Compound, light-emitting material, and light-emitting element

Abstract

This compound represented by the general formula is a light-emitting material having a short lifetime of delayed fluorescence. Two or three among R1-R4 are donor groups, at least one of which is a ring-fused indol-1-yl group, one or two among R1-R4 is / are an aryl group or a heteroaryl group, and the remaining R1-R4 is a hydrogen atom or a deuterium atom.

Description

Compound, light-emitting material and light-emitting device

[0001] The present invention relates to a compound useful as a light-emitting material and a light-emitting device using the same.

[0002] Research into improving the luminous efficiency of light-emitting elements such as organic electroluminescence elements (organic EL elements) has been actively conducted. In particular, various efforts have been made to improve the luminous efficiency by newly developing and combining electron transport materials, hole transport materials, luminescent materials, etc. that constitute organic electroluminescence elements. Among these efforts, research into organic electroluminescence elements that utilize delayed fluorescent materials has also been seen.

[0003] Delayed fluorescent materials are materials that, in an excited state, undergo reverse intersystem crossing from an excited triplet state to an excited singlet state, and then emit fluorescence when returning from the excited singlet state to the ground state. Fluorescence via this route is observed later than fluorescence from the excited singlet state (normal fluorescence) directly generated from the ground state, and is therefore called delayed fluorescence. Here, for example, when a light-emitting compound is excited by carrier injection, the probability of occurrence of the excited singlet state and the excited triplet state is statistically 25%:75%, so there is a limit to the improvement of luminous efficiency when only fluorescence from the directly generated excited singlet state is used. On the other hand, delayed fluorescent materials can utilize not only the excited singlet state but also the excited triplet state for fluorescence emission via the above-mentioned reverse intersystem crossing route, thereby achieving higher luminous efficiency than ordinary fluorescent materials.

[0004] Since this principle was clarified, various delayed fluorescent materials have been discovered through various studies. However, just because a material emits delayed fluorescence does not necessarily mean that it is useful as a light-emitting material. Some delayed fluorescent materials are relatively resistant to reverse intersystem crossing, and some have long delayed fluorescence lifetimes. In addition, some materials accumulate excitons in high current density regions, reducing luminous efficiency, or rapidly degrade when operated for long periods of time. Therefore, the reality is that there are many delayed fluorescent materials that require improvement in terms of practicality. In addition, the characteristics required of fluorescent materials have been increasing in recent years. For this reason, even excellent delayed fluorescent materials, such as compounds having the following structure, require further improvement in their properties (see Patent Document 1).

[0005]

[0006] WO2019 / 004254

[0007] The relationship between the chemical structure and properties of delayed fluorescent materials has not been fully elucidated, and as a result, it is currently difficult to generalize the chemical structures of compounds useful as luminescent materials, and many unknowns remain.

[0008] Under these circumstances, the present inventors have conducted extensive research with the aim of providing compounds that are more useful as light-emitting materials for light-emitting devices, and have conducted extensive research with the aim of deriving and generalizing a general formula for compounds that are more useful as light-emitting materials.

[0009] As a result of intensive research to achieve the above object, the present inventors have found that, among terephthalonitrile derivatives, compounds having a structure that satisfies certain conditions are useful as light-emitting materials. The present invention has been proposed based on this finding, and specifically has the following configuration.

[0010] [1] A compound represented by the following general formula (1): [In the general formula (1), R １ ~R ４Two or three of these independently represent donor groups, and at least one of them is a ring-fused indol-1-yl group. The ring-fused indol-1-yl group forms a fused ring having four or more rings by ring condensation with indole, and the fused ring may be substituted. １ ~R ４ One or two of R each independently represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom. １ ~R ４ represents a hydrogen atom or a deuterium atom.] [2] R １ ~R ４ two of R are each independently a donor group, and at least one of them is an indol-1-yl group to which the ring is fused; １ ~R ４ one of R is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group bonded at a carbon atom, and the remaining R １ ~R ４ [3] The compound according to [1], wherein R is a hydrogen atom or a deuterium atom. １ ~R ４ two of R are each independently a donor group, and at least one of them is an indol-1-yl group to which the ring is fused; １ ~R ４ [4] The compound according to [1], wherein two of R are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups bonded at a carbon atom. １ ~R ４ three of R are each independently a donor group, at least one of which is an indol-1-yl group to which the ring is fused; １ ~R ４ [5] The compound according to [1], wherein one of R is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom. １ and R ４ are each independently a donor group, and R ３[6] The compound according to any one of [1] to [4], wherein R is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom. ２ and R ４ are each independently a donor group, and R ３ is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded via a carbon atom. [7] The compound according to any one of [1] to [6], wherein the fused ring has five or more rings. [8] The compound according to [7], wherein a substituted or unsubstituted aryl group is substituted on a carbon atom constituting the skeleton of the fused ring having four or more rings. [9] The compound according to [7], wherein a nitrogen atom is contained in the skeleton of the fused ring having four or more rings, and the nitrogen atom is substituted on the nitrogen atom.

[10] The compound according to any one of [1] to [9], wherein the ring fused to the benzene ring constituting the indol-1-yl group is a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted pyrrole ring, and the furan ring, the thiophene ring, and the pyrrole ring may be further fused with another ring.

[11] The compound according to any one of [1] to

[10] , wherein the indol-1-yl group to which the ring is fused has any of the following fused rings: [In each of the above structures, a hydrogen atom may be substituted, and further, a ring may be fused.]

[12] The compound according to any one of [1] to

[10] , wherein the indol-1-yl group to which the ring is fused has any one of the following fused ring skeletons: [In each of the above structures, the hydrogen atom may be substituted, and a ring may be further fused.]

[13] The compound according to any one of [1] to

[12] , wherein the indol-1-yl group to which the ring is fused has a structure in which a heterocycle is fused at the 4- and 5-positions of the indole ring.

[14] The compound according to any one of [1] to

[13] , wherein Ar is a substituted or unsubstituted phenyl group or a substituted or unsubstituted pyridyl group.

[15] The compound according to any one of [1] to

[14] , wherein the compound consists of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

[16] A light-emitting material comprising the compound according to any one of [1] to

[15] .

[17] A light-emitting device comprising the compound according to any one of [1] to

[15] .

[18] The light-emitting device according to

[17] , wherein the light-emitting device has a light-emitting layer, and the light-emitting layer contains the compound and a host material.

[19] The light-emitting element according to

[18] , wherein the light-emitting element has a light-emitting layer, the light-emitting layer contains the compound and a light-emitting material, and light is emitted mainly from the light-emitting material.

[0011] The compounds of the present invention are useful as light-emitting materials. The compounds of the present invention also include compounds with short delayed fluorescence lifetimes. Furthermore, organic light-emitting devices using the compounds of the present invention are useful because they have high device durability.

[0012] FIG. 2 is a schematic cross-sectional view showing an example of a layer structure of an organic electroluminescence element.

[0013] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In addition, some or all of the hydrogen atoms present in the molecules of the compound used in the present invention may be replaced with deuterium atoms ( ２In the chemical structural formulae of this specification, hydrogen atoms are represented by H or are omitted. For example, when the atom bonded to the carbon atom constituting the ring skeleton of a benzene ring is omitted, it is assumed that H is bonded to the carbon atom constituting the ring skeleton at the omitted position. In the chemical structural formulae of this specification, deuterium atoms are represented by D.

[0014] [Compound represented by general formula (1)]

[0015] R in general formula (1) １ ~R ４ Two or three of these groups each independently represent a donor group. At least one of the donor groups is a substituted or unsubstituted indol-1-yl group, and a ring is fused to the indole ring constituting the indol-1-yl group, thereby forming a fused ring having four or more rings. Hereinafter, in this specification, a group satisfying this condition will be referred to as a "ring-fused indol-1-yl group."

[0016] The ring-fused indol-1-yl group may be a polycyclic ring having one ring fused to the benzene ring or pyrrole ring constituting the indol-1-yl group, or may be a polycyclic ring having two or more rings or a monocyclic ring. For example, when two rings are fused, it is preferable that one ring is fused to the benzene ring and the other ring is fused to the pyrrole ring. The two fused rings may be the same or different. A fused ring having four or more, five or more, or six or more rings may be formed by fusion of a ring to the indole ring, and it is preferable that a fused ring having five or more rings is formed. For example, a compound having a fused ring with four rings, a compound having a fused ring with five rings, a compound having a fused ring with six rings, or a compound having a fused ring with eight rings may be employed. The ring may be fused only to the 2- and 3-positions (b) of the indole ring, only to the 4- and 5-positions (e), only to the 5- and 6-positions (f), only to the 6- and 7-positions (g), or both to the 4- and 5-positions (e) and 6- and 7-positions (g). Also, the ring may be fused to any one of the 4- and 5-positions (e), 5- and 6-positions (f), and 6- and 7-positions (g) and to the 2- and 3-positions (b) (see the formula below, * indicates the bond position).

[0017] The ring directly fused to the benzene ring or pyrrole ring constituting the indol-1-yl group (when the fused ring is polycyclic, this refers to only the directly fused ring among the rings constituting the polycyclic ring) may be any of an aromatic hydrocarbon ring, an aromatic heterocycle, an aliphatic hydrocarbon ring, and an aliphatic heterocycle. A preferred case is when one or more rings selected from the group consisting of a benzene ring and an aromatic heterocycle are directly fused. The heterocycle referred to here is a ring containing a heteroatom. The heteroatom is preferably selected from an oxygen atom, a sulfur atom, a nitrogen atom, and a silicon atom, and more preferably selected from an oxygen atom, a sulfur atom, and a nitrogen atom. In a preferred embodiment, the heteroatom is an oxygen atom. In another preferred embodiment, the heteroatom is a sulfur atom. In yet another preferred embodiment, the heteroatom is a nitrogen atom. The number of heteroatoms contained as ring skeleton-constituting atoms of the heterocycle is one or more, preferably one to three, and more preferably one or two. In a preferred embodiment, the number of heteroatoms is one. When the number of heteroatoms is two or more, they are preferably the same type of heteroatom, but may be composed of different types of heteroatoms. For example, all of the two or more heteroatoms may be nitrogen atoms. The atoms constituting the ring skeleton other than the heteroatoms are carbon atoms. The number of atoms constituting the ring skeleton of the heterocycle directly fused to the benzene ring constituting the indol-1-yl group is preferably 4 to 8, more preferably 5 to 7, and even more preferably 5 or 6. In a preferred embodiment, the number of atoms constituting the ring skeleton of the heterocycle is 5. The heterocycle preferably has two or more conjugated double bonds, and the fusion of the heterocycle preferably expands the conjugated system of the indole ring (i.e., preferably has aromaticity). Preferred examples of heterocycles include a furan ring, a thiophene ring, and a pyrrole ring. The ring directly fused to the benzene ring or pyrrole ring constituting the indol-1-yl group may be further fused with another ring. Furthermore, the fused ring may be a monocyclic or fused ring. Examples of the fused ring include an aromatic hydrocarbon ring, an aromatic hetero ring, an aliphatic hydrocarbon ring, and an aliphatic hetero ring.In a preferred embodiment of the present invention, at least one heterocycle is directly fused to the benzene ring or pyrrole ring constituting the indol-1-yl group. In a preferred embodiment of the present invention, the fused ring constituting the ring-fused indol-1-yl group contains two or more heterocycles. For example, the fused ring may contain two or three heterocycles.

[0018] In this specification, an example of an aromatic hydrocarbon ring is a benzene ring. Examples of aromatic heterocycles include a furan ring, a thiophene ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, and an imidazole ring. Examples of aliphatic hydrocarbon rings include a cyclopentane ring, a cyclohexane ring, and a cycloheptane ring. Examples of aliphatic heterocycles include a piperidine ring, a pyrrolidine ring, and an imidazoline ring. Specific examples of fused rings include a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyran ring, a tetracene ring, an indole ring, an isoindole ring, a benzimidazole ring, a benzotriazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, and a cinnoline ring.

[0019] In a preferred embodiment of the present invention, the ring-fused indol-1-yl group is a benzofuran-fused indol-1-yl group, a benzothiophene-fused indol-1-yl group, an indole-fused indol-1-yl group, or a silaindene-fused indol-1-yl group. In a more preferred embodiment of the present invention, the indol-1-yl group is a benzofuran-fused indol-1-yl group, a benzothiophene-fused indol-1-yl group, or an indole-fused indol-1-yl group.

[0020] In the present invention, a substituted or unsubstituted benzofuro[2,3-e]indol-1-yl group can be used as the benzofuran-fused indol-1-yl group. A substituted or unsubstituted benzofuro[3,2-e]indol-1-yl group can also be used. A substituted or unsubstituted benzofuro[2,3-f]indol-1-yl group can also be used. A substituted or unsubstituted benzofuro[3,2-f]indol-1-yl group can also be used. A substituted or unsubstituted benzofuro[2,3-g]indol-1-yl group can also be used. A substituted or unsubstituted benzofuro[3,2-g]indol-1-yl group can also be used. The fused rings constituting these groups may or may not be fused with further rings. In the present invention, a substituted or unsubstituted benzofuro[2,3-a]carbazol-9-yl group can be used as the benzofuran-fused indol-1-yl group. A substituted or unsubstituted benzofuro[3,2-a]carbazol-9-yl group can also be used. A substituted or unsubstituted benzofuro[2,3-b]carbazol-9-yl group can also be used. A substituted or unsubstituted benzofuro[3,2-b]carbazol-9-yl group can also be used. A substituted or unsubstituted benzofuro[2,3-c]carbazol-9-yl group can also be used. A substituted or unsubstituted benzofuro[3,2-c]carbazol-9-yl group can also be used. The fused rings constituting these groups may or may not be fused with further rings. Preferred benzofuran-fused indol-1-yl groups include groups having any of the structures shown below, in which the hydrogen atoms in the structures shown below may or may not be substituted. For example, groups substituted with an aryl group such as a phenyl group, or groups substituted at the 3-position of the carbazole ring are preferred examples. Furthermore, the benzene ring in the following structure may or may not be condensed with a further ring.

[0021] A carbazol-9-yl group in which two benzofuran rings are fused at the 2- and 3-positions can also be used. Specifically, it is a group having any of the structures shown below, in which the hydrogen atoms in the structures shown below may or may not be substituted. Furthermore, the benzene ring in the structures shown below may or may not be fused with a further ring.

[0022] In the present invention, a substituted or unsubstituted benzothieno[2,3-e]indol-1-yl group can be used as the benzothiophene-fused indol-1-yl group. A substituted or unsubstituted benzothieno[3,2-e]indol-1-yl group can also be used. A substituted or unsubstituted benzothieno[2,3-f]indol-1-yl group can also be used. A substituted or unsubstituted benzothieno[3,2-f]indol-1-yl group can also be used. A substituted or unsubstituted benzothieno[2,3-g]indol-1-yl group can also be used. A substituted or unsubstituted benzothieno[3,2-g]indol-1-yl group can also be used. The fused rings constituting these groups may or may not be fused with further rings. In the present invention, a substituted or unsubstituted benzothieno[2,3-a]carbazol-9-yl group can be used as the benzothiophene-fused indol-1-yl group. A substituted or unsubstituted benzothieno[3,2-a]carbazol-9-yl group can also be used. A substituted or unsubstituted benzothieno[2,3-b]carbazol-9-yl group can also be used. A substituted or unsubstituted benzothieno[3,2-b]carbazol-9-yl group can also be used. A substituted or unsubstituted benzothieno[2,3-c]carbazol-9-yl group can also be used. A substituted or unsubstituted benzothieno[3,2-c]carbazol-9-yl group can also be used. The fused rings constituting these groups may or may not be fused with further rings. Preferred benzothiophene-fused indol-1-yl groups include groups having any of the structures shown below, in which the hydrogen atoms may or may not be substituted. For example, preferred examples include groups substituted with an aryl group such as a phenyl group, or groups substituted at the 3-position of the carbazole ring. Furthermore, the benzene ring in the structure shown below may or may not be fused with a further ring.

[0023] A carbazol-9-yl group in which two benzothiophene rings are fused at the 2- and 3-positions can also be used. Specifically, it is a group having any of the structures shown below, in which the hydrogen atoms in the structures shown below may or may not be substituted. Furthermore, the benzene ring in the structures shown below may or may not be fused with a further ring.

[0024] In the present invention, a substituted or unsubstituted indolo[2,3-e]indol-1-yl group can be used as the indole-fused indol-1-yl group. A substituted or unsubstituted indolo[3,2-e]indol-1-yl group can also be used. A substituted or unsubstituted indolo[2,3-f]indol-1-yl group can also be used. A substituted or unsubstituted indolo[3,2-f]indol-1-yl group can also be used. A substituted or unsubstituted indolo[2,3-g]indol-1-yl group can also be used. A substituted or unsubstituted indolo[3,2-g]indol-1-yl group can also be used. The fused rings constituting these groups may or may not be fused with further rings. In the present invention, a substituted or unsubstituted indolo[2,3-a]carbazol-9-yl group can be used as the indole-fused indol-1-yl group. A substituted or unsubstituted indolo[3,2-a]carbazol-9-yl group can also be employed. A substituted or unsubstituted indolo[2,3-b]carbazol-9-yl group can also be employed. A substituted or unsubstituted indolo[3,2-b]carbazol-9-yl group can also be employed. A substituted or unsubstituted indolo[2,3-c]carbazol-9-yl group can also be employed. A substituted or unsubstituted indolo[3,2-c]carbazol-9-yl group can also be employed. The fused rings constituting these groups may or may not be further fused with a ring. Preferred indole-fused indol-1-yl groups include groups having any of the structures shown below, in which the hydrogen atoms in the structures shown below may or may not be substituted. For example, preferred examples include groups substituted with an aryl group such as a phenyl group, or groups substituted at the 3-position of the carbazole ring. Furthermore, the benzene ring in the following structure may or may not be condensed with a further ring.

[0025] The "alkyl group" referred to in this specification may be linear, branched, or cyclic. Furthermore, two or more of the linear, cyclic, and branched moieties may be mixed. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. Furthermore, the number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, a 2-ethylhexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, an n-nonyl group, an isononyl group, an n-decanyl group, an isodecanyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The alkyl group as a substituent may be further substituted with a deuterium atom, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. The "alkenyl group" may be linear, branched, or cyclic. Furthermore, two or more of the linear, cyclic, and branched portions may be mixed. The number of carbon atoms in the alkenyl group may be, for example, 2 or more or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkenyl groups include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The alkenyl group as a substituent may be further substituted. The "aryl group" and "heteroaryl group" may be a monocyclic ring or a fused ring formed by condensing two or more rings. In the case of a fused ring, the number of fused rings is preferably 2 to 6, and can be selected from, for example, 2 to 4. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a quinoline ring, a pyrazine ring, a quinoxaline ring, and a naphthyridine ring.Specific examples of the arylene group or heteroarylene group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 9-anthracenyl group, a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group. For the alkyl portion of an "alkoxy group" and an "alkylthio group," the above explanation and specific examples of the alkyl group can be referenced. For the aryl portion of an "aryloxy group" and an "arylthio group," the above explanation and specific examples of the aryl group can be referenced. For the heteroaryl portion of a "heteroaryloxy group" and a "heteroarylthio group," the above explanation and specific examples of the heteroaryl group can be referenced. The ring-fused indol-1-yl group preferably has 16 or more atoms, more preferably 20 or more atoms, other than hydrogen and deuterium atoms, and can be, for example, 26 or more atoms. Furthermore, the number of atoms is preferably 80 or less, more preferably 50 or less, and even more preferably 30 or less.

[0026] In the general formula (1), the ring-fused indol-1-yl group is R １ ~R ４There may be only one, two, or three of these. When there is only one ring-fused indol-1-yl group, there may be one or two donor groups other than the ring-fused indol-1-yl group (hereinafter referred to as "other donor groups"). When there are two, they may be the same or different. When there are two ring-fused indol-1-yl groups, there may be no other donor groups, or there may be one other donor group. When there are three ring-fused indol-1-yl groups, there are no other donor groups. The other donor groups are groups with a negative Hammett σp value. Here, the "Hammett σp value" was proposed by L. P. Hammett and quantifies the effect of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, the constant (σp) is a constant specific to the substituent in the para-substituted benzene derivative, which is expressed by the following equation between the substituent and the reaction rate constant or equilibrium constant: log(k / k0) = ρσp or log(K / K0) = ρσp. In the above equation, k represents the rate constant for the benzene derivative without a substituent, k represents the rate constant for the benzene derivative substituted with a substituent, K represents the equilibrium constant for the benzene derivative without a substituent, K represents the equilibrium constant for the benzene derivative substituted with a substituent, and ρ represents a reaction constant determined by the type and conditions of the reaction. For an explanation of the "Hammett σp value" in the present invention and the numerical values ​​of each substituent, please refer to the description of the σp value in Hansch, C. et al., Chem. Rev., 91, 165-195 (1991). Groups with a negative Hammett σp value tend to exhibit electron-donating (donor) properties, while groups with a positive Hammett σp value tend to exhibit electron-withdrawing (acceptor) properties.

[0027] The other donor group in the present invention is preferably a group containing a substituted amino group. The substituent bonded to the nitrogen atom of the amino group is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. The substituted amino group is particularly preferably a substituted or unsubstituted diarylamino group or a substituted or unsubstituted diheteroarylamino group. The two aryl groups constituting the diarylamino group may be bonded to each other, or the two heteroaryl groups constituting the diheteroarylamino group may be bonded to each other. The other donor group in the present invention may be a group bonded to the nitrogen atom of the substituted amino group or a group bonded to a group to which the substituted amino group is bonded. The group to which the substituted amino group is bonded is preferably a π-conjugated group. A group bonded to the nitrogen atom of the substituted amino group is more preferred. A particularly preferred other donor group in the present invention is a substituted or unsubstituted carbazol-9-yl group. The two benzene rings constituting the carbazol-9-yl group are not fused with other rings. Substituents for the carbazol-9-yl group include alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkoxy groups, alkylthio groups, aryloxy groups, arylthio groups, heteroaryloxy groups, heteroarylthio groups, and substituted amino groups. Preferred substituents include alkyl groups, aryl groups, and substituted amino groups. For an explanation of substituted amino groups, see the description in the previous paragraph. The substituted amino group referred to here includes substituted or unsubstituted carbazolyl groups, such as substituted or unsubstituted carbazol-3-yl groups and substituted or unsubstituted carbazol-9-yl groups. The other donor group in the present invention preferably has 8 or more atoms, excluding hydrogen and deuterium atoms, more preferably 12 or more, and can be, for example, 16 or more. In addition, it is preferably 80 or less, more preferably 60 or less, and even more preferably 40 or less.

[0028] In a preferred embodiment of the present invention, the ring-fused indol-1-yl group is limited to one containing two or more heterocycles in the fused ring constituting the group, and other donor groups are referred to as "other donor groups." Examples of groups containing two or more heterocycles in the fused ring include D13 to D152 shown below. In another preferred embodiment of the present invention, the ring-fused indol-1-yl group is limited to one in which at least one heterocycle is directly fused to the benzene ring or pyrrole ring of the indole, and other donor groups are referred to as "other donor groups."

[0029] In the following, D in general formula (1) １ and D ２ Specific examples of donor groups that can be used are shown below. D7 to D152 are specific examples of ring-fused indol-1-yl groups, and D1 to D6 are specific examples of other donor groups. In the following structural formulae, Ph represents a phenyl group, and * represents the bonding position. Also, a methyl group can be used as a CH ３ For example, D2 represents a 3-methylcarbazol-9-yl group.

[0030] Compounds D1 to D152 in which all hydrogen atoms have been replaced with deuterium atoms are disclosed herein as D1d to D152d. Compounds D31 to D42 and D61 to D79 in which the phenyl group represented by "Ph" has been replaced with a pentadeuteriophenyl group (a group in which all hydrogen atoms of a phenyl group have been replaced with deuterium atoms) are disclosed herein as D31d1 to D42d1 and D61d1 to D79d1.

[0031] R in general formula (1) １ ~R ４ One or two of R each independently represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom. １ ~R ４Among R, those that are not substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups bonded via a carbon atom, or ring-fused indol-1-yl groups represent hydrogen atoms or deuterium atoms, and can be, for example, hydrogen atoms. １ ~R ４ Only one of R may be a substituted or unsubstituted aryl group, １ ~R ４ Only one of R may be a substituted or unsubstituted heteroaryl group bonded at a carbon atom. １ ~R ４ Two of R may be the same substituted or unsubstituted aryl group, or may be different substituted or unsubstituted aryl groups. １ ~R ４ Two of R may be the same substituted or unsubstituted heteroaryl group, or may be different substituted or unsubstituted heteroaryl groups. １ ~R ４ In a preferred embodiment of the present invention, one of R may be a substituted or unsubstituted aryl group and the other may be a substituted or unsubstituted heteroaryl group bonded to a carbon atom. １ ~R ４ and only one of R is a substituted or unsubstituted aryl group, or １ ~R ４ In accordance with the present invention, by employing Ar as a substituent, the ΔE ＳＴ By reducing the difference between the lowest excited singlet energy and the lowest excited triplet energy, the usefulness (luminous efficiency, etc.) of the delayed fluorescent material can be improved.

[0032] For a description of the aryl group and heteroaryl group that R and Ar may represent and their preferred ranges, please refer to the description of the aryl group and heteroaryl group in the substituent of the ring-fused indol-1-yl group. However, the heteroaryl group is a heteroaryl group bonded via a carbon atom. Examples of the substituent of the aryl group and the substituent of the heteroaryl group include alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkoxy groups, alkylthio groups, aryloxy groups, arylthio groups, heteroaryloxy groups, heteroarylthio groups, cyano groups, and groups combining these groups. Preferred groups of substituents include alkyl groups, aryl groups, alkoxy groups, alkylthio groups, and cyano groups. In a preferred embodiment of the present invention, the aryl group and the heteroaryl group are either substituted with an alkyl group or unsubstituted. Examples include an unsubstituted phenyl group and a phenyl group substituted with an alkyl group.

[0033] Specific examples of substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups bonded at a carbon atom that can be represented by Ar in general formula (1) are shown below. In the following structural formulas, t-Bu represents a tertiary butyl group, and * represents the bonding position.

[0034] Ar1 to Ar81 in which all hydrogen atoms have been replaced with deuterium atoms are disclosed herein as Ar1d to Ar81d.

[0035] The compound represented by general formula (1) preferably does not contain metal atoms, and may be a compound composed solely of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, and sulfur atoms. In a preferred embodiment of the present invention, the compound represented by general formula (1) is composed solely of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and oxygen atoms. The compound represented by general formula (1) may also be a compound composed solely of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and sulfur atoms. The compound represented by general formula (1) may also be a compound composed solely of atoms selected from the group consisting of carbon, hydrogen, deuterium, and nitrogen atoms. The compound represented by general formula (1) may also be a compound composed solely of atoms selected from the group consisting of carbon, hydrogen, and nitrogen atoms. Furthermore, the compound represented by general formula (1) may be a compound containing no hydrogen atoms but containing deuterium atoms. For example, the compound represented by general formula (1) may be a compound composed solely of atoms selected from the group consisting of carbon, deuterium, nitrogen, oxygen, and sulfur atoms. In one embodiment of the present invention, the compound represented by general formula (1) has a symmetrical structure. For example, it may have an axisymmetric structure or a rotationally symmetric structure.

[0036] Specific examples of the compound represented by general formula (1) are shown in Tables 1 to 6 below. １ , D ２ , D ３ , Ar, Ar １ , Ar ２ The structure of the compound is shown by specifying each compound. For example, in the case of compounds 1 to 125 in Table 1, Ar is fixed to Ar1, and D １ D ２ and D １ D ２ In the order of D7 to D20, D22 to D30, D36 to D48, D50 to D60, D67 to D73, and D79 to D149, the compounds 1 to 125 are identified. １ D ２is D21, and Ar is Ar2 to Ar21, Ar25 to Ar52, and Ar54 to Ar81 in this order, are designated as compounds 856 to 931, and D １ D ２ The compounds are numbered in the following manner: D31, Ar2 to Ar21, Ar25 to Ar52, and Ar54 to Ar81 are numbered as compounds 931 to 1006, and finally D １ D ２ is D152, and Ar is Ar2 to Ar21, Ar25 to Ar52, and Ar54 to Ar81, respectively, are designated as compounds 2376 to 2451. In Tables 1 to 6, the structures of compounds 1 to 25053 are individually identified and are specifically disclosed in this specification. Compounds 1d to 25053d are also disclosed in which all hydrogen atoms present in the molecules of compounds 1 to 25053 have been replaced with deuterium atoms. In addition, when rotamers exist among the following compounds, both the mixture of rotamers and each separated rotamer are also considered to be disclosed in this specification. In addition, in Tables 1 to 6 below, Ar82 has the same structure as Ar1d (a structure in which all hydrogen atoms in Ar1 have been replaced with deuterium atoms).

[0037] The molecular weight of the compound represented by general formula (1) is preferably 1500 or less, more preferably 1200 or less, even more preferably 1000 or less, and even more preferably 900 or less, when, for example, an organic layer containing the compound represented by general formula (1) is intended to be formed into a film by a vapor deposition method. The lower limit of the molecular weight is the molecular weight of the smallest compound represented by general formula (1). The compound represented by general formula (1) may be formed into a film by a coating method regardless of its molecular weight. Using a coating method, even compounds with relatively large molecular weights can be formed into a film. The compound represented by general formula (1) has the advantage of being easily soluble in organic solvents among cyanobenzene-based compounds. Therefore, the compound represented by general formula (1) is easy to apply a coating method to and can be easily purified to increase its purity. The compound represented by general formula (1) has a short delayed fluorescence lifetime (τ2), so when used in an organic light-emitting device, it can improve the luminous efficiency of the device and suppress roll-off. Therefore, an organic light-emitting device with high efficiency and excellent stability (durability) can be provided.

[0038] It is also conceivable to apply the present invention to a compound containing a plurality of structures represented by general formula (1) in the molecule and use it as a light-emitting material. For example, it is conceivable to make a polymerizable group present in advance in the structure represented by general formula (1), and then polymerize the polymerizable group to obtain a polymer, and use the polymer as a light-emitting material. Specifically, it is conceivable to make a compound containing a plurality of structures represented by general formula (1) in the molecule and use the polymerizable group as a light-emitting material. １ ~R ４ It is conceivable to prepare a monomer containing a polymerizable functional group in any one of the above, and polymerize it alone or copolymerize it with other monomers to obtain a polymer having repeating units, and use the polymer as a light-emitting material. Alternatively, it is conceivable to couple compounds having a structure represented by general formula (1) together to obtain a dimer or trimer, and use the dimer or trimer as a light-emitting material.

[0039] Examples of polymers having a repeating unit containing a structure represented by general formula (1) include polymers containing a structure represented by the following general formula (2) or (3).

[0040] In the general formula (2) or (3), Q represents a group containing the structure represented by the general formula (1), L １ and L ２ represents a linking group. The number of carbon atoms in the linking group is preferably 0 to 20, more preferably 1 to 15, and even more preferably 2 to 10. The linking group is -X １１ -L １１ Preferably, X has a structure represented by the formula: １１ represents an oxygen atom or a sulfur atom, and is preferably an oxygen atom. １１ represents a linking group, and is preferably a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group, and more preferably a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted phenylene group. １０１ , R １０２ , R １０３ and R １０４ each independently represents a substituent. Preferably, it is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a halogen atom, more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, an unsubstituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, and even more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, or an unsubstituted alkoxy group having 1 to 3 carbon atoms. L １ and L ２ is a linking group represented by R １ ~R ４ Two or more linking groups may be linked to one Q to form a crosslinked structure or a network structure.

[0041] Specific structural examples of the repeating unit include structures represented by the following formulas (4) to (7).

[0042] The polymer having repeating units containing these formulas (4) to (7) is a polymer having a repeating unit represented by R １ ~R ４The synthesis can be carried out by introducing a hydroxy group into either of the above, reacting the compound shown below with the compound as a linker to introduce a polymerizable group, and polymerizing the polymerizable group.

[0043] A polymer containing a structure represented by general formula (1) in its molecule may be a polymer consisting only of repeating units having the structure represented by general formula (1), or may be a polymer containing repeating units having other structures. Furthermore, the repeating units having the structure represented by general formula (1) contained in the polymer may be of a single type, or may contain two or more types. Examples of repeating units that do not have the structure represented by general formula (1) include those derived from monomers used in ordinary copolymerization. For example, repeating units derived from monomers having an ethylenically unsaturated bond, such as ethylene and styrene, can be mentioned.

[0044] In some embodiments, the compound represented by general formula (1) is a light-emitting material. In some embodiments, the compound represented by general formula (1) is a compound capable of emitting delayed fluorescence. In some embodiments of the present disclosure, the compound represented by general formula (1), when excited by thermal or electronic means, can emit light in the UV region, the blue, green, yellow, orange, or red region of the visible spectrum (e.g., about 420 nm to about 500 nm, about 500 nm to about 600 nm, or about 600 nm to about 700 nm), or the near-infrared region. In some embodiments of the present disclosure, the compound represented by general formula (1), when excited by thermal or electronic means, can emit light in the red or orange region of the visible spectrum (e.g., about 620 nm to about 780 nm, about 650 nm). In some embodiments of the present disclosure, the compound represented by general formula (1), when excited by thermal or electronic means, can emit light in the orange or yellow region of the visible spectrum (e.g., about 570 nm to about 620 nm, about 590 nm, about 570 nm). In certain embodiments of the present disclosure, compounds represented by general formula (1) when excited by thermal or electronic means can emit light in the green region of the visible spectrum (e.g., about 490 nm to about 575 nm, about 510 nm). In certain embodiments of the present disclosure, compounds represented by general formula (1) when excited by thermal or electronic means can emit light in the blue region of the visible spectrum (e.g., about 400 nm to about 490 nm, about 475 nm). In certain embodiments of the present disclosure, compounds represented by general formula (1) when excited by thermal or electronic means can emit light in the ultraviolet region of the spectrum (e.g., 280-400 nm). In certain embodiments of the present disclosure, compounds represented by general formula (1) when excited by thermal or electronic means can emit light in the infrared region of the spectrum (e.g., 780 nm to 2 μm).

[0045] The electronic properties of small molecule chemical libraries can be calculated using well-known ab initio quantum chemical calculations. For example, time-dependent density functional theory using a basis set known as 6-31G* and the Becke three-parameter Lee-Yang-Parr hybrid functional can be used to analyze the Hartree-Fock equations (TD-DFT / B3LYP / 6-31G*) and screen for molecular fragments (moieties) with HOMOs above a certain threshold and LUMOs below a certain threshold. Thus, donor moieties ("D") can be selected if they have a HOMO energy (e.g., ionization potential) above -6.5 eV, for example. Acceptor moieties ("A") can be selected if they have a LUMO energy (e.g., electron affinity) below -0.5 eV, for example. The bridging moiety ("B") prevents overlap between the π-conjugated systems of the donor and acceptor moieties, for example, by providing a strongly conjugated system that can tightly constrain the acceptor and donor moieties into specific configurations. In certain embodiments, compound libraries are screened using one or more of the following properties: 1. Emission near a specific wavelength; 2. Calculated triplet state above a specific energy level; 3. ΔE below a specific value. ＳＴ 4. Quantum yield above a certain value 5. HOMO level 6. LUMO level In some embodiments, the difference between the lowest singlet excited state and the lowest triplet excited state at 77 K (ΔE ＳＴ ) is less than about 0.5 eV, less than about 0.4 eV, less than about 0.3 eV, less than about 0.2 eV, or less than about 0.1 eV. In some embodiments, ΔE ＳＴ The quantum yield of the compound represented by formula (1) is less than about 0.09 eV, less than about 0.08 eV, less than about 0.07 eV, less than about 0.06 eV, less than about 0.05 eV, less than about 0.04 eV, less than about 0.03 eV, less than about 0.02 eV, or less than about 0.01 eV. In certain embodiments, the compound represented by formula (1) exhibits a quantum yield of greater than 25%, e.g., about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95% or more.

[0046] [Method for synthesizing the compound represented by general formula (1)] The compound represented by general formula (1) is a novel compound. The compound represented by general formula (1) can be synthesized by combining known reactions. For example, １ , D ２ The position where the compound is to be introduced is a (hetero)aryldifluoroterephthalonitrile substituted with a fluorine atom. １ -H and D ２ It can be synthesized by reacting —H in the presence of sodium hydride in tetrahydrofuran. １ and D ２ are different from each other, D １ -H, D ２ The reaction with —H may be carried out in two steps. Specific conditions and procedures for the reaction can be found in the examples described below.

[0047] Compositions Using Compounds of Formula (1) In some embodiments, compounds of Formula (1) may be combined with one or more materials (e.g., small molecules, polymers, metals, metal complexes, etc.) that disperse, covalently bond, coat, support, or associate with the compounds to form a solid film or layer. For example, compounds of Formula (1) may be combined with electroactive materials to form a film. In some cases, compounds of Formula (1) may be combined with hole transporting polymers. In some cases, compounds of Formula (1) may be combined with electron transporting polymers. In some cases, compounds of Formula (1) may be combined with hole transporting and electron transporting polymers. In some cases, compounds of Formula (1) may be combined with copolymers having both hole transporting and electron transporting moieties. In these embodiments, electrons and / or holes formed in the solid film or layer may interact with the compounds of Formula (1).

[0048] [Film Formation] In some embodiments, a film containing the compound of the present invention represented by general formula (1) can be formed by a wet process. In the wet process, a solution containing a composition containing the compound of the present invention is applied to a surface, and a film is formed after removing the solvent. Examples of wet processes include, but are not limited to, spin coating, slit coating, inkjet printing (spraying), gravure printing, offset printing, and flexographic printing. In the wet process, an appropriate organic solvent capable of dissolving the composition containing the compound of the present invention is selected and used. In some embodiments, a substituent (e.g., an alkyl group) that increases the solubility in organic solvents can be introduced into the compound contained in the composition. In some embodiments, a film containing the compound of the present invention can be formed by a dry process. In some embodiments, a vacuum deposition method can be used as the dry process, but is not limited to this. When using a vacuum deposition method, the compounds constituting the film may be co-deposited from separate deposition sources, or may be co-deposited from a single deposition source containing a mixture of compounds. When a single deposition source is used, a mixed powder of compound powders may be used, a compression molded product obtained by compressing the mixed powder may be used, or a mixture obtained by heating, melting, and cooling each compound may be used. In some embodiments, co-deposition can be performed under conditions where the deposition rates (weight loss rates) of multiple compounds contained in a single deposition source are the same or nearly the same, thereby forming a film having a composition ratio corresponding to the composition ratio of the multiple compounds contained in the deposition source. A film having a desired composition ratio can be easily formed by mixing multiple compounds in the same composition ratio as the composition ratio of the film to be formed and using the resulting deposition source. In some embodiments, a temperature at which the weight loss rates of the co-deposited compounds are the same can be identified, and this temperature can be used as the temperature during co-deposition.

[0049] [Examples of Use of Compounds Represented by General Formula (1)] Organic Light-Emitting Diode: One aspect of the present invention relates to the use of a compound represented by general formula (1) of the present invention as an emitting material in an organic light-emitting device. In some embodiments, the compound represented by general formula (1) of the present invention can be effectively used as an emitting material in the emitting layer of an organic light-emitting device. In some embodiments, the compound represented by general formula (1) includes a delayed fluorescent material (delayed fluorescent material) that emits delayed fluorescence. In some embodiments, the present invention provides a delayed fluorescent material having a structure represented by general formula (1). In some embodiments, the present invention relates to the use of a compound represented by general formula (1) as a delayed fluorescent material. In some embodiments, the present invention can be used as a host material and can be used together with one or more emitting materials, which may be fluorescent materials, phosphorescent materials, or TADF. In some embodiments, the compound represented by general formula (1) can also be used as a hole transport material. In some embodiments, the compound represented by general formula (1) can be used as an electron transport material. In some embodiments, the present invention relates to a method for producing delayed fluorescence from a compound represented by general formula (1). In some embodiments, an organic light-emitting device containing the compound as an emitting material emits delayed fluorescence and exhibits high light emission efficiency. In some embodiments, the light-emitting layer comprises a compound represented by general formula (1), and the compound represented by general formula (1) is aligned parallel to the substrate. In some embodiments, the substrate is a film-forming surface. In some embodiments, the orientation of the compound represented by general formula (1) relative to the film-forming surface influences or determines the propagation direction of light emitted by the aligned compound. In some embodiments, aligning the propagation direction of light emitted by the compound represented by general formula (1) improves the light extraction efficiency from the light-emitting layer. One aspect of the present invention relates to an organic light-emitting device. In some embodiments, the organic light-emitting device comprises an emitting layer. In some embodiments, the emitting layer comprises a compound represented by general formula (1) as a light-emitting material. In some embodiments, the organic light-emitting device is an organic photoluminescence device (organic PL device). In some embodiments, the organic light-emitting device is an organic electroluminescence device (organic EL device).In some embodiments, the compound represented by general formula (1) assists the light emission of other light-emitting materials contained in the light-emitting layer (as a so-called assist dopant). In some embodiments, the compound represented by general formula (1) contained in the light-emitting layer has its lowest excited singlet energy level, which is between the lowest excited singlet energy level of the host material contained in the light-emitting layer and the lowest excited singlet energy level of the other light-emitting materials contained in the light-emitting layer. In some embodiments, the organic photoluminescent device includes at least one light-emitting layer. In some embodiments, the organic electroluminescent device includes at least an anode, a cathode, and an organic layer between the anode and the cathode. In some embodiments, the organic layer includes at least an light-emitting layer. In some embodiments, the organic layer includes only an light-emitting layer. In some embodiments, the organic layer includes one or more organic layers in addition to the light-emitting layer. Examples of organic layers include a hole-transporting layer, a hole-injecting layer, an electron-blocking layer, a hole-blocking layer, an electron-injecting layer, an electron-transporting layer, and an exciton-blocking layer. In an embodiment, the hole transport layer may be a hole injection transport layer having a hole injection function, and the electron transport layer may be an electron injection transport layer having an electron injection function. An example of an organic electroluminescent device is shown in FIG.

[0050] Emitting Layer: In some embodiments, the emitting layer is a layer in which holes and electrons injected from the anode and cathode, respectively, recombine to form excitons. In some embodiments, the layer emits light. In some embodiments, only an emitting material is used as the emitting layer. In some embodiments, the emitting layer includes an emitting material and a host material. In some embodiments, the emitting material is one or more compounds of general formula (1). In some embodiments, to improve the light emission efficiency of organic electroluminescent devices and organic photoluminescent devices, singlet and triplet excitons generated in the emitting material are confined within the emitting material. In some embodiments, a host material is used in addition to the emitting material in the emitting layer. In some embodiments, the host material is an organic compound. In some embodiments, the organic compound has excited singlet and triplet energies, at least one of which is higher than those of the emitting material of the present invention. In some embodiments, the singlet and triplet excitons generated in the emitting material of the present invention are confined within the molecules of the emitting material of the present invention. In some embodiments, the singlet and triplet excitons are sufficiently confined to improve the light emission efficiency. In some embodiments, singlet and triplet excitons are not sufficiently confined while still achieving high light emission efficiency, i.e., host materials that can achieve high light emission efficiency can be used in the present invention without any particular limitations. In some embodiments, light emission occurs in the light-emitting material in the light-emitting layer of the device of the present invention. In some embodiments, the emitted light includes both fluorescence and delayed fluorescence. In some embodiments, the emitted light includes light emitted from the host material. In some embodiments, the emitted light consists of light emitted from the host material. In some embodiments, the emitted light includes light emitted from the compound represented by general formula (1) and light emitted from the host material. In some embodiments, a TADF molecule and a host material are used. In some embodiments, TADF is an assist dopant.

[0051] When a compound represented by general formula (1) is used as an assist dopant, various compounds can be used as the luminescent material (preferably a fluorescent material). Examples of such luminescent materials include anthracene derivatives, tetracene derivatives, naphthacene derivatives, pyrene derivatives, perylene derivatives, chrysene derivatives, rubrene derivatives, coumarin derivatives, pyran derivatives, stilbene derivatives, fluorene derivatives, anthryl derivatives, pyrromethene derivatives, terphenyl derivatives, terphenylene derivatives, fluoranthene derivatives, amine derivatives, quinacridone derivatives, oxadiazole derivatives, malononitrile derivatives, pyran derivatives, carbazole derivatives, julolidine derivatives, thiazole derivatives, and derivatives containing metals (Al, Zn). These exemplary skeletons may or may not have a substituent. These exemplary skeletons may also be combined. Examples of luminescent materials that can be used in combination with the assist dopant represented by general formula (1) are listed below.

[0052]

[0053] Furthermore, the compounds described in paragraphs 0220 to 0239 of WO2015 / 022974 can also be particularly preferably used as light-emitting materials used together with the assist dopant represented by general formula (1).

[0054] In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 0.1% by weight or more. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 1% by weight or more. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 50% by weight or less. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 20% by weight or less. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 10% by weight or less. In some embodiments, the host material in the light-emitting layer is an organic compound having hole-transporting and electron-transporting functions. In some embodiments, the host material in the light-emitting layer is an organic compound that prevents the wavelength of emitted light from increasing. In some embodiments, the host material in the light-emitting layer is an organic compound having a high glass transition temperature.

[0055] In some embodiments, the host material is selected from the group consisting of: In some embodiments, the light-emitting layer contains two or more types of TADF molecules with different structures. For example, the light-emitting layer may contain three materials, the host material, the first TADF molecule, and the second TADF molecule, whose excited singlet energy levels are higher in this order. In this case, the first TADF molecule and the second TADF molecule both have a difference ΔE between their lowest excited singlet energy levels and the lowest excited triplet energy level at 77 K. ＳＴis preferably 0.3 eV or less, more preferably 0.25 eV or less, more preferably 0.2 eV or less, more preferably 0.15 eV or less, even more preferably 0.1 eV or less, even more preferably 0.07 eV or less, even more preferably 0.05 eV or less, even more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less. The content of the first TADF molecules in the light-emitting layer is preferably greater than the content of the second TADF molecules. The content of the host material in the light-emitting layer is also preferably greater than the content of the second TADF molecules. The content of the first TADF molecules in the light-emitting layer may be greater than, less than, or the same as the content of the host material. In some embodiments, the composition in the light-emitting layer may be 10 to 70 wt % of the host material, 10 to 80 wt % of the first TADF molecules, and 0.1 to 30 wt % of the second TADF molecules. In one embodiment, the composition within the light-emitting layer may be 20 to 45 wt % of the host material, 50 to 75 wt % of the first TADF molecules, and 5 to 20 wt % of the second TADF molecules. In one embodiment, the luminescence quantum yield φPL1(A) upon photoexcitation of a co-deposited film of the first TADF molecules and the host material (wherein the content of the first TADF molecules in this co-deposited film is A wt %) and the luminescence quantum yield φPL2(A) upon photoexcitation of a co-deposited film of the second TADF molecules and the host material (wherein the content of the second TADF molecules in this co-deposited film is A wt %) satisfy the relationship φPL1(A) > φPL2(A). In some embodiments, the luminescence quantum yield φPL2(B) upon photoexcitation of a co-deposited film of the second TADF molecule and the host material (where the content of the second TADF molecule in this co-deposited film is B wt %) and the luminescence quantum yield φPL2(100) upon photoexcitation of a film of the second TADF molecule alone satisfy the relationship φPL2(B) > φPL2(100). In some embodiments, the emitting layer may contain three types of TADF molecules with different structures. The compound of the present invention may be any of the multiple TADF compounds contained in the emitting layer. In some embodiments, the emitting layer may be composed of a material selected from the group consisting of a host material, an assist dopant, and an emitting material. In some embodiments, the emitting layer does not contain a metal element.In some embodiments, the light-emitting layer can be made of a material consisting of only atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. Alternatively, the light-emitting layer can be made of a material consisting of only atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and oxygen atoms. Alternatively, the light-emitting layer can be made of a material consisting of only atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms. When the light-emitting layer contains a TADF material other than the compound of the present invention, the TADF material can be a known delayed fluorescent material. Preferred delayed fluorescent materials include those described in paragraphs 0008 to 0048 and 0095 to 0133 of WO2013 / 154064, paragraphs 0007 to 0047 and 0073 to 0085 of WO2013 / 011954, paragraphs 0007 to 0033 and 0059 to 0066 of WO2013 / 011955, and paragraph 0008 of WO2013 / 081088. to 0071 and 0118 to 0133, paragraphs 0009 to 0046 and 0093 to 0134 of JP 2013-256490 A, paragraphs 0008 to 0020 and 0038 to 0040 of JP 2013-116975 A, paragraphs 0007 to 0032 and 0079 to 0084 of WO 2013 / 133359 A, paragraph 0 of WO 2013 / 161437 A JP-A-2014-9352, paragraphs 0007 to 0041 and 0060 to 0069, JP-A-2014-9224, paragraphs 0008 to 0048 and 0067 to 0076, JP-A-2017-119663, paragraphs 0013 to 0025, JP-A-2017-119664, paragraphs 0013 to 0026, JP-A-2017-119665, Compounds encompassed by the general formulas described in paragraphs 0012 to 0025 of JP-A No. 017-222623, paragraphs 0010 to 0050 of JP-A No. 2017-226838, paragraphs 0012 to 0043 of JP-A No. 2018-100411, and paragraphs 0016 to 0044 of WO2018 / 047853, particularly exemplified compounds, which are capable of emitting delayed fluorescence, are included.Further, here, the following patent documents are disclosed: JP 2013-253121 A, WO 2013 / 133359 A, WO 2014 / 034535 A, WO 2014 / 115743 A, WO 2014 / 122895 A, WO 2014 / 126200 A, WO 2014 / 136758 A, WO 2014 / 133121 A, WO 20 14 / 136860, WO2014 / 196585, WO2014 / 189122, WO2014 / 168101, WO2015 / 008 580 publication, WO2014 / 203840 publication, WO2015 / 002213 publication, WO2015 / 016200 publication, WO2015 / 019725 publication, WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, JP2015-129240A, WO2015 / 129714, WO2015 / 129715, WO2015 / 13350 Preferably, the luminescent materials capable of emitting delayed fluorescence are those described in WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, and WO2015 / 159541. The above publications described in this paragraph are incorporated herein by reference.

[0056] Each component of the organic electroluminescence element and each layer other than the light-emitting layer will be described below.

[0057] Substrate: In some embodiments, the organic electroluminescent device of the present invention is supported by a substrate, which is not particularly limited and may be any material commonly used in organic electroluminescent devices, such as glass, transparent plastic, quartz, and silicon.

[0058] Anode: In some embodiments, the anode of the organic electroluminescent device is made of a metal, an alloy, a conductive compound, or a combination thereof. In some embodiments, the metal, alloy, or conductive compound has a high work function (4 eV or higher). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is CuI, indium tin oxide (ITO), SnO ２ and ZnO. In some embodiments, IDIXO (In ２ O ３ An amorphous material capable of forming a transparent conductive film, such as ZnO, is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is formed by evaporation or sputtering. In some embodiments, the film is patterned by a photolithography method. In some embodiments, if the pattern does not need to be highly accurate (e.g., greater than about 100 μm), the pattern may be formed using a mask with a shape suitable for evaporation or sputtering of the electrode material. In some embodiments, when a coating material such as an organic conductive compound can be applied, a wet film formation method such as a printing method or a coating method is used. In some embodiments, when emitted light passes through the anode, the anode has a transmittance of more than 10%, and the anode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the thickness of the anode is 10 to 1,000 nm. In some embodiments, the thickness of the anode is 10 to 200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

[0059] Cathode: In some embodiments, the cathode is made of an electrode material such as a metal with a low work function (4 eV or less) (referred to as an electron-injecting metal), an alloy, a conductive compound, or a combination thereof. In some embodiments, the electrode material is sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixture, magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al ２ O ３In some embodiments, a mixture of an electron-injecting metal and a second metal is used, the second metal being a stable metal having a higher work function than the electron-injecting metal. In some embodiments, the mixture is selected from a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al ２ O ３ ) mixture, a lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron injection properties and oxidation resistance. In some embodiments, the cathode is fabricated by forming an electrode material as a thin film by evaporation or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the cathode has a thickness of 10 nm to 5 μm. In some embodiments, the cathode has a thickness of 50 to 200 nm. In some embodiments, either the anode or the cathode of the organic electroluminescent device is transparent or semitransparent to transmit emitted light. In some embodiments, a transparent or semitransparent electroluminescent device improves light radiance. In some embodiments, the cathode is formed from a conductive, transparent material as described above for the anode, thereby forming a transparent or semitransparent cathode. In some embodiments, the device includes an anode and a cathode, both of which are transparent or semitransparent.

[0060] Injection Layer: The injection layer is a layer between the electrode and the organic layer. In some embodiments, the injection layer reduces the driving voltage and enhances the light radiance. In some embodiments, the injection layer comprises a hole injection layer and an electron injection layer. The injection layer can be disposed between the anode and the emissive layer or the hole transport layer, and between the cathode and the emissive layer or the electron transport layer. In some embodiments, an injection layer is present. In some embodiments, an injection layer is not present. Below are examples of preferred compounds that can be used as hole injection materials:

[0061]

[0062] Next, preferred examples of compounds that can be used as the electron injection material will be listed.

[0063] Barrier layer: A barrier layer is a layer that can prevent charges (electrons or holes) and / or excitons present in the light-emitting layer from diffusing outside the light-emitting layer. In some embodiments, an electron blocking layer is present between the light-emitting layer and the hole transport layer and prevents electrons from passing through the light-emitting layer to the hole transport layer. In some embodiments, a hole blocking layer is present between the light-emitting layer and the electron transport layer and prevents holes from passing through the light-emitting layer to the electron transport layer. In some embodiments, a barrier layer prevents excitons from diffusing outside the light-emitting layer. In some embodiments, the electron blocking layer and the hole blocking layer constitute an exciton blocking layer. As used herein, the terms "electron blocking layer" or "exciton blocking layer" include layers that have both the functions of an electron blocking layer and an exciton blocking layer.

[0064] Hole Blocking Layer: The hole blocking layer functions as an electron transporting layer. In some embodiments, during electron transport, the hole blocking layer prevents holes from reaching the electron transporting layer. In some embodiments, the hole blocking layer increases the probability of recombination of electrons and holes in the light-emitting layer. The materials used for the hole blocking layer may be the same materials as those described above for the electron transporting layer. Examples of preferred compounds that can be used for the hole blocking layer are listed below.

[0065]

[0066] Electron Blocking Layer: The electron blocking layer transports holes. In some embodiments, during hole transport, the electron blocking layer prevents electrons from reaching the hole transport layer. In some embodiments, the electron blocking layer increases the probability of recombination of electrons and holes in the light-emitting layer. The materials used for the electron blocking layer may be the same materials as those described above for the hole transport layer. Specific examples of preferred compounds that can be used as electron blocking materials are listed below.

[0067]

[0068] Exciton Blocking Layer: The exciton blocking layer prevents excitons generated through the recombination of holes and electrons in the emissive layer from diffusing to the charge transport layer. In some embodiments, the exciton blocking layer allows for effective confinement of excitons in the emissive layer. In some embodiments, the light emission efficiency of the device is improved. In some embodiments, the exciton blocking layer is adjacent to the emissive layer on either the anode side or the cathode side, and on both sides. In some embodiments, when the exciton blocking layer is present on the anode side, it may be present between the hole transport layer and the emissive layer and adjacent to the emissive layer. In some embodiments, when the exciton blocking layer is present on the cathode side, it may be present between the emissive layer and the cathode and adjacent to the emissive layer. In some embodiments, a hole injection layer, an electron blocking layer, or a similar layer is present between the anode and the exciton blocking layer adjacent to the emissive layer on the anode side. In some embodiments, a hole injection layer, an electron blocking layer, a hole blocking layer, or a similar layer is present between the cathode and the exciton blocking layer adjacent to the emissive layer on the cathode side. In some embodiments, the exciton blocking layer comprises an excited singlet energy and an excited triplet energy, at least one of which is higher than the excited singlet energy and excited triplet energy, respectively, of the light-emitting material.

[0069] Hole Transport Layer: The hole transport layer comprises a hole transport material. In some embodiments, the hole transport layer is a single layer. In some embodiments, the hole transport layer has multiple layers. In some embodiments, the hole transport material has one of the following properties: hole injection or transport and electron blocking. In some embodiments, the hole transport material is an organic material. In some embodiments, the hole transport material is an inorganic material. Examples of known hole transport materials that can be used in the present invention include, but are not limited to, triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, allylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers (especially thiophene oligomers), or combinations thereof. In some embodiments, the hole transport material is selected from a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound. In some embodiments, the hole transport material is an aromatic tertiary amine compound. Specific examples of preferred compounds that can be used as hole transport materials are listed below.

[0070]

[0071] Electron Transport Layer: The electron transport layer comprises an electron transport material. In some embodiments, the electron transport layer is a single layer. In some embodiments, the electron transport layer has multiple layers. In some embodiments, the electron transport material only needs to transport electrons injected from the cathode to the light-emitting layer. In some embodiments, the electron transport material also functions as a hole-blocking material. Examples of electron transport layers that can be used in the present invention include, but are not limited to, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethanes, anthrone derivatives, oxadiazole derivatives, azole derivatives, azine derivatives, or combinations thereof, or polymers thereof. In some embodiments, the electron transport material is a thiadiazole derivative or a quinoxaline derivative. In some embodiments, the electron transport material is a polymer material. Specific examples of preferred compounds that can be used as electron transport materials are listed below.

[0072]

[0073] Furthermore, examples of compounds that can be added to each organic layer are given below, which may be added as a stabilizing material, for example.

[0074]

[0075] Although specific examples of preferred materials that can be used in organic electroluminescence devices have been given, the materials that can be used in the present invention should not be construed as being limited to the following exemplary compounds. Furthermore, even compounds exemplified as materials having specific functions can be diverted to be used as materials having other functions.

[0076] Devices: In some embodiments, the light-emitting layer is incorporated into a device. For example, devices include, but are not limited to, OLED bulbs, OLED lamps, television displays, computer monitors, mobile phones, and tablets. In some embodiments, the electronic device comprises an OLED having an anode, a cathode, and at least one organic layer comprising an emissive layer between the anode and the cathode. In some embodiments, the compositions described herein can be incorporated into various photosensitive or photoactivated devices, such as OLEDs or optoelectronic devices. In some embodiments, the compositions can be useful for facilitating charge or energy transfer within the device and / or as hole transport materials. Such devices include, for example, organic light-emitting diodes (OLEDs), organic integrated circuits (OICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quenched devices (O-FQDs), light-emitting fuel cells (LECs), or organic laser diodes (O-lasers).

[0077] Bulb or Lamp: In some embodiments, an electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising an emissive layer between the anode and the cathode. In some embodiments, the device comprises OLEDs of different colors. In some embodiments, the device comprises an array comprising a combination of OLEDs. In some embodiments, the combination of OLEDs is a three-color combination (e.g., RGB). In some embodiments, the combination of OLEDs is a combination of colors that are not red, green, or blue (e.g., orange and yellow-green). In some embodiments, the combination of OLEDs is a two-color, four-color, or more-color combination. In some embodiments, the device is an OLED light comprising: a circuit board having a first side with a mounting surface and an opposite second side, the circuit board defining at least one opening; at least one OLED on the mounting surface, the at least one OLED having a light-emitting configuration including an anode, a cathode, and at least one organic layer including an emissive layer between the anode and the cathode; a housing for the circuit board; and at least one connector disposed on an end of the housing, the housing and the connector defining a package suitable for attachment to a lighting fixture. In some embodiments, the OLED light has multiple OLEDs mounted on the circuit board such that light is emitted in multiple directions. In some embodiments, a portion of the light emitted in a first direction is polarized and emitted in a second direction. In some embodiments, a reflector is used to polarize the light emitted in the first direction.

[0078] Displays or Screens: In some embodiments, the light-emitting layers of the present invention can be used in screens or displays. In some embodiments, the compounds of the present invention are deposited onto a substrate using processes such as, but not limited to, vacuum evaporation, deposition, vapor deposition, or chemical vapor deposition (CVD). In some embodiments, the substrate is a photoplate structure useful for two-sided etching to provide pixels with unique aspect ratios. The screen (also called a mask) is used in the manufacturing process of OLED displays. The corresponding artwork pattern design allows for the placement of very steep, narrow tie bars between pixels in the vertical direction and large, wide, beveled openings in the horizontal direction. This allows for the fine patterning of pixels required for high-resolution displays while optimizing chemical vapor deposition on the TFT backplane. Internal pixel patterning allows for the construction of three-dimensional pixel openings with various aspect ratios in the horizontal and vertical directions. Furthermore, the use of imaged "stripes" or halftone circles in pixel regions protects etching in certain areas until these specific patterns are undercut and removed from the substrate. At that time, all pixel areas experience similar etching rates, but their depth varies depending on the halftone pattern. Varying the size and spacing of the halftone patterns allows for etching with varying degrees of protection within a pixel, enabling the deep, localized etching required to create steep vertical bevel angles. A preferred material for the deposition mask is Invar. Invar is a metal alloy cold-rolled into long, thin sheets at steel mills. Invar cannot be electrodeposited onto a spin mandrel as a nickel mask. A suitable, low-cost method for creating open areas in a deposition mask is by wet chemical etching. In some embodiments, the screen or display pattern is a pixel matrix on a substrate. In some embodiments, the screen or display pattern is fabricated using lithography (e.g., photolithography and e-beam lithography).In some embodiments, the screen or display pattern is fabricated using wet chemical etching. In further embodiments, the screen or display pattern is fabricated using plasma etching.

[0079] Device Manufacturing Method: OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarization film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel. OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarization film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel.

[0080] Another aspect of the present invention provides a method for manufacturing an organic light-emitting diode (OLED) display, the method including: forming a barrier layer on a base substrate of a mother panel; forming a plurality of display units on the barrier layer in cell panel units; forming an encapsulation layer on each of the display units of the cell panel; and applying an organic film to an interface between the cell panels. In some embodiments, the barrier layer is an inorganic film, for example, made of SiNx, and edges of the barrier layer are covered with an organic film made of polyimide or acrylic. In some embodiments, the organic film assists in soft cutting of the mother panel into cell panel units. In some embodiments, the thin film transistor (TFT) layer includes a light-emitting layer, a gate electrode, and source / drain electrodes. Each of the plurality of display units may include a thin film transistor (TFT) layer, a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film, and the organic film applied to the interface is made of the same material as the planarization film and is formed simultaneously with the formation of the planarization film. In some embodiments, the light-emitting units are coupled to the TFT layer by a passivation layer, a planarization film therebetween, and an encapsulation layer that covers and protects the light-emitting units. In some embodiments of the manufacturing method, the organic film is not coupled to either the display unit or the encapsulation layer.

[0081] Each of the organic film and the planarization film may comprise one of polyimide and acrylic. In some embodiments, the barrier layer may be an inorganic film. In some embodiments, the base substrate may be formed of polyimide. The method may further include attaching a carrier substrate formed of a glass material to one surface of the base substrate formed of polyimide before forming a barrier layer on the other surface of the base substrate, and separating the carrier substrate from the base substrate before cutting along the interface. In some embodiments, the OLED display is a flexible display. In some embodiments, the passivation layer is an organic film disposed on the TFT layer to cover the TFT layer. In some embodiments, the planarization film is an organic film formed on the passivation layer. In some embodiments, the planarization film, like the organic film formed on the edge of the barrier layer, is formed of polyimide or acrylic. In some embodiments, the planarization film and the organic film are formed simultaneously during the manufacture of the OLED display. In some embodiments, the organic film may be formed on the edge of the barrier layer, such that a portion of the organic film is in direct contact with the base substrate and a remaining portion of the organic film is in contact with the barrier layer while surrounding the edge of the barrier layer.

[0082] In some embodiments, the light-emitting layer includes a pixel electrode, a counter electrode, and an organic light-emitting layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrode is connected to a source / drain electrode of the TFT layer. In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, an appropriate voltage is formed between the pixel electrode and the counter electrode, causing the organic light-emitting layer to emit light, thereby forming an image. Hereinafter, an image-forming unit including a TFT layer and a light-emitting unit is referred to as a display unit. In some embodiments, an encapsulation layer that covers the display unit and prevents penetration of external moisture may be formed into a thin-film encapsulation structure in which organic films and inorganic films are alternately stacked. In some embodiments, the encapsulation layer has a thin-film encapsulation structure in which multiple thin films are stacked. In some embodiments, the organic film applied to the interface portion is disposed at a distance from each of the multiple display units. In some embodiments, the organic film is formed such that a portion of the organic film directly contacts the base substrate, and a remaining portion of the organic film contacts the barrier layer while surrounding the edge of the barrier layer.

[0083] In one embodiment, the OLED display is flexible and uses a flexible base substrate made of polyimide. In some embodiments, the base substrate is formed on a carrier substrate made of a glass material, and then the carrier substrate is separated. In some embodiments, a barrier layer is formed on the surface of the base substrate opposite the carrier substrate. In one embodiment, the barrier layer is patterned according to the size of each cell panel. For example, while the base substrate is formed on all surfaces of the mother panel, the barrier layer is formed according to the size of each cell panel, thereby forming grooves at the interfaces between the barrier layers of the cell panels. Each cell panel can be cut along the grooves.

[0084] In some embodiments, the manufacturing method further includes a step of cutting along the interface, in which a groove is formed in the barrier layer and at least a portion of the organic film is formed in the groove, so that the groove does not penetrate into the base substrate. In some embodiments, a TFT layer of each cell panel is formed, and a passivation layer, which is an inorganic film, and a planarization film, which is an organic film, are disposed on and cover the TFT layer. At the same time as the planarization film, made of, for example, polyimide or acrylic, is formed, the grooves at the interface are covered with an organic film, made of, for example, polyimide or acrylic. This prevents cracks from occurring when each cell panel is cut along the grooves at the interface by allowing the organic film to absorb any impact that occurs. That is, if all barrier layers were completely exposed without the organic film, the impact would be transmitted to the barrier layer when each cell panel is cut along the grooves at the interface, thereby increasing the risk of cracks. However, in one embodiment, the grooves at the interface between the barrier layers are covered with an organic film to absorb any impact that would otherwise be transmitted to the barrier layer, allowing each cell panel to be cut softly and preventing cracks from occurring in the barrier layer. In one embodiment, the organic film and the planarization film covering the groove of the interface portion are spaced apart from each other. For example, if the organic film and the planarization film are connected to each other as one layer, external moisture may penetrate into the display unit through the planarization film and the remaining portion of the organic film, so the organic film and the planarization film are spaced apart from each other such that the organic film is spaced apart from the display unit.

[0085] In some embodiments, the display units are formed by forming light-emitting units, and an encapsulation layer is disposed on the display units to cover the display units. Thus, after the mother panel is completely manufactured, the carrier substrate supporting the base substrate is separated from the base substrate. In some embodiments, a laser beam is irradiated onto the carrier substrate, causing the carrier substrate to separate from the base substrate due to the difference in thermal expansion coefficient between the carrier substrate and the base substrate. In some embodiments, the mother panel is cut into individual cell panels. In some embodiments, the mother panel is cut along the interfaces between the cell panels using a cutter. In some embodiments, the grooves at the interfaces along which the mother panel is cut are covered with an organic film, which absorbs impact during cutting. In some embodiments, cracks in the barrier layer can be prevented during cutting. In some embodiments, the method reduces the product defect rate and stabilizes its quality. Another aspect is an OLED display having a barrier layer formed on a base substrate, display units formed on the barrier layer, an encapsulation layer formed on the display units, and an organic film applied to edges of the barrier layer.

[0086] The features of the present invention will be explained in more detail with reference to examples. The materials, processing details, processing procedures, etc. shown below can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. The emission characteristics were evaluated using a source meter (Keithley: 2400 series), a semiconductor parameter analyzer (Agilent Technologies: E5273A), an optical power meter measuring device (Newport: 1930C), an optical spectrometer (Ocean Optics: USB2000), a spectroradiometer (Topcon: SR-3), and a streak camera (Hamamatsu Photonics K.K.: C4334 model). In the following examples, compounds represented by general formula (1) were synthesized.

[0087] Example 1 Under a nitrogen atmosphere, 2,6-difluoro-3-phenyl-1,4-benzenedicarbonitrile (0.32 g, 2.0 mmol), 5,8-dihydro-5-phenylindolo[3,2-c]carbazole (0.91 g, 4.3 mmol), and Cs ２ CO ３ A solution of (1.75 g, 8.33 mmol) in dimethylformamide (15 mL) was stirred at 150° C. for 14 hours. The temperature was then returned to room temperature, and the reaction was quenched with water and methanol. The resulting precipitate was filtered, and the residue was purified by column chromatography (toluene / hexane / CHCl ３ = 8 / 1 / 1) and reprecipitation (CHCl ３ / MeOH) to give an orange solid (0.86 g, 0.99 mmol, 49%). 1 H NMR (400MHz, CDCl3, d): 8.36-8.29 (m, 2H), 8.24-8.13 (m, 3H), 7.72-7.56 (m, 10H), 7.42-7.38 (m, 10H), 7.46-7.02 (m, 7H), 6.94-6.86 (m, 1H) 6.79-6.73 (m, 1H), 5.94 (d, J=8.0Hz, 1H), 5.79 (d,J=8.0Hz, 1H). MS (ASAP): 865.47 [M+H] + Calculated value C62H36N6: 864.30

[0088] Example 2 The compound was synthesized in the same manner as in Example 1 with a yield of 25%. 1 H NMR (400MHz, CDCl3, d): 8.98 (d, J = 8.0 Hz, 1H), 8.92 (d, J = 7.6 Hz, 1H), 8.82 (t, J = 7.6 Hz, 2H), 8.23 ​​(s, 1H), 7.68-7.40 (m, 25H), 7.21-7.14 (m, 4H), 7.10-7.01 (m, 3H). MS (ASAP): 865.37 [M+H] + Calculated value C62H36N6: 864.30

[0089] Example 3 The compound was synthesized in the same manner as in Example 1 with a yield of 50%. 1 H NMR (400MHz, CDCl3, d): 8.87-8.83 (m, 4H), 7.66-7.59 (m, 8H), 7.55-7.42 (m, 14H), 7.33-7.28 (m, 2H), 7.17-7.15 (m, 4H), 7.06-6.96 (m, 6H). MS (ASAP): 941.46 [M+H] + Calculated value for C68H40N6: 940.33

[0090] Example 4 The compound was synthesized in the same manner as in Example 1 with a yield of 34%. 1 H NMR (400MHz, CDCl3, d): 8.26-8.21 (m, 2H), 8.18-8.14 (m, 2H), 7.65-7.56 (m, 10H), 7.34-7.22 (m, 8H), 7.19-7.10 (m, 4H), 6.80-6.74 (m, 2H), 5.81 (d, J = 8.0 Hz, 2H). MS (ASAP): 951.36 [M+H] + Calculated value C68H30D10N6: 950.39

[0091] Example 5 Under a nitrogen atmosphere, 2,5-difluoro-3,6-diphenyl-1,4-benzenedicarbonitrile (0.60 g, 1.9 mmol), 2-phenyl-5H-benzofuro[3,2-c]carbazole (1.58 g, 4.7 mmol), and K ２ CO ３ A solution of (0.79 g, 5.7 mmol) in dimethylformamide (30 mL) was stirred at 130°C for 22 hours. The mixture was then returned to room temperature and the reaction was quenched with water and methanol. The resulting precipitate was filtered, and the residue was purified by column chromatography (toluene / hexane = 2 / 1) and reprecipitation (toluene / hexane) to obtain an orange solid (1.07 g, 1.13 mmol, 60%). 1 H NMR (400MHz, CDCl3, d): 8.69 (s, 2H), 8.03-8.00 (m, 4H), 7.82-7.75 (m, 8H), 7.57-7.35 (m, 12H), 7.59-7.21 (m, 6H), 7.11-7.04 (m, 6H). MS (ASAP): 943.58 [M+H] + Calcd for. C68H38N4O2: 942.30

[0092] Example 6 The compound was synthesized in the same manner as in Example 5 with a yield of 80%. 1 H NMR (400MHz, CDCl3, d): 8.67 (s, 2H), 8.02-7.99 (m, 4H), 7.81-7.74 (m, 8H), 7.55-7.34 (m, 12H), 7.26-7.20 (m, 2H). MS (ASAP): 953.58 [M+H] + Calculated value for C68H28D10N4O2: 952.36

[0093] Example 7 The compound was synthesized in the same manner as in Example 5 with a yield of 82%. 1 H NMR (400MHz, CDCl3, d): 8.67 (s, 2H), 8.02-7.99 (m, 4H), 7.77-7.74 (m, 4H), 7.51-7.33 (m, 6H), 7.26-7.21 (m, 2H). MS (ASAP): 963.63 [M+H] + Calculated value C68H18D20N4O2: 962.43

[0094] (Example 8) The compound was synthesized in the same manner as in Example 5 with a yield of 48%. 1 H NMR (400MHz, CDCl3, d): 8.44 (d, J = 8.0 Hz, 2H), 8.32 (d, J = 8.4 Hz, 2H), 8.26-8.21 (m, 4H), 8.09-7.95 (m, 6H), 7.90-7.86 (m, 4H), 7.77-7.75 (m, 2H), 7.55-7.45 (m, 4H), 7.21-7.12 (m, 4H), 7.02-6.94 (m, 6H). MS (ASAP): 891.41 [M+H] + Calculated value for C64H34N4O2: 890.27

[0095] Example 9 The compound was synthesized in the same manner as in Example 5 with a yield of 71%. MS (ASAP): 890.2 [M] + Calculated value C64H34N4O2: 890.2

[0096] Example 10 The compound was synthesized in the same manner as in Example 5 with a yield of 45%. 1 H NMR (400MHz, CDCl3, d): 9.85 (d, J = 8,8 Hz, 2H), 8.36 (dd, J = 8.4, 2.4 Hz, 2H), 8.29 (d, J = 7,2 Hz, 2H), 8.26-8.16 (m, 6H), 8.09-8.02 (m, 4H), 7.93 (t, J = 6,8 Hz, 2H), 7.65 (t, J= 7,2 Hz, 2H), 7.59 (t, J = 6,8 Hz, 2H), 7.52 (t, J = 7,2 Hz, 2H), 7.38 (d, J = 8,4 Hz, 4H),7.11-7.03 (m, 6H), MS (ASAP): 891.33 [M+H] + Calculated value for C64H35N4O2: 891.28

[0097] The compounds of Examples 1 to 10 were purified by sublimation and then used to form thin films and fabricate devices.

[0098] (Preparation and Evaluation of Thin Films) Thin films were prepared by vacuum deposition on a quartz substrate at a vacuum level of 1×10 －３The compound of Example 1 and mCBP were evaporated from different evaporation sources under conditions of less than 10 Pa, and a thin film containing the compound of Example 1 at a concentration of 20 wt % was formed to a thickness of 100 nm to serve as a doped thin film. Doped thin films were also formed in the same manner using the compounds of Examples 2 to 10 instead of Example 1. Furthermore, doped thin films were also formed in the same manner using the compound of Comparative Example 1 having the following structure instead of Example 1. When 300 nm excitation light was irradiated onto each of the obtained thin films, photoluminescence was observed for all of the thin films, and the maximum emission wavelength was measured. Furthermore, the lifetime of delayed fluorescence (τ ２ ) was obtained. The results are shown in Table 8. Table 8 also shows the results of measuring the HOMO energy and LUMO energy of each compound. From the results in Table 8, it can be seen that the delayed fluorescence lifetime (τ ２ ) was found to be significantly shorter.

[0099] (Fabrication of Organic Electroluminescence Device) Each thin film was deposited by vacuum deposition on a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 100 nm was formed, at a vacuum degree of 1×10 －６The layers are laminated at a pressure of 10 Pa. First, HATCN is formed on ITO to a thickness of 10 nm, and NPD is formed on top of that to a thickness of 30 nm. Next, TrisPCz is formed on top of that to a thickness of 10 nm, and H1 is further formed on top of that to a thickness of 5 nm. Next, the compound of Example 1 and H1 are co-deposited from different evaporation sources to form a 30 nm thick light-emitting layer. At this time, the concentration of the compound of Example 1 is 35 wt %. SF3TRZ is formed on top of that to a thickness of 10 nm, and SF3TRZ and Liq are co-deposited on top of that to a thickness of 30 nm from different evaporation sources. At this time, the SF3TRZ:Liq (weight ratio) is 7:3. Next, Liq is formed to a thickness of 2 nm, and then aluminum (Al) is deposited to a thickness of 100 nm to form a cathode. Organic electroluminescence devices are similarly prepared using each of the compounds of Examples 2 to 10 instead of the compound of Example 1. The prepared organic electroluminescence devices all have a short delayed fluorescence lifetime (τ2).

[0100]

[0101] REFERENCE SIGNS LIST 1 substrate 2 anode 3 hole injection layer 4 hole transport layer 5 light emitting layer 6 electron transport layer 7 cathode

Claims

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In the general formula (1), R １ ~R ４ Two or three of the above independently represent a donor group, and at least one of the above is a ring-fused indol-1-yl group. The ring-fused indol-1-yl group forms a fused ring having 4 or more rings by ring condensation with indole, and the fused ring may be substituted. R １ ~R ４ One or two of each independently represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom. The remaining R １ ~R ４ represents a hydrogen atom or a deuterium atom. However, general formula (1) satisfies any one of the following (a) to (d). (a) At least one of the indol-1-yl groups to which the ring is fused forms any one of the following fused rings by ring fusion to indole, and the fused ring may be substituted: 【Chemistry 2】 (b) two of R 1 to R 4 are each independently a substituted or unsubstituted indolo[2,3-a]carbazol-9-yl group, a substituted or unsubstituted indolo[3,2-a]carbazol-9-yl group, a substituted or unsubstituted indolo[2,3-b]carbazol-9-yl group, a substituted or unsubstituted indolo[3,2-b]carbazol-9-yl group, a substituted or unsubstituted indolo[2,3-c]carbazol-9-yl group, or a substituted or unsubstituted indolo[3,2-c]carbazol-9-yl group; one of R 1 to R 4 is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom; and The remaining one of R 1 to R 4 is a hydrogen atom or a deuterium atom. (c) two of R 1 to R 4 are each independently a substituted or unsubstituted indolo[2,3-a]carbazol-9-yl group, a substituted or unsubstituted indolo[3,2-a]carbazol-9-yl group, a substituted or unsubstituted indolo[2,3-b]carbazol-9-yl group, a substituted or unsubstituted indolo[3,2-b]carbazol-9-yl group, a substituted or unsubstituted indolo[2,3-c]carbazol-9-yl group, or a substituted or unsubstituted indolo[3,2-c]carbazol-9-yl group; and The remaining two of R 1 to R 4 are each independently a substituted or unsubstituted deuterated aryl group. (d) Only two of R 1 to R 4 are donor groups, and the two donor groups are each independently a group having any one of the following structures: 【Chemistry 3】 [At least one of the hydrogen atoms in each of the above structures is substituted with an aryl group, and the hydrogen atoms in each of the above structures may be substituted with a group other than an aryl group.]

2. R １ ~R ４ two of the groups are each independently a donor group, and at least one of the groups is an indol-1-yl group to which the ring is fused; R １ ~R ４ is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom; The remaining R １ ~R ４ The compound according to claim 1 , wherein is a hydrogen atom or a deuterium atom.

3. R １ ~R ４ two of the groups are each independently a donor group, and at least one of the groups is an indol-1-yl group to which the ring is fused; R １ ~R ４ The compound according to claim 1 , wherein two of are substituted or unsubstituted aryl groups, or substituted or unsubstituted heteroaryl groups bonded at carbon atoms.

4. R １ ~R ４ three of the groups are each independently a donor group, and at least one of the groups is an indol-1-yl group to which the ring is fused; R １ ~R ４ The compound of claim 1 , wherein one of is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom.

5. R １ and R ４ are each independently a donor group, R ３ The compound according to claim 1 , wherein is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom.

6. R ２ and R ４ are each independently a donor group, R ３ The compound according to claim 1 , wherein is a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group bonded at a carbon atom.

7. The compound according to claim 1 , wherein the number of fused rings is 5 or more.

8. The compound according to claim 7 , wherein a carbon atom constituting a skeleton of the fused ring having four or more rings is substituted with a substituted or unsubstituted aryl group.

9. The compound according to claim 7 , wherein the skeleton of the fused ring having four or more rings contains a nitrogen atom, and the nitrogen atom is substituted with a substituted or unsubstituted aryl group.

10. The compound according to claim 1, wherein a ring fused to a benzene ring constituting the indol-1-yl group is a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted pyrrole ring, and the furan ring, the thiophene ring, and the pyrrole ring may be further fused with another ring.

11. The compound according to claim 1, wherein the indol-1-yl group to which the ring is fused has any one of the following fused rings: 【Chemistry 4】 [In each of the above structures, the hydrogen atom may be substituted, and further, a ring may be condensed.]

12. The compound according to claim 1, wherein the indol-1-yl group to which the ring is fused has any one of the following fused ring skeletons: 【Chemistry 5】 [In each of the above structures, R' represents a phenyl group. In each of the above structures, the hydrogen atom may be substituted, and further, a ring may be condensed.]

13. The compound according to claim 1, wherein the ring-fused indol-1-yl group has a structure in which a heterocycle is fused to the 4- and 5-positions of the indole ring.

14. The compound according to claim 1 , wherein Ar is a substituted or unsubstituted phenyl group, or a substituted or unsubstituted pyridyl group.

15. 2. The compound of claim 1, consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms and sulfur atoms.

16. A light-emitting material comprising the compound according to any one of claims 1 to 15.

17. A light-emitting device comprising the compound according to any one of claims 1 to 15.

18. 20. The light-emitting device of claim 17, wherein the light-emitting device has a light-emitting layer, the light-emitting layer comprising the compound and a host material.

19. 20. The light-emitting device of claim 18, wherein the light-emitting device has a light-emitting layer, the light-emitting layer comprising the compound and a light-emitting material, and emitting light primarily from the light-emitting material.

Images