Compound, organic thin film, and photoelectric conversion element

Abstract

Provided are a compound, an organic thin film, and a photoelectric conversion element. A compound represented by the following general formula is useful as a material for a photoelectric conversion element. Y is O or S, Ar1 and Ar2 are aromatic hydrocarbon groups or the like, and one of X1 to X4 is a diarylamino group or the like. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a compound useful as an electron blocking material, an organic thin film containing the compound, and a photoelectric conversion element using the organic thin film. Background Art

[0002] Photoelectric conversion elements such as light-receiving elements are widely used in imaging elements, solar cells, optical sensors, etc. Among them, image sensors as imaging elements are not only used in TV cameras and cameras mounted on smartphones, but are also beginning to be used in cameras for operation support systems, etc., and their uses and markets are expanding.

[0003] So far, inorganic materials such as Si films or Se films have been used as photoelectric conversion materials of imaging elements, and the mainstream imaging methods are three-plate type using prism color separation and single-plate type using color filters. However, although the three-plate type has high light utilization efficiency, it is difficult to miniaturize because it uses prisms, and the single-plate type is relatively easy to miniaturize because it does not use prisms, but it uses color filters instead, so the resolution and light utilization efficiency are poor (for example, refer to non-patent document 1).

[0004] Therefore, in recent years, research and development of the use of organic matter in photoelectric conversion materials has been actively carried out. Organic matter has a high wavelength selectivity for light absorption compared to inorganic matter. Therefore, by combining materials that show absorption wavelengths corresponding to the three primary colors, it is possible to construct an imaging element that efficiently utilizes the light of the three primary colors even without using a prism. Thus, a small imaging element with high light utilization efficiency can be achieved. In addition, organic photoelectric conversion materials have the following advantages: according to the selection of materials, near-infrared light or infrared light can be sensed, not limited to visible light. In addition, it is possible to achieve flexibility of components or large-area components using coating procedures that cannot be achieved with inorganic materials (for example, refer to non-patent document 2).

[0005] Accordingly, light-receiving elements using organic substances as photoelectric conversion materials are expected to be developed in the next generation of imaging elements, and several examples of such light-receiving elements have been reported so far. For example, light-receiving elements using quinacridone and quinazoline derivatives (reference patent document 1), light-receiving elements using benzothienothiophene derivatives (reference patent document 2), and light-receiving elements using indolecarbazole (reference patent document 3) have been reported.

[0006] Previous technical literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 4945146

[0009] Patent Document 2: Japanese Patent Application Publication No. 2018-170487

[0010] Patent Document 3: Japanese Patent Application Publication No. 2018-085427

[0011] Patent Document 4: Japanese Patent Application Publication No. 2011-187937

[0012] Patent Document 5: International Publication No. 2012 / 114928

[0013] Non-patent literature

[0014] Non-patent document 1: Journal of the Media Association of the Visual Information Society, 60, 3, 291 (2006)

[0015] Non-patent document 2: Adv. Mater. 28, 4766 (2016) Summary of the invention

[0016] Technical issues to be solved by the invention

[0017] In an imaging element, there are indicators such as contrast and power as indicators of characteristics. In order to improve these characteristics, it is necessary to reduce the current (dark current) that flows when light is not incident. As one of the methods for reducing such dark current, it is known to insert a hole blocking layer or an electron blocking layer (hereinafter collectively referred to as a "charge blocking layer") between the light receiving part (photoelectric conversion layer) and the electrode part. The charge blocking layer is arranged at the interface between the electrode constituting the element or the conductive film and the film stacked thereon, and has the function of controlling the reverse movement of holes or electrons and quickly transferring the required charge to the electrode or the conductive film.

[0018] However, in the manufacturing process of the imaging element, heat is applied when setting the color filter or protective film, soldering the element, etc., so the charge blocking layer is required to have high thermal stability. In contrast, many charge blocking layers to date cannot be said to have a sufficiently high glass transition temperature (Tg), and have the problem of insufficient thermal stability. On the other hand, it is reported in Patent Document 4 that the thermal stability of the element is improved by using an electron blocking material with a glass transition temperature (Tg) of 140°C or more. However, the performance of the element using this electron blocking material as a light-receiving element is insufficient.

[0019] The present invention has been completed in view of the above situation, and its purpose is to provide a compound useful as a charge blocking material. In addition, its purpose is to provide an organic thin film with high heat resistance, excellent charge blocking property and reverse charge transport property, and a photoelectric conversion element with high heat resistance, improved dark current characteristics and photoelectric conversion efficiency.

[0020] Means for solving technical problems

[0021] Therefore, the inventors have painstakingly explored in order to achieve the purpose, and as a result, it has been found that the compound having a structure fused with a benzofuran ring on an indole and carbazole ring has high heat resistance. In addition, the following insights have been obtained: excellent hole transport and electron blocking properties are manifested by introducing an arylamine structure into the fused polycyclic skeleton, thereby realizing a useful compound as an electron blocking material. The present invention is proposed based on such insights, and specifically, has the following composition.

[0022] 1) A compound represented by the following general formula (1).

[0023] [Chemical formula 1]

[0024]

[0025] In the general formula (1), Y represents O or S. 1 ~X 12 may be the same as or different from each other and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group or a substituted or unsubstituted aryloxy group, and may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring, but X 1 ~X 4 One of them is a group represented by the following general formula (2).

[0026] [Chemical formula 2]

[0027]

[0028] * represents a bonding position. L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. Ar 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group. 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4 Parts of each of the groups may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring.

[0029] 2) The compound according to 1), which is represented by the following general formula (1a).

[0030] [Chemical formula 3]

[0031]

[0032] In the general formula (1a), Ar 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, R 1 ~R 3 Ar may be the same as or different from each other and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group, and may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring. L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. A part of L and Ar 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4 Parts of each of the groups may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring.

[0033] 3) The compound according to 2), wherein Ar in the general formula (1a) 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, R 1 ~R 3 Ar may be the same as or different from each other, and are hydrogen atoms, substituted or unsubstituted aromatic hydrocarbon groups, or substituted or unsubstituted heteroaromatic hydrocarbon groups, L is a single bond or a substituted or unsubstituted aromatic hydrocarbon group, and a portion of L and Ar 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4Parts of each of the groups may be bonded to each other via single bonds to form a ring.

[0034] 4) The compound according to 1), which is represented by the following general formula (1b).

[0035] [Chemical formula 4]

[0036]

[0037] (In general formula (1b), Ar 1 and Ar 2 R may be the same as or different from each other, represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group. 4 ~R 13 may be the same as or different from each other and represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heteroaromatic hydrocarbon group. 4 , part of L and R 13 , R 8 and R 9 They may be bonded to each other to form a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

[0038] 5) The compound according to any one of 1) to 4), which has a glass transition temperature (Tg) of 170°C or higher.

[0039] 6) An electron blocking material formed from the compound described in any one of 1) to 5).

[0040] 7) An organic thin film comprising the compound described in any one of 1) to 5).

[0041] 8) A photoelectric conversion element comprising the organic thin film described in 7).

[0042] 9) The photoelectric conversion element according to 8), wherein the organic thin film is an electron blocking layer.

[0043] 10) The photoelectric conversion element according to 8) or 9), which is a light-receiving element.

[0044] Effects of the Invention

[0045] The compound of the present invention is useful as an electron blocking material. The organic film containing the compound of the present invention has high heat resistance and shows excellent hole transport and electron blocking properties. By using the organic film as an electron blocking layer, a photoelectric conversion element with high heat resistance, low dark current and high conversion efficiency can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic cross-sectional view showing a configuration example of a light receiving element of the present invention.

[0047] Figure 2 It is a schematic cross-sectional view showing another configuration example of the light receiving element of the present invention. DETAILED DESCRIPTION

[0048] Hereinafter, the content of the present invention is described in detail. The description of the constituent elements recorded below is sometimes carried out according to the representative embodiment or specific example of the present invention, but the present invention is not limited to such embodiment or specific example. In addition, in this specification, "to" is a term indicating a range, for example, the record of "5 to 10" means "5 or more and 10 or less", and refers to the range including the numerical values ​​recorded before and after "to" as the lower limit and the upper limit, and the numerical range expressed by "~" refers to the range including the numerical values ​​recorded before and after "~" as the lower limit and the upper limit.

[0049] In this specification, “transparent” means that the transmittance of visible light is 50% or more, for example, 80% or more, for example, 90% or more, for example, 99% or more. The transmittance of visible light can be measured by an ultraviolet-visible spectrophotometer.

[0050] <Compound represented by general formula (1)>

[0051] The compound of the present invention is a compound represented by the above general formula (1). The compound of the present invention includes a compound represented by the above general formula (1a) or a compound represented by the above general formula (1b).

[0052] Next, for X in the general formula (1), 1 ~X 12 ,Ar 1 ,Ar 2 ; L, Ar of general formula (2) 3 ,Ar 4 ; Ar of general formula (1a) 1 ~Ar 4 , L, R 1 ~R 3 ; Ar of general formula (1b) 1 ,Ar 2 , L, R 4 ~R 13 The represented base is explained.

[0053] Composition X 1 ~X 12 ,Ar 1 ~Ar 4 , R 1 ~R14 The aromatic ring of the "aromatic hydrocarbon group" of the "substituted or unsubstituted aromatic hydrocarbon group" represented by L may be a single ring, a condensed ring formed by condensing two or more rings, a linked ring formed by linking two or more rings via a single bond, or a spiro ring formed by linking two or more rings via a spiro bond. In the case of a condensed ring, the number of condensed rings is preferably 2 to 6, for example, 2 to 4. In the case of a linked ring, the number of linked rings is preferably 2 to 6, for example, 2 to 4. The number of carbon atoms in the aromatic ring is, for example, 6 to 30, for example, 6 to 22, for example, 6 to 18, for example, 6 to 14, for example, 6 to 10. As Ar 1 ~Ar 4 and R 1 ~R 3 Specific examples of the "aromatic hydrocarbon group" in L include, for example, phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrene group, fluorenyl group, spirobifluorenyl group, indenyl, pyrenyl group, perylenyl group, allenyl fluorenyl, and terphenylene. Specific examples of the "aromatic hydrocarbon group" in L include, for example, phenylene, biphenylene, terphenylene, naphthyl, anthracenyl, and phenanthrene.

[0054] Composition X 1 ~X 12 ,Ar 1 ~Ar 4 , R 1 ~R 14 The aromatic ring of the "aromatic heterocyclic group" of the "substituted or unsubstituted aromatic heterocyclic group" represented by and L may be a monocyclic ring or a condensed ring formed by condensing two or more rings. In the case of a condensed ring, the number of condensed rings is preferably 2 to 6, for example, 2 to 4. Examples of heteroatoms constituting the aromatic heterocyclic ring include nitrogen atoms, oxygen atoms, and sulfur atoms. The number of carbon atoms in the aromatic heterocyclic ring is, for example, 2 to 40, for example, 2 to 30, for example, 2 to 18. X 1 ~X 12 ,Ar 1 ~Ar 4 , R 1 ~R 14Specific examples of the "aromatic heterocyclic group" in L include, for example, pyridyl, pyrimidyl, triazinyl, furanyl, pyrrolyl, thienyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl, benzothiazolyl, quinoxalinyl, benzimidazolyl, pyrazolyl, dibenzofuranyl, dibenzothienyl, naphthyridinyl, phenanthrinyl, acridinyl, carbolinyl, etc. Specific examples of the "aromatic heterocyclic group" in L include, for example, thienylene, furanylene, pyridinylene, benzofuranylene, benzothienylene, etc.

[0055] Regarding the “substituted or unsubstituted fused polycyclic aromatic group”, reference can be made to the description and specific examples of the fused ring formed by condensing two or more rings in the description of the above-mentioned “substituted or unsubstituted aromatic hydrocarbon group” and “substituted or unsubstituted aromatic heterocyclic group”.

[0056] As X 1 ~X 12 , R 1 ~R 3 Specific examples of the "straight-chain or branched alkyl group having 1 to 6 carbon atoms" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl and the like. Specific examples of the "cycloalkyl group having 5 to 10 carbon atoms" include cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl and the like.

[0057] As X 1 ~X 12 , R 1 ~R 3 Specific examples of the "linear or branched alkenyl group having 2 to 6 carbon atoms" include vinyl, allyl, isopropenyl, and 2-butenyl.

[0058] As X 1 ~X 12 , R 1 ~R 3 Specific examples of the "straight-chain or branched alkoxy group having 1 to 6 carbon atoms" include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, n-pentoxy, n-hexoxy, etc., and specific examples of the "cycloalkoxy group having 5 to 10 carbon atoms" include cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, cyclooctyloxy, 1-adamantyloxy, 2-adamantyloxy, etc.

[0059] About Composition X 1 ~X 12 , R 1 ~R 3For the description of the aromatic ring of the "aryl group" of the "substituted or unsubstituted aryloxy group" represented by 1 The description of the aromatic ring of the "aromatic hydrocarbon group" in the above description. Specific examples of the "substituted or unsubstituted aryloxy group" include phenoxy, biphenyloxy, terphenyloxy, naphthoxy, anthracenyloxy, and phenanthranyloxy.

[0060] The "substituent" that may be possessed by the "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group", "substituted or unsubstituted aryloxy group" and "substituted methylene group" is not particularly limited, and examples thereof include a deuterium atom, a cyano group, a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a silyl group such as a trimethylsilyl group and a triphenylsilyl group; a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, and a propyl group; a straight-chain or branched-chain alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group; an alkenyl group such as a vinyl group and an allyl group; an aryloxy group such as a phenoxy group and a tolyloxy group; group), phenylethoxy and other aryl alkoxy groups; phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, spirobifluorenyl, indenyl, pyrenyl, peryl, allylfluorenyl, triphenylene and other aromatic hydrocarbon groups; pyridyl, thienyl, furyl, pyrrolyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl, benzothiazolyl, quinoxalinyl, benzimidazolyl, pyrazolyl, dibenzofuranyl, dibenzothienyl, carbolyl and other aromatic heterocyclic groups, and the hydrogen atoms of these substituents may be further substituted by the substituents exemplified herein.

[0061] The present invention includes Ar of the general formula (1) 1 and Ar 2 The present invention includes a compound group in which Ar of the general formula (1) is 3 and Ar 4 The present invention includes a compound group in which Ar of the general formula (1) is 3 and Ar 4 are each independently a substituted or unsubstituted aromatic hydrocarbon group and Ar 3 and Ar 4 The compound group in which at least one of the compounds has a linked ring having a structure in which two or more aromatic rings are linked by a single bond. In this case, the compound having a linked ring may be Ar 3 and Ar4 At least one of them, or both.

[0062] The present invention includes X 1 ~X 3 A compound group in which one of the groups is a group represented by the general formula (2), and the remaining two groups may be the same or different and are aromatic hydrocarbon groups that may be substituted with at least one of a deuterium atom, an alkyl group, and an aryl group, or aromatic heterocyclic groups that may be substituted with at least one of a deuterium atom, an alkyl group, and an aryl group. The present invention includes X 1 ~X 3 One of them is a group represented by the general formula (2), X 4 ~X 12 A group of compounds which may be the same or different and are hydrogen atoms, deuterium atoms, linear or branched alkyl groups having 1 to 6 carbon atoms which may have substituents, and substituted or unsubstituted aromatic hydrocarbon groups. The present invention includes X 1 ~X 3 One of them is a group represented by the general formula (2), X 4 ~X 12 A group of compounds which may be the same as or different from each other and are hydrogen atoms or deuterium atoms.

[0063] Furthermore, from the viewpoint of heat resistance and charge mobility, R in the general formula (1a) 1 ~R 3 Preferably, R is a hydrogen atom, a deuterium atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. 1 ~R 3 They may be the same as or different from each other.

[0064] The compound represented by general formula (1) has a structure represented by AB in which a partial structure B consisting of a group represented by general formula (2) and a partial structure A other than the group represented by general formula (2) are linked. Specific examples of partial structure A and partial structure B are shown below.

[0065] Specific example of partial structure A

[0066] [Chemical formula 5-1]

[0067]

[0068] [Chemical formula 5-2]

[0069]

[0070] Specific examples of partial structure B [Specific examples of the group represented by general formula (2)] [Chemical formula 6-1]

[0071]

[0072] [Chemical formula 6-2]

[0073]

[0074] For example, partial structure A can be selected from A-1, A-5 to A-9, A-12 to A-21, or from other structures. For example, partial structure A can be selected from A-1 to A-4, A-10 to A-20, or from other structures. For example, partial structure A can be selected from A-1 to A-12, or from other structures. For example, partial structure B can be selected from B-1 to B-3, B-8 to B-23, or from other structures. For example, partial structure B can be selected from B-1 to B-20, or from other structures. For example, partial structure B can be selected from B-1 to B-12, or from other structures. For example, partial structure B can be selected from B-1, B-21, B-22, or from other structures.

[0075] As a preferred group of compounds represented by the general formula (1), X 1 is a group represented by the general formula (2), X 2 and X 3 which may be the same as or different from each other and are an aromatic hydrocarbon group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, or an aromatic heterocyclic group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, Ar 1 ~Ar 4 Compound group 1 which may be the same as or different from each other and is an aromatic hydrocarbon group which may be substituted by at least one of a deuterium atom, a halogen atom, an alkyl group and an aryl group, or an aromatic heterocyclic group which may be substituted by at least one of a deuterium atom, a halogen atom, an alkyl group and an aryl group. Compound group 1 is composed of compound group 1a in which L is a single bond, compound group 1b in which L is a substituted or unsubstituted aromatic hydrocarbon group, and compound group 1c in which L is a substituted or unsubstituted aromatic heterocyclic group. Each of these compound groups 1a, 1b, and 1c may further satisfy at least one of the following additional conditions.

[0076] One of the additional conditions is that X other than the group represented by the general formula (2) 1 ~X 4 When is a hydrogen atom. One of the additional conditions is X 4 ~X 12In the case where the two groups are the same or different and are a hydrogen atom, a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkoxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group, and constitute two adjacent groups bonded to each other to form an aromatic hydrocarbon ring, X is preferably 4 ~X 12 is a hydrogen atom, a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, or a substituted or unsubstituted aromatic hydrocarbon group. 1 ~X 12 When is a hydrogen atom. One of the additional conditions is that Ar 1 ~Ar 4 The two groups may be the same or different and are aromatic hydrocarbon groups which may be substituted by at least one of a deuterium atom, a halogen atom, an alkyl group and an aryl group, preferably aromatic hydrocarbon groups which may be substituted by at least one of a deuterium atom, an alkyl group and an aryl group. 3 and Ar 4 At least one of the above is an aromatic hydrocarbon group having a structure in which two or more aromatic rings are linked by a single bond. One of the additional conditions is when Y is O. One of the additional conditions is when L is a single bond.

[0077] As another preferred compound group represented by the general formula (1), X 2 is a group represented by the general formula (2), X 1 and X 3 The aromatic hydrocarbon group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, or the aromatic heterocyclic group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, Ar 1 ~Ar 4 Compound Group 2, which may be the same as or different from each other and is an aromatic hydrocarbon group which may be substituted with at least one of a deuterium atom, a halogen atom, an alkyl group, and an aryl group, or an aromatic heterocyclic group which may be substituted with at least one of a deuterium atom, a halogen atom, an alkyl group, and an aryl group. Compound Group 2 is composed of Compound Group 2a in which L is a single bond, Compound Group 2b in which L is a substituted or unsubstituted aromatic hydrocarbon group, and Compound Group 2c in which L is a substituted or unsubstituted aromatic heterocyclic group. Each of these Compound Groups 2a, 2b, and 2c may also satisfy at least one of the additional conditions described in Compound Group 1.

[0078] As another preferred compound group represented by the general formula (1), X 3is a group represented by the general formula (2), X 1 and X 2 The aromatic hydrocarbon group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, or the aromatic heterocyclic group which may be substituted with at least one of a deuterium atom, an alkyl group and an aryl group, Ar 1 ~Ar 4 Compound Group 3, which may be the same as or different from each other and is an aromatic hydrocarbon group which may be substituted by at least one of a deuterium atom, a halogen atom, an alkyl group, and an aryl group, or an aromatic heterocyclic group which may be substituted by at least one of a deuterium atom, a halogen atom, an alkyl group, and an aryl group. Compound Group 3 is composed of Compound Group 3a in which L is a single bond, Compound Group 3b in which L is a substituted or unsubstituted aromatic hydrocarbon group, and Compound Group 3c in which L is a substituted or unsubstituted aromatic heterocyclic group. Each of these Compound Groups 3a, 3b, and 3c may also satisfy at least one of the additional conditions described in Compound Group 1.

[0079] Specific examples of the compounds represented by the general formula (1) are shown in the following tables. Tables 1 to 3 show the structures of the compounds of the general formula (1) represented by AB by determining the combination of the partial structure A and the partial structure B. The partial structure A is any one of A-1 to A-21, and the partial structure B is any one of B-1 to B-23. Specific examples of compound group 1 (X) are shown in Table 1. 1 The compounds 1-1 to 1-483 are groups represented by the general formula (2). Specific examples of compound group 2 are shown in Table 2 (X 2 The compounds 2-1 to 2-483 are groups represented by the general formula (2). Specific examples of compound group 3 are shown in Table 3 (X 3 Compounds 3-1 to 3-483) having a group represented by the general formula (2).

[0080] [Table 1]

[0081]

[0082] [Table 2]

[0083]

[0084] [Table 3]

[0085]

[0086] Compounds 1-1 to 3-483 identified in Tables 1 to 3 are specific examples of compounds of the general formula (1) wherein Y is O. The corresponding compounds wherein Y of each of these compounds is substituted from O to S are disclosed herein as compounds 1-1S to 3-483S, respectively.

[0087] As specific examples of the compound represented by the general formula (1), compounds having the following structures are also shown.

[0088] [Chemical formula 7]

[0089]

[0090] [Method for synthesizing the compound represented by general formula (1)]

[0091] For example, a halogenated product as a precursor of a final product can be synthesized by the following scheme, and the above-mentioned novel compound having a condensed polycyclic ring can be synthesized by performing a general coupling reaction using the halogenated product and palladium.

[0092] [Chemical formula 8]

[0093]

[0094] The purification of these compounds can be carried out by purification based on column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization based on solvents, etc. The identification of the compound can be carried out by NMR analysis. As physical property values, it is preferred to measure the glass transition temperature (Tg) and the energy level (HOMO level) of HOMO (Highest Occupied Molecular Orbital: the highest occupied molecular orbital). The glass transition temperature (Tg) becomes an indicator of the stability of the thin film state, and the energy level of HOMO becomes an indicator of hole transport properties.

[0095] <Organic thin film>

[0096] The organic thin film of the present invention is characterized by comprising a compound represented by the general formula (1). For the description of the compound represented by the general formula (1), reference can be made to the description in the above-mentioned column <Compound represented by the general formula (1)>.

[0097] The organic film of the present invention may be composed only of the compound represented by the general formula (1), or may contain, in addition to the compound represented by the general formula (1), a compound other than the compound represented by the general formula (1). Furthermore, the compound represented by the general formula (1) contained in the organic film may be one selected from the group of compounds represented by the general formula (1), or may be two or more.

[0098] The organic thin film of the present invention can be formed by forming a film of the compound represented by the general formula (1) by a known film forming method such as a vapor deposition method, a spin coating method, and an inkjet method. In this case, the compound represented by the general formula (1) can be formed into a film by a single type, or a plurality of types can be mixed to form a film. In addition, it can also be mixed with a compound other than the compound represented by the general formula (1) to form a film within the range that does not impair the effect of the present invention.

[0099] The compound represented by the general formula (1) of the present invention has a relatively high glass transition temperature (Tg), and the energy level of HOMO is appropriate as the energy level of a hole transport material, and has electron blocking properties. Therefore, the organic film comprising the compound represented by the general formula (1) has high heat resistance and shows excellent hole transport and electron blocking properties. Here, "electron blocking" in this specification refers to the electron injection from the anode to the organic film being hindered at its adjacent interface when the organic film is adjacently arranged on the anode. For example, in a photoelectric conversion element, the dark current becomes smaller when the organic film that becomes the object is arranged compared to the case where the organic film is not arranged. Based on this, it can be determined that the organic film has electron blocking properties.

[0100] According to the above, the compound represented by the general formula (1) is useful as an electron blocking material, and the organic film containing the compound (the organic film of the present invention) is effectively used as an electron blocking layer of an organic device such as a photoelectric conversion element. Among them, the organic film of the present invention can be suitable for a light-receiving element that converts the intensity of light into an electrical signal, especially a light-receiving element constituting an imaging element, and can also be used in a light sensor or an organic solar cell. In addition, the organic film of the present invention can be used in various organic devices such as an organic light-emitting diode or an organic transistor.

[0101] <Photoelectric conversion element>

[0102] Next, the photoelectric conversion element of the present invention will be described.

[0103] The photoelectric conversion element of the present invention is characterized by comprising an organic thin film containing a compound represented by the general formula (1). For the description of the organic thin film, reference can be made to the description in the above section <Organic Thin Film>.

[0104] The "photoelectric conversion element" in the present invention refers to an element that converts light energy into electricity. The photoelectric conversion element of the present invention includes a light receiving element, for example, a light receiving element constituting an imaging element.

[0105] The organic thin film containing the compound represented by the general formula (1) can be used as an electron blocking layer disposed between the anode and the photoelectric conversion layer. In this case, the photoelectric conversion element of the present invention is composed of at least an anode, an electron blocking layer, a photoelectric conversion layer and a cathode in sequence, wherein the electron blocking layer is composed of an organic thin film containing the compound represented by the general formula (1). Figure 1 As shown in FIG. 1 , the photoelectric conversion element of the present invention includes an element having a stacked structure in which a glass substrate 1 / transparent anode 2 / electron blocking layer 3 / photoelectric conversion layer 4 / cathode 5 are stacked in this order. Figure 2As shown, the photoelectric conversion element of the present invention includes an element having a stacked structure in which a glass substrate 1 / cathode 5 / photoelectric conversion layer 4 / electron blocking layer 3 / transparent anode 2 are stacked in this order. However, the photoelectric conversion element of the present invention is not limited to Figure 1 and Figure 2 For example, the photoelectric conversion element of the present invention has at least an anode, an electron blocking layer, a photoelectric conversion layer and a cathode in sequence, and may further have other layers between the layers. As an element having such a structure, an element having an anode, a first buffer layer (electron blocking layer), a photoelectric conversion layer, a second buffer layer (e.g., a hole blocking layer), and a cathode in sequence can be cited.

[0106] Furthermore, an organic thin film containing the compound represented by the general formula (1) can also be used for the photoelectric conversion layer.

[0107] Hereinafter, each member and each layer that can be used in the photoelectric conversion element of the present invention will be described.

[0108] (Substrate)

[0109] As the substrate in the photoelectric conversion element of the present invention, there is no particular limitation, and a glass substrate, a plastic substrate, etc. can be used, and it can be transparent or opaque. For example, polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, nitrocellulose, polyvinylidene chloride, polyvinyl alcohol, polyvinyl alcohol (polyethylenevinyl alcohol), para-polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether sulfone, polyphenylene sulfide, polysulfones, polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic acid or polyarylate, organic-inorganic hybrid resin, etc. plastic substrates, glass, quartz, aluminum oxide, silicon, silicon oxide, tantalum dioxide, tantalum pentoxide, indium tin oxide, etc. inorganic substrates, gold, copper, chromium, titanium, aluminum, etc. metal substrates, etc. Among these, glass and silicon are preferred from the viewpoint of forming a transistor.

[0110] (Photoelectric conversion layer)

[0111] The photoelectric conversion layer is a layer for converting light energy into electricity, and more specifically, a layer that generates holes and electrons by generating a charge separation state by light energy. For example, when the photoelectric conversion element of the present invention is a light receiving element, the photoelectric conversion layer generates a signal charge corresponding to the amount of light received.

[0112] The material constituting the photoelectric conversion layer may be an organic material or an inorganic material. Furthermore, the photoelectric conversion layer may be a layer having at least one layer of an organic semiconductor film. The number of organic semiconductor films constituting the photoelectric conversion layer may be one layer or multiple layers. When the photoelectric conversion layer is composed of a layer of an organic semiconductor film, the organic semiconductor film may be a p-type organic semiconductor film, an n-type organic semiconductor film, or a mixed film of a p-type organic semiconductor and an n-type organic semiconductor. The mixed film may be formed by mixing two materials or more than three materials. As an example of a photoelectric conversion layer composed of a plurality of organic semiconductor films, a structure in which two or more layers selected from a group including a p-type organic semiconductor film, an n-type organic semiconductor film, and a mixed film of a p-type organic semiconductor and an n-type organic semiconductor are stacked can be cited. Here, a buffer layer may be inserted between adjacent organic semiconductor films. Furthermore, the photoelectric conversion layer may have a bulk heterostructure in which a three-dimensional pn junction is formed by a p-type organic semiconductor and an n-type organic semiconductor.

[0113] As inorganic materials used in the photoelectric conversion layer, there can be listed crystalline silicon, amorphous silicon, microcrystalline silicon, crystalline selenium, amorphous selenium, CuInGaSe, CuInSe2, AgAlSe2, AgInS2 as chalcopyrite compounds, GaAs, InP, AlGaAs, InGaP, AlGaInP as III-V compounds, and compound semiconductor materials such as CdSe, CdS, In2Se3, Bi2Se3, PbSe, and PbS. Quantum dots composed of these materials can also be used in the photoelectric conversion layer.

[0114] The p-type organic semiconductor used in the photoelectric conversion layer is a donor organic semiconductor, which is a compound having the property of easily donating electrons, mainly represented by a hole-transporting organic compound. The p-type organic semiconductor is not particularly limited, and examples thereof include naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, pentacene derivatives, quinacridone derivatives, (chrysene) derivatives, fluoranthene derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, metal complexes using heterocyclic compounds as ligands, thienoacene materials represented by benzothiophene derivatives, dinaphthothiophene-thiophene derivatives, dianthrethiophene-thiophene derivatives, benzobisbenzothiophene derivatives, thienobisbenzothiophene derivatives, dibenzothiophene-thiophene derivatives, dithienobenzodithiophene derivatives, dibenzothiophene-dithiophene derivatives, benzodithiophene derivatives, naphthiophene derivatives, anthracene-dithiophene derivatives, tetrabenzodithiophene derivatives, and pentacene-dithiophene derivatives, amine derivatives such as triarylamine compounds and carbazole compounds, indenocarbazole derivatives, etc.

[0115] The n-type organic semiconductor used in the photoelectric conversion layer is an acceptor organic semiconductor, which refers to an organic compound with the property of easily accepting electrons, mainly represented by an electron-transporting organic compound. In more detail, it refers to an organic compound with a large electron affinity when two organic compounds are in contact. Therefore, as long as the acceptor organic compound is an organic compound with electron acceptance, any organic compound can be used. For example, condensed aromatic carbocyclic compounds (naphthalene, anthracene, fullerene, phenanthrene, tetracene, pyrene, perylene, perylene diimide, fluoranthene or these derivatives), quinacridone, compounds containing 5 to 7 members of a heterocyclic ring having one or more heteroatoms selected from the group including nitrogen atoms, oxygen atoms and sulfur atoms (for example, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline , tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole, benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazoloindene, oxadiazole, imidazopyridine, pyrrolidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine, etc.), polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silicon-based compounds, metal complexes having nitrogen-containing heterocyclic compounds as ligands, etc. In addition, it is not limited to this. As mentioned above, as long as it is an organic compound with a larger electron affinity than the organic compound used as the donor organic compound, it can be used as an acceptor organic semiconductor.

[0116] (Anode and cathode)

[0117] As the anode and cathode, any conductive material generally used as an electrode can be used without particular limitation, and examples thereof include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), molybdenum oxide (MoO), and titanium oxide; titanium oxynitride (TiN x O x ), metal nitrides such as titanium nitride (TiN); metals such as gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al); and mixtures or stacks of these metals with conductive metal oxides; organic conductive compounds such as polyaniline, polythiophene, polypyrrole; stacks of these organic conductive compounds and ITO, etc.

[0118] (Electron blocking layer)

[0119] The electron blocking layer is a layer for transporting holes generated in the photoelectric conversion layer to the anode and reducing dark current generated by electron injection from the anode.

[0120] In the photoelectric conversion element of the present invention, the electron blocking layer is composed of an organic thin film containing a compound represented by the general formula (1). For the description of the organic thin film, reference can be made to the description in the column <Organic Thin Film>.

[0121] The thickness of the electron blocking layer is, for example, 3 to 100 nm, or preferably 5 to 20 nm.

[0122] (Hole blocking layer)

[0123] In the photoelectric conversion element of the present invention, a hole blocking layer may be inserted between the cathode and the photoelectric conversion layer as necessary.

[0124] The hole blocking layer is a layer for transferring electrons generated in the photoelectric conversion layer to the cathode and reducing dark current generated by holes injected from the cathode.

[0125] The material used in the hole blocking layer is preferably a material whose work function or HOMO energy level has an absolute value greater than the work function or HOMO energy level of the material used in the electron blocking layer. For example, organic compounds and organic metal complexes containing nitrogen-containing heterocycles such as pyridine, quinoline, acridine, indole, imidazole, benzimidazole, and phenanthroline can be cited, and preferably a material with less absorption in the visible light region. In addition, when formed from a thin film of about 5nm to 20nm, fullerenes and their derivatives that have absorption in the visible light region can also be used.

[0126] Example

[0127] Below, utilize synthesis example and embodiment that feature of the present invention is further specifically described.About the material shown below, processing content, processing procedure etc., as long as do not depart from the gist of the present invention, then can suitably change.Therefore, the present invention is not limited to following embodiment.

[0128] <Synthesis of Precursor 1>

[0129] Under nitrogen flow, 10.0 g of intermediate 1, 5.72 g of potassium tert-butoxide, and 100 mL of DMSO (N, N-dimethyl sulfoxide) were added to the reaction vessel, heated to 130-145°C, and stirred for 20 hours. After cooling, 100 mL of toluene and 150 mL of brine were added to the reaction solution and separated. The obtained organic phase was dehydrated with magnesium sulfate and then concentrated. The obtained crude product was purified by silica gel column chromatography to obtain 3.64 g of pale yellowish white powder of precursor 1 (yield 44%).

[0130] [Chemical formula 9]

[0131]

[0132] The structure of the obtained pale yellowish white powder was identified using NMR.

[0133] exist 1 The following 21 hydrogen atom signals were detected in H-NMR (CDCl3).

[0134] δ (ppm)=8.72(1H), 8.77(1H), 8.66(1H), 7.80(1H), 7.53-7.48(2H), 7.47-7.37(4H), 7.33(1H), 7.20-7.08(6H), 6.79-6.72(4H).

[0135] <Synthesis of Precursor 2>

[0136] Under nitrogen flow, 15.5 g of intermediate 2, 520 mg of copper (I) iodide, 4.54 g of potassium carbonate, 683 mg of 3,5-di-tert-butyl salicylic acid, and 160 mL of DMSO were placed in a reaction vessel, heated, and stirred at 125-130°C for 10 hours. After cooling, 160 mL of water was added to the reaction solution, and the precipitated solid was collected by filtration. The obtained solid was heated and dissolved in 300 mL of toluene, and 18 g of silica was added thereto and stirred. After filtering at 90°C and removing the silica, it was concentrated, methanol was added to the precipitated solid, stirred, and filtered, thereby obtaining 10.9 g (yield 75%) of brown powder of precursor 2.

[0137] [Chemical formula 10]

[0138]

[0139] The structure of the obtained brown powder was identified using NMR.

[0140] exist 1 The following 21 hydrogen atom signals were detected in H-NMR (CDCl3).

[0141] δ(ppm)=8.74(1H), 8.67-8.63(2H), 7.90(1H), 7.55(1H), 7.51-6.71(16H).

[0142] Example 1

[0143] <Synthesis of Compound 3-1>

[0144] Precursor 1 3.50 g, bis(biphenyl-4-yl)amine 2.42 g, palladium acetate 65.1 mg, tricyclohexylphosphine (0.6 M toluene solution) 0.46 mL, sodium tert-butoxide 821 mg, xylene 50 mL were added to the reaction container and degassed, then heated and stirred at 100-115° C. for 22 hours. The reaction solution was subjected to adsorption purification operations using silica and activated clay twice and then concentrated. Methanol was added to the obtained crude product, and the precipitated solid was collected by filtration. The obtained solid was repeatedly crystallized based on THF (tetrahydrofuran) / ethyl acetate to obtain 3.96 g (yield 91%) of white powder of compound 3-1.

[0145] The structure of the obtained white powder was identified using NMR.

[0146] exist 1 The following 39 hydrogen atom signals were detected in H-NMR (CDCl3).

[0147] δ (ppm)=8.70(1H), 8.53(1H), 8.33(1H), 7.83(1H), 7.62(4H), 7.57(4H), 7.48-7.29(15H), 7.27(1H), 7.18-7.07(7H), 6.72(2H), 6.71(2H).

[0148] Example 2

[0149] <Synthesis of Compound 2-1>

[0150] In Example 1, Precursor 2 was used instead of Precursor 1, and the reaction was carried out under the same conditions to obtain 1.82 g (yield 37%) of yellow powder of Compound 2-1.

[0151] The structure of the obtained yellow powder was identified using NMR.

[0152] exist 1 The following 39 hydrogen atom signals were detected in H-NMR (CDCl3).

[0153] δ (ppm) = 8.76 (1H), 8.61 (2H), 7.70 (1H), 7.65-7.55 (8H), 7.48-7.30 (17H), 7.20-7.08 (6H), 6.76 (4H).

[0154] Example 3

[0155] <Synthesis of Compound 2-2>

[0156] In Example 2, 4-anilinobiphenyl was used instead of bis(biphenyl-4-yl)amine, and the reaction was carried out under the same conditions to obtain 1.65 g (yield 33%) of yellowish white powder of compound 2-2.

[0157] The structure of the obtained yellow-white powder was identified using NMR.

[0158] exist 1 The following 35 hydrogen atom signals were detected in H-NMR (CDCl3).

[0159] δ (ppm) = 8.74 (1H), 8.58 (2H), 7.67-7.52 (5H), 7.45-7.26 (16H), 7.18-7.05 (7H), 6.75 (4H).

[0160] <Measurement of glass transition temperature>

[0161] The glass transition temperature of each synthesized compound was measured using a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA). In addition, the glass transition temperature of the comparative compounds (EBL-1) and (EBL-2) was also measured in the same manner. The results of the glass transition temperature measurements are summarized in Table 4.

[0162] [Chemical formula 11]

[0163]

[0164] Electron blocking material of Japanese Patent No. 4945146

[0165] [Chemical formula 12]

[0166]

[0167] Electron blocking material of Japanese Patent Publication No. 2018-085427

[0168] [Table 4]

[0169] Compound Glass transition temperature(℃) Compound 3-1 175 Compound 2-1 195 Compound 2-2 176 Comparative Compound EBL-1 157 Comparative Compound EBL-2 171

[0170] As shown in Table 4, the glass transition temperatures of compounds 3-1, 2-1, and 2-2 having the structure of general formula (1) are all above 175°C, and are higher than those of comparative compounds EBL-1 and EBL-2. This shows that the compound represented by general formula (1) has high stability in a thin film state, and by using the compound represented by general formula (1), a device having excellent thermal stability can be realized.

[0171] Example 4

[0172] <Production of organic thin films>

[0173] Compound 3-1, compound 2-1, compound 2-2, comparative compound EBL-1, and comparative compound EBL-2 were each deposited on an ITO-coated substrate by vacuum deposition to a film thickness of 100 nm to prepare respective organic thin films.

[0174] <Measurement of HOMO level>

[0175] The HOMO energy level (HOMO energy level) of each of the produced organic thin films was measured using an ionization potential measuring device (Sumitomo Heavy Industries, Ltd., PYS-202). Table 5 shows the total of the absolute values ​​of the measured HOMO energy levels.

[0176] [Table 5]

[0177] Compound HOMO level (eV) Compound 3-1 5.49 Compound 2-1 5.40 Compound 2-2 5.41 Comparative Compound EBL-1 5.42 Comparative Compound EBL-2 5.52

[0178] As shown in Table 5, the absolute values ​​of the HOMO levels of Compound 3-1, Compound 2-1, and Compound 2-2 are 5.4 to 5.5 eV, which are equivalent to the HOMO levels of hole transport materials such as carbazole compounds. This confirms that the compound represented by the general formula (1) has a good hole transport ability.

[0179] The absorption spectrum of each organic thin film produced was measured using an ultraviolet visible spectrophotometer (Hitachi, Ltd., U-3000), and the gap was obtained from the absorption edge of the spectrum and the above HOMO level to calculate the LUMO level. The absolute value of the LUMO level is shown in Table 6.

[0180] [Table 6]

[0181] Compound LUMO level (eV) Compound 3-1 2.44 Compound 2-1 2.52 Compound 2-2 2.52 Comparative Compound EBL-1 1.93 Comparative Compound EBL-2 2.40

[0182] It was confirmed that the LUMO energy level of these compounds is sufficiently lower than the Fermi level of the electrode used in the anode (for example, ITO: 4.7 eV, gold: about 5.1 eV), and they have electron blocking properties.

[0183] <Fabrication of a device for measuring hole mobility>

[0184] Furthermore, compound 3-1, compound 2-1, compound 2-2, comparative compound EBL-1, and comparative compound EBL-2 were respectively deposited to a thickness of 3 to 4 μm on a glass substrate with ITO by vacuum deposition to form organic thin films. Subsequently, aluminum was deposited to a thickness of 100 nm on each organic thin film to form an electrode, thereby producing an element for hole mobility measurement.

[0185] <Measurement of hole mobility>

[0186] In order to prevent degradation caused by the adsorption of moisture or oxygen, a glass cover with a moisture absorption sheet for organic EL (gatter sheet) was prepared, and each element produced was sealed with the glass cover in a nitrogen atmosphere. The hole mobility of each element sealed with the glass cover was measured under the following measurement conditions using a transient photocurrent measurement device. The measurement results are summarized in Table 7.

[0187] (Measurement conditions)

[0188] Device: Time-of-flight measurement device TOF-401 (manufactured by Optel)

[0189] Excitation light source: nitrogen laser (337.1nm)

[0190] Light pulse width: less than 1nsec

[0191] Measuring area: 0.04cm 2

[0192] Sample temperature: 25°C

[0193] Load resistance: 50Ω

[0194] Electric field strength: 0.25MV / cm

[0195] [Table 7]

[0196] Compound <![CDATA[Hole mobility (cm 2 / Vs)]]> Compound 3-1 <![CDATA[2.8×10 -4 ]]> Compound 2-1 <![CDATA[4.9×10 -4 ]]> Compound 2-2 <![CDATA[1.3×10 -4 ]]> Comparative Compound EBL-1 <![CDATA[8.2×10 -5 ]]> Comparative Compound EBL-2 <![CDATA[8.2×10 -5 ]]>

[0197] As shown in Table 7, the hole mobility of compound 3-1, compound 2-1, and compound 2-2 is 1.3×10 -4 ~4.9×10 -4cm 2 / Vs, and the hole mobility is superior to that of the comparative compound EBL-1 and the comparative compound EBL-2.

[0198] Example 5

[0199] <Production of light-receiving element>

[0200] In this embodiment, an electron blocking layer 3, a photoelectric conversion layer 4, and a cathode 5 are sequentially deposited on a glass substrate 1 having an ITO electrode as a transparent anode 2 to produce a Figure 1 Here, the vapor deposition is performed under a reduced pressure condition of 0.0001Pa or less.

[0201] Specifically, first, the glass substrate 1 with ITO was ultrasonically cleaned in isopropyl alcohol for 20 minutes, dried on a hot plate heated to 200°C for 10 minutes, and further subjected to UV ozone treatment for 15 minutes. Compound 3-1 was evaporated on the glass substrate with ITO in a film thickness of 5nm to form an electron blocking layer 3, and SubPC (p-type semiconductor) and C60 (n-type semiconductor) were binary evaporated thereon to form a photoelectric conversion layer 4 with a film thickness of 200nm. At this time, the evaporation rate ratio of the compound was set to SubPC:C60=50:50. Gold was evaporated on the photoelectric conversion layer 4 to a film thickness of 100nm to form a cathode 5, which was used as a light receiving element 1.

[0202] [Chemical formula 13]

[0203]

[0204] Light receiving element 2, light receiving element 3 and comparative light receiving element 1 were sequentially produced in the same manner except that compound 2-1, compound 2-2 and comparative compound EBL-2 were used instead of compound 3-1 as the material of the electron blocking layer 3.

[0205] <Evaluation of light-receiving elements>

[0206] The spectral sensitivity and photocurrent of each photosensitive element produced were measured under the following measurement conditions using a spectral sensitivity measuring device. The irradiation intensity at a specific wavelength during measurement was corrected using a Si photodiode (S1337-1010BQ, manufactured by Hamamatsu Photonics KK). Regarding the dark current, the spectral radiation intensity to the photosensitive element was set to zero and the current value was measured under the same bias conditions. The measurement results are shown in Table 8.

[0207] (Measurement conditions)

[0208] Apparatus: Spectral sensitivity measuring apparatus SM-250A (manufactured by Bunkoukeiki Co., Ltd.)

[0209] Light source: Xenon lamp 150W

[0210] Spectral irradiance: 2.0mW / cm 2 (550nm)

[0211] Effective irradiation area: 10×10mm

[0212] Light receiving area: 0.04cm 2

[0213] In-plane non-uniformity: within ±5%

[0214] SourceMeter: Keithley 2635B (manufactured by KEITHLEY)

[0215] Applied bias voltage: -1~-3V

[0216] [Table 8]

[0217]

[0218] As shown in Table 8, the dark current when -3 V was applied was -9.9×10 -9 A / cm 2 , in light receiving elements 1 to 3, it becomes -5.7×10 -9 ~-7.6×10 -9 A / cm 2 In addition, the conversion efficiency EQE when -3V is applied is improved to 67-68% in light-receiving elements 1 to 3, compared with 61% in comparative light-receiving element 1. Even when -1V and -2V bias voltages are applied to the elements, light-receiving elements 1 to 3 show low dark current and high conversion efficiency EQE compared to the element of comparative light-receiving element 1. This indicates that the high electron blocking property and good hole transport property of the compound of the present invention can greatly improve the dark current characteristics and conversion efficiency of the light-receiving element.

[0219] The above results clearly show that the compound of the present invention has the HOMO level required for a blocking layer of an organic photoelectric conversion element, high heat resistance, and sufficiently high mobility, and can be particularly suitably used as a material for a light-receiving element.

[0220] Industrial Applicability

[0221] The compound of the present invention is useful as an electron blocking material. For example, in organic devices such as light-receiving elements, light sensors, organic solar cells, organic light-emitting diodes, and organic transistors constituting imaging elements, by using an organic film comprising the compound of the present invention as an electron blocking layer, device characteristics such as heat resistance and dark current characteristics and photoelectric conversion efficiency can be improved. Therefore, the industrial applicability of the present invention is high.

[0222] Explanation of symbols

[0223] 1- glass substrate, 2- transparent anode, 3- electron blocking layer, 4- photoelectric conversion layer, 5- cathode, L- light.

Claims

1. A compound represented by the following general formula (1): [Chemical formula 1] In the general formula (1), Y represents O or S, and X 1 ~X 12 may be the same as or different from each other and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group or a substituted or unsubstituted aryloxy group, and may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring, but X 1 ~X 4 One of them is a group represented by the following general formula (2), [Chemical formula 2] * represents a bonding position, L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, Ar 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and a part of L and Ar 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4 Parts of each of the groups may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring.

2. The compound according to claim 1, which is represented by the following general formula (1a): [Chemical formula 3] In the general formula (1a), Ar 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, R 1 ~R 3 Ar may be the same as or different from each other and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 6 carbon atoms which may have a substituent, a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group or a substituted or unsubstituted aryloxy group, and may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring, L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and a part of L and Ar 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4 Parts of each of the groups may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring.

3. The compound according to claim 2, wherein Ar in the general formula (1a) 1 ~Ar 4 may be the same as or different from each other, and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, R 1 ~R 3 Ar may be the same as or different from each other, and are hydrogen atoms, substituted or unsubstituted aromatic hydrocarbon groups, or substituted or unsubstituted heteroaromatic hydrocarbon groups, L is a single bond or a substituted or unsubstituted aromatic hydrocarbon group, and a portion of L and Ar 3 part of L and Ar 4 Part of Ar 3 Part of Ar 4 Parts of each of the groups may be bonded to each other via single bonds to form a ring.

4. The compound according to claim 1, which is represented by the following general formula (1b): [Chemical formula 4] In the general formula (1b), Ar 1 and Ar 2 may be the same as or different from each other, represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, L represents a single bond, a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, R 4 ~R 13 may be the same as or different from each other, and represent a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heteroaromatic hydrocarbon group, a part of L and R 4 , part of L and R 13 , R 8 and R 9 They may be bonded to each other to form a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

5. The compound according to claim 1, wherein The glass transition temperature (Tg) is 170°C or higher. 6 . An electron blocking material, comprising the compound according to claim 1 .

7. An organic thin film comprising the compound according to any one of claims 1 to 5. A photoelectric conversion element comprising the organic thin film according to claim 7.

9. The photoelectric conversion element according to claim 8, wherein The organic film is an electron blocking layer. 10 . The photoelectric conversion element according to claim 8 , which is a light receiving element.

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