Charge transport material, composition, and organic light emitting element

Abstract

A compound represented by D-Ar-Z is useful as a host material for an organic light-emitting element. D represents a donor group, Ar represents an arylene group or a biphenylene group, and Z represents a benzofuran dibenzofuranyl group, a benzo-thiopheno dibenzothiophenyl group, or the like.

Description

Technical Field

[0001] This invention relates to a compound useful as a charge transport material, compositions using the compound, and organic light-emitting elements. Background Technology

[0002] Research is actively underway to improve the luminous efficiency of light-emitting elements such as organic electroluminescent devices (organic EL devices). Particular attention has been paid to enhancing luminous efficiency by developing and combining new electron transport materials, hole transport materials, luminescent materials, and host materials that constitute organic electroluminescent devices. Among these efforts, organic electroluminescent devices utilizing delayed fluorescence materials have been developed and have attracted considerable attention (see Non-Patent Literature 1).

[0003] Delayed fluorescence materials are those that emit fluorescence upon returning to the ground state after a reverse intersystem crossing from an excited triplet state to an excited singlet state in the excited state. Because fluorescence generated via this pathway is observed later than fluorescence from an excited singlet state directly generated from the ground state (typical fluorescence), it is called delayed fluorescence. Here, for example, when a luminescent compound is excited via carrier injection, since the generation probabilities of excited singlet and excited triplet states are statistically 25%:75%, there is a limit to the improvement in luminescence efficiency if only fluorescence from the directly generated excited singlet state is used. On the other hand, because delayed fluorescence materials can also emit fluorescence from the excited triplet state via the reverse intersystem crossing pathway, in addition to the excited singlet state, they can achieve higher luminescence efficiency compared to typical fluorescent materials. Delayed fluorescence materials with this characteristic are often used together with the host material in the emissive layer of organic electroluminescent devices, effectively contributing to improved luminescence efficiency.

[0004] Previous technical documents

[0005] Patent documents

[0006] Non-patent literature 1: Uoyama et al, Nature, 492, 234-238 (2012) Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] For the host material combined with the delayed fluorescence material, a compound with a minimum excitation singlet energy higher than that of the delayed fluorescence material is selected. However, even when the host material, which is typically used in combination with conventional fluorescent materials that do not emit delayed fluorescence, is directly combined with the delayed fluorescence material, sufficient luminescence performance cannot be achieved. Especially in organic light-emitting devices using delayed fluorescence materials, there is room for improvement in device characteristics such as driving voltage. Therefore, the inventors have conducted research with the aim of improving the device characteristics in organic light-emitting devices using delayed fluorescence materials.

[0009] means for solving technical problems

[0010] As a result of in-depth research, the inventors discovered that compounds with specific structures are useful as host materials for charge transport materials. This invention is based on this insight and specifically has the following structure.

[0011] [1] A compound represented by the following general formula (1).

[0012] General formula (1)

[0013] D-Ar-Z

[0014] [In general formula (1), D represents a donor group, Ar represents a substituted or unsubstituted arylene or a substituted or unsubstituted biphenyl (wherein the two benzene rings constituting the biphenyl can be further linked to each other via a linking group), and Z represents a substituted or unsubstituted benzofuran dibenzofuranyl, a substituted or unsubstituted benzofuran dibenzothiopheneyl, a substituted or unsubstituted benzothiophene dibenzofuranyl, or a substituted or unsubstituted benzothiophene dibenzothiopheneyl.]

[0015] [2] According to the compound described in [1], wherein Ar has any one of the following skeletons.

[0016] [Chemical Formula 1]

[0017]

[0018] [In the above formula, * indicates the bonding position with D or Z. Each hydrogen atom in the above skeleton can be independently replaced by a deuterium atom or a substituent, or it can be replaced together with an adjacent hydrogen atom by a linking group to form a cyclic structure.]

[0019] [3] The compound according to [1] is represented by the following general formula (2).

[0020] [Chemical Formula 2]

[0021] General formula (2)

[0022]

[0023] In general formula (2), X 1 and X 2 Each can be used independently to represent an oxygen atom or a sulfur atom. R 1 ~R 7 Each of these can independently represent a deuterium atom or a substituent. n represents 0 or 1, n1, n2, n3, n4, n5, and n7 can independently represent any integer from 0 to 4, and n6 can represent any integer from 0 to 2. R 3 and R 4 Two adjacent R 1 Two adjacent R 2 Two adjacent R 3 Two adjacent R 4 Two adjacent R 5 Two adjacent R 6 Two adjacent R 7 They can bond together to form a ring structure.

[0024] [4] The compound according to [1] is represented by any one of the following general formulas (3-1) to (3-16).

[0025] [Chemical Formula 3-1]

[0026]

[0027] [Chemical Formula 3-2]

[0028]

[0029] In general formulas (3-1) to (3-16), R 1 ~R 7 Each of these can independently represent a deuterium atom or a substituent. n represents 0 or 1; n1, n2, n3, n4, n5, and n7 can independently represent any integer from 0 to 4; n3' and n4' can independently represent any integer from 0 to 3; and n6 can represent any integer from 0 to 2. R 3 and R 4 Two adjacent R 1 Two adjacent R 2 Two adjacent R 3 Two adjacent R 4 Two adjacent R 5 Two adjacent R 6 Two adjacent R 7 They can bond together to form a ring structure.

[0030] [5] According to the compound described in [3] or [4], wherein two adjacent R 1They do not bond with each other to form a ring structure, and two adjacent R 2 They do not bond with each other to form a ring structure.

[0031] [6] The compound according to any one of [3] to [5], wherein R 1 and R 2 None of them contain a carbazole ring structure.

[0032] [7] A charge transport material comprising any one of the compounds described in [1] to [6].

[0033] [8] The charge transport material described in [7] is the main material.

[0034] [9] A composition wherein a delayed fluorescence material is doped in a host material consisting of any one of the compounds described in [1] to [6].

[0035]

[10] The composition according to [9] is in the form of a film.

[0036]

[11] According to the composition of [9] or

[10] , wherein the delayed fluorescence material is a compound having a benzonitrile structure having one cyano group substituted as a benzene ring.

[0037]

[12] According to the composition of [9] or

[10] , wherein the delayed fluorescence material is a compound having a benzonitrile structure having two cyano groups substituted for benzene rings.

[0038]

[13] The composition according to any one of [9] to

[12] , wherein the delayed fluorescent material is a compound having a cyclic skeleton having a benzene ring constituting at least one of the carbon atoms substituted with nitrogen atoms in an azabenzene structure.

[0039]

[14] The composition according to any one of [9] to

[13] further comprises a fluorescent compound having a minimum excitation singlet energy lower than that of the host material and the delayed fluorescence material.

[0040]

[15] An organic light-emitting element having a layer composed of any one of the compositions described in [9] to

[14] .

[0041]

[16] According to the organic light-emitting element of

[15] , wherein the layer is composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms and halogen atoms.

[0042]

[17] According to the organic light-emitting element of

[15] , the layer is composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms.

[0043]

[18] The organic light-emitting element according to any one of

[15] to

[17] is an organic electroluminescent element.

[0044]

[19] An organic light-emitting element according to any one of

[15] to

[18] , wherein the composition does not contain the fluorescent compound, and the maximum component of the light emitted from the element is the light emitted from the delayed fluorescent material.

[0045]

[20] An organic light-emitting element according to any one of

[15] to

[18] , wherein the composition comprises the fluorescent compound, and the maximum component of the light emitted from the element is the light emitted from the fluorescent compound.

[0046] Invention Effects

[0047] The compounds of the present invention are useful as charge transport materials and can be effectively used in organic semiconductor devices. For example, the characteristics of an organic electroluminescent device can be improved by using the compounds of the present invention as the host material in the light-emitting layer of the device. Attached Figure Description

[0048] Figure 1 This is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent element. Detailed Implementation

[0049] The present invention will now be described in detail. The descriptions of the constituent elements described below are sometimes based on representative embodiments or specific examples of the invention, but the invention is not limited to such embodiments or specific examples. Furthermore, in this document, the numerical range indicated by “~” means a range including the values ​​described before and after “~” as a lower and upper limit value. Also, some or all of the hydrogen atoms present within the molecules of the compounds used in the present invention can be replaced by deuterium atoms (…). 2 Hydrogen atoms are substituted with H or deuterium (D). In the chemical structural formulas described herein, the hydrogen atom is represented by H or its representation is omitted. For example, when the representation of the atom bonded to a carbon atom in the ring skeleton of the benzene ring is omitted, H is bonded to a carbon atom in the omitted position. In this text, the term "substituent" means an atom or group of atoms other than hydrogen and deuterium atoms. On the other hand, the term "substituted or unsubstituted" means that the hydrogen atom can be substituted by a deuterium atom or a substituent.

[0050] [Compounds represented by general formula (1)]

[0051] The compounds of the present invention are those represented by the following general formula (1).

[0052] General formula (1)

[0053] D)-Ar-Z

[0054] In general formula (1), Z represents substituted or unsubstituted benzofuran dibenzofuranyl, substituted or unsubstituted benzofuran dibenzothiophenyl, substituted or unsubstituted benzothiophene dibenzofuranyl or substituted or unsubstituted benzothiophene dibenzothiophenyl.

[0055] In one aspect of the invention, Z is bonded to a fused ring comprising at least one furan structure. In another aspect of the invention, Z is bonded to a fused ring comprising at least one thiophene structure. In another aspect of the invention, Z is bonded to a fused ring comprising at least one furan structure and at least one thiophene structure. In another aspect of the invention, Z is bonded to a fused ring comprising at least one furan structure but not a thiophene structure. In another aspect of the invention, Z is bonded to a fused ring comprising at least one thiophene structure but not a furan structure. In another aspect of the invention, Z is bonded to a fused ring consisting of five fused rings.

[0056] In one aspect of the invention, Z is an unsubstituted benzofuran dibenzofuranyl, an unsubstituted benzofuran dibenzothiophenyl, an unsubstituted benzothiophene dibenzofuranyl, or an unsubstituted benzothiophene dibenzothiophenyl. In another aspect of the invention, Z is a substituted benzofuran dibenzofuranyl, a substituted benzofuran dibenzothiophenyl, a substituted benzothiophene dibenzofuranyl, or a substituted benzothiophene dibenzothiophenyl.

[0057] In one aspect of the invention, Z is a substituted or unsubstituted benzofuran dibenzofuranyl group. In one aspect of the invention, Z is a substituted or unsubstituted benzofuran dibenzothiophenyl group. In one aspect of the invention, Z is a substituted or unsubstituted benzothiophene dibenzofuranyl group. In one aspect of the invention, Z is a substituted or unsubstituted benzothiophene dibenzothiophenyl group.

[0058] In one aspect of the invention, Z is bonded to the benzene ring at the end of each fused ring structure constituting benzofuran dibenzofuranyl, benzofuran dibenzothiophenyl, benzothiophene dibenzofuranyl, and benzothiophene dibenzothiophene. In another aspect of the invention, Z is bonded to the benzene ring at the central portion of each fused ring structure constituting benzofuran dibenzofuranyl, benzofuran dibenzothiophenyl, benzothiophene dibenzofuranyl, and benzothiophene dibenzothiophene.

[0059] When Z is a substituted or unsubstituted benzofuran dibenzofuran group, Z may have any one of the following skeletons 1a to 1f. In one aspect of the invention, Z has any one of the skeletons 1a to 1c. In one aspect of the invention, Z has any one of the skeletons 1d to 1f. In one aspect of the invention, Z has a skeleton of skeleton 1a or 1b. In one aspect of the invention, Z has a skeleton of skeleton 1c or 1d. In one aspect of the invention, Z has a skeleton of skeleton 1e or 1f. In one aspect of the invention, Z has a skeleton of skeleton 1c.

[0060] [Chemical Formula 4]

[0061]

[0062] When Z is a substituted or unsubstituted benzofuran dibenzothiophene group, Z may have any one of the following skeletons 2a to 2f. In one aspect of the invention, Z has any one of skeletons 2a to 2c. In one aspect of the invention, Z has any one of skeletons 2d to 2f. In one aspect of the invention, Z has a skeleton of skeleton 2a or 2b. In one aspect of the invention, Z has a skeleton of skeleton 2c or 2d. In one aspect of the invention, Z has a skeleton of skeleton 2e or 2f. In one aspect of the invention, Z has a skeleton of skeleton 2c.

[0063] [Chemical Formula 5]

[0064]

[0065] When Z is a substituted or unsubstituted benzothiophene dibenzofuranyl group, Z may have any one of the following skeletons 3a to 3f. In one aspect of the invention, Z has any one of the skeletons 3a to 3c. In one aspect of the invention, Z has any one of the skeletons 3d to 3f. In one aspect of the invention, Z has a skeleton of skeleton 3a or 3b. In one aspect of the invention, Z has a skeleton of skeleton 3c or 3d. In one aspect of the invention, Z has a skeleton of skeleton 3e or 3f. In one aspect of the invention, Z has a skeleton of skeleton 3c.

[0066] [Chemical Formula 6]

[0067]

[0068] When Z is a substituted or unsubstituted benzothiophene dibenzothiophene group, Z may have any one of the following skeletons 4a to 4f. In one aspect of the invention, Z has any one of the skeletons 4a to 4c. In one aspect of the invention, Z has any one of the skeletons 4d to 4f. In one aspect of the invention, Z has a skeleton of skeleton 4a or 4b. In one aspect of the invention, Z has a skeleton of skeleton 4c or 4d. In one aspect of the invention, Z has a skeleton of skeleton 4e or 4f. In one aspect of the invention, Z has a skeleton of skeleton 4c.

[0069] [Chemical Formula 7]

[0070]

[0071] The hydrogen atoms in the frameworks 1a to 4f described above can be replaced by deuterium atoms or substituents. For example, structures in which some of the hydrogen atoms bonded to the framework are replaced by deuterium atoms or structures in which all of the hydrogen atoms bonded to the framework are replaced by deuterium atoms can be illustrated. Unsubstituted structures are preferred. Substituents can be selected from substituent group A, substituent group B, substituent group C, substituent group D, or substituent group E.

[0072] In one aspect of the invention, Z has any one of the skeletons 1a, 2a, 3a, and 4a. In one aspect of the invention, Z has any one of the skeletons 1b, 2b, 3b, and 4b. In one aspect of the invention, Z has any one of the skeletons 1c, 2c, 3c, and 4c. In one aspect of the invention, Z has any one of the skeletons 1d, 2d, 3d, and 4d. In one aspect of the invention, Z has any one of the skeletons 1e, 2e, 3e, and 4e. In one aspect of the invention, Z has any one of the skeletons 1f, 2f, 3f, and 4f. In one aspect of the invention, rings are not further fused onto skeletons 1a to 4f. In one aspect of the invention, rings are further fused onto skeletons 1a to 4f. For example, benzene rings, benzofuran structures, and benzothiophene structures may be fused together.

[0073] In general formula (1), Ar represents a substituted or unsubstituted arylene or a substituted or unsubstituted biphenylene. For a description and preferred range of the arylene, refer to the description and preferred range of the aryl group mentioned below. Ar preferably includes a substituted or unsubstituted phenylene. The phenylene can be any one of 1,2-phenylene, 1,3-phenylene, and 1,4-phenylene, preferably 1,3-phenylene or 1,4-phenylene, for example, 1,3-phenylene or 1,4-phenylene. The biphenylene is a linking group formed by two phenylene groups, and can also be any one of biphenyl-2,2'-diyl, biphenyl-3,3'-diyl, and biphenyl-4,4'-diyl, preferably biphenyl-3,3'-diyl or biphenyl-4,4'-diyl, for example, biphenyl-3,3'-diyl or biphenyl-4,4'-diyl. The two benzene rings constituting the biphenylene ring can be further linked to each other via linking groups. In one aspect of the invention, a substituted or unsubstituted dibenzofuran diyl is formed by bonding via oxygen atoms (-O-). In another aspect of the invention, a dibenzothiophene diyl structure is formed by bonding via sulfur atoms (-S-). In a preferred aspect of the invention, Ar has any of the following skeletons.

[0074] [Chemical Formula 8]

[0075]

[0076] In the aforementioned skeletons 5a to 5f, * indicates a bonding position with D or Z. Each hydrogen atom in the aforementioned skeleton can be independently substituted by a deuterium atom or a substituent, or it can be substituted together with adjacent hydrogen atoms by a linking group to form a cyclic structure. In one aspect of the invention, Ar has a skeleton of 5a or 5b. In one aspect of the invention, Ar has any one of skeletons 5c to 5f. In one aspect of the invention, Ar has a skeleton of 5c or 5d. In one aspect of the invention, Ar has a skeleton of 5e or 5f. In one aspect of the invention, Ar has a skeleton of 5c or 5e. In one aspect of the invention, Ar has a skeleton of 5d or 5fd.

[0077] The hydrogen atoms of the arylene or biphenyl group that can be used in Ar, and the hydrogen atoms in the skeleton 5a-5f, can be replaced by deuterium atoms or substituents. For example, structures in which some hydrogen atoms are replaced by deuterium atoms or structures in which all hydrogen atoms are replaced by deuterium atoms can be illustrated. Unsubstituted structures are preferred. Substituents can be selected from substituent group A, substituent group B, substituent group C, substituent group D, or substituent group E.

[0078] In general formula (1), D represents the donor group. The donor group referred to here is a group with a negative Hammett σp value. Here, "Hammett σp value" is a value proposed by L.P. Hammett, which quantifies the effect of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, it is the following equation that holds between the substituent in the para-substituted benzene derivative and the reaction rate constant or equilibrium constant:

[0079] log(k / k0)=ρσp

[0080] or

[0081] log(K / K0)=ρσp

[0082] The constant (σp) is specific to the substituents in the formula. In the above formula, k0 represents the rate constant of the benzene derivative without substituents, k represents the rate constant of the benzene derivative substituted with substituents, K0 represents the equilibrium constant of the benzene derivative without substituents, K represents the equilibrium constant of the benzene derivative substituted with substituents, and ρ represents the reaction constant determined by the type and conditions of the reaction. For a description of the "Hammett's σp value" and the number of substituents mentioned in this invention, please refer to the description of the σp value mentioned in Hansch, C. et.al., Chem. Rev., 91, 165–195 (1991). Groups with a positive σp value in Hammett tend to exhibit electron-withdrawing (acceptor) properties. In addition, in one aspect of this invention, the compound represented by general formula (1) does not contain substituents with a σp value of 0.2 or higher.

[0083] The donor group 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, more preferably a substituted or unsubstituted aryl group, and even more preferably a substituted or unsubstituted aryl group. Regarding the substituted amino group, a substituted or unsubstituted diarylamino group or a substituted or unsubstituted diheterarylamino group is particularly preferred. The two atomic groups bonded to the nitrogen atom of the substituted amino group can bond to each other to form a cyclic structure. The donor group in this invention can be a group bonded to the nitrogen atom of a substituted amino group or a group bonded to a group containing a substituted amino group. The group bonded to the substituted amino group is preferably a π-conjugated group. More preferably, it is a group bonded to the nitrogen atom of a substituted amino group or a group in which the nitrogen atom of the substituted amino group is bonded to and on the benzene ring, and even more preferably a group bonded to the nitrogen atom of a substituted amino group.

[0084] The donor group in this invention is particularly preferred as a substituted or unsubstituted carbazole-9-yl group. A benzene ring or heterocycle may be further fused to the carbazole-9-yl group. In one aspect of the invention, a benzene ring or heterocycle is not further fused to the carbazole-9-yl group. The substituents of the carbazole-9-yl group may be, for example, substituents selected from substituent group A, substituent group B, substituent group C, substituent group D, or substituent group E. Examples of preferred carbazole-9-yl groups include an unsubstituted carbazole-9-yl group, a carbazole-9-yl group with at least one substituted position at 3 and 6, and a carbazole-9-yl group with both positions substituted at 3 and 6.

[0085] In a preferred aspect of the invention, a group represented by the following general formula is used as the donor group. Ar 1 and Ar 2 Each of these can be used independently to represent phenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl, or m-terphenyl. p represents 0 or 1. When p is 1, Ar... 1 and Ar 2 They can be the same or different. * indicates the bonding position.

[0086] [Chemical Formula 9]

[0087]

[0088] In a preferred aspect of the invention, a group represented by the following general formula is used as the donor group. X 3 Represents an oxygen atom or a sulfur atom. Ar 3 and Ar 4 Each of these can independently represent phenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl, or m-terphenyl. q and r can independently represent 0 or 1, and q+r represents 1 or 2. When both q and r are 1, Ar... 3 and Ar 4 They can be the same or different. * indicates the bonding position.

[0089] [Chemical Formula 10]

[0090]

[0091] The donor group that can be used in D preferably has 13 or more atoms other than hydrogen and deuterium atoms. For example, groups in the range of 13 to 40 or groups in the range of 13 to 26 can also be selected.

[0092] The donor group that D can use can be composed of only atoms selected from hydrogen, deuterium, carbon, nitrogen and oxygen atoms, for example, it can also be composed of only atoms selected from hydrogen, deuterium, carbon and nitrogen atoms, for example, it can also be composed of only atoms selected from hydrogen, carbon and nitrogen atoms.

[0093] The following includes specific examples of donor groups that D can use, but these specific examples are not intended to limit the interpretation of donor groups that D can use. * indicates a bonding position.

[0094] [Chemical Formula 11-1]

[0095]

[0096] [Chemical Formula 11-2]

[0097]

[0098] The compound represented by general formula (1) preferably has the structure represented by the following general formula (2).

[0099] [Chemical Formula 12]

[0100] General formula (2)

[0101]

[0102] In general formula (2), X 1 and X 2 Each can be represented independently as an oxygen atom or a sulfur atom. In one aspect of the invention, X 1 and X 2 At least one of them is an oxygen atom. In one aspect of the invention, X 1 and X 2 At least one of them is a sulfur atom. In one aspect of the invention, X 1 and X 2 One of them is an oxygen atom and the other is a sulfur atom. In one aspect of the invention, X 1 and X 2 All are oxygen atoms. In one aspect of the invention, X 1 and X 2 All are sulfur atoms.

[0103] In general formula (2), X 1 Either of the two bonded benzene rings can be combined with (R 4 ) n4 Bonded benzene rings. Preferably, X is bonded in one of the two benzene rings. 2 Bonding on the unbonded benzene ring.

[0104] In general formula (2), n represents 0 or 1. In one aspect of the invention, n is 0. In another aspect of the invention, n is 1.

[0105] In general formula (2), n1, n2, n3, n4, n5, and n7 independently represent any integer from 0 to 4, and n6 represents any integer from 0 to 2. In one aspect of the invention, n1 to n6 are each independently any integer from 0 to 2. In another aspect of the invention, n1 to n6 are each independently 0 or 1. In one aspect of the invention, n1 and n2 are 0. In one aspect of the invention, n3 and n4 are 0. In one aspect of the invention, n5 and n6 are 0.

[0106] In general formula (2), R 1 ~R 7 Each can independently represent a deuterium atom or a substituent. In one aspect of the invention, R 1 ~R 7 It is a deuterium atom. As a substituent, it may be a substituent selected from the following substituent group A, substituent selected from the following substituent group B, substituent selected from the following substituent group C, substituent selected from the following substituent group D, or may include a substituent selected from the following substituent group E.

[0107] R in general formula (2) 3 and R 4 Two adjacent R 1 Two adjacent R 2 Two adjacent R 3 Two adjacent R 4 Two adjacent R 5 Two adjacent R 6 Two adjacent R 7 They can bond together to form a ring structure. In one aspect of the invention, two adjacent R... 1 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 2 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 3 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 4 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 5 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 6 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, two adjacent R... 7 They are not bonded to each other, nor do they form a ring structure. In one aspect of the invention, R3 and R 4 Two adjacent R 1 Two adjacent R 2 Two adjacent R 3 Two adjacent R 4 Two adjacent R 5 Two adjacent R 6 Two adjacent R 7 They did not bond together to form a ring structure.

[0108] Regarding aspects and preferred ranges of general formula (2), reference can be made to the corresponding description of general formula (1).

[0109] The compound represented by general formula (1) preferably has a structure represented by any one of the following general formulas (3-1) to (3-16).

[0110] [Chemical Formula 13-1]

[0111]

[0112] [Chemical Formula 13-2]

[0113]

[0114] In general formulas (3-1) to (3-16), R 1 ~R 7 Each of these can independently represent a deuterium atom or a substituent. n represents 0 or 1; n1, n2, n3, n4, n5, and n7 can independently represent any integer from 0 to 4; n3' and n4' can independently represent any integer from 0 to 3; and n6 can represent any integer from 0 to 2. R 3 and R 4 Two adjacent R 1 Two adjacent R 2 Two adjacent R 3 Two adjacent R 4 Two adjacent R 5 Two adjacent R 6 Two adjacent R 7 They can bond together to form a ring structure.

[0115] In one aspect of the invention, a structure represented by any one of general formulas (3-1) to (3-4) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-5) to (3-8) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-9) to (3-12) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-13) to (3-16) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-1), (3-5), (3-9), and (3-13) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-2), (3-6), (3-10), and (3-14) is provided. In one aspect of the invention, a structure represented by any one of general formulas (3-3), (3-7), (3-11), and (3-15) is provided. In one aspect of the invention, a structure is represented by any one of general formulas (3-4), (3-8), (3-12), and (3-16).

[0116] Regarding aspects and preferred ranges of general formulas (3-1) to (3-16), reference can be made to the corresponding descriptions of general formulas (1) and (2).

[0117] In one aspect of the present invention, the compound represented by general formula (1) has only one carbazole structure within the molecule. In one aspect of the present invention, the compound represented by general formula (1) does not contain a pyrrole ring that does not form a carbazole structure. In one aspect of the present invention, the compound represented by general formula (1) does not contain a furan ring that does not form a dibenzofuran structure. In one aspect of the present invention, the compound represented by general formula (1) does not contain a thiophene ring that does not form a dibenzothiophene structure. In one aspect of the present invention, the compound represented by general formula (1) does not contain a fused ring consisting of six or more rings.

[0118] The following are specific examples of compounds represented by general formula (1). However, the compounds represented by general formula (1) that can be used in this invention should not be interpreted limitingly as these specific examples.

[0119] [Chemical Formula 14-1]

[0120]

[0121] [Chemical Formula 14-2]

[0122]

[0123] In one aspect of the invention, a compound having an asymmetric structure is selected as the compound represented by general formula (1).

[0124] Regarding the molecular weight of the compound represented by general formula (1), for example when attempting to use it by deposition to form an organic layer containing the compound represented by general formula (1), it is preferably 1500 or less, more preferably 1200 or less, even more preferably 1000 or less, and even more preferably 900 or less. The lower limit of the molecular weight is the molecular weight of the smallest compound in the group of compounds represented by general formula (1).

[0125] Compounds represented by general formula (1) can be coated to form films regardless of their molecular weight. Even compounds with relatively large molecular weights can be coated to form films. Compounds represented by general formula (1) are readily soluble in organic solvents. Therefore, compounds represented by general formula (1) are easily adapted for coating and are readily purified to improve purity.

[0126] The compound represented by general formula (1) preferably does not contain metal atoms. For example, as a compound represented by general formula (1), a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, and sulfur atoms can be selected. For example, as a compound represented by general formula (1), a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and oxygen atoms can be selected. For example, as a compound represented by general formula (1), a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and sulfur atoms can be selected. For example, as a compound represented by general formula (1), a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and sulfur atoms can be selected. For example, as a compound represented by general formula (1), a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and sulfur atoms can be selected.

[0127] In this document, "alkyl" can be any of straight-chain, branched-chain, or cyclic. Furthermore, two or more of the straight-chain, cyclic, and branched-chain moieties can be mixed. The number of carbon atoms in an alkyl group can be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms can also be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkyl groups may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, isohexyl, n-octyl, isooctyl, n-nonyl, isononyl, n-decyl, isododecyl, cyclopentyl, cyclohexyl, and cycloheptyl. The alkyl group, as a substituent, can be further substituted with an aryl group.

[0128] The "alkenyl" group can be any of the following: straight-chain, branched-chain, or cyclic. Furthermore, two or more of the straight-chain, cyclic, and branched-chain portions can be mixed. The number of carbon atoms in the alkenyl group can be, for example, 2 or more, or 4 or more. The number of carbon atoms can also be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkenyl groups include vinyl, propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The alkenyl group, as a substituent, can be further substituted with other substituents.

[0129] "Aryl" and "heteroaryl" can be monocyclic or fused rings formed by the fusion of two or more rings. When it is a fused ring, the number of fused rings is preferably 2 to 6, for example, selected from 2 to 4. Specific examples of the ring can include benzene rings, pyridine rings, pyrimidine rings, triazine rings, naphthyl rings, anthracene rings, phenanthrene rings, triphenylene rings, quinoline rings, pyrazine rings, quinoxaline rings, naphthidine rings, or rings formed by their fusion. Specific examples of aryl or heteroaryl can include phenyl, 1-naphthyl, 2-naphthyl, 1-anthrayl, 2-anthrayl, 9-anthrayl, 2-pyridyl, 3-pyridyl, 4-pyridyl. The number of atoms constituting the ring skeleton of the aryl group is preferably 6 to 40, more preferably 6 to 20, and can also be selected in the range of 6 to 14 or in the range of 6 to 10. The number of atoms constituting the ring skeleton of the heteroaryl group is preferably 4 to 40, more preferably 5 to 20, and can also be selected in the range of 5 to 14 or in the range of 5 to 10. "Arylidene" and "heteroaryl" can be set to replace the valence number in the description of aryl and heteroaryl groups with 2 instead of 1.

[0130] In this document, "substituent group A" means selected from hydroxyl, halogen (e.g., fluorine, chlorine, bromine, iodine), alkyl (e.g., 1-40 carbon atoms), alkoxy (e.g., 1-40 carbon atoms), alkylthio (e.g., 1-40 carbon atoms), aryl (e.g., 6-30 carbon atoms), aryloxy (e.g., 6-30 carbon atoms), arylthio (e.g., 6-30 carbon atoms), heteroaryl (e.g., 5-30 atoms in the ring skeleton), and heteroaryloxy (e.g., 5-30 atoms in the ring skeleton). A group consisting of one or more of the following groups: 30, heteroarylthio (e.g., 5 to 30 atoms in the ring skeleton), acyl (e.g., 1 to 40 carbon atoms), alkenyl (e.g., 1 to 40 carbon atoms), alkoxycarbonyl (e.g., 1 to 40 carbon atoms), aryloxycarbonyl (e.g., 1 to 40 carbon atoms), heteroaryloxycarbonyl (e.g., 1 to 40 carbon atoms), silyl (e.g., trialkylsilyl with 1 to 40 carbon atoms), and nitro.

[0131] In this document, "substituent group B" means a group selected from one or more of the group consisting of alkyl (e.g., 1 to 40 carbon atoms), alkoxy (e.g., 1 to 40 carbon atoms), aryl (e.g., 6 to 30 carbon atoms), aryloxy (e.g., 6 to 30 carbon atoms), heteroaryl (e.g., 5 to 30 atoms forming the ring skeleton), heteroaryloxy (e.g., 5 to 30 atoms forming the ring skeleton), and diarylamino (e.g., 0 to 20 carbon atoms).

[0132] In this document, “substituent group C” means a group selected from one or more of the group consisting of alkyl (e.g., 1 to 20 carbon atoms), aryl (e.g., 6 to 22 carbon atoms), heteroaryl (e.g., 5 to 20 cyclic skeleton atoms), and diarylamino (e.g., 12 to 20 carbon atoms).

[0133] In this document, "substituent group D" means a group selected from one or more groups composed of alkyl (e.g., 1 to 20 carbon atoms), aryl (e.g., 6 to 22 carbon atoms), and heteroaryl (e.g., 5 to 20 cyclic skeleton atoms).

[0134] In this document, “substituent group E” means a group selected from one or more groups composed of alkyl (e.g., 1 to 20 carbon atoms) and aryl (e.g., 6 to 22 carbon atoms).

[0135] In this document, a substituent described as "substituent" or "substituted or unsubstituted" may be selected from substituent group A, substituent group B, substituent group C, substituent group D, or substituent group E.

[0136] [Synthesis of compounds represented by general formula (1)]

[0137] The compound represented by general formula (1) can be synthesized by using known synthetic methods with appropriate combinations. For example, D-Ar-Z, which is of general formula (1), can be synthesized by reacting DH with X-Ar-Z. Here, H is a hydrogen atom and X is a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom). The reaction conditions can be optimized by methods well known to those skilled in the art.

[0138] (Delayed fluorescence materials)

[0139] There are no particular limitations on the use of the compound represented by general formula (1). The compound represented by general formula (1) can be used as a host material for luminescent materials (dopersants), or as a charge transport material or luminescent material, depending on the application. When used as a host material for luminescent materials, it can be used as a host material for any of the following luminescent materials: delayed fluorescence materials, fluorescent materials that do not emit delayed fluorescence (transient fluorescence materials), and phosphorescent materials.

[0140] The compound represented by general formula (1) is particularly excellent as a host material for luminescent materials. The compound represented by general formula (1) is particularly useful as a host material for use in conjunction with delayed fluorescence materials.

[0141] The "delayed fluorescence material" described herein refers to an organic compound that exhibits a reverse intersystem crossing from an excited triplet state to an excited singlet state in the excited state, and emits delayed fluorescence upon returning from the excited singlet state to the ground state. In this invention, when the emission lifetime is measured using a fluorescence lifetime measurement system (such as the Hamamatsu Photonics KK stripe camera system), materials in which fluorescence with an observed emission lifetime of 100 ns (nanoseconds) or more are referred to as delayed fluorescence materials.

[0142] When a compound represented by general formula (1) and a delayed fluorescent material are used in combination, the delayed fluorescent material receives energy from the excited singlet state of the compound represented by general formula (1) and transitions to the excited singlet state. Furthermore, the delayed fluorescent material can receive energy from the excited triplet state of the compound represented by general formula (1) and transition to the excited triplet state. The delayed fluorescent material transitions to the excited triplet state due to the energy difference between the excited singlet state and the excited triplet state (ΔE). ST The small size of the excitation triplet state makes it easy for delayed fluorescent materials to undergo reverse intersystem crossing into excited singlet states. Delayed fluorescent materials with excited singlet states generated through these pathways contribute to luminescence.

[0143] The difference ΔE between the lowest excitation singlet energy and the lowest excitation triplet energy at 77 K in a delayed fluorescence material. ST Preferably, it is 0.3 eV or less, more preferably 0.25 eV or less, even more preferably 0.2 eV or less, even more preferably 0.15 eV or less, further 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 especially preferably 0.01 eV or less.

[0144] If ΔE STWhen the temperature is low, the material readily transitions from the excited singlet state to the excited triplet state due to the absorption of thermal energy, thus functioning as a thermally activated delayed fluorescence material. The heat emitted by the thermally activated delayed fluorescence material's absorption device facilitates a relatively easy transition from the excited triplet state to the excited singlet state, thereby enabling its excited triplet state to have good energy efficiency and contribute to luminescence.

[0145] The lowest excited singlet energy (E) of the compound in this invention S1 ) and the lowest excited triplet energy (E T1 ΔE is the value obtained through the following steps. ST To calculate E S1 -E T1 The value obtained is then calculated.

[0146] (1) Lowest excitation singlet energy (E S1 )

[0147] Prepare a thin film or toluene solution (concentration 10) of the compound to be measured. -5 A sample (mol / L) was used. The fluorescence spectrum of this sample was measured at room temperature (300 K). In the fluorescence spectrum, the vertical axis was set to emission, and the horizontal axis to wavelength. A tangent was drawn relative to the rising short-wavelength side of the emission spectrum, and the wavelength value λedge [nm] at the intersection of this tangent and the horizontal axis was determined. This wavelength value was converted into an energy value using the following conversion formula, which was taken as E. S1 .

[0148] Conversion formula: E S1 [eV] = 1239.85 / λedge

[0149] Regarding the measurement of the emission spectrum in the embodiments described later, an LED light source (M300L4 manufactured by Thorlabs Japan Inc.) was used as the excitation source, and the measurement was performed using a detector (PMA-12 multichannel spectrometer C10027-01 manufactured by Hamamatsu Photonics KK).

[0150] (2) Minimum Excitation Triplet Energy (E) T1 )

[0151] This will be related to the lowest excited singlet energy (E S1The same sample used in the phosphorescence measurement was cooled to 77 K with liquid nitrogen. The sample was then irradiated with excitation light (300 nm), and the phosphorescence was measured using a detector. A phosphorescence spectrum was generated from the emission 100 milliseconds after excitation. A tangent was drawn relative to the rising short-wavelength side of this phosphorescence spectrum, and the wavelength value λedge [nm] at the intersection of this tangent and the horizontal axis was determined. This wavelength value was converted into an energy value using the following conversion formula, which was used as E. T1 .

[0152] Conversion formula: E T1 [eV] = 1239.85 / λedge

[0153] The rising tangent on the short-wavelength side of the phosphorescence spectrum is drawn as follows. Consider the tangents at various points on the curve towards the long-wavelength side as the spectral curve moves from the short-wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side of the spectrum. As the curve rises (i.e., as the vertical axis increases), the slope of this tangent increases. The tangent drawn at the point where this slope reaches its maximum value is taken as the rising tangent for the short-wavelength side of the phosphorescence spectrum.

[0154] Furthermore, the maximum point of peak intensity with less than 10% of the maximum peak intensity of the spectrum is not included in the maximum value on the shortest wavelength side. The tangent line drawn at the point closest to the maximum value on the shortest wavelength side and where the slope value is the maximum value is set as the rising tangent line for the short wavelength side of the phosphorescence spectrum.

[0155] In a preferred aspect of the invention, a compound having a benzonitrile structure with one cyano group substituted as a benzene ring (benzonitrile derivative) is used as a delayed fluorescence material. In another preferred aspect of the invention, a compound having a dibenzonitrile structure with two cyano groups substituted as a benzene ring (dibenzonitrile derivative) is used as a delayed fluorescence material. In yet another preferred aspect of the invention, a compound having an azirbenzene structure with at least one nitrogen atom substituted in the carbon atom of the benzene ring backbone (azirbenzene derivative) is used as a delayed fluorescence material.

[0156] In a preferred aspect of the invention, a compound represented by the following general formula (4) is used as a delayed fluorescence material.

[0157] [Chemical Formula 15]

[0158] General formula (4)

[0159]

[0160] In general formula (4), R 21 ~R 23One of them represents a cyano group or a group represented by the following general formula (5), R 21 ~R 23 The remaining two and R 24 and R 25 At least one of them represents a group represented by the following general formula (6), R 21 ~R 25 The remaining part represents a hydrogen atom or a substituent (wherein the substituent is not a cyano, a group represented by the following general formula (5), or a group represented by the following general formula (6)).

[0161] [Chemical Formula 16]

[0162] General formula (5)

[0163]

[0164] In general formula (5), L 1 R represents a single bond or a divalent linker. 31 and R 32 Each symbol represents a hydrogen atom or a substituent independently, and * indicates a bonding position.

[0165] [Chemical Formula 17]

[0166] General formula (6)

[0167]

[0168] In general formula (6), L 2 R represents a single bond or a divalent linker. 33 and R 34 Each symbol represents a hydrogen atom or a substituent independently, and * indicates a bonding position.

[0169] In a preferred aspect of the invention, R 22 It is cyano. In a preferred aspect of the invention, R... 22 R is a group represented by general formula (5). In one aspect of the invention, R 21 It is a cyano group or a group represented by general formula (5). In one aspect of the invention, R 23 It is a cyano group or a group represented by general formula (5). In one aspect of the invention, R 21 ~R 23 One of them is a cyano group. In one aspect of the invention, R 21 ~R 23 One of them is a group represented by general formula (5).

[0170] In a preferred aspect of the invention, L in general formula (5) 1 It is a single bond. In one aspect of the invention, L 1The linking group is divalent, preferably a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene, more preferably a substituted or unsubstituted arylene, and even more preferably a substituted or unsubstituted 1,4-phenylene (as a substituent, for example an alkyl group having 1 to 3 carbon atoms).

[0171] In one aspect of the invention, R in general formula (5) 31 and R 32 Each group is independently selected from one or more groups chosen from the group consisting of alkyl (e.g., 1 to 40 carbon atoms), aryl (e.g., 6 to 30 carbon atoms), heteroaryl (e.g., 5 to 30 cyclic skeleton atoms), alkenyl (e.g., 1 to 40 carbon atoms), and alkynyl (e.g., 1 to 40 carbon atoms) (hereinafter, these groups are referred to as "groups of substituent group A"). In a preferred aspect of the invention, R 31 and R 32 Each aryl group is independently substituted or unsubstituted (e.g., having 6 to 30 carbon atoms), and the substituents of the aryl group may include groups of substituent group A. In a preferred aspect of the invention, R 31 and R 32 same.

[0172] In a preferred aspect of the invention, L in general formula (6) 2 It is a single bond. In one aspect of the invention, L 2 The linking group is divalent, preferably a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene, more preferably a substituted or unsubstituted arylene, and even more preferably a substituted or unsubstituted 1,4-phenylene (as a substituent, for example an alkyl group having 1 to 3 carbon atoms).

[0173] In one aspect of the invention, R in general formula (6) 33 and R 34Each of these terms independently represents a substituted or unsubstituted alkyl group (e.g., 1 to 40 carbon atoms), a substituted or unsubstituted alkenyl group (e.g., 1 to 40 carbon atoms), a substituted or unsubstituted aryl group (e.g., 6 to 30 carbon atoms), or a substituted or unsubstituted heteroaryl group (e.g., 5 to 30 carbon atoms). The substituents of the alkyl, alkenyl, aryl, and heteroaryl groups described herein may include those selected from hydroxyl, halogen (e.g., fluorine, chlorine, bromine, iodine), alkyl (e.g., 1 to 40 carbon atoms), alkoxy (e.g., 1 to 40 carbon atoms), alkylthio (e.g., 1 to 40 carbon atoms), aryl (e.g., 6 to 30 carbon atoms), aryloxy (e.g., 6 to 30 carbon atoms), arylthio (e.g., 6 to 30 carbon atoms), heteroaryl (e.g., 5 to 30 atoms forming the ring skeleton), heteroaryl (e.g., 5 to 30 atoms forming the ring skeleton), and heteroaryl. A group consisting of one or more of the following groups: thio (e.g., 5 to 30 atoms in the ring skeleton), acyl (e.g., 1 to 40 carbon atoms), alkenyl (e.g., 1 to 40 carbon atoms), alkoxycarbonyl (e.g., 1 to 40 carbon atoms), aryloxycarbonyl (e.g., 1 to 40 carbon atoms), heteroaryloxycarbonyl (e.g., 1 to 40 carbon atoms), silyl (e.g., trialkylsilyl with 1 to 40 carbon atoms), nitro, and cyano (hereinafter, these groups are referred to as "groups of substituent group B").

[0174] R 33 and R 34 They can form cyclic structures by bonding with each other via single bonds or linking groups. In particular, when R 33 and R 34 When the group is aryl, it is preferably formed into a cyclic structure through single bonds or linking groups. The linking groups may include -O-, -S-, -N(R) 35 )-、-C(R 36 (R) 37 -, -C(=O)-, preferably -O-, -S-, -N(R)- 35 )-、-C(R 36 (R) 37 -, more preferably -O-, -S-, -N(R) 35 )-. R 35 ~R 37 Each can be represented independently by a hydrogen atom or a substituent. As a substituent, a group from the substituent group A above or a group from the substituent group B below can be selected, preferably a group selected from one or more groups composed of alkyl groups having 1 to 10 carbon atoms and aryl groups having 6 to 14 carbon atoms.

[0175] The group represented by general formula (6) is preferably the group represented by the following general formula (7).

[0176] [Chemical Formula 18]

[0177] General formula (7)

[0178]

[0179] L in general formula (7) 11 Indicates a single bond or a divalent linker. Regarding L... 11 For further explanation and preferred scope, please refer to the above L. 2 Description and preferred range.

[0180] R in general formula (7) 41 ~R 48 Each can be used independently to represent a hydrogen atom or a substituent. R 41 and R 42 R 42 and R 43 R 43 and R 44 R 44 and R 45 R 45 and R 46 R 46 and R 47 R 47 and R 48 They can bond together to form a cyclic structure. The cyclic structure formed by bonding together can be an aromatic ring, an aliphatic ring, or a structure containing heteroatoms, and the cyclic structure can be a fused ring with more than two rings. The heteroatoms mentioned here are preferably atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms. Examples of the cyclic structures formed can include benzene rings, naphthalene rings, pyridine rings, pyridazine rings, pyrimidine rings, pyrazine rings, pyrrole rings, imidazole rings, pyrazole rings, imidazole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, cyclohexadiene rings, cyclohexene rings, cyclopentene rings, cycloheptanetriene rings, cycloheptadiene rings, cycloheptene rings, furan rings, thiophene rings, naphthidine rings, quinoxaline rings, quinoline rings, etc. For example, multiple rings can be formed by fusion, such as phenanthrene rings or triphenylene rings. The number of rings included in the group represented by general formula (7) can be selected from the range of 3 to 5 or from the range of 5 to 7.

[0181] R 41 ~R 48 The substituents that can be used may include groups from substituent group B above, preferably alkyl groups with 1 to 10 unsubstituted carbon atoms or aryl groups with 6 to 10 carbon atoms that can be substituted by alkyl groups with 1 to 10 unsubstituted carbon atoms. In a preferred aspect of the invention, R 41 ~R48 It is an alkyl group having 1 to 10 unsubstituted hydrogen atoms or carbon atoms. In a preferred aspect of the invention, R 41 ~R 48 It has 6 to 10 unsubstituted aryl groups, consisting of hydrogen atoms or carbon atoms. In a preferred aspect of the invention, R... 41 ~R 48 All are hydrogen atoms.

[0182] In general formula (7), * represents the bonding position.

[0183] In a preferred aspect of the invention, an azirbenzene derivative is used as a delayed fluorescence material. In another preferred aspect of the invention, the azirbenzene derivative has a benzene ring skeleton forming an azirbenzene structure with three nitrogen atoms substituted for the carbon atom. For example, an azirbenzene derivative having a 1,3,5-triazine structure is preferably selected. In another preferred aspect of the invention, the azirbenzene derivative has a benzene ring skeleton forming an azirbenzene structure with two nitrogen atoms substituted for the carbon atom. For example, it may include azirbenzene derivatives having pyridazine, pyrimidine, or pyrazine structures, and an azirbenzene derivative having a pyrimidine structure is preferably selected. In another aspect of the invention, the azirbenzene derivative has a benzene ring skeleton forming a pyrimidine structure with one nitrogen atom substituted for the carbon atom.

[0184] In a preferred aspect of the invention, a compound represented by the following general formula (8) is used as a delayed fluorescence material.

[0185] [Chemical Formula 19]

[0186] General formula (8)

[0187]

[0188] In general formula (8), Y 1 Y 2 and Y 3 At least one of them represents a nitrogen atom and the remaining part represents a methine. In one aspect of the invention, Y 1 It is a nitrogen atom and Y 2 and Y 3 It is a methine. Y is preferred. 1 and Y 2 It is a nitrogen atom and Y 3 It is methine. More preferably, Y 1 ~Y 3 All are nitrogen atoms.

[0189] In general formula (8), Z 1 ~Z 3Each can be represented independently by a hydrogen atom or a substituent, but at least one must be an acceptor substituent. An acceptor substituent means a group with a negative σp value in the Hammett equation. Z is preferred. 1 ~Z 3 At least one of them is a group containing a diarylamino structure (the nitrogen atom can be bonded to the two aryl groups), more preferably a group represented by the above general formula (6), such as a group represented by the above general formula (7). In one aspect of the invention, Z 1 ~Z 3 Only one of them is a group represented by general formula (6) or (7). In one aspect of the invention, Z 1 ~Z 3 Only two of them are independently represented by general formula (6) or (7). In one aspect of the invention, Z 1 ~Z 3 Each is independently a group represented by general formula (6) or (7). For details and preferred ranges of general formulas (6) and (7), please refer to the corresponding descriptions above. The remaining Z groups that are not represented by general formulas (6) and (7) 1 ~Z 3 Preferably, the aryl group (e.g., having 6 to 40 carbon atoms, preferably 6 to 20) is substituted or unsubstituted. Examples of substituents for the aryl group described herein include one or more groups selected from the group consisting of aryl groups (e.g., having 6 to 20 carbon atoms, preferably 6 to 14) and alkyl groups (e.g., having 1 to 20 carbon atoms, preferably 1 to 6). In one aspect of the invention, general formula (8) does not contain a cyano group.

[0190] In a preferred aspect of the invention, a compound represented by the following general formula (9) is used as a delayed fluorescence material.

[0191] [Chemical Formula 20]

[0192] General formula (9)

[0193]

[0194] In general formula (9), Ar 1 Formation can be replaced by the following A 1 and D 1 The cyclic structure represents a benzene ring, naphthalene ring, anthracene ring, or phenanthrene ring. Ar 2 Ar 3 These can form cyclic structures, representing benzene rings, naphthalene rings, pyridine rings, or benzene rings substituted with cyano groups. m1 represents any integer from 0 to 2, and m2 represents any integer from 0 to 1. A 1 This indicates cyano, phenyl, pyrimidinyl, triazolyl, or benzylnitrile. (D)1 This refers to a substituted or unsubstituted 5H-indolo[3,2,1-de]phenazine-5-yl or a substituted or unsubstituted heterocyclic fused carbazole group without a naphthalene structure, when multiple Ds are present in general formula (9). 1 They can be the same or different. And, D 1 The substituents can bond with each other to form a ring structure.

[0195] The following includes preferred compounds that can be used as delayed fluorescence materials, but the delayed fluorescence materials that can be used in this invention are not limited to these specific examples.

[0196] [Chemical Formula 21-1]

[0197]

[0198] [Chemical Formula 21-2]

[0199]

[0200] [Chemical Formula 21-3]

[0201]

[0202] [Chemical Formula 21-4]

[0203]

[0204] [Chemical Formula 21-5]

[0205]

[0206] [Chemical Formula 21-6]

[0207]

[0208] [Chemical Formula 21-7]

[0209]

[0210] In addition to the above, known delayed fluorescence materials can also be appropriately combined with compounds represented by general formula (1) in this invention. Furthermore, unknown delayed fluorescence materials can also be used.

[0211] Delayed fluorescence materials may include segments 0008–0048 and 0095–0133 as specified in WO2013 / 154064, segments 0007–0047 and 0073–0085 as specified in WO2013 / 011954, segments 0007–0033 and 0059–0066 as specified in WO2013 / 011955, and segments 0008–0071 as specified in WO2013 / 081088. Paragraphs 0118-0133, 0009-0046 and 0093-0134 of Japanese Patent Application Publication No. 2013-256490, 0008-0020 and 0038-0040 of Japanese Patent Application Publication No. 2013-116975, 0007-0032 and 0079-0084 of WO2013 / 133359, and 000... Paragraphs 8 to 0054 and 0101 to 0121, paragraphs 0007 to 0041 and 0060 to 0069 of Japanese Patent Application Publication No. 2014-9352, paragraphs 0008 to 0048 and 0067 to 0076 of Japanese Patent Application Publication No. 2014-9224, paragraphs 0013 to 0025 of Japanese Patent Application Publication No. 2017-119663, and paragraphs 0013 to 0025 of Japanese Patent Application Publication No. 2017-119664. Compounds contained in the general formulas described in paragraphs 6, paragraphs 0012 to 0025 of Japanese Patent Application Publication No. 2017-222623, paragraphs 0010 to 0050 of Japanese Patent Application Publication No. 2017-226838, paragraphs 0012 to 0043 of Japanese Patent Application Publication No. 2018-100411, and paragraphs 0016 to 0044 of WO2018 / 047853, especially exemplary compounds that emit delayed fluorescence.Furthermore, Japanese Patent Application Publication Nos. 2013-253121, WO2013 / 133359, WO2014 / 034535, WO2014 / 115743, WO2014 / 122895, WO2014 / 126200, WO2014 / 136758, and WO2014 / 133121 may also be adopted. Communiqués, WO2014 / 136860, WO2014 / 196585, WO2014 / 189122, WO2014 / 168101, WO2015 / 008580, WO2014 / 203840, WO2015 / 002213, WO2015 / 016200, WO201 Japanese Publication No. 5 / 019725, WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, Japanese Patent Application Publication No. 2015-129240, WO2015 / 129714, WO2015 / 1297 Materials that emit delayed fluorescence as described in Publications No. 15, WO2015 / 133501, WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, and WO2015 / 159541. Furthermore, the aforementioned publications described in this paragraph are incorporated herein by reference as part of this document.

[0212] The delayed fluorescence material used in this invention preferably does not contain metal atoms. For example, as a delayed fluorescence material, a compound composed of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, and sulfur atoms can be selected. For example, as a delayed fluorescence material, a compound composed of atoms selected from the group consisting of carbon, hydrogen, nitrogen, and oxygen atoms can be selected. For example, as a delayed fluorescence material, a compound composed of carbon, hydrogen, and nitrogen atoms can be selected.

[0213] (Composition)

[0214] The composition of the present invention comprises a compound represented by general formula (1) and a delayed fluorescent material. In one aspect of the present invention, the composition consists of only one or more compounds represented by general formula (1) and one or more delayed fluorescent materials. In another aspect of the present invention, the composition consists of only one compound represented by general formula (1) and one delayed fluorescent material. In another aspect of the present invention, in addition to the compound represented by general formula (1) and the delayed fluorescent material, the composition also comprises a third component. The third component described herein is neither a compound represented by general formula (1) nor a delayed fluorescent material. The third component may comprise only one type or two or more types. The content of the third component in the composition may be selected in the range of less than 30% by weight, less than 10% by weight, less than 1% by weight, or less than 0.1% by weight. In one aspect of the present invention, the third component does not emit light. In another aspect of the present invention, the third component emits fluorescence. In a preferred aspect of the present invention, the largest component of the light emitted from the composition of the present invention is fluorescence (including delayed fluorescence).

[0215] In the compositions of the present invention, the content of the compound represented by general formula (1) is greater than that of the delayed fluorescent material by weight. The content of the compound represented by general formula (1) may be selected in the range of more than 3 times by weight of the content of the delayed fluorescent material, or in the range of more than 10 times by weight, or in the range of more than 100 times by weight, or in the range of more than 1000 times by weight, and for example, in the range of less than 10000 times by weight.

[0216] In the compositions of the present invention, it is preferable to select a delayed fluorescence material having an excitation singlet energy lower than that of the compound represented by general formula (1). The difference in excitation singlet energy may be 0.1 eV or more, 0.3 eV or more, or 0.5 eV or more, or 2 eV or less, 1.5 eV or less, or 1.0 eV or less.

[0217] The compositions of the present invention preferably do not contain any metallic elements. In one aspect of the invention, the compositions are composed only of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, sulfur, boron, and halogen atoms.

[0218] Furthermore, in one aspect of the present invention, the compound represented by general formula (1) is useful as a host material for use with delayed fluorescence materials and fluorescent compounds. Therefore, in one aspect of the present invention, in addition to the compound represented by general formula (1) and the delayed fluorescence material, the composition of the present invention also comprises a fluorescent compound.

[0219] The lowest excited singlet energy (E) of fluorescent compounds S1 The preferred fluorescent compound is smaller than that represented by general formula (1) and the delayed fluorescent material. The fluorescent compound receives energy from the compound represented by general formula (1) in the excited singlet state and the delayed fluorescent material in the excited singlet state through reverse intersystem crossing to become the excited singlet state, and then emits fluorescence when returning to the ground state. As a fluorescent compound, it is not particularly limited as long as it can receive energy from the compound represented by general formula (1) and the delayed fluorescent material in this way and emit fluorescence. The emission can be fluorescence or delayed fluorescence. Among them, the luminescent material used as the fluorescent compound is preferably a luminescent material that emits fluorescence when returning from the lowest excited singlet state energy level to the ground state energy level. Two or more fluorescent compounds can be used. For example, it is possible to make the desired color of emission by using two or more fluorescent compounds with different emission colors at the same time.

[0220] Fluorescent compounds can be derived from anthracene derivatives, tetraphenylene derivatives, naphthacene derivatives, pyrene derivatives, perylene derivatives, etc. Compounds exhibiting multiple resonance effects include derivatives such as rubrene derivatives, coumarin derivatives, pyran derivatives, stilbene derivatives, fluorene derivatives, anthracene derivatives, pyrrole methylene derivatives, terphenyl derivatives, terphenylene derivatives, fluoranthene derivatives, amine derivatives, quinacridone derivatives, oxadiazole derivatives, malononitrile derivatives, pyran derivatives, carbazole derivatives, juulolidine derivatives, thiazole derivatives, derivatives containing metals (Al, Zn), and compounds with boron-containing polycyclic aromatic skeletons such as diazaboron and naphthene. These exemplary skeletons may or may not have substituents. Furthermore, these exemplary skeletons can be combined with each other.

[0221] Specific examples of fluorescent compounds may include compounds included as examples of delayed fluorescence materials. In this case, the composition of the present invention contains two or more delayed fluorescence materials, but the material with a higher minimum excitation singlet state energy functions as an auxiliary dopant, while the material with a lower minimum excitation singlet state energy functions as the main luminescent fluorescent compound. The compound used as a fluorescent compound preferably exhibits a PL luminescence quantum yield of 60% or more, more preferably 80% or more. Furthermore, the compound used as a fluorescent compound preferably exhibits an instantaneous fluorescence lifetime of 50 ns or less, more preferably 20 ns or less. Here, the instantaneous fluorescence lifetime refers to the luminescence lifetime of the earliest decaying component among multiple exponentially decaying components observed when the luminescence lifetime of a compound exhibiting thermally active delayed fluorescence is measured. Furthermore, the compound used as a third compound preferably has a fluorescence emission rate from the minimum excitation singlet state (S1) to the ground state greater than the intersystem crossing rate from S1 to the minimum excitation triplet state (T1). For methods of calculating the rate constant of the compound, refer to known literature that mentions thermally active delayed fluorescence materials (H. Uoyama, et al., Nature 492, 234 (2012) or K. Masui, et al., Org. Electron. 14, 2721, (2013) etc.).

[0222] The following includes preferred compounds that can be used in conjunction with delayed fluorescence materials, but the fluorescent compounds that can be used in this invention are not to be limited by these specific examples.

[0223] [Chemical Formula 22-1]

[0224]

[0225] [Chemical Formula 22-2]

[0226]

[0227] [Chemical Formula 22-3]

[0228]

[0229] Furthermore, the compounds described in paragraphs 0220 to 0239 of WO2015 / 022974 may also be used, particularly preferably, as the fluorescent compounds of the present invention.

[0230] Furthermore, in one aspect of the present invention, the compound represented by general formula (1) can be used together with other host materials and used as a light-emitting layer (composition) comprising multiple host materials. That is, in one aspect of the present invention, the composition of the present invention contains multiple host materials comprising a compound represented by general formula (1). In the composition of the present invention, multiple compounds represented by general formula (1) can be used, and compounds represented by general formula (1) and host materials not represented by general formula (1) can be used in combination.

[0231] The following includes preferred compounds that can be used as a second host material in conjunction with the compound represented by general formula (1), but the second host material that can be used in this invention is not to be interpreted as limiting by these specific examples.

[0232] [Chemical Formula 23-1]

[0233]

[0234] [Chemical Formula 23-2]

[0235]

[0236] The form of the compositions of the present invention is not particularly limited. In a particularly preferred aspect of the invention, the compositions are in the form of a film. The film composed of the compositions of the present invention can be formed in a wet process or in a dry process.

[0237] In a wet process, a solution obtained by dissolving the components of the present invention is coated onto a surface, and after removing the solvent, a light-emitting layer is formed. The wet process may include spin coating, slot coating, inkjet printing, gravure printing, offset printing, flexographic printing, but is not limited to these methods. In the wet process, a suitable organic solvent capable of dissolving the components of the present invention is selected. In one embodiment, a substituent (e.g., an alkyl group) that improves solubility relative to the organic solvent can be introduced into the compound contained in the components of the present invention.

[0238] As a dry process, vacuum deposition is preferred. When using vacuum deposition, the compounds constituting the composition of the present invention can be co-deposited from a single deposition source, or from a single deposition source containing a mixture of compounds. When using a single deposition source, a mixed powder of all the compounds can be used, a compression molded body formed by compressing the mixed powder can be used, or a mixture of the compounds can be used after heating, melting, mixing, and then cooling. In one embodiment, by co-depositing under conditions where the vapor deposition rates (weight loss rates) of the multiple compounds contained in a single deposition source are consistent or substantially consistent, a film with a composition ratio corresponding to the composition ratio of the multiple compounds contained in the deposition source can be formed. If multiple compounds are mixed with the same composition ratio as the composition ratio of the formed film and used as a deposition source, a film with the desired composition ratio can be easily formed. In one embodiment, the temperature at which the co-deposited compounds achieve the same weight loss rate can be determined and used as the temperature for co-deposition. When the membrane is formed by deposition, the molecular weight of each compound constituting the composition is preferably 1500 or less, more preferably 1200 or less, even more preferably 1000 or less, and even more preferably 900 or less. The lower limit of the molecular weight can be, for example, 450, 500, or 600.

[0239] (Organic light-emitting diode)

[0240] By forming a light-emitting layer composed of the composition of the present invention, excellent organic light-emitting elements such as organic photoluminescent elements (organic PL elements) or organic electroluminescent elements (organic EL elements) can be provided. The organic light-emitting element of the present invention is a fluorescent light-emitting element, wherein the majority of the light emitted from the element is fluorescence (the fluorescence described herein includes delayed fluorescence).

[0241] The thickness of the light-emitting layer can be set to, for example, 1–15 nm, 2–10 nm, or 3–7 nm.

[0242] Organic photoluminescent devices have a structure in which at least one light-emitting layer is formed on a substrate. Furthermore, organic electroluminescent devices have at least an anode, a cathode, and an organic layer formed between the anode and cathode. The organic layer includes at least the light-emitting layer, and may be formed solely of the light-emitting layer, or may have one or more organic layers in addition to the light-emitting layer. Such other organic layers may include hole transport layers, hole injection layers, electron blocking layers, hole blocking layers, electron injection layers, electron transport layers, exciton blocking layers, etc. The hole transport layer may be a hole injection and transport layer with hole injection function, and the electron transport layer may be an electron injection and transport layer with electron injection function. A specific structure of an organic electroluminescent device is shown below. Figure 1 In. Figure 1In the diagram, 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the light-emitting layer, 6 represents the electron transport layer, and 7 represents the cathode.

[0243] When the organic light-emitting element of the present invention is a multi-wavelength light-emitting organic light-emitting element, the shortest wavelength light emission can be configured to include delayed fluorescence. Furthermore, the shortest wavelength light emission can also be configured to not include delayed fluorescence.

[0244] When excited by thermal or electronic means, the organic light-emitting element using the composition of the present invention can emit light in the ultraviolet region, the blue, green, yellow, orange, and red regions of the visible spectrum (e.g., 420–500 nm, 500–600 nm, or 600–700 nm), or the near-infrared region. For example, the organic light-emitting element can emit light in the red or orange region (e.g., 620–780 nm). For example, the organic light-emitting element can emit light in the orange or yellow region (e.g., 570–620 nm). For example, the organic light-emitting element can emit light in the green region (e.g., 490–575 nm). For example, the organic light-emitting element can emit light in the blue region (e.g., 400–490 nm). For example, the organic light-emitting element can emit light in the ultraviolet spectral region (e.g., 280–400 nm). For example, the organic light-emitting element can emit light in the infrared spectral region (e.g., 780 nm–2 μm).

[0245] The maximum component of light emitted from an organic light-emitting element using the composition of the present invention is preferably light emitted from the delayed fluorescent material contained in the composition of the present invention. Light emitted from the compound represented by general formula (1) is preferably less than 10% of the light emitted from the organic light-emitting element, for example, less than 1%, less than 0.1%, less than 0.01%, or below the detection limit. Light emitted from the delayed fluorescent material can be, for example, more than 50%, more than 90%, or more than 99% of the light emitted from the organic light-emitting element. When the layer (light-emitting layer) containing the composition of the present invention contains a fluorescent material as a third component, the maximum component of light emitted from the organic light-emitting element can be light emitted from its fluorescent material. In this case, light emitted from the light-emitting material can be, for example, more than 50%, more than 90%, or more than 99% of the light emitted from the organic light-emitting element.

[0246] The following describes the components of an organic electroluminescent element and its layers other than the light-emitting layer.

[0247] Substrate:

[0248] In some embodiments, the organic electroluminescent element of the present invention is supported by a substrate, wherein the substrate is not particularly limited and may be any of those substrates commonly used in organic electroluminescent elements, such as those formed of glass, transparent plastic, quartz and silicon.

[0249] anode:

[0250] In some embodiments, the anode of the organic electroluminescent device is made of a metal, alloy, conductive compound, or a combination thereof. In some embodiments, the metal, alloy, or conductive compound has a large work function (above 4 eV). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), SnO2, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as IDIXO (In2O3-ZnO), is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is fabricated by vapor deposition or sputtering. In some embodiments, the film is patterned by photolithography. In some embodiments, when high precision (e.g., above about 100 μm) may not be required for the pattern, the pattern can be formed by vapor deposition or sputtering of the electrode material using a mask with the desired shape. In some embodiments, when a coating material (such as an organic conductive compound) can be coated, wet film formation methods, such as printing and coating, are used. In some embodiments, when emitted light passes through the anode, the transmittance of the anode is greater than 10%, and the sheet resistance of the anode is less than several hundred ohms per square meter. In some embodiments, the thickness of the anode is 10–1,000 nm. In some embodiments, the thickness of the anode is 10–200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

[0251] cathode:

[0252] In some embodiments, the cathode is made of a metal (below 4 eV) (referred to as an electron-injecting metal), alloy, conductive compound, or combination thereof, with an electrode material having a low work function. In some embodiments, the electrode material is selected from sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixtures, magnesium-silver mixtures, magnesium-aluminum mixtures, magnesium-indium mixtures, aluminum-alumina (Al2O3) mixtures, indium, lithium-aluminum mixtures, and rare earth metals. In some embodiments, a mixture of the electron-injecting metal and a second metal is used, wherein the second metal is a stable metal with a higher work function than the electron-injecting metal. In some embodiments, the mixture is selected from magnesium-silver mixtures, magnesium-aluminum mixtures, magnesium-indium mixtures, aluminum-alumina (Al2O3) mixtures, lithium-aluminum mixtures, and aluminum. In some embodiments, the mixture increases electron injection characteristics and resistance to oxidation. In some embodiments, the cathode is manufactured by forming the electrode material into a thin film using vapor deposition or sputtering. In some embodiments, the film resistivity of the cathode is below several hundred ohms per square meter. In some embodiments, the thickness of the cathode is in the range of 10 nm to 5 μm. In some embodiments, the thickness of the cathode is in the range of 50 to 200 nm. In some embodiments, either the anode or the cathode of the organic electroluminescent element is transparent or translucent in order to transmit the emitted light. In some embodiments, transparent or translucent electroluminescent elements enhance the luminous brightness.

[0253] In some embodiments, the cathode is formed using a conductive transparent material as described for the anode to form a transparent or translucent cathode. In some embodiments, the element comprises a uniformly transparent or translucent anode and cathode.

[0254] Injection layer:

[0255] The injection layer is a layer located between the electrode and the organic layer. In some embodiments, the injection layer reduces the driving voltage and enhances the luminous intensity. In some embodiments, the injection layer includes a hole injection layer and an electron injection layer. The injection layer may be disposed between the anode and the luminescent layer or hole transport layer, and between the cathode and the luminescent layer or electron transport layer. In some embodiments, an injection layer is present. In some embodiments, an injection layer is not present.

[0256] The following are examples of preferred compounds that can be used as hole injection materials.

[0257] [Chemical Formula 24]

[0258] MoO3,

[0259]

[0260] Next, preferred examples of compounds that can be used as electron injection materials are included.

[0261] [Chemical Formula 25]

[0262]

[0263] Barrier layer:

[0264] A blocking layer is a layer capable of suppressing the diffusion of charges (electrons or holes) and / or excitons in the light-emitting layer to the outside of the light-emitting layer. In some embodiments, an electron blocking layer is located between the light-emitting layer and the hole transport layer, and suppresses electrons from passing through the light-emitting layer toward the hole transport layer. In some embodiments, a hole blocking layer is located between the light-emitting layer and the electron transport layer, and suppresses holes from passing through the light-emitting layer toward the electron transport layer. In some embodiments, the blocking layer suppresses exciton diffusion to the outside of 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 function as both electron blocking layers and exciton blocking layers.

[0265] Cavity blocking layer:

[0266] The hole blocking layer functions as an electron transport layer. In some embodiments, the hole blocking layer suppresses holes from reaching the electron transport layer while transporting electrons. In some embodiments, the hole blocking layer enhances the probability of rebonding between electrons and holes in the light-emitting layer. The material used for the hole blocking layer can be the same material described for the electron transport layer.

[0267] The following are examples of preferred compounds that can be used in hole-blocking layers.

[0268] [Chemical Formula 26]

[0269]

[0270] Electron blocking layer:

[0271] Holes are transported by an electron blocking layer. In some embodiments, the electron blocking layer suppresses electrons from reaching the hole transport layer while transporting holes. In some embodiments, the electron blocking layer enhances the probability of rebonding between electrons and holes in the light-emitting layer. The material used for the electron blocking layer can be the same material described for the hole transport layer.

[0272] The following are specific examples of preferred compounds that can be used as electron blocking materials.

[0273] [Chemical Formula 27]

[0274]

[0275] Exciton blocking layer:

[0276] An exciton blocking layer suppresses the diffusion of excitons generated via the rebonding of holes and electrons in the light-emitting layer into the charge transport layer. In some embodiments, the exciton blocking layer enables effective confinement of excitons within the light-emitting layer. In some embodiments, it enhances the luminous efficiency of the device. In some embodiments, the exciton blocking layer is adjacent to the light-emitting layer on either the anode side or the cathode side, and on both sides. In some embodiments, when the exciton blocking layer is on the anode side, the layer may be located between and adjacent to the hole transport layer and the light-emitting layer. In some embodiments, when the exciton blocking layer is on the cathode side, the layer may be located between and adjacent to the light-emitting layer and the cathode. In some embodiments, a hole injection layer, an electron blocking layer, or a similar layer is located between the anode and the exciton blocking layer, with the exciton blocking layer adjacent to the light-emitting 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 located between the cathode and the exciton blocking layer, with the exciton blocking layer adjacent to the light-emitting layer on the cathode side. In some embodiments, the exciton blocking layer includes an excitation singlet energy and an excitation triplet energy, at least one of which is higher than the excitation singlet energy and excitation triplet energy of the luminescent material, respectively.

[0277] Hole transport layer:

[0278] 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.

[0279] In some embodiments, the hole transport material has one of hole injection or transport properties and electron blocking properties. 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 this invention include (but are not limited to) triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkyl derivatives, pyrazoline derivatives, dihydropyrazolone derivatives, phenylenediamine derivatives, aromatic amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrene-anthracene 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 porphyrin compounds, aromatic tertiary amines, and styrene amine compounds. 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 included below.

[0280] [Chemical Formula 28]

[0281]

[0282] Electron transport layer:

[0283] 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.

[0284] In some embodiments, the electron transport material only needs to have the function of transporting electrons injected from the cathode into the light-emitting layer. In some embodiments, the electron transport material also functions as a hole-blocking material. Examples that can be used in the electron transport layer of the present invention include (but are not limited to) nitro-substituted fluorene derivatives, dibenzoquinone derivatives, thiopiperanoxide derivatives, carbodiimide, fluorenemethane derivatives, anthraquinone dimethane, anthrone derivatives, oxadiazole derivatives, azole derivatives, aziridine derivatives, or combinations thereof, or polymers thereof. In some embodiments, the electron transport material is a thiadiazole derivatizer 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 included below.

[0285] [Chemical Formula 29]

[0286]

[0287] Furthermore, compounds that are preferred as materials that can be added to each organic layer are included. For example, they can be considered as stabilizing materials.

[0288] [Chemical Formula 30]

[0289]

[0290] Preferred materials that can be used in organic electroluminescent elements are specifically exemplified, but the materials that can be used in this invention are not limited to the compounds exemplified below. Furthermore, even compounds exemplified as materials with specific functions can be used as materials with other functions.

[0291] Device:

[0292] In some embodiments, the light-emitting layer is incorporated into the device. Examples of devices include, but are not limited to, OLED bulbs, OLED lights, television screens, computer monitors, mobile phones, and tablet computers.

[0293] In some embodiments, the electronic device includes an OLED having an anode, a cathode, and at least one organic layer containing a light-emitting layer between the anode and the cathode.

[0294] In some embodiments, the compositions described herein can be incorporated into various photosensitive or photoactivated devices, such as OLEDs or photovoltaic devices. In some embodiments, the compositions can be suitable for facilitating charge transfer or energy transfer within the device and / or for use as hole transport materials. Such devices include, for example, organic light-emitting diodes (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic photodetectors, organic photosensors, organic field-quench devices (O-FQDs), light-emitting electrochemical cells (LECs), or organic laser diodes (O-lasers).

[0295] Light bulb or lamp:

[0296] In some embodiments, the electronic device includes an OLED, the OLED including an anode, a cathode and at least one organic layer containing a light-emitting layer between the anode and the cathode.

[0297] In some embodiments, the device includes OLEDs of different colors. In some embodiments, the device includes an array comprising combinations of OLEDs. In some embodiments, the combination of OLEDs is a combination of three colors (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 combination of two, four, or more colors.

[0298] In some embodiments, the device is an OLED light, the OLED light comprising:

[0299] The circuit board has a first surface having a mounting surface and a second surface opposite thereto, and at least one opening is defined thereon;

[0300] At least one OLED is disposed on the mounting surface and has a structure in which the at least one OLED includes an anode, a cathode and at least one organic layer containing a light-emitting layer between the anode and the cathode and emits light.

[0301] Housing, used for circuit board; and

[0302] At least one connector is disposed at an end of the housing, and the housing and the connector define an encapsulation suitable for mounting to a lighting device.

[0303] In some embodiments, the OLED lamp includes a plurality of OLEDs mounted on a circuit board to emit light in multiple directions. In some embodiments, a portion of the light emitted in a first direction is deflected to be emitted in a second direction. In some embodiments, a reflector is used to deflect the light emitted in the first direction.

[0304] Monitor or screen:

[0305] In some embodiments, the light-emitting layer of the present invention can be used in a screen or display. In some embodiments, methods including (but not limited to) vacuum evaporation, deposition, vapor deposition, or chemical vapor deposition (CVD) are used to deposit the compounds involved in the present invention onto a substrate. In some embodiments, the substrate is a photographic plate structure suitable for double-sided etching, providing pixels with a unique aspect ratio. The screen (which may also be referred to as a mask) is used in methods for manufacturing OLED displays. The corresponding artwork pattern design promotes extremely steep and narrow tie-bars between pixels in the vertical direction and promotes large swept-bevel openings in the horizontal direction. This allows for tight patterning of pixels required for high-definition displays while optimizing chemical vapor deposition onto the TFT substrate.

[0306] Internal patterning of pixels allows for the construction of 3D pixel openings with varying aspect ratios in both the horizontal and vertical directions. Furthermore, imaging "strips" or halftone circles within the pixel region suppress etching in specific areas until these specific patterns are undercut and leave the substrate. At this point, all pixel regions are processed at the same etching rate, but the depth varies depending on the halftone pattern. Varying the size and spacing of the halftone patterns allows etching to be suppressed at different rates within the pixel, enabling locally deeper etching to create steep vertical bevels.

[0307] The preferred material for deposition masks is invar steel. Invar steel is a metal alloy that is cold-rolled into long thin sheets in a steel mill. Invar steel cannot be used as a nickel mask for electrodeposition onto a spin mandrel. A suitable and low-cost method for forming opening regions within a vapor deposition mask is a wet chemical etching method.

[0308] 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 other embodiments, the screen or display pattern is fabricated using plasma etching.

[0309] Method for manufacturing the device:

[0310] OLED displays are typically manufactured by forming a large motherboard and then cutting the motherboard into unit cells. Generally, each unit cell on the motherboard is formed by: forming a thin-film transistor (TFT) including an active layer and source / drain electrodes on a substrate, coating a planarization film onto the TFT, and sequentially forming a pixel electrode, a light-emitting layer, a counter electrode, and an encapsulation layer, and then cutting it from the motherboard.

[0311] OLED displays are typically manufactured by forming a large motherboard and then cutting the motherboard into unit cells. Generally, each unit cell on the motherboard is formed by: forming a thin-film transistor (TFT) including an active layer and source / drain electrodes on a substrate, coating a planarization film onto the TFT, and sequentially forming a pixel electrode, a light-emitting layer, a counter electrode, and an encapsulation layer, and then cutting it from the motherboard.

[0312] In another aspect of the present invention, a method for manufacturing an organic light-emitting diode (OLED) display is provided, the method comprising:

[0313] The process of forming a barrier layer on the substrate of the motherboard;

[0314] The process of forming multiple display units from unit board units on the barrier layer;

[0315] The process of forming an encapsulation layer on each of the display units of the unit board; and

[0316] The process of coating an organic film on the interface portion between the unit plates.

[0317] In some embodiments, the barrier layer is an inorganic film formed of, for example, SiNx, and the edge portions of the barrier layer are covered with an organic film formed of polyimide or acryloyl groups. In some embodiments, the organic film facilitates the gentle cutting of the motherboard into unit panels.

[0318] In some embodiments, the thin-film transistor (TFT) layer has a light-emitting layer, a gate electrode, and a source / drain electrode. Each of the plurality of display units may include a thin-film transistor (TFT), a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film, wherein an organic film coated on the interface portion is formed of the same material as the planarization film and is formed at the same time as the planarization film is formed. In some embodiments, the light-emitting unit is connected to the TFT layer, wherein a passivation layer, a planarization film, and an encapsulation layer are provided therebetween, and the encapsulation layer covers and protects the light-emitting unit. In some embodiments of the manufacturing method, the organic film does not contact either the display unit or the encapsulation layer.

[0319] Each of the organic film and the planarization film may comprise either polyimide or acryloyl groups. In some embodiments, the barrier layer may be an inorganic film. In some embodiments, the substrate may be formed of polyimide. The method may further include mounting a carrier substrate formed of a glass material onto another surface of the substrate before forming the barrier layer on one surface of the substrate formed of polyimide, and separating the carrier substrate from the substrate before cutting along the interface portion. In some embodiments, the OLED display is a flexible display.

[0320] 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 is formed of polyimide or acrylamide, as in the case of an organic film formed on an edge portion of the barrier layer. In some embodiments, the planarization film and the organic film are formed simultaneously when manufacturing an OLED display. In some embodiments, the organic film may be formed on an edge portion of the barrier layer such that a portion of the organic film directly contacts the substrate, and the remaining portion of the organic film contacts the barrier layer while surrounding the edge portion of the barrier layer.

[0321] In some embodiments, the light-emitting layer has 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 the source / drain electrode of the TFT layer.

[0322] In some embodiments, when a voltage is applied to the pixel electrode via the TFT layer, an appropriate voltage is formed between the pixel electrode and the opposite electrode, thereby causing the organic light-emitting layer to emit light and thus forming an image. Hereinafter, the image forming unit having a TFT layer and light-emitting units will be referred to as a display unit.

[0323] In some embodiments, the encapsulation layer covering the display units and preventing external moisture penetration can be formed as a thin-film encapsulation structure having organic and inorganic films alternately stacked. In some embodiments, the encapsulation layer has a thin-film encapsulation structure having multiple thin films stacked. In some embodiments, the organic film coated on the interface portion is spaced apart from each of the plurality of display units. In some embodiments, the organic film is formed such that a portion of the organic film directly contacts the substrate, and the remaining portion of the organic film contacts the barrier layer while surrounding the edge portion of the barrier layer.

[0324] In one embodiment, the OLED display is flexible and uses a soft substrate formed of polyimide. In some embodiments, the substrate is formed on a carrier substrate formed of a glass material, and then the carrier substrate is separated.

[0325] In some embodiments, a barrier layer is formed on the surface of the substrate opposite to the carrier substrate. In one embodiment, the barrier layer is patterned according to the size of each unit plate. For example, while forming the substrate over the entire surface of the motherboard, the barrier layer is formed according to the size of each unit plate, thereby forming a groove at the interface portion between the unit plate barrier layers. Each unit plate can be cut along the groove.

[0326] In some embodiments, the manufacturing method further includes a step of cutting along the interface portion, wherein a groove is formed in the barrier layer, wherein at least a portion of an organic film is formed in the groove, and the groove does not penetrate into the substrate. In some embodiments, a TFT layer is formed for each unit panel, and a passivation layer (i.e., an inorganic film) and a planarization film (i.e., an organic film) are disposed on the TFT layer to cover the TFT layer. The groove at the interface portion is covered with an organic film, such as a polyimide or acrylamide, while a planarization film formed of, for example, polyimide or acrylamide is formed. This is to prevent cracking by allowing the organic film to absorb shocks generated when cutting each unit panel along the groove at the interface portion. That is, if the entire barrier layer is completely exposed without the organic film, the shock generated when cutting each unit panel along the groove at the interface portion is transferred to the barrier layer, thereby increasing the risk of cracking. However, in one embodiment, because the grooves at the interface portions between the barrier layers are covered with an organic film, and this organic film absorbs impacts that would otherwise be transferred to the barrier layers, each unit panel can be cut gently, and cracking in the barrier layers can be prevented. In one embodiment, the organic film covering the grooves at the interface portions is spaced apart from the planarization film. For example, if the organic film and the planarization film are connected to each other as a single layer, then because external moisture may penetrate into the display unit through the planarization film and a portion of the residual organic film, the organic film and the planarization film are spaced apart from each other so that the organic film is separated from the display unit.

[0327] In some embodiments, a display unit is formed by forming light-emitting units, and an encapsulation layer is disposed on the display unit to cover it. Thus, after the motherboard is fully manufactured, a carrier substrate supporting the substrate is separated from the substrate. In some embodiments, when a laser beam is emitted toward the carrier substrate, the carrier substrate separates from the substrate due to the difference in thermal expansion coefficients between the carrier substrate and the substrate.

[0328] In some embodiments, the motherboard is cut into unit panels. In some embodiments, the motherboard is cut along the interface portion between the unit panels using a cutting machine. In some embodiments, because the grooves at the interface portion along which the motherboard is cut are covered with an organic film, the organic film absorbs impact during cutting. In some embodiments, cracking can be prevented from occurring in the barrier layer during cutting.

[0329] In some embodiments, the method reduces the defect rate of the product and stabilizes its quality.

[0330] On the other hand, there is an OLED display having: a barrier layer formed on a substrate; a display unit formed on the barrier layer; an encapsulation layer formed on the display unit; and an organic film coated on the edge portion of the barrier layer.

[0331] Example

[0332] The following includes synthetic examples, experimental examples, and embodiments, and further details the features of the present invention. The materials, processing contents, and processing steps shown below can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limited by the specific examples shown below. Furthermore, the evaluation of luminescence properties was performed using a source meter (Keithley 2400 series), a semiconductor parameter analyzer (Agilent Technologies Japan, Ltd. E5273A), an optical power meter (Newport Corporation 1930C), a spectrometer (OceanOptics USB2000), a spectroradiometer (TOPCON CORPORATION SR-3), a streak camera (Hamamatsu Photonics KK C4334 type), and an extended absolute quantum yield measurement device (Hamamatsu Photonics KK Quantaurus-QY Plus C13534-01).

[0333] (Synthetic Example 1) Synthesis of Compound 1

[0334] [Chemical Formula 31]

[0335]

[0336] 2-Bromobenzo[1,2-b:5,4-b′]bisbenzofuran (1.09 g, 3.23 mmol), 3-(9H-carbazole-9-yl)phenylboronic acid (1.02 g, 3.55 mmol), tetraphenylphosphine palladium(0) (0.18 g, 0.16 mmol), and potassium carbonate (1.34 g, 9.69 mmol) were dissolved in a mixed solvent of tetrahydrofuran (THF) and water (20 / 10 ml), and stirred at 75 °C for 12 hours. The reaction solution was cooled to room temperature, chloroform was added, the organic layer was washed twice with water, dried with magnesium sulfate, and the solvent was removed. The obtained solid was purified by silica gel column chromatography (developing solvent: hexane / toluene = 8:2). Furthermore, recrystallization (toluene / methanol) was performed to give compound 1 (1.22 g, 76%) as a white solid.

[0337] 1 HNMR (400MHz, CDCl3, δ): 8.5 (S, 1H), 8.29 (d, J = 2Hz, 1H), 8.19 (d, J = 8Hz, 2H), 8.03 (d, J = 8Hz, 1H), 7.93 (m, 1H), 7.81 (d, J = 8Hz, 1H), 7.7 7-7.73(m,3H),7.67(d,J=8Hz,1H),7.60(d,J=8Hz,2H),7.53(d,J=8Hz,2H),7.49-7.43(m,3H),7.39(t,J=7Hz,1H),7.33(t,J=7Hz,2H).

[0338] MS(ASAP): 500.22(M+H) + ).Calcd.for C 36 H 21 NO2:499.16.

[0339] (Synthetic Example 2) Synthesis of Compound 2

[0340] [Chemical Formula 32]

[0341]

[0342] Under a nitrogen atmosphere, dioxane (15 ml) was added to 2-bromobenzo[1,2-b:5,4-b′]bisbenzofuran (1.5 g, 4.45 mmol), pinacol diborate (1.19 g, 4.67 mmol), [1,1-bis(diphenylphosphine)ferrocene]palladium(II) dichloride (0.33 g, 0.45 mmol), and potassium acetate (1.09 g, 11.1 mmol), and the mixture was refluxed for 15 hours. After cooling the reaction solution to room temperature, 1-bromo-3-iodobenzene (1.89 g, 6.68 mmol), tetratetraphenylphosphine palladium(0) (0.25 g, 0.22 mmol), potassium carbonate (1.23 g, 8.9 mmol), tetrahydrofuran (30 ml), and water (15 ml) were added, and the mixture was refluxed for 12 hours. The reaction solution was cooled to room temperature, the solvent was removed, chloroform was added, the organic layer was washed twice with water, dried with magnesium sulfate, and the solvent was removed. The obtained solid was purified by silica gel column chromatography (developing solvent: hexane / chloroform = 7:3), thereby obtaining intermediate a (1.58 g, 86%) as a white solid.

[0343] 1 H NMR (400MHz, CDCl3, δ): 8.51 (s, 1H), 8.20 (s, 1H), 8.04 (d, J = 8Hz, 1H), 7.86 (m, 1H), 7.75 (s, 1H), 7.69-7.59 (m, 3H), 7.52-7.32 (m, 4H).

[0344] MS(ASAP): 413.93 (M+H) + ).Calcd.for C 24 H 13 BrO2: 412.01.

[0345] Under a nitrogen atmosphere, 2-(3-bromophenyl)benzo[1,2-b:5,4-b′]bisbenzofuran (intermediate a; 1.57 g, 3.8 mmol), 3,6-diphenylcarbazole (1.21 g, 3.8 mmol), tris(dibenzylacetone)dipalladium(0) (0.35 g, 0.38 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.22 g, 0.76 mmol), and sodium tert-butoxide (0.73 g, 7.6 mmol) were added to toluene (45 mL) and refluxed for 24 hours. The reaction solution was cooled to room temperature, and the toluene was removed. The obtained solid was washed with water and methanol and dried. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene / n-hexane = 1:1 to 1:4). Furthermore, recrystallization (toluene / methanol) was performed, thereby giving compound 2 (1.58 g, 64%) as a white solid.

[0346] 1 H NMR (400MHz, CDCl3, δ): 8.5 (s, 1H), 8.44 (s, 2H), 8.31 (s, 1H), 8.02 (d, J = 8Hz, 1H), 7 .97(s,1H),7.84(S,1H),7.79-7.57(m,14H),7.53-7.43(m,5H),7.39-7.34(m,3H).

[0347] MS(ASAP): 651.77 (M+H) + ).Calcd for C 48 H 29 NO2:651.22.

[0348] (Example 1)

[0349] Vacuum deposition method was used to achieve a vacuum level of 5.0 × 10⁻⁶. -5 Pa stacked the thin films on a glass substrate having an anode formed of indium tin oxide (ITO) with a film thickness of 50 nm. First, HAT-CN was formed on the ITO with a thickness of 10 nm, and NPD was formed on it with a thickness of 30 nm. Next, Tris-PCz was formed with a thickness of 10 nm. Then, delayed fluorescence material (TADF10), fluorescent material (E35), and compound 1 were co-deposited from different deposition sources to form a layer with a thickness of 40 nm, which served as the emitting layer. The concentrations of delayed fluorescence material, fluorescent material, and compound 1 in the emitting layer were 40% by mass, 0.5% by mass, and 59.5% by mass, respectively. Next, after forming SF3-TRZ with a thickness of 10 nm, Liq and SF3-TRZ were co-deposited from different deposition sources to form a layer with a thickness of 30 nm. The concentrations of Liq and SF3-TRZ in this layer were 30% by mass and 70% by mass, respectively. In addition, Liq is formed with a thickness of 2 nm, and then aluminum (Al) is vapor-deposited with a thickness of 100 nm to form a cathode, which is used as an organic electroluminescent device (EL device 1).

[0350] (Comparative Example 1)

[0351] An organic electroluminescent element (comparative EL element 1) was thus fabricated by simply changing the use of comparative compound 1 instead of compound 1 and performing the same procedures as in Example 1.

[0352] [Chemical Formula 33]

[0353]

[0354] (test)

[0355] For EL element 1 and comparator EL element 1, measurements were taken at 50.0 mA / cm. 2 The time until the luminous intensity becomes 95% of the initial luminous intensity (LT95). As a result, it was confirmed that the relative value when the comparison EL element 1 is set to 1.00 is 1.25 in EL element 1, and the element lifetime is extended by 25% by using the compound represented by general formula (1).

[0356] (Example 2)

[0357] An organic electroluminescent element (EL element 2) was thus produced by simply changing the use of compound 2 instead of compound 1 and performing the same procedures as in Example 1.

[0358] It was confirmed that the driving voltage of EL element 2 is lower than that of EL element 1.

[0359] (Example 3)

[0360] An organic electroluminescent element (EL element 3) was fabricated by changing Tris-PCz to compound 2 and performing the same process as the comparative EL element 1.

[0361] It has been confirmed that the lifespan of EL component 3 is also longer than that of EL component 1.

[0362] [Chemical Formula 34]

[0363]

[0364] Industrial availability

[0365] The compounds of the present invention are useful as various materials (especially charge transport materials) for light-emitting elements, and for example, can be used as host materials for doped delayed fluorescence materials. Using the compounds of the present invention can improve the characteristics of organic light-emitting elements such as organic electroluminescent elements. Therefore, the present invention has high industrial applicability.

[0366] Symbol Explanation

[0367] 1-Substrate, 2-Anode, 3-Hole injection layer, 4-Hole transport layer, 5-Light emission layer, 6-Electron transport layer, 7-Cathode.

Claims

1. A compound represented by the following general formula (1), In general formula (1), D represents substituted or unsubstituted carbazole-9-yl, Ar represents unsubstituted 1,2-phenylene, unsubstituted 1,3-phenylene or unsubstituted 1,4-phenylene, Z represents unsubstituted benzofuran dibenzofuranyl, unsubstituted benzofuran dibenzothiophenyl, unsubstituted benzothiophene dibenzofuranyl or unsubstituted benzothiophene dibenzothiophenyl, wherein the substituent when the carbazole-9-yl is substituted is one group or a combination of two groups selected from the group consisting of alkyl groups having 1 to 20 carbon atoms and aryl groups having 6 to 22 carbon atoms.

2. The compound according to claim 1, which is represented by the following general formula (2), [Chemical Formula 2] In general formula (2), X 1 and X 2 R represents oxygen or sulfur atoms independently, respectively. 1 ~R 7 Each can be used independently to represent a deuterium atom or a substituent, where, R 1 ~R 7 The substituents that can be used are each independently selected from one group or two groups composed of alkyl groups having 1 to 20 carbon atoms and aryl groups having 6 to 22 carbon atoms. n, n3 to n7 represent 0, and n1 and n2 independently represent any integer from 0 to 4.

3. The compound according to claim 1, wherein it is represented by any one of the following general formulas (3-1), (3-5), (3-9), and (3-13), General formula (3-1) General formula (3-5) General formula (3-9) General formula (3-13) In general formulas (3-1), (3-5), (3-9), and (3-13), R 1 R 2 R 4 ~R 7 Each can be used independently to represent a deuterium atom or a substituent, where, R 1 R 2 R 4 ~R 7 The substituents that can be used are one group or two groups selected from the group consisting of alkyl groups with 1 to 20 carbon atoms and aryl groups with 6 to 22 carbon atoms. n1 and n2 each independently represent any integer from 0 to 4, and n4 to n7 represent 0.

4. Use of the compound according to any one of claims 1 to 3 as a charge transport material.

5. As described in claim 4, it is used as the main material.

6. A composition wherein a delayed fluorescence material is doped into a host material consisting of a compound represented by the following general formula (1), General formula (1) D-Ar-Z In general formula (1), D represents substituted or unsubstituted carbazole-9-yl, Ar represents unsubstituted 1,2-phenylene, unsubstituted 1,3-phenylene or unsubstituted 1,4-phenylene, Z represents unsubstituted benzofuran dibenzofuranyl, unsubstituted benzofuran dibenzothiophenyl, unsubstituted benzothiophene dibenzofuranyl or unsubstituted benzothiophene dibenzothiophenyl, wherein the substituent when the carbazole-9-yl is substituted is one group or a combination of two groups selected from the group consisting of alkyl groups having 1 to 20 carbon atoms and aryl groups having 6 to 22 carbon atoms.

7. The composition according to claim 6, wherein it is in the form of a film.

8. The composition according to claim 6, wherein, The delayed fluorescence material is a compound with a benzonitrile structure, wherein the number of cyano groups substituted on the benzene ring in the benzonitrile structure is one.

9. The composition according to claim 6, wherein, The delayed fluorescence material is a compound with a phthalonitrile structure, wherein the number of cyano groups substituted on the benzene ring in the phthalonitrile structure is two.

10. The composition according to claim 6, wherein, The delayed fluorescence material is a compound with an azirbenzene structure, wherein at least one carbon atom in the azirbenzene ring skeleton is replaced by a nitrogen atom.

11. The composition of claim 6, further comprising a fluorescent compound having a minimum excitation singlet energy lower than that of the host material and the delayed fluorescence material.

12. An organic light-emitting element having a layer composed of the composition of any one of claims 6 to 11.

13. The organic light-emitting element according to claim 12, wherein, The layer is composed only of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, sulfur, boron, and halogen atoms.

14. The organic light-emitting element according to claim 12, wherein, The layer is composed only of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen and sulfur atoms.

15. The organic light-emitting element according to any one of claims 12 to 14, wherein it is an organic electroluminescent element.

16. The organic light-emitting element according to claim 15, wherein, The composition does not contain fluorescent compounds with a minimum excitation singlet energy lower than that of the host material and the delayed fluorescent material, and the maximum component of the light emitted from the element is the light emitted from the delayed fluorescent material.

17. The organic light-emitting element according to claim 15, wherein, The composition comprises a fluorescent compound with a minimum excitation singlet energy lower than that of the host material and the delayed fluorescence material, wherein the maximum component of the light emitted from the element is the light emitted from the fluorescent compound.

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