WO2023190159A1

WO2023190159A1 - 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

Info

Publication number: WO2023190159A1
Application number: PCT/JP2023/011821
Authority: WO
Inventors: 大貴野田; 一成川本; 和真長尾
Original assignee: 東レ株式会社
Priority date: 2022-04-01
Filing date: 2023-03-24
Publication date: 2023-10-05

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

Compounds, light emitting device materials and light emitting devices using the same, photoelectric conversion device materials, color conversion compositions, color conversion sheets, light source units, display devices, lighting devices

The present invention relates to a novel compound and a light emitting device material, a light emitting device, a photoelectric conversion device material, a color conversion composition, a color conversion sheet, a light source unit, a display device, and a lighting device using the same.

Organic thin-film light-emitting devices emit light by recombining electrons injected from the cathode and holes injected from the anode in a light-emitting layer sandwiched between the two electrodes.They can be made thinner and have a lower driving voltage. It has characteristics such as high brightness, and the ability to emit multicolor light.

In order to further increase the color gamut of display devices and lighting devices using organic light-emitting devices, materials with narrow half-value widths of emission peaks are being actively developed. As such a technique, for example, polycyclic aromatic compounds in which a plurality of aromatic rings are connected by boron atoms, nitrogen atoms, etc. (see, for example, Patent Documents 1 to 4) have been proposed.

China Patent Application Publication No. 107417715 International Publication No. 2015/102118 International Publication No. 2020/106032 International Publication No. 2020/217229

The polycyclic aromatic compounds described in Patent Documents 1 to 4 are blue light-emitting materials, and their emission wavelengths are insufficient for green light-emitting materials. Additionally, there were problems with the efficiency and durability of the light emitting device when it was used as a light emitting device. Therefore, an object of the present invention is to provide a compound having high luminous efficiency, excellent durability, and green luminescent properties.

The present invention is a compound having a structure represented by the following general formula (1).

In the above general formula (1), Ring A ¹ and Ring B ¹ are substituted or unsubstituted aromatic hydrocarbon rings having 6 to 30 ring carbon atoms, or substituted or unsubstituted aromatic hydrocarbon rings having 5 to 30 ring atoms. It is a group heterocycle.

Ring C ¹ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11 or more and 20 or less ring atoms.

Ring D ¹ is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7 or more and 20 or less ring atoms.

X is O, N-R ^A or S, and R ^A is an alkyl group, cycloalkyl group, alkenyl group, imino group, aryl group or heteroaryl group. These groups may further have a substituent. Further, R ^A may further be bonded to ring A ¹ or ring B ¹ via a linking group to form a ring structure. In that case, the linking group is a single bond, -O-, -S-, >CR ^A1 R ^A2 or >SiR ^A3 R ^A4 . R ^A1 to 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. Furthermore, R ^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 . R ^A5 to 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 further have a substituent. Good too. Furthermore, R ^A5 and R ^A6 and R ^A7 and R ^A8 may be further bonded via a linking group.

The compound of the present invention has green luminescent properties with high luminous efficiency and excellent durability. By using the compound of the present invention, it is possible to provide a light-emitting device having high light-emitting device efficiency, excellent durability, and green light-emitting characteristics.

Below, the content of the present invention will be explained in detail. The present invention is not limited to the embodiments or specific examples described below.

<Compound having a structure represented by general formula (1)>
The compound of the present invention has a structure represented by the general formula (1) described below.

As blue light-emitting materials, the polycyclic aromatic compounds described in Patent Documents 1 to 4 have strong and highly planar skeletons, and therefore exhibit high fluorescence quantum yields. Furthermore, since the peak half width at the emission wavelength is small, color purity can be improved.

As a means of making such a polycyclic aromatic compound emit green light, by directly bonding an aromatic hydrocarbon ring or an aromatic heterocycle to a polycyclic aromatic compound, the conjugation is expanded and the emission wavelength is extended. There are several methods. However, simply bonding an aromatic hydrocarbon ring or an aromatic heterocycle to a polycyclic aromatic compound does not sufficiently expand the conjugation length, making it difficult to achieve green light emission. In the present invention, as shown in the general formula (1), by condensing two polycyclic aromatic hydrocarbons, ring C ¹ and ring D ¹ , the conjugation length is expanded to make the wavelength longer, and green light is emitted. can be obtained. Furthermore, by condensing two polycyclic aromatic hydrocarbons, the vibration of the compound having the structure represented by the general formula (1) is restricted, deactivation in the excited state is suppressed, and the light emitting element of the light emitting element is Efficiency and durability can be improved.

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

From the viewpoint of further improving the color purity of green light emission, ring C ¹ and ring D ¹ contain a ring structure represented by any of the following chemical formulas (2-1) to (2-8), and are substituted or unsubstituted. Polycyclic aromatic hydrocarbons are preferred.

From the viewpoint of ease of synthesis, it is preferable that ring C ¹ and ring D ¹ are the same.

The compound having the structure represented by general formula (1) is more preferably a compound represented by general formula (3) below.

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

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

X ¹ is O, NR ²⁰ or S, and R ²⁰ is an alkyl group, cycloalkyl group, alkenyl group, imino group, aryl group or heteroaryl group. These groups may further have a substituent. Further, R ²⁰ may further be bonded to ring A ¹ or ring B ¹ via a linking group to form a ring structure. In that case, the linking group is a single bond, -O-, -S-, >CR ²¹ R ²² or >SiR ²³ R ²⁴ . R ²¹ to 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. Furthermore, R ²¹ and R ²² or R ²³ and R ²⁴ may be further bonded via a linking group.

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

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

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

In the above general formulas (4-1) to (4-5) and (5-1) to (5-2), R ¹ to R ¹⁹ are the same as R ¹ to R ¹⁹ in general formula (3). .

R ¹⁰¹ to R ¹⁰⁷ , R ¹¹⁰ to R ¹¹⁶ , R ¹²⁰ to R ¹²⁷ , R ¹³⁰ to R 131 , R ¹⁴⁰ to ^{R 141} ⁱⁿ general formulas (4-1) to (4-5) and general formula (5-1 ) to (5-2), R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹⁴ each independently represent hydrogen, halogen, cyano group, alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, Formed between an alkoxy group, an alkylthio group, an aryl ether group, an arylthioether group, an aryl group, a heteroaryl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a silyl group, or adjacent groups among these groups. It is a saturated or unsaturated ring. These groups may further have a substituent. Among these, hydrogen, an alkyl group, an aryl group, and a heteroaryl group are preferred.

In general formulas (4-1), (4-4) to (4-5), Ar ¹ to Ar ³ are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. .

In general formulas (4-2) to (4-3), Y ¹ to Y ² are each independently a single bond, O, S, CR ¹⁵⁰ R ¹⁵¹ or SiR ¹⁵² R ¹⁵³ , and in general formula (4 In -4) to (4-5), W ¹ to W ² are each independently NR ¹⁵⁴ , O or S. Here, R ¹⁵⁰ to R ¹⁵⁴ each independently represent hydrogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. Moreover, R ¹⁵⁰ and R ¹⁵¹ or R ¹⁵² and R ¹⁵³ may further be bonded via a linking group. In that case, the linking group is a single bond, -O-, -S-, >CR ²¹ R ²² or >SiR ²³ R ²⁴ . Among these, Y ¹ and Y ² are preferably single bonds from the viewpoint of further improving the color purity, light emitting element efficiency, and durability of the light emitting element.

In general formulas (5-1) to (5-2), W ³ to W ⁴ are each independently N or CR ²²⁰ . R 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 element efficiency, and durability of the light emitting element, ^R220 is preferably an aryl group.

The isotopic species of hydrogen atoms present in the molecule of the compound of the present invention is not particularly limited. For example, all hydrogen atoms in the molecule may be ¹ H, or some or all of them may be ² H (deuterium D).

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

Halogen refers to fluorine, chlorine, bromine or iodine.

A cyano group is a group whose structure is represented by -C≡N. Here, it is the carbon atom that is bonded to the other group.

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, and a tert-butyl group; It may or may not have. The number of carbon atoms in the alkyl group is not particularly limited, but from the viewpoint of availability and cost, it is preferably in the range of 1 to 20, more preferably 1 to 8. The number of carbon atoms here includes the number of carbon atoms contained in a substituent bonded to an alkyl group, and the same applies to other substituents that define the number of carbon atoms.

The cycloalkyl group refers to, for example, 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 carbon atoms forming the ring is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, allyl group, butadienyl group, and 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 or more and 20 or less.

A 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, even if it has a substituent. You don't have to. The number of carbon atoms forming the ring is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

The alkynyl group refers to, for example, 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 or more and 20 or less.

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

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.

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

An arylthioether group is an aryl ether group in which the oxygen atom of the ether bond is replaced with a sulfur atom. This may or may not have substituents. The number of ring carbon atoms in the arylthioether group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

Aryl groups include, for example, phenyl group, biphenyl group, terphenyl group, naphthyl group, fluorenyl group, benzofluorenyl group, dibenzofluorenyl group, phenanthryl group, anthracenyl group, benzophenanthryl group, and benzanthracetyl group. Indicates aromatic hydrocarbon groups such as nyl group, chrysenyl group, pyrenyl group, fluoranthenyl group, triphenylenyl group, benzofluoranthenyl group, dibenzaanthracenyl group, perylenyl group, and helicenyl group. This may or may not have substituents. Among these, phenyl group, biphenyl group, terphenyl group, naphthyl group, fluorenyl group, phenanthryl group, anthracenyl group, pyrenyl group, fluoranthenyl group, and triphenylenyl group are preferable. The number of carbon atoms forming the ring is not particularly limited, but is preferably in the range of 6 or more and 40 or less, more preferably 6 or more and 30 or less.

Furthermore, in a substituted phenyl group, when there are substituents on two adjacent carbon atoms in the phenyl group, these substituents may form a ring structure with each other. Depending on the structure, the resulting group is a "substituted phenyl group," "aryl group having a structure in which two or more rings are condensed," or "an aryl group having a structure in which two or more rings are condensed." ``heteroaryl group having a heteroaryl group''.

Heteroaryl groups include, for example, pyridyl group, furanyl group, thiophenyl group, quinolinyl group, isoquinolinyl group, pyrazinyl group, pyrimidyl group, pyridazinyl group, triazinyl group, naphthyridinyl group, cinnolinyl group, phthalazinyl group, quinoxalinyl group, quinazolinyl group, Benzofuranyl group, benzothiophenyl group, indolyl group, dibenzofuranyl group, dibenzothiophenyl group, carbazolyl group, benzocarbazolyl group, carbolinyl group, indolocarbazolyl group, benzofurocarbazolyl group, benzothienocarba Non-carbon groups such as zolyl group, dihydroindenocarbazolyl group, benzoquinolinyl group, acridinyl group, dibenzoacridinyl group, benzimidazolyl group, imidazopyridyl group, benzoxazolyl group, benzothiazolyl group, phenanthrolinyl group represents a cyclic aromatic group having one or more atoms in the ring. However, the naphthyridinyl group refers to any of the following: 1,5-naphthyridinyl group, 1,6-naphthyridinyl group, 1,7-naphthyridinyl group, 1,8-naphthyridinyl group, 2,6-naphthyridinyl group, 2,7-naphthyridinyl group. Show that. A heteroaryl group may or may not have a substituent. The number of ring-forming atoms is not particularly limited, but is preferably in the range of 3 or more and 40 or less, more preferably 3 or more and 30 or less.

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 or more and 50 or less, more preferably 6 or more and 40 or less, particularly preferably 6 or more and 30 or less.

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

Furthermore, the carboxyl group, oxycarbonyl group, and carbamoyl group may or may not have a substituent. Here, examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and these substituents may be further substituted.

The imino group refers to a functional group represented by C=NH or C ¹ -NH-C ² such as imine or imide, which may or may not have a substituent. . The number of carbon atoms in the imino group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

Examples of aromatic hydrocarbon rings include a monocyclic benzene ring, a biphenyl ring, a fused bicyclic naphthalene ring, and a tricyclic terphenyl ring (m-terphenyl, o -terphenyl, p-terphenyl), fused tricyclic ring systems such as acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, fused tetracyclic ring system such as triphenylene ring, pyrene ring, naphthacene ring, and fused pentacyclic ring system. Examples include perylene ring and pentacene ring.

Examples of aromatic heterocycles include pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring, thiadiazole ring, triazole ring, tetrazole ring, pyrazole ring, pyridine ring, and pyrimidine. ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, Quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiine ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, iso Examples include a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazane ring, an oxadiazole ring, and a thianthrene ring.

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

An example of a compound having a structure represented by general formula (1) is shown below, but the compound is not limited thereto.

A compound having a structure represented by general formula (1) is described, for example, in "Advanced. Materials", 2016, vol. 28, p. It can be produced by referring to the method described in 2777-2781.

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

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.

Regarding 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 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 using a fluorescence spectrophotometer using a diluted solution with a concentration of 10 ^-5 mol/L using toluene as a solvent. I can do it.

<Light emitting element material>
The light-emitting element material in the present invention refers to a material that includes a compound having a structure represented by general formula (1) and is used for any layer of a light-emitting element. Examples include materials used for hole injection layers, hole transport layers, light emitting layers, electron transport layers, and/or protective films (cap layers) of electrodes, which will be described later. Among these, it is suitably used for the light emitting layer because it has high light emitting device efficiency and color purity.

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

<Light emitting element>
Next, embodiments 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 between them, and emits light using 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 this organic layer is a light emitting layer.

The light emitting element of the present invention may be either a bottom emission type or a top emission type. In a top emission type light emitting element, the narrower the half width, the higher the light emitting element efficiency due to the resonance effect of the microcavity. Therefore, it is possible to achieve both color purity and light emitting element efficiency at a higher level.

The layer structure between the anode and the cathode in such a light emitting device includes, in addition to the structure consisting only of the light emitting layer, 1) light emitting layer/electron transport layer, 2) hole transport layer/light emitting layer, 3) hole transport layer/emissive layer/electron transport layer, 4) hole injection layer/hole transport layer/emissive layer/electron transport layer, 5) hole transport layer/emissive layer/electron transport layer/electron injection layer, 6) hole Injection layer/hole transport layer/emissive layer/electron transport layer/electron injection layer, 7) hole injection layer/hole transport layer/emissive layer/hole blocking layer/electron transport layer/electron injection layer, 8) positive Examples include a laminated structure such as hole injection layer/hole transport layer/electron blocking layer/light emitting layer/hole blocking layer/electron transport layer/electron injection layer.

Furthermore, the above laminated structure may be a tandem type in which a plurality of layers are laminated with an intermediate layer interposed therebetween. Examples of the intermediate layer generally include an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, an intermediate insulating layer, etc., and known material configurations can be used. As a preferred specific example of the tandem type, 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 Laminated configurations such as layer/electron injection layer may be mentioned. The light-emitting layers may be the same or different.

Furthermore, each of the above layers may be a single layer or multiple layers, and may be doped. Furthermore, in addition to the above-mentioned layers, a protective layer (cap layer) may be further included, and the light emitting element efficiency can be further improved due to the optical interference effect.

Specific examples of the structure of the light emitting element are listed below, but the structure of the present invention is not limited to these.

(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, to have little thermal deformation, and to have barrier properties that prevent water vapor and oxygen from entering the light emitting layer. Examples of the substrate include, but are not limited to, a glass plate, a ceramic plate, a resin film, a resin thin film, a metal thin plate, and the like. Among these, glass substrates are preferably used because they are transparent and easy to process. In particular, in the case of a bottom emission type light emitting element that extracts light through the substrate, a glass substrate having high transparency is preferable. Furthermore, flexible displays and foldable displays are increasing in mobile devices such as smartphones, and resin films and resin thin films obtained by hardening varnish are suitably used for this purpose. As the resin film, a heat-resistant film is used, and specific examples include polyimide film and polyethylene naphthalate film.

Further, various wirings, circuits, and switching elements using TFTs may be provided on the surface of the substrate to drive the organic EL.

(anode)
Preferably, an anode is formed on the substrate. Various wiring, 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, but in the case of a bottom emission type light emitting element, a transparent or semitransparent electrode is preferable, and in the case of a top emission type light emitting element, In this case, a reflective electrode is preferable.

Examples of the material 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), gold, silver, aluminum, chromium, etc. metals, and conductive polymers such as polythiophene, polypyrrole, and polyaniline. However, when using metal, it is preferable to make the film thin so that light can be partially transmitted. Among these, indium tin oxide (ITO) is more preferred from the viewpoint of transparency and stability.

The material for the reflective electrode is preferably one that does not absorb any light and has a high reflectance, such as metals such as aluminum, silver, and platinum.

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

The film thickness of the anode is not particularly limited, but is preferably several nm to several hundred nm.

The optimal method for forming the anode can be selected depending on the forming material, and examples include sputtering, vapor deposition, and inkjet methods. For example, when forming the anode using a metal oxide, a sputtering method is preferably used, and when forming an anode using a metal, a vapor deposition method is preferably used. Although the film thickness of the anode is not particularly limited, it is preferably several nm to several hundred nm.

(cathode)
The cathode is preferably formed on the surface opposite to the anode with the organic layer in between, and is particularly 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 translucent electrode. Preferably it is an electrode.

Generally, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys and multilayer laminated films of these metals and low work function metals such as lithium, sodium, potassium, calcium, and magnesium are used. , conductive metal oxides such as zinc oxide, indium tin oxide (ITO), and indium zinc oxide (IZO) are preferable. Among these, aluminum, silver, and magnesium are preferred as main components from the viewpoints of electrical resistance, ease of film formation, film stability, light emitting device efficiency, and the like. Furthermore, it is preferable that the layer be composed of magnesium and silver because electron injection into the electron transport layer and the electron injection layer becomes easy and driving voltage can be reduced.

(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 includes, for example, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys using these metals, silica, titania, and silicon nitride. Examples include inorganic substances, polyvinyl alcohol, polyvinyl chloride, organic polymer compounds such as hydrocarbon polymer compounds, and the like. However, in the case of a top emission type light emitting element, the material used for the protective layer is preferably selected from materials that are transparent in the visible light region.

(hole injection layer)
The hole injection layer is a layer inserted between the anode and the hole transport layer to facilitate hole injection. The hole injection layer may be a single layer or a plurality of layers may be laminated. Preferably, the presence of a hole injection layer between the hole transport layer and the anode not only allows lower voltage driving and improved durability, but also improves the carrier balance of the device and improves the light emitting device efficiency.

A preferable example of the hole injection material is an electron-donating hole injection material (donor material). These materials have a HOMO level shallower than that of the hole transport layer and are close to the work function of the anode, making it possible to reduce the energy barrier with the anode. Specifically, benzidine derivatives, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine (m-MTDATA), 4,4',4"-tris(1-naphthyl( Aromatic amine materials such as starburst arylamines such as phenyl)amino)triphenylamine (1-TNATA), carbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole Examples include heterocyclic compounds such as derivatives, phthalocyanine derivatives, and porphyrin derivatives, and polymer-based polymers such as polycarbonate and styrene derivatives having the above monomers in their side chains, polythiophenes such as PEDOT/PSS, polyaniline, polyfluorene, polyvinylcarbazole, and polysilane. Ru. Two or more types of these may be used. Alternatively, a hole injection layer may be formed by laminating a plurality of materials.

Another preferred example of the hole-injecting material is an electron-accepting hole-injecting material (acceptor material). Here, the hole injection layer may be composed of an acceptor material alone, or may be formed by doping the acceptor material into the donor material. The acceptor material is a material that forms a charge transfer complex with an adjacent hole transport layer when used alone, or with the donor material when used as a dope in the donor material. Use of such a material is more preferable because it contributes to improving the conductivity of the hole injection layer and lowering the driving voltage of the device, thereby improving the efficiency and durability of the light emitting device. Acceptor materials include metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, ruthenium oxide, charge transfer complexes such as tris(4-bromophenyl)aminium hexachloroantimonate (TBPAH), 1,4,5, 8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN6), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), fluorine Examples include n-type organic semiconductor compounds such as copper phthalocyanine, fullerene, and the like. When the hole injection layer contains an acceptor compound, the hole injection layer may be composed of one layer or a plurality of laminated layers.

(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 composed of a plurality of laminated layers.

The hole transport layer is formed using one type of hole transport material alone or by laminating or mixing two or more types of hole transport materials. Further, it is preferable that the hole transport material has high hole injection efficiency and efficiently transports the injected holes. To this end, it is required that the material has an appropriate ionization potential, high hole mobility, excellent stability, and is unlikely to generate trapping impurities.

Substances that meet these conditions include, but are not particularly limited to, benzidine derivatives, an aromatic amine material group called starburst arylamines, carbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, Heterocyclic compounds such as benzofuran derivatives, dibenzofuran derivatives, thiophene derivatives, benzothiophene derivatives, dibenzothiophene derivatives, fluorene derivatives, spirofluorene derivatives, oxadiazole derivatives, phthalocyanine derivatives, porphyrin derivatives, etc., and in polymer systems, the above monomers are used as side chains. Examples include polycarbonate, styrene derivatives, polythiophene, polyaniline, polyfluorene, polyvinylcarbazole, and polysilane.

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

The compound having the structure represented by the general formula (1) has a particularly excellent fluorescence quantum yield, a peak emission wavelength suitable for green emission, a narrow half-width, and a high color purity. Because of its excellent properties, it is preferable to use it as a dopant material for the light-emitting layer. 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, from the viewpoint of further suppressing the concentration quenching phenomenon. On the other hand, from the viewpoint of performing energy transfer more efficiently, the content of the dopant material in the light emitting layer is preferably 0.1% by weight or more, and more preferably 0.5% by weight or more.

The matrix material is preferably an organic compound that has a high charge transport ability and a high glass transition temperature. Examples of the matrix material include, but are not limited to, compounds having a condensed aryl ring such as naphthacene, pyrene, anthracene, and fluoranthene, and derivatives thereof, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl Aromatic amine derivatives such as -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 in polymer systems, polyphenylene vinylene derivatives, polypara Examples include phenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. Two or more types of these may be used, or two or more types of matrix materials may be laminated. Among these, carbazole derivatives, anthracene derivatives, and naphthacene derivatives are preferred.

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

Additionally, a phosphorescent material may be contained as a dopant material. The phosphorescent material includes at least one metal selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re). A metal complex compound is preferred, and from the viewpoint of highly efficient light emission, an iridium complex or a platinum complex is more preferred. 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.

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).

It is preferable that the light-emitting layer further contains a compound that exhibits delayed fluorescence. Compounds that exhibit delayed fluorescence have a small energy gap between the singlet excited state and the triplet excited state, causing a transition from the triplet excited state to the singlet excited state, and are materials that can utilize triplet excitons as delayed fluorescence. be. 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 having a sharp emission wavelength, a light emitting element with better light emitting element efficiency and color purity can be obtained. In this way, when the light-emitting layer contains a compound exhibiting delayed fluorescence, the light-emitting element efficiency is further improved, contributing to lower power consumption of the display. The compound exhibiting delayed fluorescence may be a single material or a plurality of materials, such as when forming an exciplex complex.

The compound exhibiting delayed fluorescence may be made of 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. Examples of compounds exhibiting such delayed fluorescence include, but are not particularly limited to, the following examples.

The light-emitting layer contains a compound having a structure represented by the above-mentioned general formula (1) as a dopant material, preferably further contains a compound exhibiting delayed fluorescence, and further contains a compound exhibiting delayed fluorescence and a matrix material. It is more preferable. When the excitation singlet energy of the dopant material is S ₁ (1), the excitation singlet energy of the compound exhibiting delayed fluorescence is S ₁ (2), and the excitation singlet energy of the matrix material is S ₁ (3), Equation 1 It is preferable to satisfy the following relationship.
S ₁ (3)>S ₁ (2)>S ₁ (1) (Formula 1)
Thereby, the matrix material can have a function of confining the energy of the compound exhibiting delayed fluorescence and the dopant material within the light emitting layer, making it possible to emit light efficiently and further improving the efficiency of the light emitting device. Examples of matrix materials that satisfy the relationship of formula 1 with the compound having the structure represented by general formula (1) or the compound exhibiting delayed fluorescence described above include, but are not particularly limited to, the following examples: can be mentioned.

(electron transport layer)
The electron transport layer is a layer into which electrons are injected from the cathode and further transports electrons. The electron transport material used in the electron transport layer is required to have high electron affinity, high electron mobility, excellent stability, and be a substance that does not easily generate impurities that become traps. Further, from the viewpoint of suppressing film quality deterioration due to crystallization, a compound having a molecular weight of 400 or more is preferable.

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-transporting layer may be composed of a single layer or a stack of a plurality of materials.

Examples of electron transport materials include polycyclic aromatic derivatives, styryl aromatic ring derivatives, quinone derivatives, phosphorus oxide derivatives, quinolinol complexes such as tris(8-quinolinolato)aluminum(III), benzoquinolinol complexes, hydroxyazole complexes, and azomethine complexes. , various metal complexes such as tropolone metal complexes and flavonol metal complexes. From the viewpoint of reducing driving voltage and further improving light emitting device efficiency, it is preferable to use a compound having a heteroaryl group containing electron-accepting nitrogen. Here, the electron-accepting nitrogen refers to a nitrogen atom forming multiple bonds with adjacent atoms. Since the heteroaryl group containing electron-accepting nitrogen has a large electron affinity, electrons can be easily injected from the cathode, allowing lower voltage driving. In addition, more electrons are supplied to the light emitting layer, and the probability of recombination increases, so that the light emitting device efficiency is further improved. 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, and imidazole. Examples include derivatives, oxazole derivatives, thiazole derivatives, triazole derivatives, oxadiazole derivatives, thiadiazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, phenanthroimidazole derivatives, and oligopyridine derivatives such as bipyridine and terpyridine. Two or more types of these may be used.

Further, it is more preferable that the electron transport material has a condensed polycyclic aromatic skeleton because the glass transition temperature is improved, the electron mobility is large, and the driving voltage can be reduced. Such a fused polycyclic aromatic skeleton is preferably a quinolinol skeleton, a triazine skeleton, a fluoranthene skeleton, an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton.

The electron transport layer may contain a donor material. Here, the donor material is a compound that improves the electron injection barrier, facilitates electron injection from the cathode or electron injection layer to the electron transport layer, and further improves the electrical conductivity of the electron transport layer.

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, and alkaline earth metals. Examples include inorganic salts, 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 types of these may be used. Among these, metallic lithium, rare earth metals, and lithium quinolinol (Liq) are preferred.

(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. . Moreover, you may contain 2 or more types of these. 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 device of the present invention preferably contains a phenanthroline derivative having a structure represented by general formula (4) in the electron injection layer.

In the above general formula (6), Ar ⁴ is selected from the group consisting of a p-valent aromatic hydrocarbon group and a p-valent aromatic heterocyclic group. p is a natural number from 1 to 3. R ³⁰¹ to 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. Among Ar ⁴ , the p phenanthrolyl groups can be substituted at any position.

Examples of the aromatic hydrocarbon group include, in the case of a monovalent group, 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 benzo Examples include phenanthryl group, benzanthracenyl group, chrysenyl group, pyrenyl group, fluoranthenyl group, triphenylenyl group, benzofluoranthenyl group, dibenzaanthracenyl group, perylenyl group, and helicenyl group. Among them, from the viewpoint of ease of synthesis and sublimation, phenyl group, biphenyl group, terphenyl group, naphthyl group, fluorenyl group, phenanthryl group, anthracenyl group, pyrenyl group, fluoranthenyl group, triphenylenyl group, and their hydrogen atoms A group from which at least a part of is removed is preferred. The aromatic hydrocarbon group may or may not have a substituent. The number of carbon atoms forming the ring is not particularly limited, but is preferably in the range of 6 or more and 40 or less, more preferably 6 or more and 30 or less. Furthermore, when there are substituents on two adjacent carbon atoms, these substituents may form a ring structure.

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

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

From the viewpoint of sublimation property and thin film forming property, p is preferably 2.

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

Furthermore, an inorganic material such as an insulator or a semiconductor can also be used for the electron injection layer. Use of these materials is preferable because short circuits in the light emitting element can be suppressed and electron injection properties can be improved.

As such an insulator, metal compounds such as alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides are preferable. Two or more types of these may be used.

(charge generation layer)
The charge generation layer in the present invention generally consists of a double layer, and specifically can be used as a pn junction charge generation layer consisting of an n-type charge generation layer and a p-type charge generation layer. The pn junction type charge generation layer generates charges or separates the charges into holes and electrons when a voltage is applied in the light emitting element, and transfers these holes and electrons to the hole transport layer and the electron transport layer. injection into the light-emitting layer via the layer. Specifically, it functions as an intermediate charge generation layer in a light emitting element 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-emission layer located on the cathode side. Therefore, the light emitting element efficiency in a light emitting element in which a plurality of light emitting layers are laminated can be improved, the driving voltage can be reduced, and the durability of the light emitting element is also improved.

The n-type charge generation layer consists of an n-type dopant and a host, and conventional materials can be used for these. For example, n-type dopants include alkali metals, alkaline earth metals, rare earth metals, and the like. Two or more types of these may be used. Among these, alkali metals or salts thereof, and rare earth metals are preferred, and lithium metal, lithium fluoride (LiF), lithium quinolinol (Liq), and ytterbium metal are more preferred. Further, examples of the host include triazine derivatives, phenanthroline derivatives, oligopyridine derivatives, and the like. Two or more types of these may be used. Among these, triazine derivatives, phenanthroline derivatives, and oligopyridine derivatives are preferred, phenanthroline derivatives and terpyridine derivatives are more preferred, phenanthroline derivatives having the structure represented by the general formula (6) above are even more preferred, and the following general formula (7) A phenanthroline derivative represented by is particularly preferred. That is, the light emitting device of the present invention preferably contains a phenanthroline derivative having a structure represented by general formula (6) in the charge generation layer, and preferably contains a phenanthroline derivative having a structure represented by general formula (7). More preferred.

In the above general formula (7), any one of Y ¹ to Y ³ is a nitrogen atom, and the others are methine groups. L ² is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group, and 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.

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

The p-type charge generation layer includes a p-type dopant and a host, and conventional materials can be used for these. For example, as a p-type dopant, tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), tetracyanoquinodimethane derivatives, radialene derivatives, iodine, FeCl ₃ , FeF ₃ , SbCl ₅ , etc. can be mentioned. Two or more types of these may be used. Among these, arylamine derivatives are preferred.

(Method for manufacturing light emitting element)
The formation method of each of the above 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 method, coating method, inkjet method, printing method, etc. . Among these, resistance heating vapor deposition is preferred from the viewpoint of device characteristics.

The thickness of the organic layer cannot be limited because it depends on the resistance value of the luminescent material, but it is preferably 1 to 1000 nm. The thickness of each of the light-emitting layer, electron transport layer, and hole transport layer is preferably 1 nm or more and 200 nm or less, more preferably 5 nm or more and 100 nm or less.

(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. Although direct current is mainly used as electrical energy here, pulsed current or alternating current can also be used. There are no particular restrictions on the current and voltage values, and required characteristic values vary depending on the purpose of the device, but from the viewpoint of power consumption and durability of the device, it is preferable that high brightness can be obtained at low voltage.

In the light-emitting element according to the embodiment of the present invention, from the viewpoint of increasing color purity, the half-width is preferably 45 nm or less, more preferably 35 nm or less, and 30 nm or less at the emission wavelength when energized. The following are more preferred.

(Applications of light emitting elements)
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 thinner and lighter, so it can be used, for example, as a display device or a lighting device. Suitably used.

Examples of display devices include display devices such as displays that use a matrix method, backlights for various devices, and the like. Backlights are mainly used for the purpose of improving the visibility of display devices such as non-self-luminous displays, and are used in liquid crystal displays, clocks, audio devices, automobile panels, display boards, signs, and the like. Among these, it can be suitably used for liquid crystal displays, and in particular, for backlights for personal computers, for which thinning is being considered.

Examples of the lighting device include medical lighting, interior lighting, etc., and it is possible to realize a lighting device that combines low power consumption, bright luminous color, and high design.

<Color conversion composition>
The compounds of the present invention may be used in color conversion compositions that convert incident light from a light emitter, such as a light source, into light of a different wavelength from the incident light. It is preferable that the color conversion composition contains the compound represented by the above-mentioned general formula (1) 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 longer wavelength than the incident light.

<Method for manufacturing color conversion composition>
The color conversion composition of the present invention can be prepared by, for example, mixing a binder resin, a compound having a structure represented by general formula (1), and additives and solvents as necessary to a predetermined composition, and then stirring and It can be obtained by homogeneously mixing or kneading using a kneader. Examples of the stirring/kneading machine include a homogenizer, a revolution-revolution type stirrer, a three-roller mill, a ball mill, a planetary ball mill, and a bead mill. After mixing or dispersing, or during the process of mixing or dispersing, defoaming is also preferably carried out under vacuum or reduced pressure conditions. Further, certain specific components may be mixed in advance, or treatments such as aging may be performed. It is also possible to remove the solvent with an evaporator to reach the desired solids concentration.

<Color conversion sheet>
The color conversion sheet of the present invention is a sheet that converts incident light from a light emitter such as a light source into light of a wavelength different from that of the incident light, and contains the color conversion composition of the present invention described above. It is preferable to convert the incident light into light with a longer wavelength than that of the incident light.

The color conversion sheet of the present invention preferably includes a color conversion layer that is a layer formed from the color conversion composition described above. The amount of residual solvent in the color conversion layer is preferably 0.5% by weight 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% by weight or more from the viewpoint of further improving the luminous efficiency of the color conversion sheet.

<Method for manufacturing color conversion sheet>
Next, an example of the method for manufacturing the color conversion sheet of the present invention will be explained. A color conversion layer is formed by applying the color conversion composition prepared by the method described above onto a base material and drying it. When the binder resin is a thermosetting resin, the color conversion composition may be applied onto the base material and then heated and cured to form a color conversion layer, and when the binder resin is a photocurable resin, the color conversion composition The material may be applied onto a substrate and then photocured to form a color conversion layer.

<Light source unit>
The light source unit of the present invention includes at least a light source and the color conversion sheet of the present invention described above. The light source included in the light source unit of the present invention serves as a source of the above-mentioned excitation light. The method of arranging the light source and the color conversion sheet is not particularly limited, and the light source and color conversion sheet may be placed in close contact with each other, or a remote phosphor format may be used in which the light source and the color conversion sheet are separated. Good too. Further, the light source unit may further include a color filter for the purpose of increasing color purity.

<Light source>
Any type of light source can be used as long as it emits light in a wavelength range that can be absorbed by the luminescent 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 electroluminescent light source, an LED light source, an incandescent light source, or sunlight. Among these, LED is a suitable light source, and for display (display device) and lighting applications, blue LED, which has a light source in the range of 430 to 500 nm, is an even more suitable light source because it can improve the color purity of blue light. be.

The light source may have one kind of luminescence peak or two or more kinds of luminescence peaks, but in order to improve color purity, it is preferable to have one kind of luminescence peak. It is also possible to use a plurality of light sources with different types of emission peaks in any combination.

The light source unit of the present invention is useful for various light sources such as space lighting and backlighting, and specifically, it can be used for display devices, lighting, interiors, signs, signboards, etc., but especially for display devices and lighting applications. It is particularly suitable for use in

<Display device, lighting device>
The display device of the present invention includes at least the light emitting element of the present invention described above and/or the color conversion sheet described above. For example, the light source unit of the present invention described above is preferably used as a backlight unit in a display device such as a liquid crystal display. Further, by using the above-described light emitting element, 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 manufactured.

Furthermore, the lighting device of the present invention includes at least the light emitting element of the present invention described above and/or the color conversion sheet of the present invention described above. For example, this lighting device emits white light by combining a blue LED light source as a light source unit and a color conversion sheet that converts the blue light from the blue LED light source into light with a longer wavelength. configured. Furthermore, a lighting device can also be obtained using the above-described light emitting element of the present invention. These lighting devices include, for example, medical lighting, interior lighting, and the like, and can achieve both bright luminescent color, high durability, and high design.

<Photoelectric conversion material>
The compound of the present invention may be used in 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 the structure represented by the general formula (1) of the present invention, but may further contain other photoelectric conversion materials in order to further increase the photoelectric conversion efficiency. .

The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

First, evaluation methods for each example and comparative example will be described below.

( ^1H -NMR)
Deuterated chloroform solutions of the compounds obtained in Examples 1 to 23 were subjected to ¹ H-NMR measurement using superconducting FTNMR EX-270 (manufactured by JEOL Ltd.), and their structures were identified.

(Light emission characteristics)
Diluted solutions of the compounds obtained in Examples 1 to 23 and Comparative Examples 1 to 6 dissolved in toluene at a concentration of 10 ^-5 mol/L were measured using a fluorescence spectrophotometer (FluoroMax-4P) manufactured by Horiba, Ltd. The emission wavelength was measured, and the peak wavelength and half-width were determined.

(Light emitting element characteristics)
A voltage was applied to the light emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 41 so that the current density was 0.1 mA/cm ² , and a spectral radiance meter CS-1000 manufactured by Konica Minolta, Inc. was used. The emission wavelength was measured using Based on the obtained emission wavelength, the light emitting device efficiency was determined on the assumption that Lambassian radiation was performed.

In addition, the emission wavelength was similarly measured when a voltage was applied to the light emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 41 so that the current density was 10 mA/cm ² , and the peak wavelength and half wavelength were measured. The price range was calculated.

A voltage was applied to the light emitting devices obtained in Examples 24 to 115 and Comparative Examples 7 to 37 so that the current density was 10 mA/cm ² , and the brightness of the light emitting devices was measured using a photodiode. Luminance. Further, a voltage was continuously applied so that the current density was 10 mA/cm ² , and the time (LT90) at which the brightness reached 90% of the initial brightness was measured, and this was used as an index of durability.

Example 1

Raw material 1A is published in Journal of American Chemical Society, 2020, vol. 142, p. It can be synthesized by the method disclosed in No. 19468-19472.

Raw material 1B is obtained from Angewandte chemie international edition, vol. 59, p. It can be synthesized by the method disclosed in No. 7813-7817.

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. did. After heating and stirring, the reaction solution was cooled to room temperature, water and toluene were added, and the mixture was separated. After distilling off the solvent under reduced pressure, the residue was purified by silica gel column chromatography to obtain intermediate INT1 (yield 73%).

A flask containing intermediate INT1 (7.9 g) and tert-butylbenzene (90 ml) was cooled to 0° C., and a 1.6 M n-butyllithium hexane solution (5.5 ml) was added dropwise. After the dropwise addition was completed, the mixture was stirred for 1 hour while being heated to room temperature. The mixture was cooled to 0° C. again, and boron tribromide (8.9 g) was added dropwise. After completion of the dropwise addition, the mixture was stirred for 1 hour while being heated to room temperature, then cooled to 0°C, N,N-diisopropylethylamine (4.6 g) was added, and then heated and stirred 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 heated and washed with toluene and butyl acetate to obtain D-1 (yield 17%). The results of ¹ H-NMR measurement of the obtained compound D-1 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).

Compound D-1 was purified by sublimation at 400° C. under a pressure of 1×10 ⁻³ Pa using an oil diffusion pump, and then used as a light emitting device material.

Table 1 shows the results of evaluating the luminescence properties of Compound D-1.

Example 2

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 under a nitrogen atmosphere. The mixture was heated and stirred at 150° C. for 2 hours. After heating and stirring, the reaction solution was cooled to room temperature, water was added, and the mixture was stirred. The precipitated solid was filtered with suction, and the solid obtained was purified by silica gel column chromatography to obtain intermediate INT2-1 (yield 61%).

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 and stirred 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%).

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 was completed, 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 heated and washed with toluene and butyl acetate, and then recrystallized from chlorobenzene to obtain D-2 (yield 28%). The results of ¹ H-NMR measurement of the obtained compound D-2 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).

Compound D-2 was purified by sublimation at 400° C. under a pressure of 1×10 ⁻³ Pa using an oil diffusion pump, and then used as a light emitting device material.

Table 1 shows the results of evaluating the luminescence properties of Compound D-2.

Examples 3-23
Compounds D-3 to D-23 having the following structures were synthesized by changing the raw materials and synthesis conditions as appropriate, and the results of evaluation in the same manner as in Example 1 are shown in Table 1.

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.

Example 24
A glass substrate (manufactured by Geomatec Co., Ltd., 11Ω/□, sputtered product) on which a 100 nm thick ITO transparent conductive film was deposited was cut into 38 mm×46 mm and etched. The obtained substrate was ultrasonically cleaned for 15 minutes using "Semico Clean" (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, placed in a vacuum evaporation device, and evacuated until the degree of vacuum in the device became 5×10 ⁻⁴ Pa or less. HAT-CN6 was deposited to a thickness of 10 nm as a hole injection layer by a resistance heating method. Next, compound HT-1 was deposited to a thickness of 40 nm as a first hole transport layer. Next, compound HT-2 was deposited to a thickness of 10 nm as a second hole transport layer. Next, as a light-emitting layer, Compound H-1 was used as a matrix material and Compound D-1 was used as a dopant material, and the dopant material was deposited to a thickness of 20 nm at a doping concentration of 1% by weight. Next, as an electron transport layer, compound ET-1 was used as an electron transport material and compound 2E-1 was used as a donor material, and the deposition rate ratio of ET-1 and 2E-1 was set to ET-1:2E-1=1. :1 to a thickness of 30 nm. Thereafter, magnesium and silver were co-evaporated to a thickness of 100 nm to form a cathode, and a 5 mm x 5 mm square light emitting element was manufactured. Note that HAT-CN6 _, HT-1, HT-2, H-1, ET-1, and 2E-1 are the compounds shown below.

Table 2 shows the results of evaluating the obtained light emitting device using the method described above.

(Examples 25-46, Comparative Examples 7-12)
A light emitting device was produced in the same manner as in Example 24, except that the compounds listed in Table 2 were used as dopant materials, and Table 2 shows the evaluation results.

Example 47
A glass substrate (manufactured by Geomatec Co., Ltd., 11Ω/□, sputtered product) on which a 100 nm thick ITO transparent conductive film was deposited was cut into 38 mm×46 mm and etched. The obtained substrate was ultrasonically cleaned for 15 minutes using "Semico Clean" (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, placed in a vacuum evaporation device, and evacuated until the degree of vacuum in the device became 5×10 ⁻⁴ Pa or less. Using a resistance heating method, HAT-CN6 was first deposited to a thickness of 10 nm as a hole injection layer, and then HT-3 was deposited to a thickness of 30 nm as a hole transport layer. Next, as a light-emitting layer, H-2 is used as a matrix material, compound D-1 is used as a dopant material, and compound H-3, which is a compound showing delayed fluorescence, is mixed in a weight ratio of 79.0:1.0:20. It was deposited to a thickness of 30 nm. Subsequently, ET-2 was laminated to a thickness of 10 nm as a hole blocking layer, and ET-3 was laminated to a thickness of 40 nm as an electron transport layer. 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 100 nm to form a cathode, thereby producing a 5 mm x 5 mm square light emitting element. Note that HT-3, H-2, H-3, ET-2, and ET-3 are the compounds shown below.

Table 3 shows the results of evaluating the obtained light emitting device using the method described above.

(Examples 48-69, Comparative Examples 13-18)
A light emitting device was produced in the same manner as in Example 47 except that the compounds listed in Table 3 were used as dopant materials, and Table 3 shows the evaluation results.

Example 70
(Tandem type light emitting element evaluation)
A glass substrate (manufactured by Geomatec Co., Ltd., 11Ω/□, sputtered product) on which a 100 nm thick ITO transparent conductive film was deposited was cut into 38 mm×46 mm and etched. The obtained substrate was ultrasonically cleaned for 15 minutes using "Semico Clean" (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, placed in a vacuum evaporation device, and evacuated until the degree of vacuum in the device became 5×10 ⁻⁴ Pa or less. Using a resistance heating method, HAT-CN6 was first deposited to a thickness of 10 nm as a hole injection layer, and then HT-3 was deposited to a thickness of 30 nm as a hole transport layer. Next, as a light-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 are used. , in a weight ratio of 79.0:1.0:20 to a thickness of 30 nm. Subsequently, ET-2 was laminated to a thickness of 10 nm as a hole blocking layer, and ET-3 was laminated to a thickness of 40 nm as an electron transport layer. Subsequently, as an n-type charge generation layer, compound ET-4 as an n-type host and metallic lithium as an n-type dopant were laminated to a thickness of 10 nm at a deposition rate ratio of 99:1. Furthermore, HAT-CN6 was laminated to a thickness of 10 nm as a p-type charge generation layer. Thereon, a 30 nm thick hole transport layer and a 30 nm light emitting layer were formed in the same manner as above. Further, 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. 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 to form a cathode, thereby producing a 5 mm x 5 mm square tandem light emitting device.

When the obtained light emitting device was evaluated by the method described above, the light emitting device efficiency was 31.8% and the LT90 was 185 hours.

(Examples 71-92)
A light emitting device was produced in the same manner as in Example 70, except that the compound listed in Table 4 was used instead of D-1 as the dopant material. The evaluation results are shown in Table 4.

(Examples 93-115)
Light emission was carried out in the same manner as in Example 70, except that Compound ET-5 was used instead of Compound ET-4, which is an n-type host, as the n-type charge generation layer, and the compounds listed in Table 4 were used as the dopant materials. The device was fabricated. The evaluation results are shown in Table 4.

(Comparative Examples 19 to 37)
A light-emitting device was produced in the same manner as in Example 70, except that Bphen was used instead of the n-type host compound ET-4 as the n-type charge generation layer, and the compounds listed in Table 5 were used as the dopant materials. did. The evaluation results are shown in Table 5.

Note that ET-4, ET-5 and Bphen are the compounds shown below.

As described above, the following inventions [1] to [17] are described in this specification.
[1] A compound having a structure represented by the above general formula (1).
[2] The compound according to [1], wherein in general formula (1), L is a single bond.
[3] A substituted or unsubstituted polycyclic aromatic hydrocarbon in which ring C ¹ and ring D ¹ contain a ring structure represented by any of the above general formulas (2-1) to (2-8). The compound according to [1] or [2].
[4] The compound according to any one of [1] to [3], wherein in general formula (1), ring C ¹ and ring D ¹ are the same.
[5] The compound according to any one of [1] to [4], which has a structure represented by the above general formula (3).
[6] The compound according to [5], wherein X ¹ is NR ²⁰ and R ²⁰ is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.
[7] The compound having the structure represented by the general formula (3) has a structure represented by any of the general formulas (4-1) to (4-5) [5] or [6] Compounds described.
[8] The compound according to any one of [5] to [7], wherein X ¹ is NR ²⁰ and R ²⁰ is a substituted or unsubstituted alkenyl group or a substituted or unsubstituted imino group.
[9] The compound having the structure represented by the above general formula (3) has a structure represented by the above general formula (5-1) or (5-2) [5] to [8] Compounds described.
[10] A light emitting device material comprising the compound according to any one of [1] to [9].
[11] It has a cathode, an anode, and one or more organic layers disposed between the cathode and the anode, and at least one of the organic layers is described in any one of [1] to [9]. A light emitting device containing a compound of
[12] The light emitting device according to [11], wherein the organic layer containing the compound according to any one of [1] to [9] is a light emitting layer.
[13] The light emitting device according to [12], wherein the light emitting layer contains a matrix material.
[14] The light emitting device according to [12] or [13], wherein the light emitting layer contains a compound exhibiting delayed fluorescence.
[15] The light emitting layer contains a matrix material and a compound exhibiting delayed fluorescence, the excitation singlet energy of the matrix material is S ₁ (1), the excitation singlet energy of the compound exhibiting delayed fluorescence is S ₁ (2), When the excited singlet energy of the compound according to any one of [1] to [5] is S ₁ (3), the light emission according to any one of [12] to [14], which satisfies the relationship of formula 1. element.
S 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 type organic electroluminescent device.
[20] 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 that of the incident light, the color conversion composition containing the compound according to any one of [1] to [9] and a binder resin. thing.
[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 element according to any one of [11] to [19].
[25] A display device including 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 including the light source unit according to [23].

Claims

A compound having a structure represented by the following general formula (1).

(In the above general formula (1), Ring A 1 and Ring B 1 are substituted or unsubstituted aromatic hydrocarbon rings having 6 to 30 ring atoms, or substituted or unsubstituted aromatic hydrocarbon rings having 5 to 30 ring atoms. It is an aromatic heterocycle.
Ring C 1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 11 or more and 20 or less ring atoms.
Ring D 1 is a substituted or unsubstituted polycyclic aromatic hydrocarbon having 7 or more and 20 or less ring atoms.
X is O, N-R A or S, and R A is an alkyl group, cycloalkyl group, alkenyl group, imino group, aryl group or heteroaryl group. These groups may further have a substituent. Further, R A may further be bonded to ring A 1 or ring B 1 via a linking group to form a ring structure. In that case, the linking group is a single bond, -O-, -S-, >CR A1 R A2 or >SiR A3 R A4 . R A1 to 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. Furthermore, R 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 . R A5 to 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 further have a substituent. Good too. Furthermore, R 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.
Claim 1, wherein ring C 1 and ring D 1 are substituted or unsubstituted polycyclic aromatic hydrocarbons containing a ring structure represented by any one of chemical formulas (2-1) to (2-8). compound.
The compound according to claim 1, wherein in general formula (1), ring C 1 and ring D 1 are the same.
The compound according to claim 1, having a structure represented by the following general formula (3).

(In the above general formula (3), R 1 to R 19 are each independently hydrogen, halogen, cyano group, alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group) , aryl ether group, arylthioether group, aryl group, heteroaryl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, nitro group or silyl group.These groups may further have a substituent. good.
Ring A 1 and ring B 1 are as described in general formula (1).
X 1 is O, NR 20 or S, and R 20 is an alkyl group, cycloalkyl group, alkenyl group, imino group, aryl group or heteroaryl group. These groups may further have a substituent. Further, R 20 may further be bonded to ring A 1 or ring B 1 via a linking group to form a ring structure. In that case, the linking group is a single bond, -O-, -S-, >CR 21 R 22 or >SiR 23 R 24 . R 21 to 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. Furthermore, R 21 and R 22 or R 23 and R 24 may be further bonded via a linking group. )
6. The compound according to claim 5, wherein X 1 is NR 20 and R 20 is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.
The compound according to claim 5, wherein the compound having a structure represented by the general formula (3) has a structure represented by any of the following general formulas (4-1) to (4-5).

(In the above general formulas (4-1) to (4-5), R 1 to R 19 are as described in general formula (1).
R 101 to R 107 , R 110 to R 116 , R 120 to R 127 , R 130 to R 131 and R 140 to R 141 each independently represent hydrogen, halogen, cyano group, alkyl group, cycloalkyl group, Alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, silyl group, or any of these It is a saturated or unsaturated ring formed between adjacent groups. These groups may further have a substituent.
Ar 1 to Ar 3 each independently represent a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.
Y 1 to Y 2 are each independently a single bond, O, S, CR 150 R 151 or SiR 152 R 153 .
W 1 to W 2 are each independently NR 154 , O or S.
Here, R 150 to R 154 each independently represent hydrogen, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and these groups may further have a substituent. Furthermore, R 150 and R 151 or R 152 and R 153 may be further bonded via a linking group. )
6. The compound according to claim 5, wherein X 1 is NR 20 and R 20 is a substituted or unsubstituted alkenyl group or a substituted or unsubstituted imino group.
The compound according to claim 5, wherein the compound having a structure represented by the general formula (3) has a structure represented by the following general formula (5-1) or (5-2).

(In the above general formulas (5-1) to (5-2), R 1 to R 19 are as described in general formula (3).
R 201 to R 207 and R 210 to R 214 each independently represent hydrogen, halogen, cyano group, alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, silyl group, or a saturated or unsaturated ring formed between adjacent groups among these groups. . These groups may further have a substituent.
W 3 to W 4 are each independently N or CR 220 . R 220 is hydrogen, an alkyl group, a cycloalkyl group, an aryl group or a heteroaryl group, and these groups may further have a substituent. )
A light emitting device material comprising the compound according to any one of claims 1 to 9.
A light-emitting element comprising a cathode, an anode, and one or more organic layers disposed between the cathode and the anode, and at least one of the organic layers contains the compound according to claim 1.
The light emitting device according to claim 11, wherein the organic layer containing the compound according to claim 1 is a light emitting layer.
13. The light emitting device according to claim 12, wherein the light emitting layer further contains a matrix material.
The light emitting device according to claim 12, wherein the light emitting layer further contains a compound exhibiting delayed fluorescence.
The light-emitting layer further contains a matrix material and a compound exhibiting delayed fluorescence, and the excitation singlet energy of the matrix material is S 1 (1), the excitation singlet energy of the compound exhibiting delayed fluorescence is S 1 (2), and the general formula 13. The light emitting device according to claim 12, which satisfies the relationship of Formula 1, where the excited singlet energy of the compound having the structure represented by (1) is S 1 (3).
S 1 (1)>S 1 (2)>S 1 (3) (Formula 1)
The light emitting device according to claim 12, further comprising a charge generation layer.
The light emitting device according to claim 16, wherein the charge generation layer contains a phenanthroline derivative represented by the following general formula (6).

(In general formula (6), Ar 1 is selected from the group consisting of a p-valent aromatic hydrocarbon group and a p-valent aromatic heterocyclic group. p is a natural number from 1 to 3. R 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.Among Ar 1 , p phenanthrolyl groups The replacement position is any position.)
The light emitting device according to claim 16, wherein the charge generation layer contains a phenanthroline derivative represented by the following general formula (7).

(In general formula (7), any one of Y 1 to Y 3 is a nitrogen atom, and the others are methine groups; L 1 is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group or a substituted or unsubstituted anthrylene group, and L 2 is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted anthrylene group; provided that these groups are substituted or When the substituent is an alkyl group or an alkoxy group; A is a phenyl group or a pyridyl group, and n is 0 or 1.)
The light emitting device according to claim 12, which is a top emission type organic electroluminescent device.
A photoelectric conversion element material comprising the compound according to any one of claims 1 to 9.
A color conversion composition that converts incident light into light of a wavelength different from that of the incident light, the color conversion composition comprising the compound according to any one of claims 1 to 9 and a binder resin.
A color conversion sheet comprising the color conversion composition according to claim 21 or a cured product thereof.
A light source unit comprising a light source and the color conversion sheet according to claim 22.
A display device comprising the light emitting element according to any one of claims 11 to 19.
A display device comprising the light source unit according to claim 23.
A lighting device comprising the light emitting element according to any one of claims 11 to 19.
A lighting device comprising the light source unit according to claim 23.