In this specification, the lowest excitation singlet energy (S １ The fluorescence emission spectrum (λ) is the value obtained by measuring the fluorescence emission spectrum of a thin film sample of each material (a single film if it is a host material, or a mixed film with the host material if it is a host material in other cases) and converting the wavelength at the short-wavelength end of the spectrum into energy. The fluorescence emission spectrum can be measured by irradiating the sample with excitation light at room temperature (25°C, 298K) and spectrally analyzing the light produced by photoexcitation with a spectrometer. Data acquisition is possible with, for example, the Hitachi spectrofluorometer "F-4500", but is not limited to this. The wavelength (λ) at which the emission intensity on the short-wavelength side of the spectrum becomes 10% of the peak intensity of the fluorescence emission spectrum is calculated. Ｅｍｉｓｓｉｏｎ The value obtained by converting ) into energy is the lowest excitation singlet energy (S １ ) was used as the conversion formula. The following equation [1] was used. Here, h represents Planck's constant and c represents the speed of light. S １ = (h × c) / λ Ｅｍｉｓｓｉｏｎ = 1239.84 / λ Ｅｍｉｓｓｉｏｎ [1]

[0017] Also, the lowest excited triplet energy (T １ The phosphorescence emission spectrum is obtained by measuring the phosphorescence emission spectrum and converting the wavelength at the short-wavelength end of the spectrum into energy. The phosphorescence emission spectrum can be measured by irradiating the sample with excitation light at a low temperature (-196°C, 77K) and spectrally separating the light generated by photoexcitation by wavelength using a spectrometer.

[0018] In this specification, the terms used to describe the structure of compounds are specifically as follows:

[0019] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, iodine, astatine, and tennessine.

[0020] The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, s-butyl group, octyl group, cyclohexyl group, t-pentyl group, 3-methylpentan-3-yl group, 1-adamantyl group, and 2-adamantyl group.

[0021] The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, and more preferably an alkoxy group having 1 to 10 carbon atoms. Specifically, examples include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, an isopropyl group, a t-butoxy group, a 2-ethyl-octyloxy group, a benzyloxy group, etc.

[0022] A silyl group is a group in which a silicon atom has a substituent. The substituent may be a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The substituted or unsubstituted alkyl group on the silicon atom may be a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. The substituted or unsubstituted aryl group on the silicon atom may be a substituted or unsubstituted aryl group having 6 to 10 carbon atoms. The silyl group may be a trialkylsilyl group or a triarylsilyl group. Specifically, examples include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0023] The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 18 carbon atoms, and even more preferably 6 to 12 carbon atoms. Specifically, examples include, but are not limited to, phenyl, biphenyl, naphthyl, phenanthrenyl, triphenylenyl, indenyl, terphenyl, fluorenyl, pyrenyl, anthracenyl, perilenyl, chrysenyl, and fluoranthenyl groups.

[0024] The heterocyclic group is preferably a heteroaryl group, and the heteroaryl group is preferably one having 3 to 24 carbon atoms, more preferably one having 3 to 18 carbon atoms, and even more preferably one having 3 to 12 carbon atoms. Specifically, examples include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, and phenanthrolyl groups.

[0025] The amino group is preferably a substituted amino group that is substituted with an alkyl group or an aryl group, and more preferably a substituted amino group that is substituted with an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. Specifically, examples include, but are not limited to, N-methylamino group, N-ethylamino group, N,N-dimethylamino group, N,N-diethylamino group, N-methyl-N-ethylamino group, N-benzylamino group, N-methyl-N-benzylamino group, N,N-dibenzyloamino group, anilino group, N,N-diphenylamino group, N,N-dinaphthylamino group, N,N-difluorenylamino group, N-phenyl-N-tolylamino group, N,N-ditolylamino group, N-methyl-N-phenylamino group, N,N-dianisorylamino group, N-mesityl-N-phenylamino group, N,N-dimesitylamino group, N-phenyl-N-(4-t-butylphenyl)amino group, N-phenyl-N-(4-trifluoromethylphenyl)amino group, N-piperidyl group, etc.

[0026] Examples of aryloxy groups include, but are not limited to, phenoxy groups.

[0027] Examples of heteroaryloxy groups include, but are not limited to, thienyloxy groups.

[0028] Examples of substituents that the alkyl, alkoxy, amino, aryloxy, silyl, aryl, heteroaryl, and heteroaryloxy groups may further have include, but are not limited to, deuterium, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups, aralkyl groups such as benzyl groups, aryl groups such as phenyl and biphenyl groups, heteroaryl groups such as pyridyl and pyrrolyl groups, amino groups such as dimethylamino, diethylamino, dibenzylamino, diphenylamino, and ditolylamino groups, alkoxy groups such as methoxy, ethoxy, and propoxy groups, aryloxy groups such as phenoxy groups, halogen atoms such as fluorine, chlorine, bromine, and iodine, and cyano groups.

[0029] [First Embodiment] An organic light-emitting element according to the first embodiment of the present disclosure comprises, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer contains a first organic compound and a second organic compound.

[0030] <First Organic Layer and Second Organic Layer> The first and second organic layers contain a compound represented by the following general formula (1a) or (1b) and a fluorescent material.

[0031]

[0032] In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９ Each of these is independently selected from the group consisting of a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group.

[0033] Ra and Rb represent substituents on the carbon atom of the benzene ring, respectively, and are independently selected from the group consisting of deuterium, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Multiple Ra and Rb groups may be the same or different, and adjacent substituents between Ra groups or between Rb groups may form a ring. If a ring is formed, it may contain carbon atoms or heteroatoms, and may form an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom.

[0034] When adjacent substituents of Ra and Rb form rings, the fused ring structure may consist only of carbon atoms, such as naphthalene rings, anthracene rings, chrysene rings, pyrene rings, triphenylene rings, fluorantene rings, and phenanthrene rings, or it may be a fused ring structure containing heteroatoms, such as carbazole rings, fluorene rings, dibenzofuran rings, dibenzothiophene rings, dibenzoselenophene rings, dibenzoterlofene rings, and spirofluorene rings.

[0035] n and m are integers from 1 to 5.

[0036] The materials of general formulas (1a) and (1b) have low minimum excitation triplet energies and can efficiently receive excess excitation triplet energy in the light-emitting layer. This enables the realization of long-life organic light-emitting devices with suppressed degradation of the light-emitting layer. Furthermore, by generating singlet excitons from the received excitation triplets through excitation triplet-triplet annihilation and utilizing these singlet excitons for fluorescence emission, it is possible to obtain organic light-emitting devices with high luminescence efficiency.

[0037] As the fluorescent luminescent material contained in the first and second organic layers, the same material as the second organic compound described later can be used.

[0038] The compound represented by the above general formula (1a) or (1b) can maintain the stability of the light-emitting layer by receiving excess excitation triplet energy within the light-emitting layer, thereby enabling the production of an organic light-emitting device with excellent operating lifetime. Furthermore, the compounds of general formulas (1a) and (1b) can upconvert the received excitation triplet energy to excitation singlet energy, and then transfer that excitation singlet energy to the fluorescent material via a Förster-type energy transfer mechanism, converting it into fluorescence emission, thus suppressing a decrease in luminescence efficiency.

[0039] The following are representative compounds represented by the above general formulas (1a) and (1b), but this list is not limited to them.

[0040]

[0041] In the first organic layer and the second organic layer, the mass ratio of the compound represented by general formula (1a) or (1b) is preferably 95% by mass or more, and more preferably 99% by mass or more, when the total mass of the first and second organic layers is considered to be 100% by mass. The content of the fluorescent luminescent compound is preferably 0.5% by mass or more and within 5% by mass, and more preferably within 1% by mass. By reducing the concentration, concentration quenching and shifts or broadening of the emission spectrum can be suppressed.

[0042] Furthermore, at least one of the first organic layer and the second organic layer may contain a compound represented by general formula (1a) or (1b) and an organic compound with lower minimum singlet excitation energy and lower minimum triplet excitation energy than the fluorescent material.

[0043] <First Organic Compound> In this embodiment, the first organic compound has the lowest excitation singlet energy (S １ ) and the lowest excited triplet energy (T １The compound has a difference (ΔEst) of 0.25 eV or less. The first organic compound is preferably a compound with a ΔEst of 0.20 eV or less, more preferably a compound with a ΔEst of 0.15 eV or less, and even more preferably a compound with a ΔEst of 0.10 eV or less. A small value in this regard makes it easier for reverse intersystem crossing of excitons to occur, resulting in high luminescence efficiency, and also reduces excess excitation triplet energy, thus enabling the creation of an organic light-emitting element with a long operating lifetime.

[0044] The first organic compound is preferably one with a lower minimum excited triplet energy than the compound represented by general formula (1a) and the compound represented by general formula (1b).

[0045] The first organic compound is the compound represented by the following general formula (2).

[0046]

[0047] In general formula (2), R １１ ~R １８ R is independently selected from the group consisting of hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, cyano groups, and silyl groups, and adjacent substituents may be bonded to each other to form a ring. If a ring is formed, it may contain carbon atoms or heteroatoms. Here, R １１ ~R １８ In this case, adjacent substituents are R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １５ and R １６ , R １６ and R １７ , R １７ and R １８ It refers to.

[0048] R １１ ~R １８Preferred heteroatoms include hydrogen atoms, unsubstituted or phenyl-substituted carbazole groups, and unsubstituted or alkyl-substituted phenyl groups. If a ring is formed, it is preferable to form an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom. In particular, a fluorene ring or a benzochalcogenofen ring is preferred, and benzofuran rings, benzothiophene rings, indazole rings, and unsubstituted or alkyl-substituted indan rings are preferred.

[0049] n is an integer between 1 and 5, and m is an integer between 1 and 3.

[0050] EWG represents an electron-withdrawing substituent, and multiple EWGs may be the same or different. The electron-withdrawing group may be a substituent consisting of an alkyl fluoride, a cyano group, or a heterocycle containing a nitrogen atom. Specifically, examples include substituents including pyridine, pyrimidine, pyridazine, triazine, pyrazole, imidazole, trifluoromethyl group, or cyano group, with triazine groups being preferred if they are unsubstituted or substituted with alkyl-substituted phenyl groups.

[0051] R ２０ R represents a substituent, selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R ２０ These may be the same or different. Specifically, alkyl groups, phenyl groups substituted with alkyl groups or phenyl groups, and cyano groups are preferred.

[0052] l is an integer between 0 and 4.

[0053] m + n + l may be an integer between 2 and 6, preferably between 2 and 5, and more preferably between 2 and 4.

[0054] The compound represented by the above general formula (2) is preferably the compound represented by the following general formula (2a).

[0055]

[0056] In general formula (2a), R １１ ~R １８ , R ３１ and R ３２ Each of these is independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group. １１ ~R １８ Adjacent substituents may bond to each other to form a ring. If a ring is formed, it may contain carbon atoms or heteroatoms, and may form an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatoms may be nitrogen atoms, oxygen atoms, sulfur atoms, or selenium atoms. ３１ and R ３２ Preferred examples include substituted or alkyl-substituted phenyl groups.

[0057] R ２０ R represents a substituent, each independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R ２０ These may be the same or different. Specifically, alkyl groups, substituted or substituted phenyl groups, and cyano groups are preferred.

[0058] l is an integer between 0 and 4, m is an integer between 1 and 2, and n is an integer between 1 and 5.

[0059] m + n + l may be an integer between 2 and 6, preferably between 2 and 5, and more preferably between 2 and 4.

[0060] Furthermore, the compound represented by the above general formula (2a) is preferably a compound represented by the following general formula (2a-1) or (2a-2).

[0061]

[0062] In General Formula (2a-1) and General Formula (2a-2), R １１ to R １３ , R ３１ and R ３２ each represent a substituent, and are each independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R １１ to R １３ , R ３１ and R ３２ may be the same or different. Preferred examples of R ３１ and R ３２ include a phenyl group substituted with a substituted or alkyl group.

[0063] n is an integer of 0 to 2, n' and n'' are each an integer of 0 to 4, and m and m' are each an integer of 0 to 5.

[0064] R ２１ to R ２４ are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group.

[0065] X is an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, SiRR' or CRR'. R and R' are each independently selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. Preferred examples of X include an oxygen atom and a sulfur atom.

[0066] Further, the compound represented by the general formula (2) is preferably a compound represented by the following general formula (2b-1) or (2b-2).

[0067]

[0068] In general formula (2b-1), R １１ to R １８ are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and adjacent substituents may be bonded to each other to form a ring. When forming a ring, the ring may contain carbon atoms or heteroatoms, and may form an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom.

[0069] R ２０ represents a substituent, and is selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R ２０ may be the same or different.

[0070] l is an integer of 0 to 4, m is an integer of 1 to 3, and n is an integer of 1 to 5.

[0071] In general formula (2b-2), R １１ to R １３ , R ２０ each represent a substituent, and are each independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group. A plurality of R １１ to R １３ , R ２０ may be the same or different.

[0072] X is an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, SiRR', or CRR'. R and R' are independently selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group.

[0073] l is an integer from 0 to 4, m is an integer from 1 to 3, n is an integer from 0 to 2, n' and n'' are integers from 0 to 4, and z is an integer from 1 to 5.

[0074] m+n+l and m+z+l may each be an integer between 2 and 6, preferably between 2 and 5.

[0075] The compounds represented by the above general formulas (2), (2a), (2a-1), (2a-2), (2b-1), and (2b-2) have a small difference between the lowest excited singlet energy and the lowest excited triplet energy (0.25 eV or less), making it easy to convert triplet excitons into singlet excitons through reverse intersystem crossing. By emitting fluorescence through a second organic compound, it becomes possible to provide a highly efficient organic light-emitting device with high emission intensity. Furthermore, since the excess triplet excitons are reduced, the stability of the compound itself is improved, and the operating life of the organic light-emitting device can also be extended.

[0076] Examples of representative compounds represented by the above general formulas (2), (2a), (2a-1), (2a-2), (2b-1), and (2b-2) include, but are not limited to, the compounds listed below.

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090] <Second Organic Compound> In this embodiment, the second organic compound plays the role of a guest material that ultimately emits light and is a material capable of fluorescence emission. Here, fluorescence emission refers to the phenomenon in which energy is released as light when returning from a singlet excited state to the ground state. It may also be a material that, like a thermally activated delayed fluorescence material, goes from a triplet excited state to a singlet excited state through reverse intersystem crossing and releases energy as light when returning from the singlet excited state to the ground state.

[0091] The second organic compound is preferably a blue light-emitting material. Specifically, the wavelength of the emission peak showing the highest emission intensity is preferably between 440 nm and 480 nm. Furthermore, from the viewpoint of obtaining blue light emission with excellent color purity, the full width at half maximum of the second organic compound is preferably 30 nm or less.

[0092] A second type of organic compound is the compound represented by the following general formula (3).

[0093]

[0094] In general formula (3), Cy １ ~Cy ３Each of these is independently a ring structure having 5 to 13 carbon atoms, or a heterocyclic structure having 4 to 12 carbon atoms containing a heteroatom. Specifically, preferred examples include a benzene ring, indene ring, naphthothiophene ring, benzothiophene ring, benzofuran ring, benzoselenophene ring, dibenzothiophene ring, dibenzofuran ring, dibenzoselenophene ring, and indazole ring. More preferably, the rings are a benzene ring, indene ring, benzothiophene ring, or benzofuran ring.

[0095] R １１ , R １２ , R １４ These are Cy １ ~Cy ３ Represents a substituent on a carbon atom or heteroatom, independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, cyano groups, and silyl groups, and includes multiple R １１ , R １２ , R １４ These may be the same or different. Specifically, preferred examples include alkyl groups, unsubstituted or alkyl-substituted phenyl groups, unsubstituted or alkyl groups, carbazole groups substituted with alkyl groups, phenyl groups, or carbazole groups, and alkyl-substituted acridinyl groups. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0096] l, m, and n are substituents R, respectively. １１ and R １２ , R １４ This represents the number, where l and m are integers from 0 to 8, and n is an integer from 0 to 7.

[0097] X is a boron atom or a nitrogen atom, and Y and Z are an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, BR, and NR. Here, R is independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups.

[0098] At least one of X, Y, and Z is a boron atom or BR. If X is a boron atom, Y and Z are not BR, and if X is not a boron atom, Y and Z may be BR.

[0099] R １１ and R １２ , R １１ and R, R １２ and R, R １４ R and R may bond to each other to form a ring. If a ring is formed, it may contain carbon atoms or heteroatoms.

[0100] The second organic compound may also preferably be a compound represented by the following general formula (3a-1) or (3a-2).

[0101]

[0102] In general formulas (3a-1) and (3a-2), Cy １ ~Cy ５ Each of these is independently a ring structure having 5 to 13 carbon atoms, or a heterocyclic structure having 4 to 12 carbon atoms containing a heteroatom. Specifically, preferred examples include a benzene ring, indene ring, naphthothiophene ring, benzothiophene ring, benzofuran ring, benzoselenophene ring, dibenzothiophene ring, dibenzofuran ring, dibenzoselenophene ring, and indazole ring. More preferably, the rings are a benzene ring, indene ring, benzothiophene ring, or benzofuran ring.

[0103] R １１ ~R １５ These are Cy １ ~Cy ５A substituent on a carbon atom or heteroatom is represented and is independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. １１ ~R １５ These may be the same or different. When a ring is formed, it may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom. Specifically, alkyl groups, diphenylamino groups, unsubstituted or alkyl-substituted phenyl groups, and unsubstituted or alkyl-substituted carbazole groups are preferred. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0104] Here, adjacent substituents refer to substituents bonded to adjacent carbon atoms.

[0105] l and l' are substituents R, respectively. １１ and R １２ The number of substituents R is represented, and m and m' are substituents R, respectively. １３ and R １５ This represents the number of substituents R, where n is the substituent R. １４ It represents the number.

[0106] In general formula (3a-1), l, l', m, and m' are between 0 and 8, and n is an integer between 0 and 2.

[0107] In general formula (3a-2), l and l' are integers from 0 to 8, and m, m', and n are integers from 0 to 6.

[0108] R in general formula (3a-1) １１ and R １２ , R １２ and R １３ , R １５ and R １１These may be bonded to each other to form a ring, and R in general formula (3a-2) １１ and R １４ , R １２ and R １４ These elements may bond to each other to form a ring. If a ring is formed, the ring may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring, and the heteroatoms may be nitrogen atoms, oxygen atoms, sulfur atoms, or selenium atoms.

[0109] X is a nitrogen atom.

[0110] X １ and X ２ , Y １ and Y ２ R is an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, and SiRR''. Here, R and R'' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. Preferably, R and R'' are alkyl groups, unsubstituted or alkyl-substituted phenyl groups. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0111] Furthermore, the second organic compound is preferably a compound represented by the following general formula (3a-3).

[0112]

[0113] In general formula (3a-3), R １１ ~R １４ , R ２１ and R ２４ , R ３１Each substituent may be independently selected from the group consisting of hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. If a ring is formed, the ring may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring, and the heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom. Specifically, alkyl groups, diphenylamino groups, and unsubstituted or alkyl-substituted phenyl groups are preferred. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0114] Here, adjacent substituents are R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R ２１ and R ２２ , R ２２ and R ２３ , R ２３ and R ２４ , R １１ and R ２４ It refers to.

[0115] Y １ and Y ２ The members are CRR', an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, and SiRR'. Here, R and R' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. Specifically, oxygen atoms, sulfur atoms, amino groups, and especially phenylamino groups are preferred.

[0116] Cy １ and Cy ２Each of these can be independently represented by the following general formula (3a-3') or general formula (3a-3'').

[0117]

[0118] In general formulas (3a-3') and (3a-3''), * represents the bonding position with * in general formula (3a-3), and represents the boron atom and Y, respectively. １ and Y ２ It combines with it to form a ring.

[0119] X １ and X ２ R is independently selected from the group consisting of oxygen, sulfur, selenium, tellurium, NR, SiRR'', and CR''. R and R'' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups.

[0120] R ４１ ~R ４４ , R ５１ and R ５４ R can be independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. Here, R ４１ ~R ４４ In this case, adjacent substituents are R ４１ and R ４２ , R ４２ and R ４３ , R ４３ and R ４４ This refers to R. ５１ ~R ５４ The same applies to R. When a ring is formed, the ring may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring, and the heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom.４１ ~R ４４ , R ５１ and R ５４ Specifically, alkyl groups, aryl groups, particularly phenyl groups, amino groups, and particularly diphenylamino groups are preferred. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms.

[0121] The compounds represented by general formulas (3), (3a-1), (3a-2), and (3a-3) exhibit localization of the HOMO (highest occupied orbital) and LUMO (lowest unoccupied orbital) due to multiple resonance effects. This suppresses structural relaxation in the excited state, resulting in a narrow full width at half maximum and high color purity of blue emission. Furthermore, reverse intersystem crossing from excited triplet to excited singlet occurs efficiently, enabling high emission efficiency.

[0122] Representative compounds represented by general formulas (3), (3a-1), (3a-2), and (3a-3) include, but are not limited to, the following compounds.

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] Furthermore, the compound used as the second organic compound is preferably a compound represented by the following general formula (4-1) or (4-2).

[0136]

[0137] In general formulas (4-1) and (4-2), Cy ４ This is a ring structure having 5 to 13 carbon atoms or a heterocyclic structure having 4 to 12 carbon atoms containing a heteroatom. Specifically, benzene rings and naphthalene rings are preferred examples.

[0138] R １１ ~R １７ , R ２１ ~R ２７ R can be independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. Here, R １１ ~R １７ In this case, adjacent substituents are R １１ and R １２ , R １２ and R １３ , R １４ and R １５ , R １５ and R １６ , R １６ and R １７ This refers to R. ２１ ~R ２７ The same applies to the following. When a ring is formed, the ring may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring, and the heteroatom may be a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom.

[0139] R １１ ~R １７ , R ２１ ~R ２７Specifically, preferred examples include alkyl groups, phenyl groups, alkyl-substituted phenyl groups, amino groups, diphenylamino groups, triazine groups, and diphenyltriazine groups. The alkyl group may have 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Also, R, １１ ~R １７ , R ２１ ~R ２７ If the ring structure is formed, it is preferably a benzochalcogenphene ring, and particularly preferably a benzofuran ring.

[0140] X' and Y' are an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, SiRR', or CRR'. Here, R and R' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. Specifically, oxygen atoms, sulfur atoms, and selenium atoms are preferred.

[0141] R ３１ is Cy ４ A substituent on R is independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. ３１ These may be the same or different. Specifically, alkyl groups, or phenyl groups substituted with alkyl groups, cyano groups, fluorine atoms, or methyl fluoride groups are preferred.

[0142] n is R ３１ It represents a number and is an integer from 0 to 6.

[0143] Compounds represented by general formulas (4-1) and (4-2) can produce blue light emission with a narrow emission spectrum width and high color purity, and also have high oscillator intensity and high fluorescence quantum yield (PLQY), making it possible to realize highly efficient organic light-emitting devices. Furthermore, these materials have the lowest excitation triple energy (T １ Because it has low ) and excellent stability, it becomes a long-life organic light-emitting element.

[0144] Representative compounds represented by general formulas (4-1) and (4-2) include, but are not limited to, the following compounds.

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153] <Other materials for the light-emitting layer> The light-emitting layer according to this embodiment may also contain a third organic compound different from the first and second organic compounds. The third organic compound is preferably higher in minimum singlet energy and minimum excited triplet energy than the first and second organic compounds. Furthermore, the third organic compound is preferably higher in minimum excited triplet energy than the compound represented by general formula (1a) and the compound represented by general formula (1b).

[0154] An example of a compound that can be used as a third organic compound is the third organic compound represented by the following general formula (5).

[0155]

[0156] In general formula (5), R １１ ~R １８Each of these substituents may be independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. １１ ~R １８ Specifically, examples include alkyl groups, substituted or unsubstituted phenyl groups, and the like.

[0157] Here, R １１ ~R １８ In this case, adjacent substituents are R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １５ and R １６ , R １６ and R １７ , R １７ and R １８ This refers to a ring. Furthermore, the ring may be an aromatic hydrocarbon ring or a heteroaromatic ring.

[0158] Cy Ａ This refers to a ring structure having 6 to 13 carbon atoms, or a heterocyclic structure having 5 to 12 carbon atoms including a heteroatom. The ring structure consists of carbon atoms, hydrogen atoms, and deuterium atoms, while the heterocyclic structure consists of carbon atoms, hydrogen atoms, deuterium atoms, and heteroatoms. The same applies hereinafter. Cy Ａ Specifically, preferred examples include benzene rings, pyridine rings, biphenyl rings, terphenyl rings, triazine rings, carbazole rings, and indazole rings.

[0159] n is Cy Ａ It represents the number of rings and is an integer between 1 and 5.

[0160] R ａ Cy ＡThis represents a substituent on an atom forming a ring, and is selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups.

[0161] n' is substituent R ａ It represents a number and is an integer from 1 to 9.

[0162] R １１ ~R １８ , and R ａ At least one of them has the structure of the following general formulas (5a) to (5d).

[0163]

[0164] In general formulas (5a) to (5d), X １ ~X ３ , Y １ Y ４ These are carbon atoms or nitrogen atoms, which may be the same or different from each other.

[0165] Z １ It is one of the following atoms: nitrogen, oxygen, sulfur, selenium, or tellurium.

[0166] R ２１ ~R ２５ , R ３１ ~R ３６ , R ４１ and R ４２ , R ５１ ~R ５３ The substituents represent atoms that form each ring structure and are independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring.

[0167] Here, adjacent substituents are R ２１ and R ２２ , R ２２ and R ２３ , R ２３ and R ２４ , R ２４ and R ２５ , R ３１ and R ３２ , R ３２ and R ３３ , R ３３ and R ３４ , R ３４ and R ３５ , R ３５ and R ３６ , R ４１ and R ４２ , R ５１ and R ５２ , R ５２ and R ５３ When there are multiple m atoms, R is bonded to adjacent carbon atoms. ４１ When there are multiple m' atoms, R is bonded to adjacent carbon atoms. ４２ When there are multiple l atoms, R is bonded to adjacent carbon atoms. ５１ When there are multiple l' atoms, R is bonded to adjacent carbon atoms. ５２ When there are multiple l'' atoms, R is bonded to adjacent carbon atoms. ５３ This refers to a pair of rings. The ring may contain carbon atoms or heteroatoms, and may be an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom.

[0168] m and m', l and l', and l'' represent the number of substituents, respectively, where m and m' are integers from 0 to 4, and l, l', and l'' are integers from 0 to 5.

[0169] Also, Z １ If R is a nitrogen atom, ４３ Z is selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. １ If R is not a nitrogen atom, ４３It is a hydrogen atom.

[0170] * represents R in general formula (5). １１ ~R １８ and R ａ The bond position in is represented, and the general formulas (5a) to (5d) are determined by the bond position of *. Ａ It may be directly bonded to the ring.

[0171] R ａ Specifically, alkyl groups, fluorene, carbazole, dibenzofuran, dibenzothiophene, diphenylphosphine oxide, and in general formula (5c), Z １ Y is an oxygen atom or a sulfur atom ３ Preferred examples include fused heterocycles of nitrogen atoms, and fused heterocycles in which one or two nitrogen atoms are contained in one benzene ring in triphenylene.

[0172] The material represented by general formula (5) has excellent hole transport properties, and the charge balance within the light-emitting layer can be arbitrarily adjusted by adjusting the amount added to the light-emitting layer, thus enabling the realization of highly efficient and long-life organic light-emitting devices.

[0173] Examples of typical compounds represented by general formula (5) include, but are not limited to, the following compounds.

[0174]

[0175]

[0176]

[0177]

[0178] In the light-emitting layer, the mass ratio of the third organic compound is more preferably greater than the mass ratio of the first and second organic compounds, and is preferably 50% by mass or more, and more preferably 60% by mass or more, when the entire light-emitting layer is considered as 100% by mass. Furthermore, in order to exhibit excellent charge transport properties, it is preferable that the third organic compound has at least one carbazole group. The content of the first organic compound is preferably 5% by mass or more and within 50% by mass, and more preferably within 30% by mass. By reducing the concentration, aggregation can be prevented, concentration quenching and shifts in the emission spectrum can be suppressed, and by setting an appropriate content, it is possible to lower the voltage of the device, thereby realizing an organic light-emitting element with high efficiency and excellent color purity. The second organic compound is preferably 0.5% by mass or more and within 10% by mass. By dispersing it at a low concentration, concentration quenching and broadening of the emission spectrum can be suppressed.

[0179] In this embodiment, if the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe > 1, it is preferable that the film thickness of the first or second organic layer on the electron injection side is greater than the film thickness of the second or first organic layer on the hole injection side. If μh / μe < 1, it is preferable that the film thickness of the first or second organic layer on the hole injection side is greater than the film thickness of the second or first organic layer on the electron injection side.

[0180] The hole mobility and electron mobility of the light-emitting layer are measured, for example, by the Time-of-Flight (TOF) method. In the TOF method, a sample in which the light-emitting layer to be measured is sandwiched between electrodes is irradiated with pulsed light to generate carriers, and the mobility can be calculated from the time (t) required for these carriers to pass through the light-emitting layer due to the electric field applied between the electrodes using the following formula: Mobility (μ) = L ２ / (V・t)

[0181] Here, L is the thickness of the light-emitting layer being measured, V is the applied voltage, and t is the time required for the signal to pass through the light-emitting layer (transient time).

[0182] Furthermore, hole mobility and electron mobility can be independently evaluated depending on the polarity of the electric field applied to the light-emitting layer.

[0183] The film thickness of the light-emitting layer is preferably 50 nm or less.

[0184] <Other Compounds> In addition to the organic compounds according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host materials, luminescent compounds, electron-injecting or electron-transporting compounds, etc., can be used together as needed. Examples of these compounds are listed below.

[0185] (Hole Transport Materials) As hole-injection transport materials, materials with high hole mobility are preferred to facilitate the injection of holes from the anode and to transport the injected holes to the light-emitting layer. Furthermore, materials with a high glass transition temperature are preferred to suppress the crystallization of organic compounds in the organic light-emitting element. Examples of low-molecular-weight and high-molecular-weight materials with hole-injection transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. In addition, the above-mentioned hole-injection transport materials are also suitably used in electron-blocking layers. Furthermore, when the hole-injection layer is fabricated by a coating method, a mixture of polyethylenedioxythiophene and polystyrene sulfonic acid (PEDOT:PSS), which is commonly used as a hole-injection material, may be used.Specific examples of compounds used as hole-injection transport materials are shown below, but are of course not limited to these.

[0186]

[0187]

[0188] Among the hole-injection transport materials listed, HT16 to HT18 can reduce the driving voltage when used in the layer in contact with the anode. HT16 is widely used in organic light-emitting devices. HT2 to HT7, HT10, HT12, HT22 to 28 may be used in the organic compound layer adjacent to HT16. Hole-transporting polymer compounds such as polyphenylene vinylene (PPV), polyfluorene (PF), polyvinylcarbazole (PVK), and their derivatives may also be used. In addition to these, for example, SiO ２It is also possible to use inorganic insulating layers such as SiN or organosilicon polymers such as siloxane. Furthermore, multiple materials may be used in a single organic compound layer.

[0189] In addition to the luminescent layer in this embodiment, when a luminescent layer is provided by lamination, for example, compounds such as those listed below can be used. Guest materials mainly involved in luminescence include donor-acceptor type organic compounds, boron-containing complexes, indocarbazole fused ring compounds, 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-quinolinolate)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. Furthermore, when a luminescent layer is produced by coating, polymer compounds with luminescence properties are mainly used. This is because polymer compounds tend to exhibit high glass transition temperatures, making them less prone to crystallization compared to low molecular weight systems. Specific examples of materials used include polymer compounds such as polyphenylene vinylene (PPV), polyfluorene (PF), polyvinylcarbazole (PVK), and their derivatives.

[0190] (Electron Transport Materials) Electron transport materials can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and are selected considering the balance with the hole mobility of the hole transport material. Examples of materials with electron transport properties include oxadiazole 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 suitably used in hole blocking layers.

[0191] The following are specific examples of compounds used as electron transport materials, but of course, they are not the only ones.

[0192]

[0193] Electron-injectable materials can be arbitrarily selected from those that allow for easy electron injection from the cathode, taking into consideration the balance with hole injection properties. Organic compounds include n-type dopants and reducing dopants. Examples include alkali metal compounds such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fluvalene derivatives, and acridine derivatives.

[0194] It can also be used in combination with the electron transport materials mentioned above.

[0195] [Second Embodiment] The following describes an organic light-emitting element according to the second embodiment, but any content that overlaps with the first embodiment will be omitted.

[0196] The organic light-emitting element in the second embodiment of this disclosure comprises, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode. The light-emitting layer contains an organic compound represented by general formula (5), which was listed as the third organic compound in the first embodiment, and a fluorescent light-emitting material. In this embodiment, the organic compound contained in the light-emitting layer can reduce ΔEst, and the excitation triplet energy can be effectively recovered, resulting in a high luminescence efficiency and a long-life organic light-emitting element.

[0197] Furthermore, similar to the first embodiment, the organic light-emitting element of this embodiment also contains a compound represented by general formula (1a) or (1b) in the first organic layer and the second organic layer adjacent to the light-emitting layer. This compound receives excess excitation triplet energy in the light-emitting layer, maintaining the chemical stability of the light-emitting layer and enabling the production of an organic light-emitting element with a long operating life. In addition, the compounds represented by general formulas (1a) and (1b) can upconvert the received triplet excitons to singlet excitons and transfer their excitation singlet energy to a fluorescent material via a Förster-type energy transfer mechanism, thereby converting it into fluorescence emission. This also helps to suppress a decrease in luminescence efficiency.

[0198] In this embodiment, the same effect can be obtained even if the light-emitting layer includes an organic compound represented by the following general formula (6a), an organic compound represented by the following general formula (6b), and a fluorescent light-emitting material. The compound represented by the following general formula (6a) and the organic compound represented by the general formula (6b) form a complex.

[0199]

[0200] In the above general formulas (6a) and (6b), R ３１ ~R ３８ R is independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. Here, R ３１ ~R ３８ In this case, adjacent substituents are R ３１ and R ３２ , R ３２ and R ３３ , R ３４ and R ３５ , R ３５ and R ３６ , R ３６ and R ３７This refers to [a specific compound]. When forming a ring, it may contain carbon atoms or heteroatoms, and may form an aromatic hydrocarbon ring or a heteroaromatic ring. The heteroatom may be a nitrogen atom, oxygen atom, sulfur atom, or selenium atom. Cy Ａ and Cy Ｂ These are, respectively, fused ring structures with 6 to 18 carbon atoms or heterocyclic structures with 5 to 15 carbon atoms containing 1 to 3 heteroatoms.

[0201] n' is Cy Ａ and Cy Ｂ These represent the number of rings and are integers from 1 to 5.

[0202] R ｃ and R ｄ Cy Ａ and Cy Ｂ Each substituent on an atom forming a ring is independently selected from the group consisting of a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group.

[0203] m' is R ｃ and R ｄ These represent the number of each element, and are integers from 1 to 5.

[0204] Ar １ and Ar ２ Each of these is independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, and substituted or unsubstituted heteroaryloxy groups.

[0205] X is a carbon atom or a nitrogen atom, and they may be the same or different from each other.

[0206] Furthermore, in the organic light-emitting element of this embodiment, the first organic layer and the light-emitting layer, and the light-emitting layer and the second organic layer must be in contact with each other, but other layers such as a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, and an electron injection layer may also be present. Also, the laminate of the first organic layer, the light-emitting layer, and the second organic layer arranged between the electrodes does not necessarily have to be just one, and multiple such laminates may be stacked. There is also no problem in having a charge generation layer between each laminate.

[0207] <Third Organic Compound> In this embodiment, the compound represented by general formula (5) contained in the light-emitting layer is a material that can transfer its excitation energy to the fluorescent light-emitting material, and is the same compound listed as the third organic compound in the first embodiment.

[0208] Furthermore, the fluorescent material used in this embodiment is preferably the same as the second organic compound mentioned in the first embodiment. Other materials and components are the same as in the first embodiment.

[0209] In this embodiment, the content of the fluorescent material in the light-emitting layer is preferably 0.5% by mass or more and 5% by mass or less, and more preferably 1% by mass or less. By reducing the concentration, density quenching and shifts or broadening of the emission spectrum can be suppressed.

[0210] In this embodiment, the configuration other than the features described above is the same as in the first embodiment.

[0211] [Third Embodiment] The organic light-emitting element according to this embodiment comprises a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, the first organic layer comprises a compound represented by general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe < 1, and the first layer is provided between the light-emitting layer and the second electrode when μh / μe > 1.

[0212] In this embodiment, when μh / μe < 1, it means that the electron mobility is greater than the hole mobility within the light-emitting layer. Therefore, the hole-electron recombination region within the light-emitting layer is ubiquitous on the first electrode side. As a result, excitons generated within the light-emitting layer are more likely to leak into the organic layer between the first electrode and the light-emitting layer. Also, when μh / μe > 1, it means that the hole mobility is greater than the electron mobility within the light-emitting layer. Therefore, the hole-electron recombination region within the light-emitting layer is ubiquitous on the second electrode side. As a result, excitons generated within the light-emitting layer are more likely to leak into the organic layer between the second electrode and the light-emitting layer.

[0213] Therefore, in this embodiment, by providing the first layer according to the relationship between hole mobility and electron mobility, excitons leaked from the light-emitting layer can be recovered. As a result, the organic light-emitting device according to this embodiment has excellent operating life. Furthermore, since the first layer contains a light-emitting material, excitons leaked from the light-emitting layer can contribute to the light emission from the first organic layer. Therefore, the organic light-emitting device according to this embodiment is expected to have excellent luminescence efficiency.

[0214] In this embodiment, it is preferable that the first organic layer contains a compound represented by general formula (1a) or (1b) and an organic compound whose lowest excited singlet energy and lowest excited triplet energy are higher than those of the fluorescent material.

[0215] In this embodiment, the configuration other than the features described above is the same as in the first embodiment.

[0216] [Fourth Embodiment] The organic light-emitting element according to this embodiment comprises a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises an organic compound represented by general formula (5) listed as the third organic compound in the first embodiment and a fluorescent light-emitting material, wherein the first organic layer comprises a compound represented by general formula (1a) or (1b) and a fluorescent light-emitting material, wherein the first electrode is an anode, and the first layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe > 1, and the first layer is provided between the light-emitting layer and the second electrode when μh / μe > 1.

[0217] In this embodiment, when μh / μe < 1, it means that the electron mobility is greater than the hole mobility within the light-emitting layer. Therefore, the hole-electron recombination region within the light-emitting layer is ubiquitous on the first electrode side. As a result, excitons generated within the light-emitting layer are more likely to leak into the organic layer between the first electrode and the light-emitting layer. Also, when μh / μe > 1, it means that the hole mobility is greater than the electron mobility within the light-emitting layer. Therefore, the hole-electron recombination region within the light-emitting layer is ubiquitous on the second electrode side. As a result, excitons generated within the light-emitting layer are more likely to leak into the organic layer between the second electrode and the light-emitting layer.

[0218] Therefore, in this embodiment, by providing the first layer according to the relationship between hole mobility and electron mobility, excitons leaked from the light-emitting layer can be recovered. As a result, the organic light-emitting device according to this embodiment has excellent operating life. Furthermore, since the first layer contains a light-emitting material, excitons leaked from the light-emitting layer can contribute to the light emission from the first organic layer. Therefore, the organic light-emitting device according to this embodiment is expected to have excellent luminescence efficiency.

[0219] In this embodiment, it is preferable that the first organic layer contains a compound represented by general formula (1a) or (1b) and an organic compound whose lowest excited singlet energy and lowest excited triplet energy are higher than those of the fluorescent material.

[0220] In this embodiment, the configuration other than the features described above is the same as in the second embodiment.

[0221] [Other Components of the Organic Light-Emitting Device] The following describes other components that constitute the organic light-emitting device of the first to fourth embodiments.

[0222] The organic light-emitting element has a first electrode, an organic compound layer including a light-emitting layer, and a second electrode on a substrate. The organic compound layer includes the first organic layer and the second organic layer mentioned in the above embodiment. A protective layer, a color filter, a microlens, etc., may be provided on the second electrode. If a color filter is provided, a planarization layer may be provided between it and the protective layer. The planarization layer can be made of acrylic resin or the like. The same applies when a planarization layer is provided between the color filter and the microlens.

[0223] <Substrate> Examples of substrates include quartz, glass, silicon wafers, resins, and metals. The substrate may also be equipped with switching elements such as transistors and wiring, and an insulating layer may be provided on top of them. The insulating layer can be made of any material that allows for the formation of contact holes between it and the first electrode, while ensuring insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, and silicon nitride can be used.

[0224] <Electrodes> A pair of electrodes can be used. The pair of electrodes consists of a first electrode and a second electrode. Specifically, 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 the higher potential is the anode, and the other is the cathode. Alternatively, the electrode that supplies holes to the light-emitting layer may be the anode, and the electrode that supplies electrons may be the cathode.

[0225] The anode material should ideally have a high work function. For example, elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, or mixtures containing these, or alloys combining them, as well as metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0226] These electrode materials may be used individually or in combination of two or more types. Furthermore, the anode may consist of a single layer or multiple layers.

[0227] When used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. These materials can also function as reflective films without serving as electrodes. Furthermore, when used as a transparent electrode, oxide transparent conductive layers such as indium tin oxide (ITO) or indium zinc oxide can be used, but are not limited to these. Photolithography techniques can be used to form the electrodes.

[0228] Materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, elemental metals such as aluminum, titanium, manganese, silver, lead, and chromium, or mixtures containing these. Alternatively, alloys combining these elemental metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium oxide (ITO) can also be used. These electrode materials may be used individually or in combination of two or more. The cathode may also be 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 important as long as silver aggregation is reduced. For example, the ratio of silver to other metals may be 1:1, 3:1, etc.

[0229] 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 using DC and AC sputtering methods is more preferable because it provides good film coverage and makes it easier to reduce resistance.

[0230] <Organic Compound Layer> The organic compound layer includes the light-emitting layer, the first organic layer, and the second organic layer according to this embodiment. In addition to these, it may also include a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer as needed. The organic compound layer is mainly composed of organic compounds, but may also contain inorganic atoms and inorganic compounds. For example, it may contain copper, lithium, magnesium, barium, ytterbium, aluminum, iridium, platinum, molybdenum, zinc, etc.

[0231] The organic compound layer constituting the organic light-emitting element according to this embodiment is formed by the method described below.

[0232] The organic compound layer can be formed using dry processes such as vacuum deposition, ionization deposition, sputtering, or plasma deposition. Alternatively, a wet process can be used, in which the compound is dissolved in a suitable solvent and the layer is formed by a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0233] By forming layers using methods such as vacuum deposition or solution coating, crystallization is less likely to occur, resulting in excellent stability over time. Furthermore, when forming films using coating methods, it is possible to combine the film with an appropriate binder resin.

[0234] Examples of the binder resins mentioned above include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin.

[0235] Furthermore, these binder resins may be used individually as homopolymers or copolymers, or as a mixture of two or more types. Additionally, known additives such as plasticizers, antioxidants, and UV absorbers may be used in combination as needed.

[0236] <Protective Layer> A protective layer may be provided on the cathode. For example, by bonding glass with a desiccant to the cathode, the intrusion of water and other substances into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. Alternatively, a passivation film of silicon nitride or the like may be provided on the cathode to reduce the intrusion of water and other substances into the organic compound layer. For example, after forming the cathode, the material may be transported to another chamber without breaking the vacuum and a silicon nitride film with a thickness of 2 μm may be formed by CVD to serve as a protective layer. A protective layer may also be provided using atomic deposition (ALD) after the film formation by CVD. The material of the film formed by ALD is not limited, but may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed on the film formed by ALD by CVD. The film formed by ALD may have a thinner film thickness than the film formed by CVD. Specifically, the film thickness of the film formed by the ALD method may be 50% or less, and even 10% or less, of the film thickness of the film formed by the CVD method.

[0237] <Color Filter> A color filter may be provided on top of the protective layer. For example, a color filter that takes into account the size of the organic light-emitting element may be provided on a separate substrate and bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer as described above using photolithography technology. The color filter may be made of polymer.

[0238] <Planarizing Layer> A planarizing layer may be provided between the color filter and the protective layer. The planarizing layer is provided for the purpose of reducing the unevenness of the layer below. It may also be called a material resin layer without limiting its purpose. The planarizing layer may be composed of an organic compound, and may be low molecular weight or high molecular weight, but high molecular weight is preferred.

[0239] The planarization layer may be provided above or below the color filter, and its constituent materials may be the same or different. Specifically, examples include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, urea resin, etc.

[0240] <Microlenses> The organic light-emitting element according to this embodiment may have optical elements such as microlenses on the light-emitting side. The microlenses may be made of acrylic resin, epoxy resin, etc. The microlenses may be used to increase the amount of light extracted from the organic light-emitting element or to control the direction of the extracted light. The microlenses may have a hemispherical shape. If they have a hemispherical shape, among the tangents that are tangent to the hemisphere, there is a tangent that is parallel to the insulating layer, and the point of contact between that tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be similarly determined in any cross-sectional view. That is, among the tangents that are tangent to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the point of contact between that tangent and the semicircle is the vertex of the microlens.

[0241] Furthermore, the midpoint of a microlens can also be defined. In the cross-section of a microlens, a line segment can be imagined from the point where one arc shape begins to the point where another arc shape begins, and the midpoint of this line segment can be called the midpoint of the microlens. The cross-section used to determine the vertices and midpoints may be a cross-section perpendicular to the insulating layer.

[0242] <Opposite Substrate> An opposing substrate may be provided on the planarization layer. The opposing substrate is called an opposing substrate because it is provided in a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. The opposing substrate may be a second substrate if the aforementioned substrate is referred to as the first substrate.

[0243] <Pixel Circuit> The light-emitting device having an organic light-emitting element of this embodiment may have a pixel circuit connected to the light-emitting element. The pixel circuit may be an active-matrix type that independently controls the light emission of each of the multiple light-emitting elements. 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 include a light-emitting element, a transistor that controls the light emission brightness of the light-emitting element, a transistor that controls the light emission timing, a capacitor that holds the gate voltage of the transistor that controls the light emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0244] 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 the transistors constituting the pixel circuit may be smaller than the mobility of the transistors constituting the display control circuit.

[0245] The slope of the current-voltage characteristics of the transistors constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors constituting the display control circuit. The slope of the current-voltage characteristics can be measured using the so-called Vg-Ig characteristic.

[0246] <Pixels> The organic light-emitting device having an organic light-emitting element of this embodiment has a plurality of pixels. Each pixel has sub-pixels that emit light of a different color from the others. The sub-pixels may each have, for example, RGB emission colors. Each pixel emits light in a region also called a pixel aperture.

[0247] Pixels can take on known arrangements in a plan view. For example, they may be in a stripe arrangement, delta arrangement, pentile arrangement, or Bayer arrangement. The shape of subpixels in a plan view may be any known shape. For example, rectangles, rhombuses, hexagons, etc. Of course, even if it is not a precise shape, if it is close to a rectangle, it is included in the category of rectangles. The shape of subpixels and the pixel arrangement can be used in combination.

[0248] <Applications of Organic Light-Emitting Element> The organic light-emitting element according to the present embodiment can be used as a constituent member of a display device or a lighting device. Other applications include an exposure light source for electrophotographic image forming apparatuses, a backlight for liquid crystal display devices, and a light-emitting device having a color filter on a white light source.

[0249] The display device may also be an image information processing apparatus that has an image input unit for inputting image information from an area CCD, a linear CCD, a memory card or the like, has an information processing unit for processing the input information, and displays the input image on a display unit.

[0250] Further, the display unit included in the imaging apparatus or the inkjet printer may have a touch panel function. The driving method of this touch panel function is not particularly limited, and may be an infrared method, a capacitive method, a resistive film method, or an electromagnetic induction method. The display device may also be used for a display unit of a multi-function printer.

[0251] Next, the display device according to the present embodiment will be described with reference to the drawings.

[0252] FIG. 1A and FIG. 1B are schematic cross-sectional views showing examples 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).

[0253] FIG. 1A is an example of a pixel that is a constituent element of the display device according to the present embodiment. The pixel includes a sub-pixel 10. The sub-pixels are divided into 20R, 20G, and 20B by their emitted light. The emission colors may be distinguished by the wavelengths emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel has, on the interlayer insulating layer 1, a reflective electrode 12 which is a first electrode, an insulating layer 13 covering an end of the reflective electrode 12, an organic compound layer 14 covering the first electrode and the insulating layer 13, a second electrode 15, a protective layer 16, and a color filter 17.

[0254] The interlayer insulating layer 11 may have a transistor or a capacitive element disposed thereunder or therein. The transistor and the first electrode may be electrically connected via a contact hole or the like (not shown).

[0255] The insulating layer 13 is also referred to as a bank or a pixel separation film. It covers an end of the first electrode and is arranged surrounding the first electrode. The portion where the insulating layer 13 is not disposed is in contact with the organic compound layer 14 and serves as a light-emitting region.

[0256] The second electrode 15 may be a transparent electrode, a reflective electrode, or a semi-transmissive electrode.

[0257] The protective layer 16 reduces penetration of moisture into the organic compound layer 14. Although the protective layer 16 is illustrated as a single layer, it may be a plurality of layers. Each layer may be an inorganic compound layer or an organic compound layer.

[0258] The color filter 17 is classified into 17R, 17G, and 17B according to its color. The color filter 17 may be formed on a planarization film (not shown). Further, a resin protective layer (not shown) may be provided over the color filter 17. The color filter 17 may be formed on the protective layer 16, or may be provided on a counter substrate such as a glass substrate and then bonded thereto.

[0259] The display device of Figure 1B illustrates an organic light-emitting element 36 and a TFT 28 as an example of a transistor. A substrate 2 made of glass, silicon or the like, and an insulating layer 22 provided over the substrate 1. Active elements 28 such as TFTs are arranged over the insulating layer 22, and a gate electrode 23, a gate insulating film 24, and a semiconductor layer 25 of the active element 28 are arranged. The active element 28 further includes a semiconductor layer 25, a drain electrode 26, and a source electrode 27. An insulating film 29 is provided over the active element 28. The anode 31 constituting the organic light-emitting element 36 and the source electrode 27 are connected via a contact hole 30 provided in the insulating film 29.

[0260] Furthermore, the method of electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element 26 and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the configuration shown in Figure 1B. In other words, it is sufficient for either the anode or cathode to be electrically connected to either the source electrode or the drain electrode of the TFT. TFT refers to a thin-film transistor.

[0261] In the display device shown in Figure 1B, the organic compound layer 32 is depicted as a single layer, but the organic compound layer 32 may consist of multiple layers. A first protective layer 34 and a second protective layer 35 are provided on the cathode 33 to reduce the degradation of the organic light-emitting element.

[0262] In the display device shown in Figure 1B, a transistor is used as the switching element, but other switching elements may be used instead.

[0263] Furthermore, the transistor used in the display device shown in Figure 1B is not limited to a transistor using a single-crystal silicon wafer; it may also be a thin-film transistor having an active layer on an insulating surface of the substrate. Examples of the active layer include non-single-crystal silicon such as single-crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0264] The transistors included in the display device shown in Figure 1B may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the transistors are fabricated by processing the substrate itself, such as a Si substrate. In other words, having transistors within a substrate can be seen as the substrate and transistors being formed as a single unit.

[0265] The organic light-emitting element according to this embodiment has its luminescence controlled by a TFT, which is an example of a switching element, and by providing multiple organic light-emitting elements on one surface, an image can be displayed according to the luminescence of each element. The switching element according to this embodiment is not limited to a TFT, but may also be a transistor made of low-temperature polysilicon, or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also mean "within the substrate." Whether to provide a transistor within the substrate or to use a TFT is selected depending on the size of the display area; for example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0266] Figure 2 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The display panel 1005 may have an organic light-emitting element according to this embodiment. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005, respectively. Transistors are printed on the circuit board 1007. The battery 1008 does not need to be provided if the display device is not a portable device, or it may be provided in a different location even if it is a portable device.

[0267] The display device according to this embodiment may have a color filter having red, green, and blue colors. The color filter may have the red, green, and blue colors arranged in a delta array.

[0268] The display device according to this embodiment may be used in the display unit of a mobile terminal. In that case, it may have both display and operation functions. Examples of mobile terminals include smartphones and other mobile phones, tablets, and head-mounted displays.

[0269] The display device according to this embodiment may be used in the display unit of an imaging device having an image sensor that receives light. The imaging device may have a display unit that displays information acquired by the image sensor. Furthermore, the display unit may be a display unit exposed to the outside of the imaging device, or a display unit located inside the viewfinder. The imaging device may be a digital camera or a digital video camera.

[0270] Figure 3A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 and the rear display 1102 may have organic light-emitting elements according to this embodiment. In that case, the viewfinder 1101 and the rear display 1102 may display not only the image to be captured, but also environmental information, imaging instructions, etc. Environmental information may include the intensity of ambient light, the direction of ambient light, the speed at which the subject is moving, the possibility of the subject being obscured by an obstacle, etc.

[0271] Since the optimal timing for imaging is very short, it is best to display the information as quickly as possible. Therefore, it is preferable to use a display device using the organic light-emitting element according to this embodiment, because organic light-emitting elements have a fast response speed.

[0272] The imaging device 1100 may further include an optical section (not shown). The lenses in the optical section may be one or more, and they form an image on the image sensor housed in the housing 1104. The focus can be adjusted by adjusting the relative positions of the multiple lenses. This operation can also be performed automatically. The imaging device may also be called a photoelectric converter. The photoelectric converter does not capture images sequentially, but may include imaging methods such as detecting the difference from the previous image or extracting from an image that is always being recorded.

[0273] Figure 3B is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type response unit. The operation unit may also be a biometric recognition unit that recognizes fingerprints to unlock or otherwise perform actions. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. Images captured by the camera function are displayed on the display unit. Examples of electronic devices include smartphones and laptop computers.

[0274] Figures 4A and 4B are schematic diagrams showing an example of a display device according to this embodiment. Figure 4A is a display device such as a television monitor or a PC monitor. The display device 1300 has a housing 1301 and a display unit 1302. An organic light-emitting element according to this embodiment is used in the display unit 1302.

[0275] The display device 1300 may have a housing 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in Figure 4A. The lower edge of the housing 1301 may also serve as the base.

[0276] Furthermore, the housing 1301 and the display unit 1302 may be curved. Their radius of curvature may be between 5000 mm and 6000 mm.

[0277] Figure 4B is a schematic diagram showing another example of a display device according to this embodiment. The display device 1310 in Figure 4B is configured to be foldable 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 have organic light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single display device without seams. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may together display a single image.

[0278] Figure 5A is a schematic diagram showing an example of a lighting device according to this embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, and a circuit board 1403. The light source 1402 has an organic light-emitting element according to this embodiment. The lighting device 1400 may have an optical film 1404 to improve the color rendering of the light source. The lighting device 1400 may also have a light diffusion section 1405 to effectively diffuse the light from the light source. The lighting device 1400 having a light diffusion section 1405 allows light to be delivered over a wide area. The optical film 1404 and the light diffusion section 1405 may be provided on the light-emitting side of the lighting. A cover may be provided on the outermost part as needed.

[0279] The lighting device is, for example, a device for illuminating a room. The lighting device may emit white light, daylight white light, or any other color from blue to red. The lighting device according to this embodiment may have a dimming circuit for adjusting the brightness of these colors. The lighting device according to this embodiment may also have a power supply circuit connected to the organic light-emitting element according to this embodiment. The power supply circuit may be a circuit that converts AC voltage to DC voltage. White is defined as a color temperature of 4200K, and daylight white is defined as a color temperature of 5000K. The lighting device according to this embodiment may further have a color filter.

[0280] Furthermore, the lighting device according to this embodiment may have a heat dissipation section. The heat dissipation section releases heat from inside the device to the outside, and examples include metals, ceramics, and the like with high thermal conductivity.

[0281] Figure 5B is a schematic diagram of an automobile, which is an example of a mobile body according to this embodiment. The automobile has a taillight, which is an example of a lighting device. The automobile 1500 has a taillight 1501 and a body 1503, and the taillight may illuminate when the brakes are applied or the like. The body 1503 may also be called the machine body. The automobile 1500 may have a window 1502 attached to the body 1503.

[0282] The tail lamp 1501 has an organic light-emitting element according to this embodiment. The tail lamp may have a protective member to protect the light source. The protective member has a reasonably high strength and can be made of any transparent material, but it is preferably made of polycarbonate or the like. A frangic acid derivative, an acrylonitrile derivative, or the like may be mixed with the polycarbonate.

[0283] The window 1502 may be a transparent display if it is not a window for checking the front and rear of the automobile. The transparent display has an organic light-emitting element according to this embodiment. In this case, the constituent materials such as electrodes of the organic light-emitting element according to this embodiment are made of transparent material.

[0284] The mobile body according to this embodiment includes a drive force generating unit that generates a driving force mainly used for the movement of the mobile body, and one or both of the rotating bodies mainly used for the movement of the mobile body. The drive force generating unit may be an engine, a motor, etc. The rotating body may be a tire, a wheel, a ship's propeller, an aircraft's propeller, etc. Specifically, it may be a bicycle, an automobile, a train, a ship, an aircraft, a drone, etc. The mobile body may have a body and a light fixture provided on the body. The light fixture may emit light to make the position of the body known.

[0285] With reference to Figure 6A and Figure 6B, application examples of the display devices of the above-described respective embodiments will be described. The display device can be applied to systems that can be worn as wearable devices such as smart glasses, head-mounted displays, and smart contacts, for example. The display device that can be used in a wearable device may include an imaging apparatus capable of photoelectrically converting visible light, and a display apparatus capable of emitting visible light.

[0286] Figure 6A and Figure 6B are schematic diagrams illustrating an example of eyeglasses (smart glasses) according to the present embodiment. Eyeglasses 1600 (smart glasses) will be described using Figure 6A. The eyeglasses 1600 have a display unit on the back surface side of a lens 1601. The display unit includes the organic light-emitting element according to the present embodiment. Furthermore, an imaging apparatus 1602 such as a CMOS sensor or a SPAD may be provided on the front surface side of the lens 1601.

[0287] The eyeglasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies electric power to the imaging apparatus 1602 and the display unit. In addition, the control device 1603 controls the operations of the imaging apparatus 1602 and the display unit. The lens 1601 is formed with an optical system for condensing light from the imaging apparatus 1602 and the display unit.

[0288] The eyeglasses 1610 (smart glasses) will be described using Figure 6B. The eyeglasses 1610 have a control device 1612, and the control device 1612 is equipped with a display device having an organic light-emitting element according to this embodiment. The control device 1612 may further have an imaging device corresponding to the imaging device 1602. An optical system for projecting light emitted from the control device 1612 is formed on the lens 1611, and an image is projected onto the lens 1611. The control device 1612 functions as a power supply that supplies power to the imaging device and the display device, and also controls the operation of the imaging device and the display device. The control device may have a gaze detection unit that detects the wearer's gaze. Gaze detection may use infrared light. The infrared light-emitting unit emits infrared light towards the eyeball of the user who is gazing at the displayed image. An image of the eyeball is obtained by detecting the reflected light from the eyeball of the emitted infrared light with an imaging unit having a light-receiving element. By having a reduction means that reduces the light from the infrared light-emitting unit to the display unit in planar view, the deterioration of image quality is reduced.

[0289] The control device 1612 detects the user's gaze toward the displayed image from the image of the eyeball obtained by imaging with infrared light. Any known method can be applied to gaze detection using the image of the eyeball. For example, a gaze detection method based on the Purkinje image obtained by the reflection of the irradiated light from the cornea can be used.

[0290] More specifically, gaze detection processing is performed based on the pupil-corneal reflection method. Using the pupil-corneal reflection method, a gaze vector representing the orientation (rotation angle) of the eyeball is produced based on the pupil image and Purkinje image contained in the captured image of the eyeball, thereby detecting the user's gaze.

[0291] The display device according to this embodiment may include an imaging device having a light-receiving element, and the display image of the display device may be controlled based on the user's gaze information from the imaging device.

[0292] Specifically, the display device determines a first field of view that the user is fixated on, and a second field of view other than the first field of view, based on gaze information. The first and second field of view may be determined by the display device's control unit, or they may be determined by an external control unit and received by the display device. Within the display area of ​​the display device, the display resolution of the first field of view may be controlled to be higher than the display resolution of the second field of view. In other words, the resolution of the second field of view may be lower than that of the first field of view.

[0293] Furthermore, the display area has a first field of view area and a second field of view area different from the first field of view area, and based on gaze information, the area with higher priority is determined from the first field of view area and the second field of view area. The first field of view area and the second field of view area may be determined by the control device of the display device, or they 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 the areas other than the high-priority area. In other words, the resolution of areas with relatively lower priority may be set lower.

[0294] Furthermore, AI may be used to determine the first field of view area and the field of view areas with higher priority. The AI ​​may be a model configured to estimate the angle of line of sight and the distance to the target object at the end of the line of sight from the image of the eye, using the image of the eye and the direction the eye was actually looking in the image as training data. The AI ​​may be provided by the display device, the imaging device, or an external device. If the external device has the AI, it can preferably be applied to smart glasses that further have an imaging device for capturing images of the outside. The smart glasses can display the captured external information in real time.

[0295] Figure 7A is a schematic diagram showing an example of an image forming apparatus according to this embodiment. The image forming apparatus 1700 is an electrophotographic image forming apparatus and includes a photoreceptor 1707, an exposure light source 1708, a charging unit 1710, a developing unit 1711, a transfer unit 1712, a transport roller 1713, and a fuser 1715. Light 1709 is irradiated from the exposure light source 1708, and an electrostatic latent image is formed on the surface of the photoreceptor 1707. This exposure light source 1708 has an organic light-emitting element according to this embodiment. The developing unit 1711 contains toner or the like. The charging unit 1710 charges the photoreceptor 1707. The transfer unit 1712 transfers the developed image to a recording medium 1714. The transport roller 1713 transports the recording medium 1714. The recording medium 1714 is, for example, paper. The fuser 1715 fixes the image formed on the recording medium 1714.

[0296] Figures 7B and 7C are diagrams showing the exposure light source 1708, schematic diagrams showing how multiple light-emitting units 1726 are arranged on a long substrate. The arrow 1727 indicates the direction of the column in which the organic light-emitting elements are arranged. This column direction is the same as the direction of the axis in which the photoreceptor 1707 rotates. This direction can also be called the long axis direction of the photoreceptor 1707. Figure 7B shows a configuration in which the light-emitting units 1726 are arranged along the long axis direction of the photoreceptor 1707. Figure 7C is a different configuration from Figure 7B, in which the light-emitting units 1726 are arranged alternately in the column direction in the first and second columns, respectively. The first and second columns are arranged at different positions in the row direction. In the first column, multiple light-emitting units 1726 are arranged with intervals between them. In the second column, light-emitting units 1726 are located at positions corresponding to the intervals between the light-emitting units 36 in the first column. That is, multiple light-emitting units 1726 are also arranged with intervals between them in the row direction. The arrangement in Figure 7C can also be described as a grid pattern, a houndstooth pattern, or a checkerboard pattern.

[0297] As described above, by using the device employing the organic light-emitting element according to this embodiment, stable display with good image quality is possible even during long-term display.

[0298] [Included Configurations] The disclosure of this embodiment includes the following configurations.

[0299] (Configuration 1-1) An organic light-emitting element comprising, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, and the first and second organic layers each independently comprise a compound represented by the general formula (1a) or (1b) and a fluorescent light-emitting material.

[0300] (Configuration 1-2) The organic light-emitting element according to Configuration 1-1, characterized in that when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe > 1, the thickness of the first organic layer or the second organic layer on the electron injection side is greater than the thickness of the second organic layer or the first organic layer on the hole injection side, and when μh / μe < 1, the thickness of the first organic layer or the second organic layer on the hole injection side is greater than the thickness of the second organic layer or the first organic layer on the electron injection side.

[0301] (Configuration 1-3) The organic light-emitting element according to any one of Configurations 1-1 or 1-2, characterized in that at least one of the first organic layer and the second organic layer contains an organic compound that has a lower singlet excitation energy and a lower triplet excitation energy higher than the compound represented by the general formula (1a) or (1b) and the fluorescent light-emitting material.

[0302] (Configuration 2-1) An organic light-emitting element comprising, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer comprises an organic compound represented by the general formula (5) and a fluorescent light-emitting material, and the first and second organic layers each independently comprise a compound represented by the general formula (1a) or (1b) and a fluorescent light-emitting material.

[0303] (Configuration 2-2) The organic light-emitting element according to Configuration 2-1, characterized in that when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe > 1, the thickness of the first organic layer or the second organic layer on the electron injection side is greater than the thickness of the second organic layer or the first organic layer on the hole injection side, and when μh / μe < 1, the thickness of the first organic layer or the second organic layer on the hole injection side is greater than the thickness of the second organic layer or the first organic layer on the electron injection side.

[0304] (Configuration 2-3) The organic light-emitting element according to either Configuration 2-1 or 2-2, characterized in that at least one of the first organic layer and the second organic layer contains an organic compound that has a lower singlet excitation energy and a lower triplet excitation energy higher than the compound represented by the general formula (1a) or (1b) and the fluorescent light-emitting material.

[0305] (Configuration 3-1) An organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, the first organic layer comprises a compound represented by the general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first organic layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe < 1, and the first organic layer is provided between the light-emitting layer and the second electrode when μh / μe > 1.

[0306] (Configuration 3-2) The organic light-emitting element according to Configuration 3-1, characterized in that the first organic layer contains a compound represented by the general formula (1a) or (1b) and an organic compound whose lowest excited singlet energy and lowest excited triplet energy are higher than those of the fluorescent light-emitting material.

[0307] (Configuration 4-1) An organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises an organic compound represented by the general formula (5) and a fluorescent light-emitting material, the first organic layer comprises a compound represented by the general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first organic layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe < 1, and the first organic layer is provided between the light-emitting layer and the second electrode when μh / μe > 1.

[0308] (Configuration 4-2) The organic light-emitting element according to Configuration 4-1, characterized in that the first organic layer contains a compound represented by the general formula (1a) or (1b) and an organic compound whose lowest excitation singlet energy and lowest excitation triplet energy are higher than those of the fluorescent light-emitting material.

[0309] (Configuration 5) An organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, or 3-2, characterized in that the lowest excited triplet energy of the compound represented by the general formula (1a) and the compound represented by the general formula (1b) is lower than the lowest excited triplet energy of the first organic compound.

[0310] (Configuration 6) The organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, or 5, wherein the light-emitting layer contains a third organic compound different from the first organic compound and the second organic compound, and the lowest singlet excitation energy of the third organic compound is higher than the lowest singlet excitation energies of the first organic compound and the second organic compound.

[0311] (Configuration 7) The organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5, or 6, wherein the light-emitting layer contains a third organic compound different from the first organic compound and the second organic compound, and the lowest excited triplet energy of the third organic compound is higher than the lowest excited triplet energies of the first organic compound and the second organic compound.

[0312] (Configuration 8) An organic light-emitting element according to any one of Configurations 2-1 to 2-3, 4-1, or 4-2, characterized in that the lowest excited triplet energy of the compound represented by general formula (1a) and the compound represented by general formula (1b) is lower than the lowest excited triplet energy of the organic compound represented by general formula (5).

[0313] (Configuration 9-1) The organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5 to 7, characterized in that the compound represented by the general formula (1a) or (1b) has the function of upconverting the excited triplet energy to the excited singlet energy.

[0314] (Configuration 9-2) The organic light-emitting element according to any one of Configurations 2-1 to 2-3, 4-1, 4-2, or 8, characterized in that the compound represented by the general formula (1a) or (1b) has the function of upconverting the excited triplet energy to the excited singlet energy.

[0315] (Configuration 10) The organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5 to 7, or 9-1, characterized in that the first organic compound is a compound represented by the general formula (2).

[0316] (Configuration 11) The organic light-emitting element according to Configuration 10, characterized in that the first organic compound is a compound represented by the general formula (2a).

[0317] (Configuration 12) The organic light-emitting element according to Configuration 10, characterized in that the first organic compound is a compound represented by the general formula (2a-1) or (2b-2).

[0318] (Configuration 13) The organic light-emitting element according to Configuration 10, characterized in that the first organic compound is a compound represented by the general formula (2b-1) or (2b-2).

[0319] (Configuration 14) An organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5 to 7, 9-1, 10 to 13, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the general formula (3).

[0320] (Configuration 15) An organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5 to 7, 9-1, 10 to 13, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the general formula (3a-1) or (3a-2).

[0321] (Configuration 16) The organic light-emitting element according to Configuration 14 or 15, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the general formula (3a-3).

[0322] (Configuration 17) An organic light-emitting element according to any one of Configurations 1-1 to 1-3, 3-1, 3-2, 5 to 7, 9-1, 10 to 13, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the general formula (4-1) or (4-2).

[0323] (Configuration 18) An organic light-emitting element according to any one of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 17, characterized in that the film thickness of the light-emitting layer is 50 nm or less.

[0324] (Configuration 19) A display device having a plurality of pixels, wherein at least one of the plurality of pixels is an organic light-emitting element as described in any of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 18, and a transistor connected to the organic light-emitting element.

[0325] (Configuration 20) A photoelectric conversion device comprising an optical section having a plurality of lenses, an image sensor that receives light that has passed through the optical section, and a display section that displays an image captured by the image sensor, wherein the display section has an organic light-emitting element as described in any of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 18.

[0326] (Configuration 21) An electronic device characterized by comprising: a display unit having an organic light-emitting element as described in any of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 18; a housing on which the display unit is provided; and a communication unit provided in the housing for communicating with the outside.

[0327] (Configuration 22) A lighting device characterized by comprising a light source having an organic light-emitting element as described in any of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 18, and a light-diffusing part or optical film that transmits the light emitted by the light source.

[0328] (Configuration 23) A mobile body characterized by having a lamp having an organic light-emitting element as described in any of Configurations 1-1 to 1-3, 2-1 to 2-3, 3-1, 3-2, 4-1, 4-2, 5 to 8, 9-1, 9-2, 10 to 18, and a body on which the lamp is provided.

[0329] Examples are described below, but this disclosure is not limited to these configurations. The compounds used in these examples are as follows.

[0330]

[0331] (Example 1) A so-called bottom-emission type organic light-emitting device, which extracts light from the indium tin oxide (ITO) electrode side placed on a glass substrate, was fabricated and evaluated as follows. The compounds used in the device are shown below.

[0332] A first electrode made of ITO with a thickness of 50 nm is formed on a glass substrate, and each thin film is deposited by vacuum deposition to a thickness of 1 × 10 －５The films were sequentially deposited under Pa vacuum. First, compound HI was deposited on the above ITO as a hole injection layer to a thickness of 10 nm. Next, compound HT was deposited as a hole transport layer to a thickness of 35 nm. Subsequently, compound 1-1 and compound 1-2 were simultaneously deposited from different deposition sources to form a first organic film with a thickness of 10 nm. The mass ratio of the two compounds at this time was compound 1-1:compound 1-2 = 1:2. Next, compound HO, compound TA, and compound EM were simultaneously deposited from different deposition sources to form a film with a thickness of 30 nm as an emissive layer. The mass ratio of each compound in this emissive layer was HO:TA:EM = 79:20:1. Subsequently, similar to the first organic layer, a co-deposited film of compound 1-1 and compound 1-2 was deposited to a thickness of 10 nm. Here again, the mass ratio of the two compounds was compound 1-1:compound 1-2 = 99:1. Subsequently, compound ET was deposited as an electron transport layer to a thickness of 30 nm. Furthermore, compound EI was deposited as an electron injection layer to a thickness of 1 nm. Finally, an organic light-emitting device was fabricated by depositing a 100 nm layer of aluminum (Al) as a second electrode.

[0333] (Comparative Example 1) An organic light-emitting element was fabricated in the same manner as in Example 1, except that compound EB was deposited as an electron blocking layer with a thickness of 10 nm instead of the first organic layer, and compound HB was deposited as a hole blocking layer with a thickness of 10 nm instead of the second organic layer.

[0334] (Comparative Example 2) An organic light-emitting element was fabricated in the same manner as in Example 1, except that compound EB was deposited as an electron blocking layer with a thickness of 10 nm instead of the first organic layer.

[0335] (Comparative Example 3) An organic light-emitting element was fabricated in the same manner as in Example 1, except that a compound HB was deposited as a hole-blocking layer with a thickness of 10 nm instead of the second organic layer.

[0336] Table 1 shows the configuration of each organic light-emitting device in Example 1 and Comparative Examples 1 to 3, and Table 2 shows the minimum singlet and triplet excitation energies of the main materials.

[0337]

[0338]

[0339] <Evaluation of Organic Light-Emitting Devices> Voltage was applied to each organic light-emitting device in Example 1 and Comparative Examples 1 to 3 to illuminate them, and the electroluminescent (EL) emission characteristics of each device were measured. The initial characteristics of the devices were measured as the EL spectrum, driving voltage [V], and luminous efficiency (external quantum efficiency: EQE). A Topcon spectroradiometer "SR-5A" was used to measure the EL spectrum. The lifetime characteristics of the devices were measured as 1 mA / cm² at the light-emitting pixel. ２ A constant current was applied, and the time (LT90) until the brightness reached 90% of the initial brightness was measured. The evaluation results for each element are shown in Table 3.

[0340] Note that the maximum emission wavelength λ is found here. ｍａｘ [nm], emission width at half maximum FWHM [nm], and emission chromaticity CIE (x, y) are all calculated with a current load of 10 mA / cm². ２ This is time measurement data.

[0341]

[0342] In Example 1, both the first organic layer and the second organic layer, consisting of compound 1-1 and compound 1-2, were positioned in contact with the light-emitting layer, resulting in a very long operating life.

[0343] Comparative Example 1 was a device in which compound EB was used as the electron blocking layer instead of the first organic layer, and compound HB was deposited as the hole blocking layer instead of the second organic layer. Although it showed a high luminous efficiency EQE, its operating life was extremely short.

[0344] Comparative Example 2 was a device in which compound EB was deposited as an electron blocking layer instead of the first organic layer. Although the second organic layer was used, the initial characteristics of light emission and the operating life were almost the same as those of Comparative Example 1.

[0345] Comparative Example 3 is an element in which compound HB is deposited as a hole-blocking layer instead of the second organic layer, and the first organic layer is positioned in contact with the light-emitting layer. Although Comparative Example 3 shows a decrease in luminous efficiency, the operating life is significantly improved.

[0346] From the above, it has been found that the organic light-emitting element according to this embodiment can exhibit an excellent operating life.

[0347] The present invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are attached to make the scope of the invention public.

[0348] This application claims priority based on Japanese Patent Application No. 2025-066836, filed on April 15, 2025, and all of its contents are incorporated herein by reference.

[0349] 14, 32 Organic compound layer 18, 36 Organic light-emitting element 1000, 1300, 1310 Display device 1100 Imaging device 1104, 1203, 1313 Housing 1200 Electronic equipment 1201, 1302, 1311, 1312 Display unit 1707 Photoreceptor 1708 Exposure light source

Claims

1. An organic light-emitting element comprising, in this order, a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, and the first and second organic layers each independently comprise a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material. [In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９ Each of the following groups is independently selected from the group consisting of hydrogen atoms, deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Ra and Rb each represent substituents on the carbon atom of the benzene ring and are independently selected from the group consisting of deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Multiple Ra and Rb groups may be the same or different, and adjacent substituents between Ra groups or between Rb groups may form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. n and m are integers between 1 and 5.

2. An organic light-emitting device having a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, a second organic layer in contact with the light-emitting layer, and a second electrode in this order, wherein the light-emitting layer contains an organic compound represented by the following general formula (5) and a fluorescent light-emitting material, and the first and second organic layers each independently contain a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material. [In general formula (5), １１ to R １８ are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and adjacent substituents may be bonded to each other to form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. Cy Ａ is a ring structure having 6 to 13 carbon atoms, or a heterocyclic structure having 5 to 12 carbon atoms including a heteroatom. n is an integer of 1 to 5. R ａ is Cy Ａ represents a substituent for the atoms forming the ring, and is each independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group, and a plurality of R ａ may be the same or different. n' is an integer of 1 to 9. R １１ to R １８ , and R ａ at least one of them has a structure of any one of the following general formulas (5a) to (5d). In general formulas (5a) to (5d), X １ to X ３ , Y １ to Y ４ Each of these is independently either a carbon atom or a nitrogen atom. １ R is one of the following atoms: nitrogen, oxygen, sulfur, selenium, or tellurium. ２１ ~R ２５ , R ３１ ~R ３６ , R ４１ and R ４２ , R ５１ ~R ５３ R represents substituents on the atoms forming each ring structure, and is independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, carbon atoms or heteroatoms may be included. ４１ and R ４２ , R ５１ ~R ５３ If there are multiple instances, they may be the same or different. m and m' are integers from 0 to 4, and l, l', and l'' are integers from 0 to 5. １ If R is a nitrogen atom, ４３ Z is selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. １ If R is not a nitrogen atom, ４３ * is a hydrogen atom. * represents R in general formula (5). １１ ~R １８ and R ａ The bond position in is represented, and the general formulas (5a) to (5d) are determined by the bond position of *. Ａ It may be directly bonded to the ring. [In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９ Each of the following groups is independently selected from the group consisting of hydrogen atoms, deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Ra and Rb each represent substituents on the carbon atom of the benzene ring and are independently selected from the group consisting of deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Multiple Ra and Rb groups may be the same or different, and adjacent substituents between Ra groups or between Rb groups may form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. n and m are integers between 1 and 5.

3. An organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises a first organic compound and a second organic compound, the difference between the lowest excited singlet energy and the lowest excited triplet energy of the first organic compound is 0.25 eV or less, the second organic compound is a fluorescent light-emitting material, the first organic layer comprises a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first organic layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe < 1, and the first organic layer is provided between the light-emitting layer and the second electrode when μh / μe > 1. [In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９ Each of the following groups is independently selected from the group consisting of hydrogen atoms, deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Ra and Rb each represent substituents on the carbon atom of the benzene ring and are independently selected from the group consisting of deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Multiple Ra and Rb groups may be the same or different, and adjacent substituents between Ra groups or between Rb groups may form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. n and m are integers between 1 and 5.

4. An organic light-emitting element comprising a first electrode, a first organic layer, a light-emitting layer in contact with the first organic layer, and a second electrode, wherein the light-emitting layer comprises an organic compound represented by the following general formula (5) and a fluorescent light-emitting material, the first organic layer comprises a compound represented by the following general formula (1a) or (1b) and a fluorescent light-emitting material, the first electrode is an anode, and the first organic layer is provided between the first electrode and the light-emitting layer when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe < 1, and the first organic layer is provided between the light-emitting layer and the second electrode when μh / μe > 1. [In general formula (5), R １１ ~R １８ Each of these atoms may be independently selected from the group consisting of hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, carbon atoms or heteroatoms may be included. Cy Ａ This is a ring structure with 6 to 13 carbon atoms, or a heterocyclic structure with 5 to 12 carbon atoms containing a heteroatom. n is an integer from 1 to 5. ａ Cy Ａ Representing substituents on ring-forming atoms, each independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, with a plurality of R ａ n' may be the same or different. n' is an integer from 1 to 9. １１ ~R １８ , and R ａ At least one of them has the structure of one of the following general formulas (5a) to (5d). In general formulas (5a) to (5d), X １ ~X ３ , Y １ Y ４ Each of these is independently either a carbon atom or a nitrogen atom. １ R is one of the following atoms: nitrogen, oxygen, sulfur, selenium, or tellurium. ２１ ~R ２５ , R ３１ ~R ３６ , R ４１ and R ４２ , R ５１ ~R ５３ R represents substituents on the atoms forming each ring structure, and is independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, carbon atoms or heteroatoms may be included. ４１ and R ４２ , R ５１ ~R ５３ If there are multiple instances, they may be the same or different. m and m' are integers from 0 to 4, and l, l', and l'' are integers from 0 to 5. １ If R is a nitrogen atom, ４３ Z is selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. １ If R is not a nitrogen atom, ４３ * is a hydrogen atom. * represents R in general formula (5). １１ ~R １８ and R ａ The bond position in is represented, and the general formulas (5a) to (5d) are determined by the bond position of *. Ａ It may be directly bonded to the ring. [In general formulas (1a) and (1b), R １１ ~R １８ , R ２０ ~R ２９ Each of the following groups is independently selected from the group consisting of hydrogen atoms, deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Ra and Rb each represent substituents on the carbon atom of the benzene ring and are independently selected from the group consisting of deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups. Multiple Ra and Rb groups may be the same or different, and adjacent substituents between Ra groups or between Rb groups may form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. n and m are integers between 1 and 5.

5. The organic light-emitting element according to claim 1 or 3, characterized in that the lowest excited triplet energy of the compound represented by general formula (1a) and the compound represented by general formula (1b) is lower than the lowest excited triplet energy of the first organic compound.

6. The organic light-emitting element according to claim 1 or 3, wherein the light-emitting layer contains a third organic compound different from the first organic compound and the second organic compound, and the lowest singlet excitation energy of the third organic compound is higher than the lowest singlet excitation energies of the first organic compound and the second organic compound.

7. The organic light-emitting element according to claim 1 or 3, wherein the light-emitting layer comprises a third organic compound different from the first organic compound and the second organic compound, and the lowest excited triplet energy of the third organic compound is higher than the lowest excited triplet energies of the first organic compound and the second organic compound.

8. The organic light-emitting element according to claim 2 or 4, characterized in that the lowest excited triplet energy of the compound represented by general formula (1a) and the compound represented by general formula (1b) is lower than the lowest excited triplet energy of the organic compound represented by general formula (5).

9. The organic light-emitting element according to any one of claims 1 to 4, characterized in that the compound represented by the general formula (1a) or (1b) has the function of upconverting the excited triplet energy to the excited singlet energy.

10. The organic light-emitting element according to claim 1 or 3, characterized in that the first organic compound is a compound represented by the following general formula (2). [In general formula (2), R １１ ~R １８ Each substituent is independently selected from the group consisting of hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, cyano groups, and silyl groups, and adjacent substituents may be bonded to each other to form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. n is an integer from 1 to 5, and m is an integer from 1 to 3. EWG represents an electron-withdrawing substituent, and multiple EWGs may be the same or different. R ２０ R represents a substituent, selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R ２０ [These two values ​​may be the same or different. l is an integer between 0 and 4.] 11. The organic light-emitting device according to claim 1 or 3, wherein at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the following general formula (3). [In general formula (3), Cy １ to Cy ３ each independently represent a ring structure having 5 to 13 carbon atoms, or a heterocyclic structure having 4 to 12 carbon atoms including a hetero atom. R １１ , R １２ , R １４ each represent a substituent on a carbon atom or a hetero atom of Cy １ to Cy ３ , and are each independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a cyano group, and a silyl group, and a plurality of R １１ , R １２ , R １４ may be the same or different. l and m are each an integer of 0 to 8, and n is an integer of 0 to 7. X is a boron atom or a nitrogen atom, and Y and Z are an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, BR, or NR. Here, R is each independently selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, and a substituted or unsubstituted silyl group. At least one of X, Y, and Z is a boron atom or BR. R １１ and R １２ , R １１ and R, R １２ and R, R １４ and R may be bonded to each other to form a ring. When forming a ring, the ring may contain a carbon atom or a hetero atom.] 12. The organic light-emitting element according to claim 1 or 3, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the following general formula (3a-1) or (3a-2). [In general formulas (3a-1) and (3a-2), Cy １ ~Cy ５ These are, independently, ring structures with 5 to 13 carbon atoms, or heterocyclic structures with 4 to 12 carbon atoms containing heteroatoms. １１ ~R １５ These are Cy １ ~Cy ５ R represents a substituent on a carbon atom or heteroatom, independently selected from the group consisting of deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, it may contain carbon atoms or heteroatoms. Multiple R １１ ~R １５ These may be the same or different. In general formula (3a-1), l, l', m and m' are from 0 to 8, and n is an integer from 0 to 2. In general formula (3a-2), l and l' are from 0 to 8, and m, m' and n are integers from 0 to 6. R in general formula (3a-1) １１ and R １２ , R １２ and R １３ , R １５ and R １１ These may be bonded to each other to form a ring, and R in general formula (3a-2) １１ and R １４ , R １２ and R １４ These atoms may bond to each other to form a ring. If a ring is formed, it may contain carbon atoms or heteroatoms. X is a nitrogen atom. １ and X ２ , Y １ and Y ２ The atoms are an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, NR, and SiRR''. Here, R and R'' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups.

13. The organic light-emitting element according to claim 1 or 3, characterized in that at least one of the second organic compound and the fluorescent light-emitting material is a compound represented by the following general formula (4-1) or (4-2). [In general formulas (4-1) and (4-2), Cy ４ This is a ring structure with 5 to 13 carbon atoms or a heterocyclic structure with 4 to 12 carbon atoms containing a heteroatom. １１ ~R １７ , R ２１ ~R ２７ R and Y' are independently selected from the group consisting of hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, substituted or unsubstituted silyl groups, and cyano groups, and adjacent substituents may bond to each other to form a ring. When a ring is formed, carbon atoms or heteroatoms may be included. X' and Y' are oxygen atoms, sulfur atoms, selenium atoms, tellurium atoms, NR, SiRR', or CRR'. Here, R and R' are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted amino groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryloxy groups, and substituted or unsubstituted silyl groups. ３１ is Cy ４ A substituent on R is independently selected from the group consisting of a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. ３１ [These two values ​​may be the same or different. n is an integer between 0 and 6.] 14. The organic light-emitting element according to claim 1 or 2, characterized in that when the relationship between the hole mobility μh and the electron mobility μe of the light-emitting layer is μh / μe > 1, the film thickness of the first organic layer or the second organic layer on the electron injection side is thicker than the film thickness of the second organic layer or the first organic layer on the hole injection side, and when μh / μe < 1, the film thickness of the first organic layer or the second organic layer on the hole injection side is thicker than the film thickness of the second organic layer or the first organic layer on the electron injection side.

15. The organic light-emitting element according to claim 1 or 2, characterized in that at least one of the first organic layer and the second organic layer contains an organic compound that has a lower minimum singlet excitation energy and a lower minimum triplet excitation energy than the compound represented by the general formula (1a) or (1b) and the fluorescent light-emitting material.

16. The organic light-emitting element according to claim 3 or 4, characterized in that the first organic layer includes an organic compound that has a lower singlet excitation energy and a lower triplet excitation energy higher than the compound represented by the general formula (1a) or (1b) and the fluorescent light-emitting material.

17. The organic light-emitting element according to any one of claims 1 to 4, characterized in that the film thickness of the light-emitting layer is 50 nm or less.

18. A display device having a plurality of pixels, wherein at least one of the plurality of pixels comprises an organic light-emitting element according to any one of claims 1 to 4 and a transistor connected to the organic light-emitting element.

19. A photoelectric conversion device comprising an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image captured by the image sensor, wherein the display unit has an organic light-emitting element as described in any one of claims 1 to 4.

20. An electronic device comprising: a display unit having an organic light-emitting element as described in any one of claims 1 to 4; a housing on which the display unit is provided; and a communication unit provided in the housing for communicating with the outside.

21. A lighting device comprising a light source having an organic light-emitting element as described in any one of claims 1 to 4, and a light-diffusing portion or optical film that transmits light emitted by the light source.

22. A mobile body characterized by comprising a lamp having an organic light-emitting element as described in any one of claims 1 to 4, and a body on which the lamp is provided.

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