Compound, light-emitting element material and light-emitting element obtained using same, photoelectric conversion element material, color conversion composition, color conversion sheet, light source unit, display device, and lighting device

Abstract

The purpose of the present invention is to provide a compound which exhibits high luminous efficiency and excellent durability and has green light emission characteristics. The present invention is a compound which has a structure represented by general formula (1). In general formula (1), ring A1 and ring B1 are each a substituted or unsubstituted aromatic hydrocarbon ring having 6-30 ring-forming carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5-30 ring-forming atoms. Ring C1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11-20 ring-forming atoms. Ring D1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7-20 ring-forming atoms. X is O, N-RA or S, and RA is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group or a heteroaryl group. These groups may have substituent groups. In addition, RA may bond to ring A1 or ring B1 via a linking group to form a ring. In this case, the linking group is a single bond, -O-, -S-, >CRA1RA2 or >SiA3RA4. RA1 to RA4 are each independently hydrogen, a halogen, an alkyl group, a cycloalkyl group, an aryl group or a heteroaryl group, and these groups may have substituent groups. In addition, RA1 and RA2 or RA3 and RA4 may be bonded via a linking group. L is a single bond, O, S, >CRA5RA6 or >SiRA7RA8. RA5 to RA8 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group and a heteroaryl group, and these groups may have substituent groups. In addition, RA5 and RA6 may be bonded via a linking group, and RA7 and RA8 may be bonded via a linking group.

Description

Compound, light-emitting element material and light-emitting element using the same, photoelectric conversion element material, color conversion composition, color conversion sheet, light source unit, display device, and lighting device

[0001] The present invention relates to a novel compound, and to a light-emitting element material, a light-emitting element, a photoelectric conversion element material, a color-converting composition, a color-converting sheet, a light source unit, a display device, and a lighting device, all of which use the compound.

[0002] Organic thin-film light-emitting devices emit light when electrons injected from a cathode and holes injected from an anode recombine in the light-emitting layer sandwiched between the two electrodes. These devices have the following characteristics: they can be made thin, their driving voltage is low, their brightness is high, and they are capable of emitting multicolor light.

[0003] To further widen the color gamut of display devices and lighting devices using organic light-emitting elements, active development is being conducted on materials with narrow half-widths of emission peaks. As such technology, for example, polycyclic aromatic compounds in which multiple aromatic rings are linked by boron atoms, nitrogen atoms, etc. (see, for example, Patent Documents 1 to 4) have been proposed.

[0004] Chinese Patent Application Publication No. 107417715 International Publication No. 2015 / 102118 International Publication No. 2020 / 106032 International Publication No. 2020 / 217229

[0005] The polycyclic aromatic compounds described in Patent Documents 1 to 4 are blue-emitting materials, and their emission wavelengths are insufficient for use as green-emitting materials. Furthermore, when used as light-emitting devices, they have problems with light-emitting device efficiency and durability. Therefore, an object of the present invention is to provide a compound having green-emitting properties with high luminous efficiency and excellent durability.

[0006] The present invention is a compound having a structure represented by the following general formula (1):

[0007]

[0008] In the above general formula (1), ring A １ and ring B １ is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5 to 30 ring atoms.

[0009] Ring C １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11 to 20 ring atoms.

[0010] Ring D １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7 to 20 ring atoms.

[0011] X is O, N-R Ａ or S, and R Ａ is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group, or a heteroaryl group. These groups may further have a substituent. Ａ is further connected to ring A via a linking group. １ or ring B １ In this case, the linking group may be a single bond, —O—, —S—, >CR Ａ１ R Ａ２ or >SiR Ａ３ R Ａ４ It is. Ａ１ ~R Ａ４ are each independently hydrogen, halogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. Ａ１ and R Ａ２ or R Ａ３ and R Ａ４ may be further bonded via a linking group.

[0012] L is a single bond, O, S, >CR Ａ５ R Ａ６ or >SiR Ａ７ R Ａ８ It is. Ａ５ ~R Ａ８ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these groups may further have a substituent. Ａ５ and R Ａ６ and R Ａ７ and R Ａ８ may be further bonded via a linking group.

[0013] The compound of the present invention has high luminous efficiency, excellent durability, and green luminescence characteristics. The compound of the present invention can provide a light-emitting element having high luminous efficiency, excellent durability, and green luminescence characteristics.

[0014] The present invention will be described in detail below, but the present invention is not limited to the embodiments and specific examples described below.

[0015] <Compound Having a Structure Represented by General Formula (1)> The compound of the present invention has a structure represented by general formula (1) described below.

[0016] The polycyclic aromatic compounds described in Patent Documents 1 to 4 have a strong and highly planar skeleton as blue light-emitting materials, and therefore exhibit high fluorescence quantum yields. In addition, the half-width of the peak at the emission wavelength is small, which allows for improved color purity.

[0017] As a means for making such polycyclic aromatic compounds emit green light, there is a method of extending the conjugation by directly bonding an aromatic hydrocarbon ring or an aromatic heterocycle to the polycyclic aromatic compound, thereby extending the wavelength of the emitted light. However, simply bonding an aromatic hydrocarbon ring or an aromatic heterocycle to the polycyclic aromatic compound does not sufficiently extend the conjugation length, making it difficult to realize green light emission. In the present invention, as shown in general formula (1), ring C １ and Ring D １ By condensing the two polycyclic aromatic hydrocarbons, the conjugation length is extended to increase the wavelength, thereby obtaining green light emission. Furthermore, by condensing the two polycyclic aromatic hydrocarbons, the vibration of the compound having the structure represented by general formula (1) is restricted, deactivation in the excited state is suppressed, and the light-emitting efficiency and durability of the light-emitting element can be improved.

[0018]

[0019] In the above general formula (1), ring A １ and ring B １ is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5 to 30 ring atoms.

[0020] Ring C１ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11 to 20 ring atoms.

[0021] Ring D １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7 to 20 ring atoms.

[0022] X is O, N-R Ａ or S, and R Ａ is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group, or a heteroaryl group. These groups may further have a substituent. Ａ is further connected to ring A via a linking group. １ or ring B １ In this case, the linking group may be a single bond, —O—, —S—, >CR Ａ１ R Ａ２ or >SiR Ａ３ R Ａ４ It is. Ａ１ ~R Ａ４ are each independently hydrogen, halogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. Ａ１ and R Ａ２ or R Ａ３ and R Ａ４ may be further bonded via a linking group.

[0023] L is a single bond, O, S, >CR Ａ５ R Ａ６ or >SiR Ａ７ R Ａ８ It is. Ａ５ ~R Ａ８ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these groups may further have a substituent. Ａ５ and R Ａ６ and R Ａ７ and R Ａ８ may be further bonded via a linking group.

[0024] From the viewpoint of further improving the color purity, light-emitting efficiency, and durability of the light-emitting device, L is preferably a single bond.

[0025] From the viewpoint of further improving the color purity of green light emission, ring C １ and Ring D １ is preferably a substituted or unsubstituted polycyclic aromatic hydrocarbon containing a ring structure represented by any one of the following chemical formulas (2-1) to (2-8).

[0026]

[0027] From the viewpoint of ease of synthesis, ring C １ and Ring D １ are preferably the same.

[0028] The compound having the structure represented by general formula (1) is more preferably a compound represented by the following general formula (3).

[0029]

[0030] In the above general formula (3), R １ ~R １９ are each independently hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, carboxyl, oxycarbonyl, carbamoyl, amino, nitro, or silyl. These groups may further have a substituent. Among these, hydrogen, alkyl, aryl, and heteroaryl groups are preferred.

[0031] Ring A １ and ring B １ are each independently a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5 to 30 ring atoms. １ is preferably a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 10 ring carbon atoms. １ is preferably a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 10 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5 to 10 ring atoms.

[0032] X １ is O, N-R ２０ or S, and R ２０ is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group, or a heteroaryl group. These groups may further have a substituent. ２０ is further connected to ring A via a linking group. １ or ring B １ In this case, the linking group may be a single bond, —O—, —S—, >CR ２１ R ２２ or >SiR ２３ R ２４ It is. ２１ ~R ２４ are each independently hydrogen, halogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. ２１ and R ２２ or R ２３ and R ２４ may be further bonded via a linking group.

[0033] From the viewpoint of further improving the color purity of green light emission, X １ is N-R ２０ is preferred, and R ２０ is preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted imino group.

[0034] X １ N-R ２０ and R ２０ is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, a compound having a structure represented by any one of the following general formulas (4-1) to (4-5) is more preferable, which can further improve the color purity, light-emitting efficiency, and durability of the light-emitting element.

[0035] X １ N-R ２０ and R ２０is a substituted or unsubstituted alkenyl group or a substituted or unsubstituted imino group, a compound having a structure represented by the following general formula (5-1) or (5-2) is more preferable, which can further improve the color purity, light-emitting element efficiency, and durability of the light-emitting element.

[0036]

[0037]

[0038]

[0039] In the above general formulae (4-1) to (4-5) and (5-1) to (5-2), R １ ~R １９ is R in general formula (3). １ ~R １９ is the same as

[0040] R in general formulas (4-1) to (4-5) １０１ ~R １０７ , R １１０ ~R １１６ , R １２０ ~R １２７ , R １３０ ~R １３１ , R １４０ ~R １４１ and R in general formulas (5-1) to (5-2) ２０１ ~R ２０７ , R ２１０ ~R ２１４ are each independently hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, carboxyl, oxycarbonyl, carbamoyl, amino, silyl, or a saturated or unsaturated ring formed between adjacent groups among these. These groups may further have a substituent. Among these, hydrogen, alkyl, aryl, and heteroaryl groups are preferred.

[0041] In the general formulae (4-1), (4-4) to (4-5), Ar １ ~Ar ３are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

[0042] In the general formulae (4-2) and (4-3), Y １ ~Y ２ are each independently a single bond, O, S, or CR １５０ R １５１ or SiR １５２ R １５３ In the general formulas (4-4) and (4-5), W １ ~W ２ are each independently NR １５４ , O or S. Where R １５０ ~R １５４ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. １５０ and R １５１ or R １５２ and R １５３ may be further bonded via a linking group. In this case, the linking group may be a single bond, —O—, —S—, >CR ２１ R ２２ or >SiR ２３ R ２４ Among these, Y １ and Y ２ is preferably a single bond from the viewpoint of further improving the color purity, light-emitting efficiency, and durability of the light-emitting device.

[0043] In the general formulas (5-1) and (5-2), W ３ ~W ４ are each independently N or C—R ２２０ It is. ２２０ is hydrogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. From the viewpoint of further improving the color purity, light-emitting efficiency, and durability of the light-emitting element, R ２２０ is preferably an aryl group.

[0044] The isotopes of hydrogen atoms present in the molecules of the compound of the present invention are not particularly limited. For example, １H, or part or all of ２ H (Deuterium D).

[0045] In the following description, "unsubstituted" in the context of "substituted or unsubstituted" means that a hydrogen atom or a deuterium atom is bonded.

[0046] Halogen refers to fluorine, chlorine, bromine or iodine.

[0047] A cyano group is a group having the structure -C≡N, where it is the carbon atom that is bonded to other groups.

[0048] The alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which may or may not have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but from the standpoint of availability and cost, it is preferably in the range of 1 to 20, more preferably 1 to 8. The number of carbon atoms referred to here includes the number of carbon atoms contained in a substituent bonded to the alkyl group, and the same applies to other substituents that specify the number of carbon atoms.

[0049] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group, such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group, which may or may not have a substituent. The number of ring carbon atoms is not particularly limited, but is preferably in the range of 3 to 20.

[0050] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, or a butadienyl group, which may or may not have a substituent. The number of carbon atoms in the alkenyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0051] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, which may or may not have a substituent. The number of ring carbon atoms is not particularly limited, but is preferably in the range of 3 to 20.

[0052] The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group, which may or may not have a substituent. The number of carbon atoms in the alkynyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0053] The alkoxy group refers to a functional group in which an aliphatic hydrocarbon group is bonded via an ether bond, such as a methoxy group, an ethoxy group, or a propoxy group, and may or may not have a substituent. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably in the range of 1 to 20.

[0054] An alkylthio group is an alkoxy group in which the oxygen atom of the ether bond is replaced with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. The number of carbon atoms in the alkylthio group is not particularly limited, but is preferably in the range of 1 to 20.

[0055] The aryl ether group refers to a group in which an aromatic hydrocarbon group is bonded via an ether bond, such as a phenoxy group, and may or may not have a substituent. The number of ring carbon atoms of the aryl ether group is not particularly limited, but is preferably in the range of 6 to 40.

[0056] An aryl thioether group is an aryl ether group in which the oxygen atom of the ether bond is replaced with a sulfur atom. This group may or may not have a substituent. The number of ring carbon atoms of the aryl thioether group is not particularly limited, but is preferably in the range of 6 to 40.

[0057] The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, an anthracenyl group, a benzophenanthryl group, a benzanthracenyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, or a helicenyl group. These groups may or may not have a substituent. Among these, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, a fluoranthenyl group, or a triphenylenyl group is preferred. The number of ring carbon atoms is not particularly limited, but is preferably 6 to 40, more preferably 6 to 30.

[0058] Furthermore, in a substituted phenyl group, when two adjacent carbon atoms in the phenyl group each have a substituent, the substituents may together form a ring structure. Depending on the structure, the resulting group may fall into one or more of the categories of a "substituted phenyl group," an "aryl group having a structure in which two or more rings are fused," and a "heteroaryl group having a structure in which two or more rings are fused."

[0059] The heteroaryl group refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, such as a pyridyl group, a furanyl group, a thiophenyl group, a quinolinyl group, an isoquinolinyl group, a pyrazinyl group, a pyrimidyl group, a pyridazinyl group, a triazinyl group, a naphthyridinyl group, a cinnolinyl group, a phthalazinyl group, a quinoxalinyl group, a quinazolinyl group, a benzofuranyl group, a benzothiophenyl group, an indolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzocarbazolyl group, a carbolinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a dihydroindenocarbazolyl group, a benzoquinolinyl group, an acridinyl group, a dibenzoacridinyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group. Here, the naphthyridinyl group refers to any of a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, and a 2,7-naphthyridinyl group. The heteroaryl group may or may not have a substituent. The number of ring atoms is not particularly limited, but is preferably in the range of 3 to 40, more preferably 3 to 30.

[0060] The amino group is a substituted or unsubstituted amino group. The number of carbon atoms in the amino group is not particularly limited, but is preferably in the range of 2 to 50, more preferably 6 to 40, and particularly preferably 6 to 30.

[0061] The silyl group refers to a functional group to which a substituted or unsubstituted silicon atom is bonded, and examples thereof include alkylsilyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, and vinyldimethylsilyl, and arylsilyl groups such as phenyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, and trinaphthylsilyl. The number of carbon atoms in the silyl group is not particularly limited, but is preferably in the range of 1 to 30.

[0062] The carboxyl group, oxycarbonyl group, and carbamoyl group may or may not have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these substituents may be further substituted.

[0063] The imino group is, for example, a C═NH group such as imine or imide, or a C １ -NH-C ２ The number of carbon atoms in the imino group is not particularly limited, but is preferably in the range of 2 to 20.

[0064] Examples of aromatic hydrocarbon rings include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), a fused tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a fused tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, a fused pentacyclic perylene ring, a pentacene ring, and the like.

[0065] Examples of aromatic heterocycles include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a chiral ring, a cyclohexyl benzoyl ... Examples of such rings include a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, and a thianthrene ring.

[0066] In addition, in all of the above groups, the substituents when substituted include halogen, cyano group, alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, aryl thioether group, aryl group, heteroaryl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, nitro group, and silyl group, and further, specific substituents that are preferred in the description of each substituent are preferred. Furthermore, these substituents may be further substituted with the above-mentioned substituents.

[0067] Examples of compounds having a structure represented by general formula (1) are shown below, but the present invention is not limited to these.

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] The compound having the structure represented by general formula (1) can be produced by referring to the method described in, for example, "Advanced Materials," 2016, vol. 28, pp. 2777-2781.

[0103] The obtained compound having a structure represented by general formula (1) is preferably purified by organic synthesis techniques such as recrystallization or column chromatography, and then further purified by heating under reduced pressure, generally called sublimation purification, to remove low-boiling components and improve the purity.

[0104] The purity of the compound having the structure represented by general formula (1) is preferably 99% by weight or more from the viewpoint of stabilizing the characteristics of the light-emitting device.

[0105] In terms of the emission wavelength of the compound having the structure represented by general formula (1), from the viewpoint of further improving the color purity of green light emission, the peak wavelength is preferably 500 nm or more and 550 nm or less, and more preferably 510 nm or more and 540 nm or less. Here, the emission wavelength of the compound having the structure represented by general formula (1) is measured by a method in which toluene is used as a solvent at a concentration of 10 －５ It can be measured using a fluorescence spectrophotometer using a diluted solution of 100 mol / L.

[0106] <Light-emitting device material> In the present invention, the light-emitting device material refers to a material that includes a compound having a structure represented by general formula (1) and is used in any layer of a light-emitting device. Examples include materials that are used in the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and / or protective film (cap layer) of an electrode, which will be described later. Among these, materials that have high light-emitting device efficiency and color purity are preferably used in the light-emitting layer.

[0107] The light-emitting element material may contain other components in addition to the compound having the structure represented by general formula (1). Examples of the other components include those exemplified as materials for forming the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and / or protective film (cap layer) of the electrode, which will be described later.

[0108] <Light-emitting device> Next, an embodiment of the light-emitting device of the present invention will be described. The light-emitting device of the present invention has a cathode, an anode, and one or more organic layers disposed therebetween, and emits light by electrical energy. It is preferable that at least one of the organic layers contains a compound having a structure represented by the above-mentioned general formula (1), and that such organic layer is a light-emitting layer.

[0109] The light-emitting device of the present invention may be either a bottom-emission type or a top-emission type. In a top-emission type light-emitting device, the narrower the half-width, the higher the light-emitting efficiency due to the resonance effect of the microcavity. Therefore, it is possible to achieve both high levels of color purity and high light-emitting efficiency.

[0110] The layer configuration between the anode and the cathode in such a light-emitting element may be a configuration consisting of only a light-emitting layer, or may be a laminate configuration such as 1) light-emitting layer / electron transport layer, 2) hole transport layer / light-emitting layer, 3) hole transport layer / light-emitting layer / electron transport layer, 4) hole injection layer / hole transport layer / light-emitting layer / electron transport layer, 5) hole transport layer / light-emitting layer / electron transport layer / electron injection layer, 6) hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer, 7) hole injection layer / hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer, or 8) hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer.

[0111] Furthermore, a tandem type may be used in which a plurality of the above-mentioned laminated structures are laminated via an intermediate layer. Examples of the intermediate layer include an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, and an intermediate insulating layer, and known material structures can be used. A preferred example of a tandem type is a laminated structure such as 9) hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / charge generation layer / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer. The light-emitting layers may be the same or different from each other.

[0112] Each of the above layers may be a single layer or multiple layers, and may be doped. In addition to the above layers, a protective layer (cap layer) may be further provided, which can further improve the efficiency of the light-emitting device by optical interference.

[0113] Specific examples of the configuration of the light-emitting element are given below, but the configuration of the present invention is not limited to these.

[0114] (Substrate) It is preferable to form the light-emitting element on a substrate in order to maintain the mechanical strength of the light-emitting element, minimize thermal deformation, and provide barrier properties that prevent water vapor and oxygen from penetrating the light-emitting layer. The substrate is not particularly limited, but examples include glass plates, ceramic plates, resin films, thin resin films, and thin metal plates. Among these, glass substrates are preferably used because of their transparency and ease of processing. In particular, for bottom-emission light-emitting elements that extract light through the substrate, highly transparent glass substrates are preferred. Furthermore, flexible displays and foldable displays are becoming increasingly common, primarily in mobile devices such as smartphones, and for these applications, resin films and thin resin films obtained by curing varnish are preferably used. Heat-resistant films are used as resin films, and specific examples include polyimide films and polyethylene naphthalate films.

[0115] Furthermore, various wirings and circuits for driving the organic EL, and switching elements using TFTs may be provided on the surface of the substrate.

[0116] (Anode) The anode is preferably formed on the substrate. Various wirings, circuits, and switching elements may be interposed between the substrate and the anode. The material used for the anode is not particularly limited as long as it can efficiently inject holes into the organic layer. In the case of a bottom-emission light-emitting element, it is preferably a transparent or semi-transparent electrode, and in the case of a top-emission light-emitting element, it is preferably a reflective electrode.

[0117] Examples of materials for the transparent or translucent electrode include conductive metal oxides such as zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); metals such as gold, silver, aluminum, and chromium; and conductive polymers such as polythiophene, polypyrrole, and polyaniline. However, when using a metal, it is preferable to make the film thin so that light can be semi-transmitted. Among these, indium tin oxide (ITO) is more preferred from the viewpoints of transparency and stability.

[0118] The material of the reflective electrode is preferably one that does not absorb any light and has high reflectivity, and examples thereof include metals such as aluminum, silver, and platinum.

[0119] Two or more of these electrode materials may be used, or a plurality of materials may be laminated.

[0120] The thickness of the anode is not particularly limited, but is preferably from several nm to several hundred nm.

[0121] The method for forming the anode can be selected optimally depending on the material used, and examples thereof include sputtering, vapor deposition, and inkjet printing. For example, sputtering is preferably used when the anode is made of a metal oxide, and vapor deposition is preferably used when the anode is made of a metal. The thickness of the anode is not particularly limited, but is preferably several nanometers to several hundred nanometers.

[0122] The cathode is formed on the surface opposite to the anode with the organic layer sandwiched therebetween, and is preferably formed on the surface of the electron transport layer or the electron injection layer. The material used for the cathode is not particularly limited as long as it can efficiently inject electrons into the light emitting layer, but in the case of a bottom emission type light emitting element, it is preferably a reflective electrode, and in the case of a top emission type light emitting element, it is preferably a semi-transparent electrode.

[0123] Generally, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys or multilayer laminate films of these metals with low work function metals such as lithium, sodium, potassium, calcium, and magnesium, and conductive metal oxides such as zinc oxide, indium tin oxide (ITO), and indium zinc oxide (IZO) are preferred. Among these, aluminum, silver, and magnesium are preferred as the main component from the viewpoints of electrical resistance, ease of film formation, film stability, light-emitting element efficiency, and the like. Furthermore, a structure composed of magnesium and silver is preferred because it facilitates electron injection into the electron transport layer and electron injection layer, thereby enabling a reduction in driving voltage.

[0124] (Protective Layer) For cathode protection, it is preferable to laminate a protective layer (cap layer) on the cathode. The material constituting the protective layer is not particularly limited, but examples thereof include metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys using these metals, inorganic substances such as silica, titania, and silicon nitride, and organic polymer compounds such as polyvinyl alcohol, polyvinyl chloride, and hydrocarbon polymer compounds. However, in the case of a top-emission light-emitting element, it is preferable that the material used for the protective layer be selected from materials that are optically transparent in the visible light region.

[0125] (Hole injection layer) The hole injection layer is inserted between the anode and the hole transport layer to facilitate hole injection. The hole injection layer may be a single layer or a laminate of multiple layers. The presence of a hole injection layer between the hole transport layer and the anode not only enables lower voltage driving and improves durability, but also improves the carrier balance of the element, thereby improving the light-emitting element efficiency, which is preferable.

[0126] A preferred example of the hole injection material is an electron-donating hole injection material (donor material), which has a shallower HOMO level than the hole transport layer and is close to the work function of the anode, thereby reducing the energy barrier with the anode. Specific examples include aromatic amine-based materials such as benzidine derivatives, starburst arylamines such as 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine (m-MTDATA) and 4,4',4"-tris(1-naphthyl(phenyl)amino)triphenylamine (1-TNATA), etc., heterocyclic compounds such as carbazole derivatives, pyrazoline derivatives, stilbene-based compounds, hydrazone-based compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, and porphyrin derivatives, and polymer-based materials such as polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polythiophenes such as PEDOT / PSS, polyaniline, polyfluorene, polyvinylcarbazole, and polysilane. Two or more of these materials may be used. Furthermore, a plurality of materials may be laminated to form the hole injection layer.

[0127] Another preferred example of the hole injection material is an electron-accepting hole injection material (acceptor material). The hole injection layer may be composed of an acceptor material alone, or the donor material may be doped with the acceptor material. The acceptor material is a material that forms a charge-transfer complex with the adjacent hole transport layer when used alone, or with the donor material when used as a dopant. The use of such a material is more preferred because it contributes to improving the conductivity of the hole injection layer and reducing the driving voltage of the device, thereby improving the efficiency and durability of the light-emitting device. Examples of acceptor materials include metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, and ruthenium oxide, charge-transfer complexes such as tris(4-bromophenyl)aminium hexachloroantimonate (TBPAH), n-type organic semiconductor compounds such as 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN6), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and fluorinated copper phthalocyanine, and fullerenes. When the hole-injection layer contains an acceptor compound, the hole-injection layer may be a single layer, or may be configured by laminating multiple layers.

[0128] (Hole Transport Layer) The hole transport layer is a layer that transports holes injected from the anode to the light emitting layer. The hole transport layer may be a single layer or may be configured by laminating multiple layers.

[0129] The hole transport layer is formed by using one hole transport material alone or by laminating or mixing two or more hole transport materials. It is preferable that the hole transport material has high hole injection efficiency and efficiently transports the injected holes. To this end, the material must have an appropriate ionization potential, high hole mobility, excellent stability, and be less likely to generate impurities that act as traps.

[0130] Substances that satisfy these conditions are not particularly limited, but examples include heterocyclic compounds such as benzidine derivatives, aromatic amine materials called starburst arylamines, carbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, dibenzofuran derivatives, thiophene derivatives, benzothiophene derivatives, dibenzothiophene derivatives, fluorene derivatives, spirofluorene derivatives, oxadiazole derivatives, phthalocyanine derivatives, and porphyrin derivatives, and polymers such as polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polythiophenes, polyanilines, polyfluorenes, polyvinylcarbazoles, and polysilanes.

[0131] (Light-emitting layer) The light-emitting layer is a layer that emits light by excitation energy generated by the recombination of holes and electrons. The light-emitting layer may be composed of a single material, but from the viewpoint of color purity, it preferably contains a dopant material that emits light with a narrow half-width and a matrix material.

[0132] Compounds having a structure represented by general formula (1) are preferably used as dopant materials in the light-emitting layer because they have particularly excellent fluorescence quantum yield, an emission wavelength peak suitable for green emission, a narrow half-value width, and excellent color purity. From the viewpoint of further suppressing concentration quenching, the content of the dopant material in the light-emitting layer is preferably 5% by weight or less, more preferably 2% by weight or less. On the other hand, from the viewpoint of more efficient energy transfer, the content of the dopant material in the light-emitting layer is preferably 0.1% by weight or more, more preferably 0.5% by weight or more.

[0133] The matrix material is preferably an organic compound having high charge transport capability and a high glass transition temperature. Examples of the matrix material include, but are not limited to, compounds having fused aryl rings such as naphthacene, pyrene, anthracene, and fluoranthene, and derivatives thereof, aromatic amine derivatives such as N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, metal chelated oxinoid compounds such as tris(8-quinolinato)aluminum(III), bisstyryl derivatives such as distyrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, pyrrolopyrrole derivatives, thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, and polymers such as polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. Two or more of these may be used, or two or more matrix materials may be laminated together. Among these, carbazole derivatives, anthracene derivatives, and naphthacene derivatives are preferred.

[0134] The dopant material may contain a fluorescent material other than the compound having the structure represented by general formula (1). Specific examples include compounds having a fused aryl ring such as naphthacene, pyrene, anthracene, and fluoranthene, and derivatives thereof, compounds having a heteroaryl ring and derivatives thereof, distyrylbenzene derivatives, aminostyryl derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, coumarin derivatives, azole derivatives and metal complexes thereof, and aromatic amine derivatives. Two or more of these may be used.

[0135] The dopant material may contain a phosphorescent material. The phosphorescent material is preferably a metal complex compound containing at least one metal selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re). From the viewpoint of highly efficient luminescence, an iridium complex or a platinum complex is more preferable. The ligand preferably has a nitrogen-containing heteroaryl group such as a phenylpyridine skeleton, a phenylquinoline skeleton, or a carbene skeleton, but is not limited thereto.

[0136] However, from the viewpoint of further improving color purity, it is preferable that the dopant material is only a compound having a structure represented by general formula (1).

[0137] The light-emitting layer preferably further contains a compound exhibiting delayed fluorescence. A compound exhibiting delayed fluorescence is a material that has a small energy gap between the singlet excited state and the triplet excited state, undergoes a transition from the triplet excited state to the singlet excited state, and triplet excitons can be utilized as delayed fluorescence. When this delayed fluorescence is utilized in an organic light-emitting device, the light-emitting device efficiency can be further improved. Furthermore, when Förster-type energy transfer occurs from the singlet excited state of the compound exhibiting delayed fluorescence to the singlet excited state of the dopant material, fluorescence emission from the singlet excited state of the dopant material is observed. Here, when the dopant material is a fluorescent material with a sharp emission wavelength, a light-emitting device with improved light-emitting device efficiency and color purity can be obtained. Thus, when the light-emitting layer contains a compound exhibiting delayed fluorescence, the light-emitting device efficiency is further improved, contributing to lower power consumption of the display. The compound exhibiting delayed fluorescence may be a single material, or may be a combination of multiple materials, as in the case of forming an exciplex complex.

[0138] The compound exhibiting delayed fluorescence may be a single material or a plurality of materials, and known materials can be used.Specific examples include benzonitrile derivatives, triazine derivatives, disulfoxide derivatives, carbazole derivatives, indolocarbazole derivatives, dihydrophenazine derivatives, thiazole derivatives, and oxadiazole derivatives.Such compounds exhibiting delayed fluorescence are not particularly limited, but examples include the following.

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146] The light-emitting layer preferably contains a compound having a structure represented by the general formula (1) as a dopant material, and further contains a compound exhibiting delayed fluorescence, and more preferably contains a compound exhibiting delayed fluorescence and a matrix material. １ (1) The excited singlet energy of a compound exhibiting delayed fluorescence is S １ (2) The excited singlet energy of the matrix material is S １ When (3) is used, it is preferable to satisfy the relationship of Equation 1. １ (3) > S １ (2) > S １(1) (Formula 1) This allows the matrix material to have the function of confining the energy of the compound exhibiting delayed fluorescence and the dopant material within the light-emitting layer, enabling efficient light emission and further improving the light-emitting device efficiency. Matrix materials that satisfy the relationship of Formula 1 with the compound having a structure represented by general formula (1) or the compound exhibiting delayed fluorescence described above are not particularly limited, but examples include the following.

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] (Electron transport layer) The electron transport layer is a layer into which electrons are injected from the cathode and further transports the electrons. The electron transport material used in the electron transport layer is required to have a large electron affinity, a large electron mobility, excellent stability, and to be a substance that is unlikely to generate impurities that become traps. Furthermore, from the viewpoint of suppressing film quality deterioration due to crystallization, a compound with a molecular weight of 400 or more is preferred.

[0159] The electron transport layer in the present invention also includes a hole blocking layer that can efficiently block the movement of holes. The hole blocking layer and the electron transport layer may be formed of a single material or a laminate of multiple materials.

[0160] Examples of electron transport materials include polycyclic aromatic derivatives, styryl aromatic ring derivatives, quinone derivatives, phosphorus oxide derivatives, and various metal complexes such as quinolinol complexes of tris(8-quinolinolato)aluminum(III), benzoquinolinol complexes, hydroxyazole complexes, azomethine complexes, tropolone metal complexes, and flavonol metal complexes. From the viewpoint of reducing the driving voltage and further improving the efficiency of light-emitting devices, it is preferable to use a compound having a heteroaryl group containing electron-accepting nitrogen. Here, electron-accepting nitrogen refers to a nitrogen atom that forms a multiple bond with an adjacent atom. Heteroaryl groups containing electron-accepting nitrogen have a large electron affinity, which facilitates electron injection from the cathode and enables lower-voltage driving. Furthermore, the supply of electrons to the light-emitting layer increases, increasing the recombination probability and further improving the efficiency of light-emitting devices. Examples of compounds having a heteroaryl group structure containing electron-accepting nitrogen include pyridine derivatives, triazine derivatives, pyrazine derivatives, pyrimidine derivatives, quinoline derivatives, quinoxaline derivatives, quinazoline derivatives, naphthyridine derivatives, benzoquinoline derivatives, phenanthroline derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, triazole derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, phenanthroimidazole derivatives, oligopyridine derivatives such as bipyridine and terpyridine, etc. Two or more of these may be used.

[0161] Furthermore, it is more preferable that the electron transport material has a condensed polycyclic aromatic skeleton, since the glass transition temperature is improved, the electron mobility is large, and the driving voltage can be reduced. As such a condensed polycyclic aromatic skeleton, a quinolinol skeleton, a triazine skeleton, a fluoranthene skeleton, an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton is preferable.

[0162] The electron transport layer may contain a donor material. Here, the donor material is a compound that improves the electron injection barrier, thereby facilitating electron injection from the cathode or the electron injection layer into the electron transport layer, and further improving the electrical conductivity of the electron transport layer.

[0163] Preferred examples of donor materials include alkali metals such as Li, inorganic salts containing alkali metals such as LiF, complexes of alkali metals and organic substances such as lithium quinolinol, alkaline earth metals, inorganic salts containing alkaline earth metals, complexes of alkaline earth metals and organic substances, rare earth metals such as Eu and Yb, inorganic salts containing rare earth metals, and complexes of rare earth metals and organic substances. Two or more of these may be used. Among these, metallic lithium, rare earth metals, and lithium quinolinol (Liq) are preferred.

[0164] (Electron Injection Layer) In the present invention, an electron injection layer may be provided between the cathode and the electron transport layer. Generally, the electron injection layer is formed for the purpose of assisting the injection of electrons from the cathode to the electron transport layer, and is composed of a compound having a heteroaryl ring structure containing electron-accepting nitrogen or the above-mentioned donor material. Two or more of these may be contained. Among these, triazine derivatives, phenanthroline derivatives, and oligopyridine derivatives are preferred, phenanthroline derivatives and terpyridine derivatives are more preferred, and phenanthroline derivatives having a structure represented by the following general formula (4) are even more preferred. That is, the light-emitting element of the present invention preferably contains a phenanthroline derivative having a structure represented by general formula (4) in the electron injection layer.

[0165]

[0166] In the above general formula (6), Ar ４ is selected from the group consisting of p-valent aromatic hydrocarbon groups and p-valent aromatic heterocyclic groups, where p is a natural number from 1 to 3. ３０１ ~R ３０８ may be the same or different and are selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an aryl group, and a heteroaryl group. ４ In the above, the substitution positions of the p phenanthrolyl groups are arbitrary positions.

[0167] Examples of monovalent aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, anthracenyl, benzophenanthryl, benzanthracenyl, chrysenyl, pyrenyl, fluoranthenyl, triphenylenyl, benzofluoranthenyl, dibenzoanthracenyl, perylenyl, and helicenyl groups. Among these, from the viewpoints of ease of synthesis and sublimation, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluoranthenyl, and triphenylenyl groups, as well as groups obtained by removing at least some of the hydrogen atoms from these groups, are preferred. The aromatic hydrocarbon group may or may not have a substituent. The number of ring carbon atoms is not particularly limited, but is preferably 6 to 40, more preferably 6 to 30. In addition, when two adjacent carbon atoms each have a substituent, these substituents may together form a ring structure.

[0168] The aromatic heterocyclic group refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, and in the case of a monovalent group, for example, a pyridyl group, a furanyl group, a thiophenyl group, a quinolinyl group, an isoquinolinyl group, a pyrazinyl group, a pyrimidyl group, a pyridazinyl group, a triazinyl group, a naphthyridinyl group, a cinnolinyl group, a phthalazinyl group, a quinoxalinyl group, a quinazolinyl group, a benzofuranyl group, a benzothiophenyl group, an indolyl group, a dibenzofuranyl group, a Examples of aromatic heterocyclic groups include a phenyl group, a dibenzothiophenyl group, a carbazolyl group, a benzocarbazolyl group, a carbolinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a dihydroindenocarbazolyl group, a benzoquinolinyl group, an acridinyl group, a dibenzoacridinyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, and a phenanthrolinyl group. However, the naphthyridinyl group refers to a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, or a 2,7-naphthyridinyl group. The aromatic heterocyclic group may or may not have a substituent. The number of ring carbon atoms of the aromatic heterocyclic group is not particularly limited, but is preferably in the range of 2 or more and 40 or less, more preferably 2 or more and 30 or less.

[0169] The aromatic hydrocarbon group or aromatic heterocyclic group may further have a substituent other than the phenanthryl group.

[0170] From the viewpoint of sublimation property and thin film formability, p is preferably 2.

[0171] An example of a phenanthroline derivative having a structure represented by general formula (6) is shown below.

[0172]

[0173] Furthermore, inorganic insulating or semiconducting materials can also be used for the electron injection layer, which is preferable because the use of these materials can prevent short circuits in the light emitting element and improve the electron injection properties.

[0174] Such an insulator is preferably a metal compound such as an alkali metal chalcogenide, an alkaline earth metal chalcogenide, an alkali metal halide, an alkaline earth metal halide, etc. Two or more of these may be used.

[0175] (Charge Generation Layer) The charge generation layer in the present invention generally comprises a double layer, and specifically, can be used as a pn junction charge generation layer comprising an n-type charge generation layer and a p-type charge generation layer. When a voltage is applied to the light-emitting device, the pn junction charge generation layer generates charges or separates the charges into holes and electrons, and injects these holes and electrons into the light-emitting layer via the hole transport layer and electron transport layer. Specifically, it functions as an intermediate charge generation layer in a light-emitting device in which light-emitting layers are stacked. The n-type charge generation layer supplies electrons to the first light-emitting layer located on the anode side, and the p-type charge generation layer supplies holes to the second light-emitting layer located on the cathode side. Therefore, the light-emitting device efficiency can be improved in a light-emitting device in which multiple light-emitting layers are stacked, the driving voltage can be reduced, and the durability of the light-emitting device can also be improved.

[0176] The n-type charge generating layer comprises an n-type dopant and a host, and conventional materials can be used for these. Examples of n-type dopants include alkali metals, alkaline earth metals, and rare earth metals. Two or more of these may be used. Among these, alkali metals or their salts, and rare earth metals are preferred, with metallic lithium, lithium fluoride (LiF), lithium quinolinol (Liq), and metallic ytterbium being more preferred. Furthermore, examples of hosts include triazine derivatives, phenanthroline derivatives, and oligopyridine derivatives. Two or more of these may be used. Among these, triazine derivatives, phenanthroline derivatives, and oligopyridine derivatives are preferred, with phenanthroline derivatives and terpyridine derivatives being more preferred, and phenanthroline derivatives having a structure represented by the general formula (6) being even more preferred, with phenanthroline derivatives represented by the following general formula (7) being particularly preferred. That is, the light-emitting element of the present invention preferably contains a phenanthroline derivative having a structure represented by general formula (6) in the charge generating layer, and more preferably contains a phenanthroline derivative represented by general formula (7).

[0177]

[0178] In the above general formula (7), Y １ ~Y ３ Any one of L is a nitrogen atom, and the others are methine groups. ２ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group, L ３ is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group. However, when these groups are substituted, the substituent is an alkyl group or an alkoxy group. A is a phenyl group or a pyridyl group, and m is 0 or 1.

[0179] An example of the phenanthroline derivative represented by the general formula (7) is shown below.

[0180]

[0181] The p-type charge generating layer is composed of a p-type dopant and a host, and conventional materials can be used for these. For example, the p-type dopant can be tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), a tetracyanoquinodimethane derivative, a radialene derivative, iodine, or FeCl. ３ , FeF ３ , SbCl ５ These may be used in combination of two or more kinds. Among these, arylamine derivatives are preferred.

[0182] (Method for manufacturing light-emitting element) The method for forming each of the layers constituting the light-emitting element may be either a dry process or a wet process, and examples thereof include resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, coating, inkjet printing, etc. Among these, resistance heating evaporation is preferred from the viewpoint of element characteristics.

[0183] The thickness of the organic layer is not limited because it depends on the resistance value of the light-emitting substance, but is preferably 1 to 1,000 nm. The thickness of each of the light-emitting layer, electron transport layer, and hole transport layer is preferably 1 nm to 200 nm, more preferably 5 nm to 100 nm.

[0184] (Characteristics of Light-Emitting Element) The light-emitting element according to the embodiment of the present invention has a function of converting electrical energy into light. While direct current is primarily used as the electrical energy, pulsed current or alternating current can also be used. There are no particular limitations on the current value and voltage value, and the required characteristic values ​​vary depending on the purpose of the element. However, from the viewpoint of the power consumption and durability of the element, it is preferable that high brightness can be obtained at a low voltage.

[0185] In the light-emitting element according to the embodiment of the present invention, from the viewpoint of increasing color purity, in terms of further improving color purity at the emission wavelength when current is applied, the half-value width is preferably 45 nm or less, more preferably 35 nm or less, and even more preferably 30 nm or less.

[0186] (Use of Light-Emitting Device) The light-emitting device according to the embodiment of the present invention can achieve both high light-emitting device efficiency and high color purity, and can also be made thin and lightweight, and is therefore suitable for use as, for example, a display device or a lighting device.

[0187] Examples of display devices include display devices such as displays that display using a matrix system, and backlights for various devices. Backlights are primarily used to improve the visibility of display devices such as non-self-luminous displays, and are used in liquid crystal displays, clocks, audio equipment, automotive panels, display boards, signs, etc. Among these, they can be suitably used as backlights for liquid crystal displays, particularly for personal computers, which are being considered for thinning.

[0188] Examples of lighting devices include medical lighting and interior lighting, and lighting devices that combine low power consumption, vivid luminous colors, and high design quality can be realized.

[0189] <Color-Converting Composition> The compound of the present invention may be used in a color-converting composition that converts incident light from a light-emitting body such as a light source into light with a wavelength different from that of the incident light. The color-converting composition preferably contains the compound represented by the general formula (1) described above and a binder resin. Here, converting into light with a wavelength different from that of the incident light preferably means converting into light with a wavelength longer than that of the incident light.

[0190] <Method for Producing Color-Converting Composition> The color-converting composition of the present invention can be obtained, for example, by mixing a binder resin, a compound having a structure represented by general formula (1), and, if necessary, additives and solvents, etc., to a predetermined composition, and then homogeneously mixing or kneading the mixture using a stirrer / kneader. Examples of stirrers / kneaders include homogenizers, planetary stirrers, three-roller stirrers, ball mills, planetary ball mills, and bead mills. After mixing or dispersing, or during the mixing or dispersing process, degassing is preferably performed under vacuum or reduced pressure conditions. It is also possible to premix certain components or to perform treatments such as aging. It is also possible to remove the solvent using an evaporator to achieve a desired solids concentration.

[0191] <Color Conversion Sheet> The color conversion sheet of the present invention is a sheet that converts incident light from a light emitting body such as a light source into light with a wavelength different from that of the incident light, and contains the color conversion composition of the present invention described above. It is preferable that the color conversion sheet converts incident light into light with a wavelength longer than that of the incident light.

[0192] The color conversion sheet of the present invention preferably includes a color conversion layer formed from the color conversion composition described above. The amount of residual solvent in the color conversion layer is preferably 0.5 wt % or less from the viewpoint of further improving the durability of the color conversion sheet. On the other hand, the amount of residual solvent in the color conversion layer is preferably 0.1 wt % or more from the viewpoint of further improving the luminous efficiency of the color conversion sheet.

[0193] <Manufacturing Method of Color Conversion Sheet> Next, an example of a manufacturing method of the color conversion sheet of the present invention will be described. The color conversion composition prepared by the above-mentioned method is applied to a substrate and dried to form a color conversion layer. When the binder resin is a thermosetting resin, the color conversion composition may be applied to the substrate and then heat-cured to form the color conversion layer. When the binder resin is a photocurable resin, the color conversion composition may be applied to the substrate and then photocured to form the color conversion layer.

[0194] <Light Source Unit> The light source unit of the present invention includes at least a light source and the above-described color conversion sheet of the present invention. The light source included in the light source unit of the present invention is a source of the above-described excitation light. The arrangement of the light source and the color conversion sheet is not particularly limited, and the light source and the color conversion sheet may be closely attached to each other, or a remote phosphor type in which the light source and the color conversion sheet are separated from each other may be used. Furthermore, the light source unit may be further provided with a color filter for the purpose of increasing color purity.

[0195] <Light Source> Any light source can be used as long as it emits light in a wavelength range that can be absorbed by the light-emitting material. For example, any light source can be used in principle, such as a hot cathode tube, a cold cathode tube, a fluorescent light source such as an inorganic EL, an organic electroluminescence element light source, an LED light source, an incandescent light source, or sunlight. Among these, an LED is a preferred light source, and for displays (display devices) and lighting applications, a blue LED having a light source in the range of 430 to 500 nm is even more preferred because it can enhance the color purity of blue light.

[0196] The light source may have one emission peak or two or more emission peaks, but in order to improve color purity, it is preferable to have one emission peak. It is also possible to use a combination of multiple light sources with different emission peaks.

[0197] The light source unit of the present invention is useful for various light sources such as spatial lighting and backlighting, and specifically can be used for applications such as display devices, lighting, interior design, signs, and billboards, but is particularly suitable for use in display devices and lighting.

[0198] <Display Device, Lighting Device> The display device of the present invention includes at least the light-emitting element of the present invention and / or the color conversion sheet. For example, the light source unit of the present invention is preferably used as a backlight unit in a display device such as a liquid crystal display. Furthermore, by using the light-emitting element described above, a display device such as an organic EL display that displays in a matrix and / or segment format and has high luminous efficiency and excellent durability can be produced.

[0199] Furthermore, the lighting device of the present invention includes at least the above-described light-emitting element of the present invention and / or the above-described color conversion sheet of the present invention. For example, this lighting device is configured to emit white light by combining a blue LED light source as a light source unit with a color conversion sheet that converts the blue light from the blue LED light source into light with a longer wavelength. Furthermore, a lighting device can also be obtained using the above-described light-emitting element of the present invention. Examples of such lighting devices include medical lighting and interior lighting, and they can combine vivid light emission colors, high durability, and excellent design.

[0200] <Photoelectric Conversion Material> The compound of the present invention may be used as a photoelectric conversion material constituting a photoelectric conversion layer in a photoelectric conversion element having a photoelectric conversion layer between an anode and a cathode. The photoelectric conversion material may be composed only of the compound having a structure represented by general formula (1) of the present invention, or may further contain other photoelectric conversion materials in order to further increase photoelectric conversion efficiency.

[0201] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0202] First, the evaluation methods used in each of the examples and comparative examples will be described below.

[0203] ( １ H-NMR) The deuterated chloroform solutions of the compounds obtained in Examples 1 to 23 were analyzed using a superconducting FTNMR EX-270 (manufactured by JEOL Ltd.). １ The structure was identified by H-NMR measurement.

[0204] (Light Emitting Properties) The compounds obtained in Examples 1 to 23 and Comparative Examples 1 to 6 were dissolved in toluene at a concentration of 10 －５ The emission wavelength of the diluted solution of 100 mol / L was measured using a FluoroMax-4P spectrophotometer manufactured by Horiba Ltd., and the peak wavelength and half-width were determined.

[0205] (Light-emitting device characteristics) The light-emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 41 were subjected to a current density of 0.1 mA / cm ２A voltage was applied so that the emission wavelength was measured using a spectroradiometer CS-1000 manufactured by Konica Minolta, Inc. From the emission wavelength thus obtained, the light-emitting element efficiency was calculated on the assumption that Lambertian radiation was performed.

[0206] In addition, the light-emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 41 were subjected to a current density of 10 mA / cm ２ The emission wavelength when a voltage was applied so as to satisfy the following equation was similarly measured, and the peak wavelength and half width were calculated.

[0207] The light-emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 37 were subjected to a current density of 10 mA / cm ２ A voltage was applied so that the current density was 10 mA / cm. The luminance of the light-emitting element was measured using a photodiode, and the measured luminance was taken as the initial luminance. ２ A voltage was continuously applied so that the brightness reached 90% of the initial brightness, and the time (LT90) required for the brightness to reach 90% of the initial brightness was measured and used as an index of durability.

[0208] Example 1

[0209]

[0210] Raw material 1A can be synthesized by the method disclosed in Journal of American Chemical Society, 2020, vol. 142, pp. 19468-19472.

[0211] The raw material 1B can be synthesized by the method disclosed in Angewandte chemie international edition, vol. 59, pp. 7813-7817.

[0212] Raw material 1A (5.5 g), raw material 1B (8.6 g), potassium phosphate (3.9 g), and N,N-dimethylformamide (60 ml) were placed in a flask and heated and stirred at 150°C for 6 hours under a nitrogen atmosphere. After heating and stirring, the reaction solution was cooled to room temperature, and water and toluene were added to separate the solution. The solvent was distilled off under reduced pressure, and the resulting mixture was purified by silica gel column chromatography to obtain intermediate INT1 (yield 73%).

[0213] A flask containing intermediate INT1 (7.9 g) and tert-butylbenzene (90 ml) was cooled to 0°C, and 1.6 M n-butyllithium hexane solution (5.5 ml) was added dropwise. After the dropwise addition, the mixture was stirred for 1 hour while warming to room temperature. The mixture was again cooled to 0°C, and boron tribromide (8.9 g) was added dropwise. After the dropwise addition, the mixture was stirred for 1 hour while warming to room temperature, then cooled to 0°C, and N,N-diisopropylethylamine (4.6 g) was added, followed by heating and stirring at 150°C for 10 hours. The reaction solution was cooled to 0°C and quenched with methanol. The precipitated solid was collected by suction filtration. The obtained solid was washed with toluene and butyl acetate under heating to obtain D-1 (yield 17%). The obtained compound D-1 １ The results of H-NMR measurement are shown below. １ H-NMR (CDCl ３ (d=ppm)): 10.26 (s, 1H), 9.21 (s, 1H), 8.97 (d, 1H), 8.70 (m, 5H), 8.49 (s, 1H), 8.40 (t, 2H), 8.26 ( m, 4H), 7.93 (d, 1H), 7.82 (m, 2H) 7.71 (m, 5H), 7.22 (t, 2H), 6.36 (m, 2H) 1.74 (s, 9H), 1.57 (s, 9H).

[0214] Compound D-1 was added to a 1×10 －３ The resulting material was purified by sublimation at 400° C. under a pressure of 100 Pa, and then used as a light-emitting device material.

[0215] The results of evaluation of the luminescence properties of Compound D-1 are shown in Table 1.

[0216] Example 2

[0217]

[0218] Raw material 1B (3.9 g), 1,3-dibromo-5-fluorobenzene (3.2 g), potassium phosphate (2.7 g), and N,N-dimethylformamide (85 ml) were placed in a flask and heated with stirring at 150°C for 2 hours under a nitrogen atmosphere. After heating and stirring, the reaction solution was cooled to room temperature, and water was added and stirred. The precipitated solid was filtered under suction, and the obtained solid was purified by silica gel column chromatography to obtain intermediate INT2-1 (yield 61%).

[0219] Intermediate INT2-1 (3.6 g), p,p'-ditolylamine (2.3 g), bis(dibenzylideneacetone)palladium(0) (0.06 g), tri-tert-butylphosphonium tetrafluoroborate (0.06 g), sodium tert-butoxide (1.4 g), and o-xylene (50 ml) were placed in a flask and heated with stirring at 100°C for 3 hours under a nitrogen atmosphere. After heating and stirring, the mixture was cooled to room temperature and purified by column chromatography to obtain intermediate INT2-2 (91%).

[0220] Boron tribromide (3.8 g) was added dropwise to a flask containing intermediate INT2-2 (7.0 g) and toluene (75 ml) under a nitrogen atmosphere. After the dropwise addition, the mixture was heated and stirred at 100°C for 4 hours. After heating and stirring, the mixture was cooled to 0°C and quenched with methanol. The precipitated solid was collected by suction filtration. The obtained solid was washed with toluene and butyl acetate under heating, and then recrystallized from chlorobenzene to obtain D-2 (yield 28%). １ The results of H-NMR measurement are shown below. １ H-NMR (CDCl ３ (d=ppm)): 10.17 (s, 1H), 8.98 (s, 1H), 8.93 (s, 1H), 8.70 (m, 3H), 8.57 (d, 1H), 8.41 (d, 2H), 8.32 (d, 1H), 8.00 (d, 1H), 7.84 (t , 1H), 7.71 (m, 5H), 7.34 (d, 3H), 7.21 (m, 12H), 6.87 (d, 1H), 6.40 (m, 2H), 5.92 (s, 1H), 2.62 (s, 3H), 2.45 (s, 3H), 2.42 (s, 6H).

[0221] Compound D-2 was added to a 1×10 －３ The resulting material was purified by sublimation at 400° C. under a pressure of 100 Pa, and then used as a light-emitting device material.

[0222] The results of evaluation of the luminescence properties of Compound D-2 are shown in Table 1.

[0223] Examples 3 to 23 Compounds D-3 to D-23 having the structures shown below were synthesized by appropriately changing the raw materials and synthesis conditions. They were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0224]

[0225]

[0226]

[0227]

[0228] Comparative Examples 1 to 6 Compounds EX-1 to EX-6 having the following structures were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0229]

[0230]

[0231] Example 24 A glass substrate (manufactured by Geomatec Co., Ltd., 11 Ω / □, sputtered product) on which a 100 nm ITO transparent conductive film had been deposited was cut into a size of 38 mm x 46 mm and etched. The resulting substrate was ultrasonically cleaned for 15 minutes using "Semicoclean" (registered trademark) 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then washed with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before fabricating the element, and then placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was adjusted to 5 x 10 －４ The chamber was evacuated to a pressure of 10 Pa or less. Using a resistance heating method, HAT-CN6 was vapor-deposited to a thickness of 10 nm as a hole injection layer. Next, compound HT-1 was vapor-deposited to a thickness of 40 nm as a first hole transport layer. Next, compound HT-2 was vapor-deposited to a thickness of 10 nm as a second hole transport layer. Next, compound H-1 was used as a matrix material and compound D-1 as a dopant material to vapor-deposit a thickness of 20 nm as a light-emitting layer, with the dopant concentration of the dopant material being 1 wt %. Next, compound ET-1 was used as an electron transport material and compound 2E-1 as a donor material, with the electron transport layer being vapor-deposited to a thickness of 30 nm with the vapor deposition rate ratio of ET-1 to 2E-1 being ET-1:2E-1 = 1:1. Thereafter, magnesium and silver were co-deposited to a thickness of 100 nm to form a cathode, and a 5 mm x 5 mm square light-emitting device was fabricated. Note that HAT-CN6 、 HT-1, HT-2, H-1, ET-1, and 2E-1 are the compounds shown below.

[0232]

[0233] The obtained light-emitting device was evaluated by the above-mentioned method, and the results are shown in Table 2.

[0234] Examples 25 to 46, Comparative Examples 7 to 12 Light-emitting devices were fabricated in the same manner as in Example 24 except that the compounds shown in Table 2 were used as dopant materials, and the evaluation results are shown in Table 2.

[0235]

[0236] Example 47 A glass substrate (manufactured by Geomatec Co., Ltd., 11 Ω / □, sputtered product) on which a 100 nm ITO transparent conductive film had been deposited was cut into a size of 38 mm x 46 mm and etched. The resulting substrate was ultrasonically cleaned for 15 minutes using "Semicoclean" (registered trademark) 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then washed with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before fabricating the element, and then placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was adjusted to 5 x 10 －４ The chamber was evacuated until the pressure reached 10 Pa or less. Using a resistance heating method, first, 10 nm of HAT-CN6 was vapor-deposited as a hole injection layer, followed by 30 nm of HT-3 as a hole transport layer. Next, as an emitting layer, H-2 was vapor-deposited as a matrix material, Compound D-1 was vapor-deposited as a dopant material, and Compound H-3, a compound exhibiting delayed fluorescence, in a weight ratio of 79.0:1.0:20 to a thickness of 30 nm. Subsequently, 10 nm of ET-2 was vapor-deposited as a hole blocking layer, and 40 nm of ET-3 was vapor-deposited as an electron transport layer. Next, 0.5 nm of 2E-1 was vapor-deposited as an electron injection layer, and then 100 nm of magnesium and silver were co-vapor-deposited to form a cathode, and a 5 mm x 5 mm square light-emitting device was fabricated. HT-3, H-2, H-3, ET-2, and ET-3 are the compounds shown below.

[0237]

[0238] The obtained light-emitting device was evaluated by the above-mentioned method, and the results are shown in Table 3.

[0239] Examples 48 to 69, Comparative Examples 13 to 18 Light-emitting devices were fabricated in the same manner as in Example 47 except that the compounds shown in Table 3 were used as dopant materials, and the evaluation results are shown in Table 3.

[0240]

[0241] Example 70 (Evaluation of Tandem Light-Emitting Device) A glass substrate (manufactured by Geomatec Co., Ltd., 11 Ω / □, sputtered product) on which a 100 nm ITO transparent conductive film had been deposited was cut into a size of 38 mm x 46 mm and etched. The obtained substrate was subjected to ultrasonic cleaning for 15 minutes using "Semicoclean" (registered trademark) 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then washed with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before fabricating the device, and then placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was adjusted to 5 x 10 －４ The chamber was evacuated to a pressure of 10 Pa or less. Using a resistance heating method, first, 10 nm of HAT-CN6 was deposited as a hole injection layer, followed by 30 nm of HT-3 as a hole transport layer. Next, as an emitting layer, a host material (third compound) H-2, a dopant material (first compound) Compound G-1, and a TADF material (second compound) Compound H-3 were deposited to a thickness of 30 nm in a weight ratio of 79.0:1.0:20. Subsequently, 10 nm of ET-2 was deposited as a hole blocking layer, and 40 nm of ET-3 was deposited as an electron transport layer. Subsequently, as an n-type charge generating layer, 10 nm of Compound ET-4, an n-type host, and metallic lithium, an n-type dopant, were deposited at a deposition rate ratio of 99:1. Furthermore, 10 nm of HAT-CN6 was deposited as a p-type charge generating layer. A 30 nm hole transport layer and a 30 nm emitting layer were formed thereon in the same manner as above. Further, ET-2 was deposited to a thickness of 10 nm as a hole-blocking layer, and ET-3 was deposited to a thickness of 40 nm as an electron-transporting layer in this order. Next, 2E-1 was deposited to a thickness of 0.5 nm as an electron-injection layer, and then magnesium and silver were co-deposited to a thickness of 1000 nm as a cathode to prepare a tandem light-emitting device measuring 5 mm × 5 mm.

[0242] The obtained light-emitting device was evaluated by the above-mentioned method, and the light-emitting efficiency was 31.8% and the LT90 was 185 hours.

[0243] Examples 71 to 92 Light-emitting devices were fabricated in the same manner as in Example 70, except that the compounds shown in Table 4 were used as the dopant material in place of D-1.

[0244] Examples 93 to 115 Light-emitting devices were fabricated in the same manner as in Example 70, except that compound ET-5 was used in place of compound ET-4 as the n-type host for the n-type charge generation layer, and the compounds shown in Table 4 were used as the dopant material. The evaluation results are shown in Table 4.

[0245] Comparative Examples 19 to 37 Light-emitting devices were fabricated in the same manner as in Example 70, except that, for the n-type charge generation layer, Bphen was used instead of the n-type host compound ET-4, and the compounds shown in Table 5 were used as the dopant material. The evaluation results are shown in Table 5.

[0246]

[0247]

[0248]

[0249] ET-4, ET-5 and Bphen are the compounds shown below.

[0250]

[0251] As described above, the present specification describes the following inventions [1] to

[17] . [1] A compound having a structure represented by the above general formula (1). [2] The compound according to [1], wherein in the general formula (1), L is a single bond. [3] Ring C １ and Ring D １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon containing a ring structure represented by any one of the general formulas (2-1) to (2-8). １ and Ring D １ [5] The compound according to any one of [1] to [4], having a structure represented by the general formula (3). [6] X １ N-R ２０ and R ２０is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. [7] The compound according to [5] or [6], wherein the compound having a structure represented by the general formula (3) has a structure represented by any one of the general formulas (4-1) to (4-5). [8] X １ N-R ２０ and R ２０ is a substituted or unsubstituted alkenyl group or a substituted or unsubstituted imino group. [9] The compound according to any one of [5] to [8], wherein the compound having a structure represented by the general formula (3) has a structure represented by the general formula (5-1) or (5-2).

[10] A light-emitting device material comprising the compound according to any one of [1] to [9].

[11] A light-emitting device having a cathode, an anode, and one or more organic layers disposed between the cathode and the anode, wherein at least one of the organic layers contains the compound according to any one of [1] to [9].

[12] The light-emitting device according to

[11] , wherein the organic layer containing the compound according to any one of [1] to [9] is an emitting layer.

[13] The light-emitting device according to

[12] , wherein the emitting layer contains a matrix material.

[14] The light-emitting device according to

[12] or

[13] , wherein the emitting layer contains a compound exhibiting delayed fluorescence.

[15] The light-emitting device according to

[15] , wherein the emitting layer contains a matrix material and a compound exhibiting delayed fluorescence, and wherein the excited singlet energy of the matrix material is converted to S １ (1) The excited singlet energy of a compound exhibiting delayed fluorescence is S １ (2) The excited singlet energy of the compound according to any one of [1] to [5] is S １ The light-emitting element according to any one of

[12] to

[14] , wherein when (3) is satisfied, the relationship of formula 1 is satisfied. １ (1) > S １ (2) > S １(3) (Formula 1)

[16] The light-emitting device according to any one of

[12] to

[15] , further comprising a charge generation layer.

[17] The light-emitting device according to

[16] , wherein the charge generation layer contains a phenanthroline derivative represented by the above general formula (6).

[18] The light-emitting device according to

[16] , wherein the charge generation layer contains a phenanthroline derivative represented by the above general formula (7).

[19] The light-emitting device according to any one of

[12] to

[18] , which is a top-emission organic electroluminescent device.

[20] A photoelectric conversion element material comprising the compound according to any one of [1] to [9].

[21] A color conversion composition that converts incident light into light of a wavelength different from the incident light, the color conversion composition comprising the compound according to any one of [1] to [9] and a binder resin.

[22] A color conversion sheet comprising the color conversion composition according to

[21] or a cured product thereof.

[23] A light source unit comprising a light source and the color conversion sheet according to

[22] .

[24] A display device comprising the light-emitting device according to any one of

[11] to

[19] .

[25] A display device comprising the light source unit according to

[23] .

[26] A lighting device comprising the light emitting element according to any one of

[11] to

[19] .

[27] A lighting device comprising the light source unit according to

[23] .

Claims

1. A compound having a structure represented by the following general formula (1): 【Chemistry 1】 (In the above general formula (1), ring A １ and ring B １ is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic ring having 5 to 30 ring atoms. Ring C １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11 to 20 ring atoms. Ring D １ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7 to 20 ring atoms. X is O, N-R Ａ or S, and R Ａ is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group, or a heteroaryl group. These groups may further have a substituent. Ａ is further connected to ring A via a linking group. １ or ring B １ In this case, the linking group may be a single bond, —O—, —S—, >CR Ａ１ R Ａ２ Or >SiR Ａ３ R Ａ４ It is. Ａ１ ~R Ａ４ are each independently hydrogen, halogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. Ａ１ and R Ａ２ or R Ａ３ and R Ａ４ may be further bonded via a linking group. L is a single bond, O, S, >CR Ａ５ R Ａ６ Or >SiR Ａ７ R Ａ８ It is. Ａ５ ~R Ａ８ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these groups may further have a substituent. Ａ５ and R Ａ６ and R Ａ７ and R Ａ８ may be further bonded via a linking group.

2. The compound according to claim 1, wherein in general formula (1), L is a single bond.

3. Ring C １ and Ring D １ The compound according to claim 1, wherein the compound is a substituted or unsubstituted polycyclic aromatic hydrocarbon containing a ring structure represented by any one of chemical formulas (2-1) to (2-8). 【Chemistry 2】

4. The compound according to claim 1, wherein ring C 1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon represented by chemical formula (2-3), and ring D 1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon represented by chemical formula (2-2), (2-3), (2-4) or (2-6).

5. In general formula (1), ring C １ and Ring D １ The compound according to claim 1, wherein

6. The compound according to claim 1, having a structure represented by the following general formula (3): 【Transformation 3】 (In the above general formula (3), R １ ~R １９ are each independently hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, carboxyl, oxycarbonyl, carbamoyl, amino, nitro, or silyl. These groups may further have a substituent. Ring A １ and ring B １ is as described in general formula (1). X １ is O, N-R ２０ or S, and R ２０ is an alkyl group, a cycloalkyl group, an alkenyl group, an imino group, an aryl group, or a heteroaryl group. These groups may further have a substituent. ２０ is further connected to ring A via a linking group. １ or ring B １ In this case, the linking group may be a single bond, —O—, —S—, >CR ２１ R ２２ Or >SiR ２３ R ２４ It is. ２１ ~R ２４ are each independently hydrogen, halogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. ２１ and R ２２ or R ２３ and R ２４ may be further bonded via a linking group.

7. X １ N-R ２０ and R ２０ The compound according to claim 6, wherein is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

8. The compound according to claim 6, wherein the compound having a structure represented by the general formula (3) has a structure represented by any one of the following general formulas (4-1) to (4-5): 【Chemistry 4】 【Transformation 5】 (In the above general formulas (4-1) to (4-5), R １ ~R １９ is as described in general formula (1). R １０１ ~R １０７ , R １１０ ~R １１６ , R １２０ ~R １２７ , R １３０ ~R １３１ and R １４０ ~R １４１ are each independently hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, carboxyl, oxycarbonyl, carbamoyl, amino, or silyl, or a saturated or unsaturated ring formed between adjacent groups among these. These groups may further have a substituent. Ar １ ~Ar ３ are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. Y １ ~Y ２ are each independently a single bond, O, S, or CR １５０ R １５１ or SiR １５２ R １５３ is. W １ ~W ２ are each independently NR １５４ , O or S. Here, R １５０ ~R １５４ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. １５０ and R １５１ or R １５２ and R １５３ may be further bonded via a linking group.

9. X １ N-R ２０ and R ２０ The compound according to claim 6, wherein is a substituted or unsubstituted alkenyl group or a substituted or unsubstituted imino group.

10. The compound according to claim 7, wherein ring A 1 is a substituted or unsubstituted benzene ring.

11. The compound described in claim 1, having an emission peak wavelength in a diluted solution of 510 nm or more and 540 nm or less.

12. The compound according to claim 6, wherein the compound having a structure represented by general formula (3) has a structure represented by the following general formula (5-1) or (5-2): 【Transformation 6】 (In the above general formulas (5-1) to (5-2), R １ ~R １９ is as described in general formula (3). R ２０１ ~R ２０７ and R ２１０ ~R ２１４ are each independently hydrogen, halogen, cyano, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, carboxyl, oxycarbonyl, carbamoyl, amino, or silyl, or a saturated or unsaturated ring formed between adjacent groups among these. These groups may further have a substituent. W ３ ~W ４ are each independently N or C—R ２２０ It is. ２２０ represents hydrogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent.

13. A light-emitting device material comprising the compound according to any one of claims 1 to 12.

14. A light-emitting device comprising a cathode, an anode, and one or more organic layers disposed between the cathode and the anode, wherein at least one of the organic layers contains the compound according to claim 1.

15. 15. The light-emitting device according to claim 14, wherein the organic layer containing the compound according to claim 1 is a light-emitting layer.

16. The light-emitting device according to claim 15 , wherein the light-emitting layer further comprises a matrix material.

17. The light-emitting element according to claim 15 , wherein the light-emitting layer further contains a compound that exhibits delayed fluorescence.

18. The light-emitting layer further contains a matrix material and a compound exhibiting delayed fluorescence, and the excited singlet energy of the matrix material is converted to S １ (1) The excited singlet energy of a compound exhibiting delayed fluorescence is S １ (2) The excited singlet energy of the compound having the structure represented by general formula (1) is S １ 16. The light-emitting device according to claim 15, which satisfies the relationship of formula 1 when (3). S １ (1) > S １ (2) > S １ (3) (Equation 1)

19. The light-emitting device according to claim 15, further comprising a charge generation layer.

20. 20. The light-emitting device according to claim 19, wherein the charge generating layer contains a phenanthroline derivative represented by the following general formula (6): 【Transformation 7】 (In the general formula (6), Ar １ is selected from the group consisting of p-valent aromatic hydrocarbon groups and p-valent aromatic heterocyclic groups, where p is a natural number from 1 to 3. １０１ ~R １０８ may be the same or different and are selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an aryl group, and a heteroaryl group. １ The substitution positions of the p phenanthrolyl groups are arbitrary.

21. 20. The light-emitting device according to claim 19, wherein the charge generating layer contains a phenanthroline derivative represented by the following general formula (7): 【Transformation 8】 (In the general formula (7), Y １ ~Y ３ one of the groups is a nitrogen atom, and the others are methine groups; １ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group, L ２ represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group; provided that when these groups are substituted, the substituent is an alkyl group or an alkoxy group; A represents a phenyl group or a pyridyl group, and n is 0 or 1.

22. The light-emitting device according to claim 15, which is a top-emission organic electroluminescent device.

23. A photoelectric conversion element material comprising the compound according to any one of claims 1 to 12.

24. A color-changing composition that converts incident light into light of a wavelength different from that of the incident light, the color-changing composition comprising the compound according to any one of claims 1 to 12 and a binder resin.

25. A color-changing sheet comprising the color-changing composition according to claim 24 or a cured product thereof.

26. A light source unit comprising a light source and the color conversion sheet according to claim 25.

27. A display device comprising the light-emitting device according to any one of claims 14 to 22.

28. A display device comprising the light source unit according to claim 26.

29. A lighting device comprising the light-emitting element according to any one of claims 14 to 22.

30. A lighting device comprising the light source unit according to claim 26.

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