Photoelectric conversion element, imaging element, light sensor, method for producing imaging element, and compound

Abstract

The present invention addresses the problem of providing a photoelectric conversion element which has excellent response speed when receiving blue green light and the response speed of which has low dependency on electrical field intensity. A photoelectric conversion element according to the present invention comprises a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, wherein the photoelectric conversion film contains at least one compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2).

Description

Photoelectric conversion element, imaging element, optical sensor, imaging element manufacturing method, compound

[0001] The present invention relates to a photoelectric conversion element, an imaging element, an optical sensor, a method for manufacturing an imaging element, and a compound.

[0002] In recent years, development of elements (e.g., imaging elements) having a photoelectric conversion film has progressed. For example, Patent Document 1 discloses a dye compound having a specific structure as a compound applicable to organic solar cells and the like.

[0003] US Patent Application Publication No. 2022 / 0135587

[0004] With the demand for improved performance of imaging devices, optical sensors, and the like, there is a demand for photoelectric conversion elements that exhibit excellent characteristics. One example of the characteristics required of a photoelectric conversion element is an excellent response speed when blue-green light is received. Furthermore, the response speed of the photoelectric conversion element is also required to be resistant to change even when the electric field strength is changed, i.e., the electric field strength dependency of the response speed is small. In response to such demands, the present inventors fabricated and investigated a photoelectric conversion element containing the compound disclosed in Patent Document 1, and found that the response speed when blue-green light is received and the electric field strength dependency of the response speed need to be improved. Note that the blue-green light refers to light with a wavelength of 450 to 580 nm.

[0005] Therefore, an object of the present invention is to provide a photoelectric conversion element that has an excellent response speed when receiving blue-green light and that has a small dependency of the response speed on electric field strength. Another object of the present invention is to provide an imaging element, an optical sensor, a method for manufacturing an imaging element, and a compound related to the photoelectric conversion element.

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0007] [1] A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, wherein the photoelectric conversion film contains at least one compound of a compound represented by formula (1) described later and a compound represented by formula (2) described later. [2] The photoelectric conversion element according to [1], wherein the group represented by formula (A-1) described later is a group represented by formula (A-2) described later. [3] The photoelectric conversion element according to [2], wherein the group represented by formula (A-2) is a group represented by formula (C-1) described later or a group represented by formula (C-2) described later. [4] The photoelectric conversion element according to any one of [1] to [3], wherein the photoelectric conversion film further contains an n-type organic semiconductor, and the photoelectric conversion film has a bulk heterostructure formed by mixing the compound represented by formula (1) and the n-type organic semiconductor. [5] The photoelectric conversion element according to [4], wherein the n-type organic semiconductor comprises a fullerene selected from the group consisting of fullerenes and derivatives thereof. [6] The photoelectric conversion element according to any one of [1] to [5], wherein the photoelectric conversion film further comprises a p-type organic semiconductor. [7] The photoelectric conversion element according to any one of [1] to [6], wherein the photoelectric conversion film further comprises a dye. [8] The photoelectric conversion element according to any one of [1] to [7], wherein one or more intermediate layers are provided between the conductive film and the transparent conductive film in addition to the photoelectric conversion film. [9] An imaging element comprising the photoelectric conversion element according to any one of [1] to [8].

[10] An optical sensor comprising the photoelectric conversion element according to any one of [1] to [8].

[11] A method for manufacturing an imaging element, comprising the step of manufacturing the photoelectric conversion element according to any one of [1] to [8].

[12] A compound represented by the following formula (1) or the following formula (2).

[13] The compound according to

[12] , wherein the group represented by formula (A-1) described later is a group represented by formula (A-2) described later.

[14] The compound according to

[13] , wherein the group represented by formula (A-2) is a group represented by formula (C-1) described later or a group represented by formula (C-2) described later.

[0008] According to the present invention, a photoelectric conversion element having an excellent response speed when receiving blue-green light and a small dependency of the response speed on electric field strength can be provided. Furthermore, according to the present invention, an imaging element, an optical sensor, a method for manufacturing an imaging element, and a compound related to the photoelectric conversion element can also be provided.

[0009] 1 is a schematic cross-sectional view showing an example of the configuration of a photoelectric conversion element.

[0010] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0011] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] In this specification, a hydrogen atom may be either a protist atom (a normal hydrogen atom) or a deuterium atom (for example, a deuterium atom). In this specification, when there are multiple substituents, linking groups, etc. (hereinafter also referred to as "substituents, etc.") represented by a specific symbol, or when multiple substituents, etc. are specified at the same time, this means that the respective substituents, etc. may be the same or different from each other. This also applies to the specification of the number of substituents, etc.

[0013] In this specification, unless otherwise specified, examples of the "substituent" include the groups exemplified as the substituent W below.

[0014] (Substituent W) The substituent W in this specification will be described. Examples of the substituent W include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group (a heteroaryl group, or an aliphatic heterocyclic group), a cyano group, a nitro group, an alkoxy group, an aryloxy group, a silyl group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryl ... Examples of the substituent W include an anyloxy group, a primary, secondary, or tertiary amino group (including an anilino group), an alkylthio group, an arylthio group, a heterocyclic thio group, an alkyl or arylsulfinyl group, an alkyl or arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a phosphono group, a carboxy group, a phosphate group, a sulfonic acid group, a hydroxy group, a thiol group, an acylamino group, a carbamoyl group, a ureido group, and a boronic acid group. Furthermore, each of the above groups may further have a substituent (e.g., one or more of the above groups, etc.), if possible. For example, an alkyl group which may have a substituent is also included as one form of the substituent W. Furthermore, when the substituent W has a carbon atom, the number of carbon atoms contained in the substituent W is, for example, 1 to 20. The number of atoms other than hydrogen atoms contained in the substituent W is, for example, 1 to 30. The specific compounds described below may have, as substituents, a carboxy group, a salt of a carboxy group, a salt of a phosphate group, a sulfonic acid group, a salt of a sulfonic acid group, a hydroxy group, a thiol group, an acylamino group, a carbamoyl group, a ureido group, a boronic acid group (-B(OH) ２ ) and / or does not have a primary amino group.

[0015] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0016] In this specification, the aliphatic hydrocarbon group may be linear, branched, or cyclic. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group. Furthermore, in this specification, unless otherwise specified, the number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. The alkyl group may be linear, branched, or cyclic. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclopropyl group, and a cyclopentyl group. Furthermore, the alkyl group may be a cycloalkyl group, a bicycloalkyl group, or a tricycloalkyl group, and may have these ring structures as partial structures. In the alkyl group that may have a substituent, examples of the substituent that the alkyl group may have include the groups exemplified for the substituent W. Of these, an aryl group (preferably having 6 to 18 carbon atoms, more preferably having 6 carbon atoms), a heteroaryl group (preferably having 5 to 18 carbon atoms, more preferably having 5 to 6 carbon atoms), or a halogen atom (preferably a fluorine atom or a chlorine atom) is preferred.

[0017] In this specification, unless otherwise specified, the alkyl group moiety in the alkoxy group is preferably the above-mentioned alkyl group. The alkyl group moiety in the alkylthio group is preferably the above-mentioned alkyl group. In the alkoxy group which may have a substituent, examples of the substituent that the alkoxy group may have include the same as the substituent in the alkyl group which may have a substituent. In the alkylthio group which may have a substituent, examples of the substituent that the alkylthio group may have include the same as the substituent in the alkyl group which may have a substituent.

[0018] In this specification, unless otherwise specified, the alkenyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkenyl group is preferably 2 to 20. In the alkenyl group which may have a substituent, examples of the substituent that the alkenyl group may have include the same as the substituents in the alkyl group which may have a substituent. In this specification, unless otherwise specified, the alkynyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkynyl group is preferably 2 to 20. In the alkynyl group which may have a substituent, examples of the substituent that the alkynyl group may have include the same as the substituents in the alkyl group which may have a substituent.

[0019] In this specification, unless otherwise specified, an aromatic ring or an aromatic ring constituting an aromatic ring group may be either a monocyclic ring or a polycyclic ring (e.g., 2 to 6 rings). A monocyclic aromatic ring is an aromatic ring having only one aromatic ring structure as a ring structure. A polycyclic (e.g., 2 to 6 rings) aromatic ring is an aromatic ring having a plurality of (e.g., 2 to 6) condensed aromatic ring structures as a ring structure. The number of ring members in the aromatic ring is preferably 5 to 15. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. When the aromatic ring is an aromatic heterocycle, the number of heteroatoms contained as ring member atoms is, for example, 1 to 10. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, a phenanthrene ring, and a fluorene ring.Examples of the aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring (e.g., a 1,2,3-triazine ring, a 1,2,4-triazine ring, and a 1,3,5-triazine ring), a tetrazine ring (e.g., a 1,2,4,5-tetrazine ring), a quinoxaline ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzopyrrole ring, a benzofuran ring, a benzothiophene ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a naphthopyrrole ring, a naphthofuran ring, a naphthothiophene ring, a naphthoimidazole ring, a naphthoxazole ring, a pyrroloimidazole ring (e.g., a 5H-pyrrolo[1,2-a]imidazole ring), an imidazooxazole ring (e.g., an imidazo[2,1-b]oxazole ring). , thienothiazole rings (for example, thieno[2,3-d]thiazole rings, etc.), benzothiadiazole rings, benzodithiophene rings (for example, benzo[1,2-b:4,5-b']dithiophene rings, etc.), thienothiophene rings (for example, thieno[3,2-b]thiophene rings, etc.), thiazolothiazole rings (for example, thiazolo[5,4-d]thiazole rings, etc.), naphthodithiophene rings (for example, naphtho[2,3 [2,1-b:6,7-b']dithiophene ring, naphtho[2,1-b:6,5-b']dithiophene ring, naphtho[1,2-b:5,6-b']dithiophene ring, 1,8-dithiadicyclopenta[b,g]naphthalene ring, etc.), benzothienobenzothiophene ring, dithieno[3,2-b:2',3'-d]thiophene ring, and 3,4,7,8-tetrathiadicyclopenta[a,e]pentalene ring.

[0020] As used herein, the term "aromatic ring group" includes, for example, a group obtained by removing one or more hydrogen atoms (e.g., 1 to 5) from the above-mentioned aromatic ring. As used herein, the term "aryl group" includes, for example, a group obtained by removing one hydrogen atom from a ring corresponding to an aromatic hydrocarbon ring among the above-mentioned aromatic rings. As used herein, the term "heteroaryl group" includes, for example, a group obtained by removing one hydrogen atom from a ring corresponding to an aromatic heterocycle among the above-mentioned aromatic rings. As used herein, the term "arylene group" includes, for example, a group obtained by removing two hydrogen atoms from a ring corresponding to an aromatic hydrocarbon ring among the above-mentioned aromatic rings. As used herein, the term "heteroarylene group" includes, for example, a group obtained by removing two hydrogen atoms from a ring corresponding to an aromatic heterocycle among the above-mentioned aromatic rings. In the optionally substituted aromatic ring group, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted arylene group, and optionally substituted heteroarylene group, the types of substituents that these groups may have include, for example, the groups exemplified for the substituent W. When these groups which may have a substituent have a substituent, the number of the substituents may be one or more (for example, 1 to 4, etc.).

[0021] As used herein, the term "non-aromatic ring" refers to a ring structure that does not fall under the category of aromatic rings, and examples thereof include an aliphatic hydrocarbon ring and an aliphatic heterocycle. Examples of the aliphatic hydrocarbon ring include a cycloalkane, a cycloalkene, and a cycloalkyne. Examples of the aliphatic heterocycle include a pyrrolidine ring, an oxolane ring, a thiolane ring, a piperidine ring, a tetrahydropyran ring, a thiane ring, a piperazine ring, a morpholine ring, a quinuclidine ring, an azetidine ring, an oxetane ring, an aziridine ring, a dioxane ring, and a γ-butyrolactone ring. As used herein, the term "aliphatic hydrocarbon ring group" includes, for example, a group obtained by removing one hydrogen atom from a ring that falls under the category of an aliphatic hydrocarbon ring. As used herein, the term "aliphatic heterocyclic group" includes, for example, a group obtained by removing one hydrogen atom from a ring that falls under the category of an aliphatic heterocycle.

[0022] In this specification, when a formula showing a chemical structure contains a plurality of identical symbols indicating the type or number of groups, the contents of the plurality of identical symbols are independent of each other, and the contents of the plurality of identical symbols may be the same or different, unless otherwise specified. In this specification, when a formula showing a chemical structure contains a plurality of groups of the same type (e.g., alkyl groups, etc.), the specific contents of the plurality of groups of the same type are independent of each other, and the specific contents of the plurality of groups of the same type may be the same or different, unless otherwise specified.

[0023] In this specification, the bonding direction of a divalent group (e.g., -CO-O-, etc.) is not limited unless otherwise specified. For example, when Y is -CO-O- in a compound represented by the formula "X-Y-Z," the compound may be either "X-O-CO-Z" or "X-CO-O-Z."

[0024] In this specification, with respect to compounds that may have geometric isomers (cis-trans isomers), the general formula or structural formula representing the compound may be described in only one of the cis and trans forms for convenience. Even in such cases, unless otherwise specified, the form of the compound is not limited to either the cis or trans form, and the compound may be in either the cis or trans form.

[0025] In this specification, unless otherwise specified, * in a formula indicates a bonding position.

[0026] [Photoelectric conversion element] The photoelectric conversion element of the present invention is a photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, and the photoelectric conversion film contains at least one compound (hereinafter also referred to as a "specific compound") selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2).

[0027] Although the reason why the photoelectric conversion element having the above configuration can solve the problems of the present invention is not entirely clear, the inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is still within the scope of the present invention. The specific compound is a so-called ADA-type dye compound having a donor portion (D) and an acceptor portion (A). ADA-type dye compounds tend to have high aggregation properties due to their conjugated structure. As represented by Formulas (1) and (2), the specific compound has specific substituents at specific positions, which suppresses excessive aggregation between the specific compounds, thereby achieving efficient charge separation in the photoelectric conversion film. It is also speculated that the presence of a specific cyclic acceptor structure contributes to suppressing aggregation between the specific compounds. As a result, it is believed that a photoelectric conversion element containing the specific compound has excellent response speed and a small electric field strength dependency of the response speed. Hereinafter, achieving at least one of a superior response speed and a small electric field strength dependency of the response speed is also referred to as "excellent effects of the present invention."

[0028] FIG. 1 shows a cross-sectional schematic diagram of one embodiment of the photoelectric conversion element of the present invention. The photoelectric conversion element 10a shown in FIG. 1 has a configuration in which a conductive film (hereinafter also referred to as the "lower electrode") 11 functioning as a lower electrode, an electron blocking film 16A, a photoelectric conversion film 12 containing a specific compound, and a transparent conductive film (hereinafter also referred to as the "upper electrode") 15 functioning as an upper electrode are stacked in this order. FIG. 2 shows an example of the configuration of another photoelectric conversion element. The photoelectric conversion element 10b shown in FIG. 2 has a configuration in which an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15 are stacked in this order on a lower electrode 11. Note that the stacking order of the electron blocking film 16A, the photoelectric conversion film 12, and the hole blocking film 16B in FIGS. 1 and 2 may be changed as appropriate depending on the application and characteristics.

[0029] In the photoelectric conversion element 10a (or 10b), it is preferable that light is incident on the photoelectric conversion film 12 through the upper electrode 15. When the photoelectric conversion element 10a (or 10b) is used, a voltage can be applied. In this case, the lower electrode 11 and the upper electrode 15 form a pair of electrodes, and a voltage of 1×10 is applied between the pair of electrodes. －５ ~1 x 10 ７ In terms of performance and power consumption, it is preferable to apply a voltage of 1×10 V / cm. －４ ~1 x 10 ７ V / cm is more preferable, and 1×10 －３ ~5 x 10 ６ V / cm is more preferable. Regarding the voltage application method, it is preferable to apply the voltage so that the electron blocking film 16A side serves as the cathode and the photoelectric conversion film 12 side serves as the anode in FIGS. 1 and 2. When the photoelectric conversion element 10a (or 10b) is used as a photosensor or incorporated into an imaging element, a voltage can be applied in a similar manner. As will be described in detail later, the photoelectric conversion element 10a (or 10b) can be suitably used as an imaging element. The configuration of each layer constituting the photoelectric conversion element of the present invention will be described in detail below.

[0030] [Photoelectric Conversion Film] The photoelectric conversion element has a photoelectric conversion film.

[0031] <Specific Compound> The photoelectric conversion film contains a specific compound, which is at least one compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2).

[0032]

[0033] In formula (1), R １ and R ２ each independently represents a hydrogen atom or a substituent. １ and X ２ are each independently -CR ａ１ = or represents a nitrogen atom. ａ１ represents a hydrogen atom or a substituent. ３ and R ４ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 5 or less carbon atoms. １ and A２ each independently represents a group represented by formula (A-1). In formula (A-1), * represents a bonding position. In formula (A-1), C １ represents a ring containing two or more carbon atoms which may have a substituent. １ represents a sulfur atom, an oxygen atom, and ═NR Ｗ２ or =CR Ｗ３ R Ｗ４ Represents R Ｗ２ represents a hydrogen atom or a substituent. Ｗ３ and R Ｗ４ each independently represents a cyano group, —SO ２ R Ｗ５ , -COOR Ｗ６ or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ each independently represents an aliphatic hydrocarbon group which may have a substituent, an aromatic ring group which may have a substituent, or an aliphatic heterocyclic group which may have a substituent. １ and R ２ Each of R independently represents a hydrogen atom or a substituent. Cy represents an aromatic ring containing two or more carbon atoms and which may have a substituent. R ５ represents an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, a silyl group, or a halogen atom. ６ represents a hydrogen atom or a substituent. １ and A ２ each independently represents a group represented by formula (C-1) or a group represented by formula (C-2). In formula (C-1), * represents a bonding position. X ｃ１ and X ｃ２ are each independently an oxygen atom, a sulfur atom, or ═C(CN) ２ Represents. C ３ represents an aromatic ring which may have a substituent. In formula (C-2), * represents a bonding position. X ｃ３ ~X ｃ５ R each independently represents an oxygen atom or a sulfur atom. ｃ１ and R ｃ２ each independently represents a hydrogen atom or a substituent.

[0034] In formula (1), R １ and R ２ each independently represents a hydrogen atom or a substituent. Examples of the substituent include the substituents exemplified for the substituent W. In terms of the effects of the present invention being more excellent, R １ and R ２ is preferably a hydrogen atom.

[0035] In formula (1), X １ and X ２ are each independently -CR ａ１ = or a nitrogen atom. In terms of the effects of the present invention being more excellent, X １ and X ２ As for -CR ａ１ = is preferred.

[0036] R ａ１ represents a hydrogen atom or a substituent. Examples of the substituent include the substituents exemplified in the above-mentioned substituent W. More specifically, examples of the substituent include a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, an alkoxy group, an aryloxy group, and a silyl group. The alkyl group, the alkenyl group, the alkynyl group, the aryl group, the heterocyclic group, the alkoxy group, and the aryloxy group may have a substituent. Examples of the substituent include the substituents exemplified in the above-mentioned substituent W, and a substituent selected from the substituent group S described below is preferred.

[0037] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or a chlorine atom being preferred.

[0038] The alkyl group may be linear, branched, or cyclic. The cyclic alkyl group may be monocyclic or polycyclic. That is, it may be a cycloalkyl group, a bicycloalkyl group, a tricycloalkyl group, or the like. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, even more preferably 1 to 5 carbon atoms, particularly preferably 1 to 3 carbon atoms, and particularly preferably 2 or 3 carbon atoms.

[0039] The alkenyl group and alkynyl group may be linear, branched, or cyclic. The cyclic alkenyl group and alkynyl group may be monocyclic or polycyclic. For example, they may be cycloalkenyl groups or bicycloalkenyl groups. The alkenyl group and alkynyl group preferably have 2 to 21 carbon atoms, more preferably 2 to 11 carbon atoms, even more preferably 2 to 5 carbon atoms, and particularly preferably 2 to 4 carbon atoms.

[0040] The aryl group may be either monocyclic or polycyclic, with monocyclic being preferred. The aryl group preferably has 5 to 18 carbon atoms, more preferably 6 to 10, and even more preferably 6 to 8. The definition and specific examples of the aryl group are as described above, with a phenyl group or naphthyl group being preferred, and a phenyl group being more preferred. The aryl group may have a substituent, as described above. When the aryl group has a substituent, the number of substituents is not particularly limited, but is preferably 1 to 3.

[0041] The heterocyclic group may be either monocyclic or polycyclic, with monocyclic being preferred. The number of ring members in the heterocyclic group is preferably 5 to 20, more preferably 5 to 12, and even more preferably 5 to 8. The number of carbon atoms in the heterocyclic group is preferably 1 to 20, more preferably 3 to 10, and even more preferably 4 to 6. Examples of heteroatoms contained in the heterocyclic group include sulfur, oxygen, nitrogen, selenium, tellurium, phosphorus, silicon, and boron atoms, with sulfur, oxygen, or nitrogen being preferred. The heterocyclic group may be either an aromatic heterocyclic group or an aliphatic heterocyclic group. The definition and specific examples of the aromatic heterocyclic group are as described above, with thiophene, furan, thiazole, or pyridine ring groups being preferred. Specific examples of the aliphatic heterocyclic group are as described above, with piperidine ring groups being preferred. The heterocyclic group may have a substituent, as described above. When the heterocyclic group has a substituent, the number of substituents is not particularly limited, but 1 to 3 is preferred.

[0042] The alkyl group of the alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 10, still more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, a t-butoxy group, and a cyclopropoxy group.

[0043] The aryl group contained in the aryloxy group may be either monocyclic or polycyclic. The number of carbon atoms in the aryloxy group is preferably 5 to 18, more preferably 6 to 10, and even more preferably 6 to 8. Examples of the aryloxy group include a phenoxy group.

[0044] The silyl group is —Si(R Ｓｉ ) ３ R is a group represented by the formula: Ｓｉ R each independently represents an alkyl group, an alkenyl group, an alkynyl group, or an aryl group. Ｓｉ The definitions and preferred embodiments of the alkyl group, alkenyl group, alkynyl group, and aryl group represented by R ａ１ These are the same as the alkyl group, alkenyl group, alkynyl group, and aryl group exemplified as the substituent represented by the formula:

[0045] The above-mentioned substituent is also preferably a substituent selected from a halogen atom, an alkyl group, or an aromatic heterocyclic group.

[0046] The above-mentioned substituent group S will be described in detail. Substituent group S: halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, aryl groups which may have a substituent, heterocyclic groups which may have a substituent, and silyl groups. The alkyl groups, alkenyl groups, alkynyl groups, and alkoxy groups in the above-mentioned substituent group S may have a halogen atom.

[0047] The definitions and preferred embodiments of the alkenyl group, alkynyl group, alkoxy group, aryloxy group, aryl group, heterocyclic group, and silyl group in the above-mentioned substituent group S are as follows: ａ１is the same as each of the groups exemplified as the substituent represented by the formula:

[0048] Examples of the substituent that the aryl group and heterocyclic group in the above-mentioned substituent group S may have include the substituents exemplified for the above-mentioned substituent W. A substituent selected from the substituent group S is preferable, and a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a silyl group is more preferable.

[0049] The substituent selected from the above-mentioned substituent group S is also preferably a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a silyl group.

[0050] In formula (1), R ３ and R ４each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 5 or less carbon atoms. The aliphatic hydrocarbon group has 5 or less carbon atoms, preferably 1 to 4, more preferably 1 to 3, and particularly preferably 2 to 3. The aliphatic hydrocarbon group may be linear, branched, cyclic, or a combination thereof. Examples of the linear aliphatic hydrocarbon group having 5 or less carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, a vinyl group, an ethynyl group, an allyl group, and a propargyl group, with a methyl group or an ethyl group being preferred. Examples of the branched aliphatic hydrocarbon group having 5 or less carbon atoms include an isopropyl group, an isobutyl group, a t-butyl group, a s-butyl group, a neopentyl group, an isopentyl group, a s-pentyl group, a t-pentyl group, and a 1-ethylpropyl group, with an isopropyl group being preferred. Examples of the cyclic aliphatic hydrocarbon group having 5 or less carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a bicyclo[1.1.1]pentyl group, with a cyclopropyl group being preferred. The aliphatic hydrocarbon group having 5 or less carbon atoms may be a group combining the above-mentioned linear aliphatic hydrocarbon group and a cyclic aliphatic hydrocarbon group, as long as it has 5 or less carbon atoms, and may be, for example, a cyclopropylmethyl group, a 2-ethylcyclopropyl group, a 2,2-dimethylcyclopropyl group, etc. R ３ and R ４ is preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group.

[0051] In formula (1), A １ and A ２ each independently represents a group represented by formula (A-1).

[0052]

[0053] In formula (A-1), * represents a bonding position.

[0054] In formula (A-1), C １ represents a ring containing two or more carbon atoms which may have a substituent. １The two carbon atoms contained in are the two carbon atoms specified in formula (A-1). The number of carbon atoms in the ring is preferably 3 to 30, more preferably 3 to 20, and even more preferably 3 to 10. The number of carbon atoms in the ring is the number including the two carbon atoms specified in the formula. The ring may be either an aromatic ring or a non-aromatic ring. The ring may be either a monocyclic or polycyclic ring, and is preferably a 5-membered ring, a 6-membered ring, or a fused ring containing at least one of a 5-membered ring and a 6-membered ring. The number of carbon atoms in the fused ring containing at least one of a 5-membered ring and a 6-membered ring is preferably 6 to 20, more preferably 6 to 15, and even more preferably 8 to 10. The ring may have a heteroatom. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom, and a sulfur atom, a nitrogen atom, or an oxygen atom is preferred. The number of heteroatoms in the ring is preferably 0 to 10, and more preferably 0 to 5. １ Among the carbon atoms constituting the ring represented by the formula (A-1), the carbon atom at the bonding position marked with * and W １ Carbon atoms other than the carbon atom bonded to may be substituted with a carbonyl carbon (>C=O) or a thiocarbonyl carbon (>C=S).

[0055] Above C １ Examples of the substituent that the ring represented by the formula (I) may have include the groups exemplified for the substituent W above, and a halogen atom, an alkyl group, an aromatic ring group, a cyano group, or a silyl group is preferred, with a halogen atom or an alkyl group being more preferred. The alkyl group may be linear, branched, or cyclic, with a linear group being preferred. The alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 1 to 3 carbon atoms.

[0056] Above C １The ring represented by the formula (I) is preferably a ring used as an acidic nucleus (for example, the acidic nucleus in a merocyanine dye), and examples thereof include the following nuclei: (a) 1,3-dicarbonyl nucleus: for example, a 1,3-indandione nucleus, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, and 1,3-dioxane-4,6-dione; (b) pyrazolinone nucleus: for example, 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, and 1-(2-benzothiazolyl)-3-methyl-2-pyrazolin-5-one; (c) isoxazolinone nucleus: for example, 3-phenyl-2-isoxazolin-5-one and 3-methyl-2-isoxazolin-5-one; (d) oxindole nucleus: for example, 1-alkyl-2,3-dihydro-2-oxindole; (e) 2,4,6-trioxohexahydropyrimidine nucleus: for example, barbituric acid, 2-thiobarbituric acid, and derivatives thereof. Examples of the derivatives include 1-alkyl compounds such as 1-methyl and 1-ethyl, 1,3-dialkyl compounds such as 1,3-dimethyl, 1,3-diethyl, and 1,3-dibutyl, 1,3-diaryl compounds such as 1,3-diphenyl, 1,3-di(p-chlorophenyl), and 1,3-di(p-ethoxycarbonylphenyl), 1-alkyl-1-aryl compounds such as 1-ethyl-3-phenyl, and 1,3-diheteroaryl compounds such as 1,3-di(2-pyridyl). (f) 2-thio-2,4-thiazolidinedione nucleus: for example, rhodanine and derivatives thereof. Examples of the derivatives include 3-alkylrhodanines such as 3-methylrhodanine, 3-ethylrhodanine, and 3-allylrhodanine, 3-arylrhodanines such as 3-phenylrhodanine, and 3-heteroarylrhodanines such as 3-(2-pyridyl)rhodanine. (g) 2-thio-2,4-oxazolidinedione nucleus (2-thio-2,4-(3H,5H)-oxazoledione nucleus): for example, 3-ethyl-2-thio-2,4-oxazolidinedione. (h) thianaphthenone nucleus: for example, 3(2H)-thianaphthenone-1,1-dioxide. (i) 2-thio-2,5-thiazolidinedione nucleus: for example, 3-ethyl-2-thio-2,5-thiazolidinedione.(j) 2,4-thiazolidinedione nucleus: for example, 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, and 3-phenyl-2,4-thiazolidinedione. (k) thiazolin-4-one nucleus: for example, 4-thiazolinone and 2-ethyl-4-thiazolinone. (l) 2,4-imidazolidinedione (hydantoin) nucleus: for example, 2,4-imidazolidinedione and 3-ethyl-2,4-imidazolidinedione. (m) 2-thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus: for example, 2-thio-2,4-imidazolidinedione and 3-ethyl-2-thio-2,4-imidazolidinedione. (n) Imidazolin-5-one nucleus: for example, 2-propylmercapto-2-imidazolin-5-one, etc. (o) 3,5-pyrazolidinedione nucleus: for example, 1,2-diphenyl-3,5-pyrazolidinedione and 1,2-dimethyl-3,5-pyrazolidinedione, etc. (p) Benzothiophen-3(2H)-one nucleus: for example, benzothiophen-3(2H)-one, oxobenzothiophen-3(2H)-one, and dioxobenzothiophen-3(2H)-one, etc. (q) Indanone nucleus: for example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1-indanone, and 3,3-dimethyl-1-indanone, etc. (r) Benzofuran-3-(2H)-one nucleus: for example, benzofuran-3-(2H)-one, etc. (s) 2,2-dihydrophenalene-1,3-dione nucleus, etc.

[0057] In formula (A-1), W １ represents an oxygen atom, a sulfur atom, and ═NR Ｗ２ , or =CR Ｗ３ R Ｗ４ Represents W. １ is preferably an oxygen atom or a sulfur atom, more preferably an oxygen atom, in that the effects of the present invention are more excellent. Ｗ２ represents a hydrogen atom or a substituent. Examples of the substituent include the groups exemplified above as the substituent W. Ｗ３ and R Ｗ４ each independently represents a cyano group, —SO ２ R Ｗ５ , -COOR Ｗ６, or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ R each independently represent an aliphatic hydrocarbon group which may have a substituent, an aromatic ring group which may have a substituent, or an aliphatic heterocyclic group which may have a substituent. The definition of the aliphatic hydrocarbon group is as described above, and an aliphatic hydrocarbon group having 1 to 3 carbon atoms is preferred. The definition of the aromatic ring group is as described above, and an aromatic hydrocarbon ring group is preferred, and a phenyl group is more preferred. The definition of the aliphatic heterocyclic group is as described above, and the heteroatom contained in the aliphatic heterocyclic group is preferably a sulfur atom, an oxygen atom, or a nitrogen atom. R Ｗ５ ~R Ｗ７ Examples of the substituent that each group represented by the following formula may have include the substituents exemplified for the substituent W above.

[0058] The group represented by formula (A-1) is preferably a group represented by formula (A-2) in that the effects of the present invention are more excellent.

[0059]

[0060] In formula (A-2), * represents a bonding position.

[0061] In formula (A-2), C ２ represents a ring containing at least three carbon atoms, which may have a substituent. ２The three carbon atoms contained in the ring are the three carbon atoms specified in formula (A-2). The number of carbon atoms in the ring is preferably 3 to 30, more preferably 3 to 20, and even more preferably 3 to 10. The number of carbon atoms in the ring is the number including the three carbon atoms specified in the formula. The ring may be either an aromatic ring or a non-aromatic ring. The ring may be either a monocyclic or polycyclic ring, and is preferably a 5-membered ring, a 6-membered ring, or a fused ring containing at least one of a 5-membered ring and a 6-membered ring. The number of carbon atoms in the fused ring containing at least one of a 5-membered ring and a 6-membered ring is preferably 6 to 20, more preferably 6 to 15, and even more preferably 8 to 10. The ring may contain a heteroatom. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom, with a sulfur atom, a nitrogen atom, or an oxygen atom being preferred. The number of heteroatoms contained in the ring is preferably 0 to 10, and more preferably 0 to 5. Above C ２ Among the carbon atoms constituting the ring represented by the formula (A-2), the carbon atom at the bonding position marked with * and Y ２ or Y ３ A carbon atom other than the carbon atom bonded to the ring C may be substituted with a carbonyl carbon (>C=O) or a thiocarbonyl carbon (>C=S). １ The substituents are the same as those that may be possessed by the group.

[0062] In formula (A-2), W ２ and W ３ each independently represents an oxygen atom, a sulfur atom, or ═NR Ｗ２ , or =CR Ｗ３ R Ｗ４ In terms of achieving better effects of the present invention, an oxygen atom or a sulfur atom is preferred, and an oxygen atom is more preferred. Ｗ２ ~R Ｗ４ is as described above.

[0063] The group represented by formula (A-2) is preferably a group represented by formula (C-1) or a group represented by formula (C-2), and more preferably a group represented by formula (C-2), in terms of better effects of the present invention.

[0064]

[0065] In formula (C-1), * represents a bonding position.

[0066] In formula (C-1), X ｃ１ and X ｃ２ are each independently an oxygen atom, a sulfur atom, or ═C(CN) ２ The effect of the present invention is more excellent, and therefore, X ｃ１ and X ｃ２ is preferably an oxygen atom or a sulfur atom, more preferably an oxygen atom. ｃ１ and X ｃ２ is preferably an oxygen atom, and X ｃ１ and X ｃ２ is more preferably an oxygen atom.

[0067] In formula (C-1), C ３ represents an aromatic ring which may have a substituent. The aromatic ring may be either a monocyclic or polycyclic ring. The number of ring members in the aromatic ring is preferably 4 to 30, more preferably 5 to 12, and even more preferably 5 to 8. The number of ring members in the aromatic ring is the number including the two carbon atoms specified in the formula. The aromatic ring may be either an aromatic hydrocarbon ring or an aromatic heterocycle, and an aromatic hydrocarbon ring is preferred. ３ The aromatic ring represented by the formula (I) is as described above, and is preferably a benzene ring, a naphthalene ring, an anthracene ring, a pyrene ring, a thiophene ring, a furan ring, a thiazole ring, an oxazole ring, a pyridine ring, a thienothiophene ring, a benzothiophene ring, a benzofuran ring, a pyrazine ring, a pyrimidine ring, or a pyridazine ring, more preferably a benzene ring, a naphthalene ring, or a thiophene ring, and even more preferably a benzene ring. Examples of the substituent that the aromatic ring may have include the groups exemplified by the substituent W, and an alkyl group or a halogen atom is preferred. The number of substituents that the aromatic ring may have is not particularly limited, but is preferably 0 to 8, and more preferably 0 to 4.

[0068] In formula (C-2), * represents a bonding position.

[0069] In formula (C-2), Xｃ３ ~X ｃ５ Each of X independently represents an oxygen atom or a sulfur atom. ｃ３ and X ｃ４ is preferably an oxygen atom, and X ｃ３ ~X ｃ５ is more preferably an oxygen atom.

[0070] In formula (C-2), R ｃ１ and R ｃ２ each independently represents a hydrogen atom or a substituent. Examples of the substituent include the groups exemplified by the substituent W above, with an alkyl group or an aryl group being preferred, and an alkyl group being more preferred. The alkyl group may be linear, branched, or cyclic, with a linear group being preferred. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 6, even more preferably 1 to 3, and particularly preferably 1 or 2. The aryl group may be monocyclic or polycyclic, with a phenyl group being preferred. The aryl group may further have a substituent, and examples of the substituent include the groups exemplified by the substituent W above.

[0071] In formula (2), R １ and R ２ each independently represents a hydrogen atom or a substituent. Examples of the substituent include the substituents exemplified for the substituent W. In terms of the effects of the present invention being more excellent, R １ and R ２ is preferably a hydrogen atom.

[0072] In formula (2), Cy represents an aromatic ring containing two or more carbon atoms and optionally having a substituent. The two carbon atoms contained in Cy are the two carbon atoms explicitly shown in formula (2). The aromatic ring may be either a monocyclic or polycyclic ring, with a monocyclic ring being preferred. The aromatic ring may be either an aromatic hydrocarbon ring or an aromatic heterocyclic ring, with an aromatic hydrocarbon ring being preferred. Specific examples of the aromatic hydrocarbon ring are as described above, with a benzene ring or a naphthalene ring being preferred, and a benzene ring being more preferred. Examples of heteroatoms contained in the aromatic heterocyclic ring are as described above, with a nitrogen atom, a sulfur atom, or an oxygen atom being preferred. Specific examples of the aromatic heterocyclic ring are as described above, with a thiophene ring, a furan ring, a thiazole ring, or a pyridine ring being preferred.

[0073] Examples of the substituent that the aromatic ring may have include the substituents exemplified above for the substituent W. More specifically, examples include an aliphatic hydrocarbon group that may have a substituent, an aryl group that may have a substituent, a heterocyclic group that may have a substituent, a silyl group, and a halogen atom, and an aliphatic hydrocarbon group that may have a substituent is preferred. ５ The types of the substituents are as follows: ５ Cy may be the same as or different from the group represented by R ５ In addition, when further substituents are present, R ５ The number of substituents other than R is preferably 1 to 4, more preferably 1 or 2. ５ In the case where Cy has a further substituent other than R ６ It is also preferable that the compound represented by formula (2) has a substituent on the carbon atom adjacent to the carbon atom at the bonding position to the benzene ring substituted with . That is, it is also preferable that the compound represented by formula (2) is a compound represented by formula (2-1).

[0074]

[0075] In formula (2-1), R １ , R ２ , A １ , A ２, R ５ , and R ６ is R in formula (2). １ , R ２ , A １ , A ２ , R ５ , and R ６ It is the same as Cy ２ represents an aromatic ring containing 3 or more carbon atoms and which may have a substituent. ２ The three carbon atoms contained in R are the three carbon atoms specified in formula (2). The preferred embodiment of the aromatic ring is the same as the aromatic ring represented by Cy in formula (2). ７ represents a substituent. ７ Preferred embodiments of the substituent represented by R ５ It is the same as R ７ is R ５ It is also preferable that the group is the same as

[0076]

[0062] Examples of the substituent that may be possessed by each of the groups given as specific examples of the substituent that may be possessed by the aromatic ring represented by Cy include the substituents exemplified by the substituent W described above, and a substituent selected from the substituent group S described above is preferred.

[0077] The aliphatic hydrocarbon group exemplified as a substituent that the aromatic ring represented by Cy may have includes an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group being preferred. The definitions and preferred embodiments of the alkyl group, alkenyl group, and alkynyl group are the same as those of the alkyl group, alkenyl group, and alkynyl group in the above-mentioned substituent group S. It is also preferred that the alkyl group, alkenyl group, and alkynyl group be branched.

[0078] The definitions and preferred embodiments of the aryl group, heterocyclic group, silyl group, and halogen atom exemplified as the substituent that the aromatic ring represented by Cy may have are the same as those of the aryl group, heterocyclic group, and silyl group in the above-mentioned substituent group S.

[0079] The substituent that the aromatic ring represented by Cy may have is also preferably a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, and a silyl group.

[0080] In formula (2), R ５ represents an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, a silyl group, or a halogen atom, and is preferably an aliphatic hydrocarbon group. ５ The definitions and preferred embodiments of the optionally substituted aliphatic hydrocarbon group, the optionally substituted aryl group, the optionally substituted heterocyclic group, the silyl group, and the halogen atom represented by the following formula (I) are the same as those of the groups exemplified as the substituents that the aromatic ring represented by Cy may have. ５ is also preferably a substituent selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, and a silyl group.

[0081] In formula (2), R ６ represents a hydrogen atom or a substituent, and is preferably a substituent in that the effects of the present invention are more excellent. ６ Examples of the substituent represented by the formula (I) include the substituents exemplified by the substituent W described above. More specifically, the substituents include halogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, cyano groups, alkoxy groups, aryloxy groups, and silyl groups. The alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, alkoxy groups, and aryloxy groups may have a substituent. Examples of the substituent include the substituents exemplified by the substituent W described above, and a substituent selected from the substituent group S described above is preferred. R ６ The definition and preferred embodiments of the substituent represented by the formula ａ１ is the same as each of the groups exemplified as the substituent represented by the formula:

[0082] R ６Among these, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or a silyl group is preferable, and an alkyl group or an aryl group which may have a substituent is more preferable.

[0083] In formula (2), A １ and A ２ each independently represents a group represented by formula (C-1) or a group represented by formula (C-2). Formula (C-1) and formula (C-2) are as described above. A １ and A ２ As the group represented by formula (C-2), a group represented by formula (C-2) is preferred in terms of achieving better effects of the present invention.

[0084] Specific examples of the specific compound are shown below, but the present invention is not limited to these.

[0085]

[0086]

[0087] In the specific compounds exemplified above, A represents any of the following groups: In addition, two A's present in the specific compounds exemplified above may be the same or different.

[0088]

[0089]

[0090]

[0091] B in the specific compounds exemplified above represents any of the following groups: Note that two B's present in the specific compounds exemplified above may be the same or different.

[0092]

[0093]

[0094] The molecular weight of the specific compound is preferably 300 to 1200, more preferably 350 to 1000, and even more preferably 400 to 800. When the molecular weight is within the above range, the sublimation temperature of the specific compound is lowered, and it is presumed that the specific compound has excellent suitability for production.

[0095] The specific compound preferably has an ionization potential of −5.0 to −6.0 eV in a single film from the viewpoints of stability when used as a p-type organic semiconductor and matching of the energy level with an n-type organic semiconductor.

[0096] The maximum absorption wavelength of the specific compound is preferably in the wavelength range of 400 to 600 nm, more preferably in the range of 450 to 580 nm. The maximum absorption wavelength is a value measured in a solution state (solvent: chloroform) after adjusting the absorption spectrum of the specific compound to a concentration such that the absorbance is 0.5 to 1.0. However, if the specific compound is insoluble in chloroform, the maximum absorption wavelength of the specific compound is determined by evaporating the specific compound and measuring the value using the specific compound in a film state.

[0097] The specific compound is particularly useful as a material for a photoelectric conversion film used in an imaging device, an optical sensor, or a photovoltaic cell. The specific compound often functions as a dye in the photoelectric conversion film. The specific compound can also be used as a coloring material, a liquid crystal material, an organic semiconductor material, a charge transport material, a pharmaceutical material, and a fluorescent diagnostic material.

[0098] The specific compound may be purified as necessary. Examples of methods for purifying the specific compound include sublimation purification, purification using silica gel column chromatography, purification using gel permeation chromatography, reslurry washing, reprecipitation purification, purification using an adsorbent such as activated carbon, and recrystallization purification.

[0099] The content of the specific compound in the photoelectric conversion film (=film thickness of the specific compound in terms of a single layer / film thickness of the photoelectric conversion film × 100) is not particularly limited, but is preferably 5 to 75% by volume, more preferably 10 to 50% by volume, and even more preferably 15 to 40% by volume. Only one type of specific compound may be used, or two or more types may be used. When two or more types are used, it is preferable that the total amount thereof is in the above range.

[0100] <n-Type Organic Semiconductor> The photoelectric conversion film preferably contains an n-type organic semiconductor in addition to the specific compound. The n-type organic semiconductor is a compound different from the specific compound. The n-type organic semiconductor is an acceptor organic semiconductor material (compound) and refers to an organic compound that has the property of easily accepting electrons. In other words, the n-type organic semiconductor refers to the organic compound that has a larger electron affinity when two organic compounds are used in contact with each other. In other words, any organic compound can be used as the acceptor organic semiconductor as long as it is an organic compound with electron-accepting properties. Examples of n-type organic semiconductors include fullerenes selected from the group consisting of fullerenes and derivatives thereof; fused aromatic carbon ring compounds (e.g., naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, and fluoranthene derivatives); 5- to 7-membered heterocyclic compounds having at least one selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom (e.g., pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, and thiazole). ), polyarylene compounds; fluorene compounds; cyclopentadiene compounds; silyl compounds; 1,4,5,8-naphthalenetetracarboxylic dianhydride; 1,4,5,8-naphthalenetetracarboxylic diimide derivatives; anthraquinodimethane derivatives; diphenylquinone derivatives; bathocuproine, bathophenanthroline, and derivatives thereof; triazole compounds; distyrylarylene derivatives; metal complexes having a nitrogen-containing heterocyclic compound as a ligand; silole compounds; 3,4,9,10-perylenetetracarboxylic dianhydride; 3,4,9,10-perylenetetracarboxylic diimide derivatives; and the compounds described in paragraphs

[0056] to

[0057] of JP-A No. 2006-100767.

[0101] As the n-type organic semiconductor (compound), fullerenes selected from the group consisting of fullerenes and derivatives thereof are preferred. For example, fullerene C ６０ , fullerene C ７０, fullerene C ７６ , fullerene C ７８ , fullerene C ８０ , fullerene C ８２ , fullerene C ８４ , fullerene C ９０ , fullerene C ９６ , fullerene C ２４０ , fullerene C ５４０ and mixed fullerenes. Examples of fullerene derivatives include compounds in which a substituent is added to the above-mentioned fullerenes. The substituent is preferably an alkyl group, an aryl group, or a heterocyclic group. Preferred fullerene derivatives are the compounds described in JP-A-2007-123707.

[0102] The molecular weight of the n-type organic semiconductor is preferably 200 to 1,200, more preferably 200 to 900.

[0103] The maximum absorption wavelength of the n-type organic semiconductor is preferably 400 nm or less or in the range of 500 to 600 nm.

[0104] The photoelectric conversion film preferably has a bulk heterostructure formed in a state in which a specific compound and an n-type organic semiconductor are mixed. The bulk heterostructure is a layer in the photoelectric conversion film in which a specific compound and an n-type organic semiconductor are mixed and dispersed. The photoelectric conversion film having a bulk heterostructure can be formed by either a wet method or a dry method. The bulk heterostructure is described in detail in paragraphs

[0013] to

[0014] of JP 2005-303266 A.

[0105] The difference in electron affinity between the specific compound and the n-type organic semiconductor is preferably 0.1 eV or more.

[0106] When the photoelectric conversion film contains an n-type organic semiconductor, the content of the n-type organic semiconductor in the photoelectric conversion film (thickness of the n-type organic semiconductor in terms of a single layer / thickness of the photoelectric conversion film × 100) is preferably 15 to 75 vol%, more preferably 20 to 60 vol%, and still more preferably 20 to 50 vol%.

[0107] When the n-type organic semiconductor contains fullerenes, the content of the fullerenes relative to the total content of the n-type organic semiconductors (film thickness of fullerenes converted into a single layer / total film thickness of each n-type organic semiconductor converted into a single layer × 100) is preferably 50 to 100% by volume, more preferably 80 to 100% by volume. Fullerenes may be used singly or in combination of two or more types.

[0108] In terms of the response speed of the photoelectric conversion element, the content of the specific compound relative to the total content of the specific compound and the n-type organic semiconductor (film thickness in monolayer equivalent of the specific compound / (film thickness in monolayer equivalent of the specific compound + film thickness in monolayer equivalent of the n-type organic semiconductor) x 100) is preferably 20 to 80% by volume, more preferably 40 to 80% by volume. When the photoelectric conversion film contains an n-type organic semiconductor and a p-type organic semiconductor, the content of the specific compound (film thickness in monolayer equivalent of the specific compound / (film thickness in monolayer equivalent of the specific compound + film thickness in monolayer equivalent of the n-type organic semiconductor + film thickness in monolayer equivalent of the p-type organic semiconductor) x 100) is preferably 10 to 75% by volume, more preferably 15 to 50% by volume. It is preferable that the photoelectric conversion film is substantially composed of the specific compound, the n-type organic semiconductor, and a p-type organic semiconductor that is included as desired. "Substantially" means that the total content of the specific compound, n-type organic semiconductor, and p-type organic semiconductor relative to the total mass of the photoelectric conversion film is 90 to 100% by volume, preferably 95 to 100% by volume, and more preferably 99 to 100% by volume.

[0109] <p-Type Organic Semiconductor> The photoelectric conversion film preferably contains a p-type organic semiconductor in addition to the specific compound. The p-type organic semiconductor is a compound different from the specific compound. The p-type organic semiconductor is a donor organic semiconductor material (compound) and refers to an organic compound that has the property of easily donating electrons. In other words, the p-type organic semiconductor refers to the organic compound that has a smaller ionization potential when two organic compounds are used in contact with each other. The p-type organic semiconductor may be used alone or in combination of two or more types.

[0110] Examples of p-type organic semiconductors include triarylamine compounds (e.g., N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), 4,4'-bis[N-(naphthyl)-N-phenyl-amino]biphenyl (α-NPD), compounds described in paragraphs

[0128] to

[0148] of JP-A No. 2011-228614, compounds described in paragraphs

[0052] to

[0063] of JP-A No. 2011-176259, compounds described in paragraphs

[0119] to

[0158] of JP-A No. 2011-225544, compounds, compounds described in paragraphs

[0044] to

[0051] of JP-A No. 2015-153910, and compounds described in paragraphs

[0086] to

[0090] of JP-A No. 2012-094660, etc.), pyrazoline compounds, styrylamine compounds, hydrazone compounds, polysilane compounds, thiophene compounds (for example, thienothiophene derivatives, dibenzothiophene derivatives, benzodithiophene derivatives, dithienothiophene derivatives, [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives, thieno[3,2-f:4,5-f']bis[1] Benzothiophene (TBBT) derivatives, compounds described in paragraphs

[0031] to

[0036] of JP2018-014474A, compounds described in paragraphs

[0043] to

[0045] of WO2016 / 194630A, compounds described in paragraphs

[0025] to

[0037] and

[0099] to

[0109] of WO2017 / 159684A, compounds described in paragraphs

[0029] to

[0034] of JP2017-076766A, compounds described in paragraphs

[0015] to

[0025] of WO2018 / 207722A, and compounds described in paragraph [00 45] to

[0053] , compounds described in paragraphs

[0045] to

[0055] of WO2019 / 058995, compounds described in paragraphs

[0063] to

[0089] of WO2019 / 081416, compounds described in paragraphs

[0033] to

[0036] of JP2019-80052A, compounds described in paragraphs

[0044] to

[0054] of WO2019 / 054125, compounds described in paragraphs

[0041] to

[0046] of WO2019 / 093188, compounds described in paragraphs

[0034] to

[0037] of JP2019-050398A,Compounds described in paragraphs

[0033] to

[0036] of JP-A No. 2018-206878, compounds described in paragraph

[0038] of JP-A No. 2018-190755, compounds described in paragraphs

[0019] to

[0021] of JP-A No. 2018-026559, compounds described in paragraphs

[0031] to

[0056] of JP-A No. 2018-170487, compounds described in paragraphs

[0036] to

[0041] of JP-A No. 2018-166200 Compounds described in paragraphs

[0055] to

[0082] of JP-A No. 2018-113425, compounds described in paragraphs

[0041] to

[0050] of JP-A No. 2018-113425, compounds described in paragraphs

[0044] to

[0048] of JP-A No. 2018-085430, compounds described in paragraphs

[0041] to

[0045] of JP-A No. 2018-056546, compounds described in paragraphs

[0042] to

[0049] of JP-A No. 2018-046267, and paragraphs of JP-A No. 2018-014474

[0031] to

[0036] compounds described in paragraphs

[0036] to

[0046] of WO2018 / 016465, and compounds described in paragraphs

[0045] to

[0048] of JP-A-2020-010024, etc.), cyanine compounds, oxonol compounds, polyamine compounds, indole compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, fused aromatic carbocyclic compounds (e.g., naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pentacene derivatives, pyrene derivatives, perylene derivatives, and fluoranthene derivatives), porphyrin compounds, phthalocyanine compounds, triazole compounds, oxadiazole compounds, imidazole compounds, polyarylalkane compounds, pyrazolone compounds, amino-substituted chalcone compounds, oxazole compounds, fluorenone compounds, silazane compounds, and metal complexes having a nitrogen-containing heterocyclic compound as a ligand. Examples of p-type organic semiconductors include benzoxazole compounds (for example, compounds described in Figures 3 to 7 of JP-A-2022-123944), dicarbazole compounds (for example, compounds described in Figures 2 to 5 of JP-A-2022-122839), benzoquinazoline compounds (for example, compounds described in paragraphs

[0053] to

[0056] of JP-A-2022-120323),Azine compounds (for example, compounds described in paragraphs

[0041] to

[0042] of JP-A No. 2022-120273), compounds described in Figures 2 to 10 of JP-A No. 2022-115832, indolotriphenylene compounds (for example, compounds described in paragraphs

[0065] to

[0072] of JP-A No. 2022-108268), indolocarbazole compounds (for example, compounds described in paragraphs

[0052] to [00 73] and the compounds described in paragraph

[0028] of JP-A No. 2022-100258), triscarbazolylphenyl compounds (for example, the compounds described in paragraphs

[0038] to

[0040] of JP-A No. 2022-181226), the compounds described in paragraphs

[0070] to

[0082] of JP-A No. 2022-027575, and the compounds described in paragraphs

[0051] to

[0064] of JP-A No. 2021-163968. Examples of p-type organic semiconductors include compounds having a smaller ionization potential than n-type organic semiconductors, and if this condition is met, the organic dyes exemplified as n-type organic semiconductors can be used. Examples of compounds that can be used as p-type organic semiconductor compounds are listed below.

[0111]

[0112]

[0113]

[0114]

[0115] The difference in ionization potential between the specific compound and the p-type organic semiconductor is preferably 0.1 eV or more.

[0116] When the photoelectric conversion film contains a p-type organic semiconductor, the content of the p-type organic semiconductor in the photoelectric conversion film (thickness of the p-type organic semiconductor in terms of a single layer / thickness of the photoelectric conversion film × 100) is preferably 15 to 75 vol%, more preferably 20 to 60 vol%, and still more preferably 25 to 50 vol%.

[0117] The photoelectric conversion film containing the specific compound is a non-luminescent film and has characteristics different from those of an organic electroluminescent device (OLED: Organic Light Emitting Diode). A non-luminescent film means a film having a luminescence quantum efficiency of 1% or less, preferably 0.5% or less, more preferably 0.1% or less. The lower limit is often 0% or more.

[0118] <Dye> The photoelectric conversion film preferably contains a dye in addition to the specific compound. The dye is a compound different from the specific compound. The dye is preferably an organic dye. Examples of the organic dye include cyanine dyes, styryl dyes, hemicyanine dyes, merocyanine dyes (including zeromethine merocyanine (simple merocyanine)), rhodacyanine dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squarylium dyes, croconium dyes, azamethine dyes, coumarin dyes, arylidene dyes, anthraquinone dyes, triphenylmethane dyes, azo dyes, azomethine dyes, metallocene dyes, fluorenone dyes, fulgide dyes, perylene dyes, phenazine dyes, phenothiazine dyes, quinone dyes, diphenylmethane dyes, polyene dyes, acridine dyes, and benzophenone dyes. Examples of the dye include clidinone dyes, diphenylamine dyes, quinophthalone dyes, phenoxazine dyes, phthaloperylene dyes, dioxane dyes, porphyrin dyes, chlorophyll dyes, phthalocyanine dyes, subphthalocyanine dyes, metal complex dyes, imidazoquinoxaline dyes described in WO 2020 / 013246, WO 2022 / 168856, JP 2023-010305, and JP 2023-010299, acceptor-donor-acceptor type dyes in which two acidic nuclei are bonded to a donor, and donor-acceptor-donor type dyes in which two donors are bonded to an acceptor. Among these, cyanine dyes, imidazoquinoxaline dyes, or acceptor-donor-acceptor type dyes are preferred in terms of maximum absorption wavelength, etc.

[0119] The maximum absorption wavelength of the dye is preferably in the visible light region, more preferably in the wavelength range of 400 to 650 nm, and even more preferably in the wavelength range of 450 to 650 nm.

[0120] The content of the dye relative to the total content of the specific compound and the dye in the photoelectric conversion film (= (film thickness of the dye in terms of a single layer / (film thickness of the specific compound in terms of a single layer+film thickness of the dye in terms of a single layer)×100)) is preferably 5 to 75 vol%, more preferably 5 to 60 vol%, and still more preferably 5 to 50 vol%.

[0121] <Film formation method> Examples of the film formation method for the photoelectric conversion film include dry film formation methods. Examples of dry film formation methods include physical vapor deposition methods such as vapor deposition (particularly vacuum deposition), sputtering, ion plating, and MBE (Molecular Beam Epitaxy), as well as CVD (Chemical Vapor Deposition) methods such as plasma polymerization, and vacuum deposition methods are preferred. When forming the photoelectric conversion film by vacuum deposition, manufacturing conditions such as the degree of vacuum and deposition temperature can be set according to conventional methods.

[0122] The thickness of the photoelectric conversion film is preferably from 10 to 1,000 nm, more preferably from 50 to 800 nm, and even more preferably from 50 to 500 nm.

[0123] [Electrodes] The photoelectric conversion element preferably has electrodes. The electrodes (upper electrode (transparent conductive film) 15 and lower electrode (conductive film) 11) are made of a conductive material. Examples of conductive materials include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Since light is incident through the upper electrode 15, it is preferable that the upper electrode 15 is transparent to the light to be detected. Examples of materials constituting the upper electrode 15 include conductive metal oxides such as tin oxide doped with antimony or fluorine (ATO: Antimony Tin Oxide, FTO: Fluorine-doped Tin Oxide), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO: Indium Tin Oxide), and indium zinc oxide (IZO); metal thin films such as gold, silver, chromium, and nickel; mixtures or laminates of these metals and conductive metal oxides; and organic conductive materials such as polyaniline, polythiophene, and polypyrrole; and nanocarbon materials such as carbon nanotubes and graphene. Of these, conductive metal oxides are preferred in terms of high conductivity and transparency.

[0124] Typically, when the conductive film is made thinner than a certain range, the resistance value often increases rapidly. In a solid-state imaging device incorporating a photoelectric conversion element according to this embodiment, the sheet resistance may be 100 to 10,000 Ω / □, and there is a wide degree of freedom in the range of film thickness that can be reduced. Furthermore, the thinner the upper electrode (transparent conductive film) 15, the less light it absorbs, and generally the higher the light transmittance. An increase in light transmittance is desirable because it increases light absorption in the photoelectric conversion film and enhances photoelectric conversion performance. Considering the suppression of leakage current, the increase in the resistance value of the thin film, and the increase in transmittance that accompany a reduction in film thickness, the thickness of the upper electrode 15 is preferably 5 to 100 nm, and more preferably 5 to 20 nm.

[0125] Depending on the application, the lower electrode 11 may be made transparent or may be made non-transparent and reflect light. Examples of materials constituting the lower electrode 11 include conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); metals such as gold, silver, chromium, nickel, titanium, tungsten, and aluminum; conductive compounds such as oxides or nitrides of these metals (e.g., titanium nitride (TiN)); mixtures or laminates of these metals and conductive metal oxides; organic conductive materials such as polyaniline, polythiophene, and polypyrrole; and carbon materials such as carbon nanotubes and graphene.

[0126] The method for forming the electrodes can be appropriately selected depending on the electrode material. Specific examples include wet methods such as printing and coating; physical methods such as vacuum deposition, sputtering, and ion plating; and chemical methods such as CVD and plasma CVD. When the electrode material is ITO, examples include electron beam methods, sputtering, resistance heating deposition, chemical reaction methods (such as the sol-gel method), and coating of a dispersion of indium tin oxide.

[0127] [Charge-blocking film: electron-blocking film, hole-blocking film] The photoelectric conversion element preferably has one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film. Examples of the intermediate layer include a charge-blocking film. When the photoelectric conversion element has this film, the properties (quantum efficiency, response speed, etc.) of the resulting photoelectric conversion element are more excellent. Examples of the charge-blocking film include an electron-blocking film and a hole-blocking film.

[0128] <Electron Blocking Film> The electron blocking film is a donor organic semiconductor material (compound), and the above-mentioned p-type organic semiconductor can be used. Polymer materials can also be used as the electron blocking film. Examples of polymer materials include polymers of phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, as well as derivatives thereof.

[0129] The electron blocking film may be composed of multiple films. The electron blocking film may be composed of an inorganic material. In general, inorganic materials have a higher dielectric constant than organic materials, so when an inorganic material is used for the electron blocking film, a higher voltage is applied to the photoelectric conversion film, resulting in higher quantum efficiency. Examples of inorganic materials that can be used for the electron blocking film include calcium oxide, chromium oxide, chromium copper oxide, manganese oxide, cobalt oxide, nickel oxide, copper oxide, gallium copper oxide, strontium copper oxide, niobium oxide, molybdenum oxide, indium copper oxide, indium silver oxide, and iridium oxide.

[0130] <Hole-Blocking Film> The hole-blocking film is an acceptor organic semiconductor material (compound), and the n-type organic semiconductors described above can be used. The hole-blocking film may be composed of multiple films.

[0131] Examples of methods for producing a charge blocking film include dry film formation and wet film formation. Examples of dry film formation methods include vapor deposition and sputtering. Vapor deposition may be either physical vapor deposition (PVD) or chemical vapor deposition (CVD), with physical vapor deposition such as vacuum deposition being preferred. Examples of wet film formation methods include inkjet printing, spray printing, nozzle printing, spin coating, dip coating, casting, die coating, roll coating, bar coating, and gravure coating, with the inkjet method being preferred in terms of high-precision patterning.

[0132] The thickness of each of the charge blocking films (electron blocking film and hole blocking film) is preferably from 3 to 200 nm, more preferably from 5 to 100 nm, and even more preferably from 5 to 30 nm.

[0133] [Substrate] The photoelectric conversion element may further include a substrate. Examples of the substrate include a semiconductor substrate, a glass substrate, and a plastic substrate. The substrate is usually positioned such that a conductive film, a photoelectric conversion film, and a transparent conductive film are stacked in this order on the substrate.

[0134] [Sealing Layer] The photoelectric conversion element may further have a sealing layer. The performance of photoelectric conversion materials may be significantly degraded in the presence of degrading factors such as water molecules. Therefore, the degradation can be prevented by covering and sealing the entire photoelectric conversion film with a sealing layer made of ceramics such as dense metal oxides, metal nitrides, or metal nitride oxides, or diamond-like carbon (DLC), which do not allow water molecules to penetrate. Examples of sealing layers include those described in paragraphs

[0210] to

[0215] of JP 2011-082508 A, the contents of which are incorporated herein by reference.

[0135] [Method for manufacturing photoelectric conversion element] Examples of methods for manufacturing photoelectric conversion elements include known manufacturing methods. Specifically, for example, methods for manufacturing photoelectric conversion elements include a step of forming a conductive film on a substrate, a step of forming a photoelectric conversion film, and a step of forming a transparent conductive film. The method for manufacturing a photoelectric conversion element may include other steps (for example, a step of forming a charge blocking film and a step of forming a sealing layer) in addition to the above. The method for forming each layer is as described above.

[0136] [Imaging element] An example of an application of a photoelectric conversion element is an imaging element. An imaging element is an element that converts the optical information of an image into an electrical signal, and typically has multiple photoelectric conversion elements arranged in a matrix on the same plane, with each photoelectric conversion element (pixel) converting the optical signal into an electrical signal and outputting the electrical signal pixel by pixel from the imaging element. For this reason, each pixel is composed of one or more photoelectric conversion elements and one or more transistors. The manufacturing method of an imaging element is not particularly limited, but examples include a method including the step of manufacturing the photoelectric conversion element described above.

[0137] [Optical Sensor] Other applications of the photoelectric conversion element include, for example, a photocell and an optical sensor, and the photoelectric conversion element of the present invention is preferably used as an optical sensor. As an optical sensor, the photoelectric conversion element may be used alone, or may be used as a line sensor in which the photoelectric conversion elements are arranged linearly or as a two-dimensional sensor in which the photoelectric conversion elements are arranged on a plane.

[0138] [Compound] The present invention also includes inventions of specific compounds.

[0139] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0140] [Compounds used in photoelectric conversion film] The materials used in the photoelectric conversion film are shown below.

[0141] [Synthesis of Compound (1)] Compound (1) was synthesized according to the following scheme.

[0142]

[0143] <Synthesis of Intermediate (1-2)> A 1 mol / L zinc chloride tetrahydrofuran solution (30 mL, 30.0 mmol) was added dropwise to a 1 mol / L ethylmagnesium bromide tetrahydrofuran solution (30 mL, 30.0 mmol) cooled to 0°C, and the reaction solution was then warmed to room temperature and stirred for 30 minutes. Compound (1-1) (510 mg, 2.07 mmol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct (411 mg, 0.50 mmol) were then added to the reaction solution to obtain a mixed solution. The mixed solution was reacted at 80°C for 3 hours, then cooled to 0°C, quenched by the addition of water (10 mL), and extracted with ethyl acetate (100 mL). The resulting organic phase was washed with 25% by mass brine (100 mL), dried over magnesium sulfate, and filtered. The resulting filtrate was concentrated under reduced pressure. The crude product obtained by vacuum concentration was purified using silica gel column chromatography (eluent: hexane:ethyl acetate=49:1 to 19:1) and dried under reduced pressure to obtain intermediate (1-2) (510 mg, yield 42%).

[0144] <Synthesis of Intermediate (1-3)> A mixture of intermediate (1-2) (510 mg, 2.07 mmol) and tetrahydrofuran (41 mL) was cooled to -78°C, and 2.6 mol / L n-butyllithium (2.35 mL, 6.21 mmol) was added dropwise. After stirring the reaction mixture at -78°C for 1 hour, N,N-dimethylformamide (0.80 mL, 10.4 mmol) was added, and the temperature was raised to 0°C. Water (10 mL) and then 1 mol / L hydrochloric acid (10 mL) were added to quench the reaction, and the mixture was extracted with dichloromethane (100 mL). The resulting organic phase was washed with 15% by mass brine (50 mL), dried over magnesium sulfate, filtered, and the resulting filtrate was concentrated under reduced pressure. The crude product obtained by vacuum concentration was purified using silica gel column chromatography (eluent: dichloromethane) and dried under reduced pressure to obtain intermediate (1-3) (520 mg, yield 83%).

[0145] <Synthesis of Compound (1)> Intermediate (1-3) (250 mg, 0.83 mmol), 1,3-dimethylbarbituric acid (336 mg, 2.15 mmol), toluene (25 mL), and piperidine (16.4 μL, 0.17 mmol) were mixed to obtain a mixed solution. The mixed solution was stirred at 100°C for 4 hours and then allowed to cool to room temperature. The precipitated solid was separated by filtration, and the crude product was dispersed and washed with toluene. The obtained solid was dried under reduced pressure at 200°C and then purified by sublimation to obtain 451 mg of compound (1) (yield 94%). The structure of compound (1) was confirmed by LDI-MS as follows. LDI-MS (compound (1)): 578 (M+)

[0146] [Synthesis of Compound (8)] Compound (8) was synthesized according to the following scheme.

[0147]

[0148] Synthesis of Intermediate (8-2) Compound (1-1) (3.2 g, 6.58 mmol), 2,6-dimethylphenylboronic acid (3.8 g, 25.3 mmol), cesium carbonate (12 g, 36.8 mmol), cyclopentyl methyl ether (64 mL), and water (16 mL) were added to obtain a mixture. After degassing the mixture, the atmosphere was returned to nitrogen, and SPhos Pd G3 ((2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl)[2-(2'-amino-1,1'-biphenyl)]palladium(II) methanesulfonate, 250 mg, 0.32 mmol) was added, followed by a reaction at 110°C for 2 hours. The mixture was then cooled to room temperature and extracted with water (50 mL) and ethyl acetate (200 mL). The resulting organic phase was washed with 25% by mass brine (100 mL), dried over sodium sulfate, and then filtered. The resulting filtrate was concentrated under reduced pressure. The crude product obtained by concentration under reduced pressure was purified using silica gel column chromatography (eluent: dichloromethane only) and dried under reduced pressure to obtain intermediate (8-2) (2.26 g, yield 89%).

[0149] <Synthesis of Intermediate (8-3) and Compound (8)> Intermediate (8-3) was synthesized according to the synthesis method of Intermediate (1-3), and Compound (8) was synthesized according to the synthesis method of Compound (1). The structure of Compound (8) was confirmed by LDI-MS as follows. LDI-MS (Compound (8)): 730 (M+)

[0150] The compounds used in the photoelectric conversion film in each of the Examples and Comparative Examples other than Compound (1) and Compound (8) were synthesized according to the synthesis method of Compound (1) and Compound (8).

[0151] [Specific Compounds] The specific compounds used in the photoelectric conversion film and comparative compounds for comparison are shown below. Note that compounds (1) to (12) are specific compounds, and compounds (R-1) to (R-6) are comparative compounds.

[0152]

[0153] [n-type organic semiconductor] C60: fullerene (C ６０ )

[0154] [p-type organic semiconductor]

[0155]

[0156] [Evaluation] The photoelectric conversion element was evaluated for quantum efficiency when receiving blue-green light (wavelength 450 nm), response speed, electric field strength dependency of response speed, and manufacturability by the following methods.

[0157] [Fabrication of Photoelectric Conversion Element] A photoelectric conversion element having the configuration shown in FIG. 2 was fabricated using the various components shown above. Here, the photoelectric conversion element comprises a lower electrode 11, an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15. Specifically, amorphous ITO was formed on a glass substrate by sputtering to form a lower electrode 11 (thickness: 30 nm), and compound (EB-1) was further formed on the lower electrode 11 by vacuum heating deposition to form an electron blocking film 16A (thickness: 30 nm). Subsequently, with the glass substrate at room temperature, each specific compound or each comparative compound shown in Table 1 and an n-type organic semiconductor (fullerene (C ６０)) and a p-type organic semiconductor (P-1) were co-deposited by vacuum deposition to form a film having a thickness of 80 nm in terms of a single layer. This resulted in a photoelectric conversion film 12 having a bulk heterostructure of 240 nm. At this time, the film formation rate of the photoelectric conversion film 12 was 1.0 Å / sec. Furthermore, a compound (EB-2) was deposited on the photoelectric conversion film 12 to form a hole blocking film 16B (thickness: 10 nm). Amorphous ITO was deposited on the hole blocking film 16B by sputtering to form an upper electrode 15 (transparent conductive film) (thickness: 10 nm). After a SiO film was formed as a sealing layer on the upper electrode 15 by vacuum deposition, aluminum oxide (Al ２ O ３ The resulting laminate was heated in a glove box at 150° C. for 30 minutes to obtain a photoelectric conversion element.

[0158]

[0159] [Dark Current] The dark current of each of the obtained photoelectric conversion elements was measured by the following method. ５ A voltage was applied to the photoelectric conversion element so as to obtain an electric field strength of 50 nA / cm. The current value in a dark place (dark current) was measured. As a result, the dark current was 50 nA / cm for all the photoelectric conversion elements. ２ It was confirmed that the dark current was sufficiently low.

[0160] [Quantum Efficiency] The quantum efficiency of each photoelectric conversion element was measured when blue-green light was received by the following method. ５ After applying a voltage to achieve an electric field strength of 1000 V / cm, light was irradiated from the upper electrode (transparent conductive film) side to evaluate the quantum efficiency (photoelectric conversion efficiency) at a wavelength of 450 nm, and the quantum efficiency (relative ratio) was calculated according to formula (S1). From the obtained value, the quantum efficiency was evaluated according to the following evaluation criteria. In practical terms, the quantum efficiency is preferably evaluated as C or higher. Formula (S1): Quantum efficiency (relative ratio) = (photoelectric conversion efficiency of each photoelectric conversion element) / (photoelectric conversion efficiency of the photoelectric conversion element of Example 5)

[0161] A: Quantum efficiency (relative ratio) is 1.2 or more. B: Quantum efficiency (relative ratio) is 1.0 or more and less than 1.2. C: Quantum efficiency (relative ratio) is 0.8 or more and less than 1.0. D: Quantum efficiency (relative ratio) is less than 0.8.

[0162] [Response Speed] The response speed of each photoelectric conversion element when blue-green light was received was evaluated by the following method. ５ A voltage was applied so as to achieve an electric field strength of 1000 V / cm. Thereafter, an LED (light emitting diode) was momentarily turned on to irradiate light from the upper electrode (transparent conductive film) side, and the photocurrent at a wavelength of 450 nm at that time was measured with an oscilloscope to measure the rise time from 0% signal intensity to 97% signal intensity, and the relative response speed was calculated according to formula (S2). From the obtained value, the response speed was evaluated according to the following evaluation criteria. In practical terms, the response speed is preferably evaluated as C or higher. Formula (S2): Relative response speed = (rise time of each photoelectric conversion element) / (rise time of the photoelectric conversion element of Example 5)

[0163] A: Relative response speed is less than 1.0 B: Relative response speed is 1.0 or more and less than 1.5 C: Relative response speed is 1.5 or more and less than 2.0 D: Relative response speed is 2.0 or more

[0164] [Dependence of response speed on electric field strength] The dependence of the response speed on electric field strength when blue-green light was received was evaluated for each photoelectric conversion element by the following method. In the evaluation of the response speed, a voltage of 7.5×10 was applied to each photoelectric conversion element. ４ The same procedure was followed except that the pressure was changed to 7.5 × 10 ４ The rise time at 7.5 V / cm was measured. The electric field strength dependency of the response speed was calculated according to formula (S3), and the electric field strength dependency of the response speed was evaluated according to the following evaluation criteria. In formula (S3), the numerator and denominator are values ​​measured for the photoelectric conversion element of the same Example or Comparative Example. In practice, the electric field strength dependency of the response speed is preferably evaluated as C or higher. Formula (S3): Electric field strength dependency of response speed = (applied voltage of each photoelectric conversion element 7.5 × 10 ４ V / cm) / (applied voltage of each photoelectric conversion element 3.0×10５ rise time in V / cm)

[0165] A: The electric field strength dependency of the response speed is less than 3.0. B: The electric field strength dependency of the response speed is 3.0 or more and less than 4.0. C: The electric field strength dependency of the response speed is 4.0 or more and less than 5.0. D: The electric field strength dependency of the response speed is 5.0 or more.

[0166] [Manufacturing Suitability] The manufacturability of each photoelectric conversion element was evaluated using the following method. Photoelectric conversion elements (B) of each Example or Comparative Example were fabricated using the same procedure as in the above [Fabrication of Photoelectric Conversion Element], except that the deposition rate of the photoelectric conversion film 12 was set to 3.0 Å / sec. The quantum efficiency (photoelectric conversion efficiency) of the resulting photoelectric conversion element (B) was measured using the same method as in the above [Quantum Efficiency]. The photoelectric conversion element obtained in the above [Fabrication of Photoelectric Conversion Element], in which the deposition rate of the photoelectric conversion film 12 was 1.0 Å / sec, was designated as photoelectric conversion element (A), and the relative ratio B / A of the quantum efficiency (photoelectric conversion efficiency) was calculated according to formula (S4). From the obtained value, the manufacturability was evaluated according to the following evaluation criteria. In formula (S4), the photoelectric conversion element (B) and the photoelectric conversion element (A) in the numerator and denominator were photoelectric conversion elements fabricated using the same material. The closer the value of the relative ratio B / A is to 1, the less the performance of the photoelectric conversion element is likely to deteriorate even when the film formation rate is increased, i.e., the better the manufacturability. In practical terms, a manufacturability rating of C or higher is preferable. Formula (S4): Relative ratio B / A = (photoelectric conversion efficiency of photoelectric conversion element (B)) / (photoelectric conversion efficiency of photoelectric conversion element (A))

[0167] A: The relative ratio B / A is 0.90 or more. B: The relative ratio B / A is 0.85 or more and less than 0.90. C: The relative ratio B / A is 0.80 or more and less than 0.85. D: The relative ratio B / A is less than 0.80.

[0168] [Results] The evaluation results are shown in Table 1 below. In the table, the column "Formula (1), Formula (2)" indicates "A" when the photoelectric conversion element contains a specific compound represented by formula (1) or formula (2), and indicates "B" otherwise. In the table, the column "Formula (A-2)" indicates the specific compound A. １ and A ２is a group represented by formula (A-2), it is marked as "A", and in other cases it is marked as "B". In the table, the column "Formula (C-1), Formula (C-2)" indicates the value of A for a specific compound. １ and A ２ is a group represented by formula (C-1), it is designated as "(C-1)", and when it is a group represented by formula (C-2), it is designated as "(C-2)".

[0169]

[0170] From the results shown in Table 1, it was confirmed that the photoelectric conversion element of the present invention has an excellent response speed when receiving blue-green light and has a small dependency of the response speed on the electric field strength. It was also confirmed that the photoelectric conversion element of the present invention has an excellent quantum efficiency when receiving blue-green light and is also excellent in manufacturability.

[0171] From a comparison of Examples 6 and 7 with Examples 1 to 5, it is found that in formula (1), A １ and A ２ is a group represented by formula (A-2), the effects of the present invention are more excellent. １ and A ２ is a group represented by formula (C-2), it has been confirmed that the effects of the present invention are more excellent, and the quantum efficiency and manufacturability are more excellent. ｃ３ ~X ｃ５ It was confirmed that when is an oxygen atom, the manufacturing suitability is better. From a comparison between Example 8 and Example 11, it was confirmed that when the compound represented by formula (2) is a compound represented by formula (2-1), the quantum efficiency and response speed when blue-green light is received are better.

[0172] 10a, 10b Photoelectric conversion element 11 Conductive film (lower electrode) 12 Photoelectric conversion film 15 Transparent conductive film (upper electrode) 16A Electron blocking film 16B Hole blocking film

Claims

1. A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, wherein the photoelectric conversion film contains at least one compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2). 【Chemistry 1】 In formula (1), R １ and R ２ Each of these independently represents a hydrogen atom or a substituent. X １ and X ２ Each of these is independently -CR ａ１ = or represents a nitrogen atom. R ａ１ represents a hydrogen atom or substituent. R ３ and R ４ Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 5 or fewer carbon atoms. A １ and A ２ each independently represents a group represented by the formula (A-1). In the formula (A-1), * represents a bonding position. In formula (A-1), C １ This represents a ring containing two or more carbon atoms, which may have substituents. W １ This consists of a sulfur atom, an oxygen atom, and =NR Ｗ２ or = CR Ｗ３ R Ｗ４ It represents. R Ｗ２ represents a hydrogen atom or a substituent. R Ｗ３ and R Ｗ４ These are, independently, a cyano group and -SO ２ R Ｗ５ , -COOR Ｗ６ or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ Each of these independently represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aromatic ring group, or an optionally substituted aliphatic heterocyclic group. In formula (2), R １ and R ２ Each of these independently represents a hydrogen atom or a substituent. Cy represents an aromatic ring containing two or more carbon atoms, which may have substituents. R ５ This represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aryl group, an optionally substituted heterocyclic group, a silyl group, or a halogen atom. R ６ represents a hydrogen atom or substituent. A １ and A ２ Each of these independently represents either the group represented by formula (C-1) or the group represented by formula (C-2). In equation (C-1), * indicates the bonding position. X ｃ１ and X ｃ２ These are, independently, an oxygen atom, a sulfur atom, or =C(CN) ２ It represents. C ３ This represents an aromatic ring that may have substituents. In equation (C-2), * indicates the bonding position. X ｃ３ ~X ｃ５ Each of these independently represents either an oxygen atom or a sulfur atom. R ｃ１ and R ｃ２ Each of these independently represents a hydrogen atom or a substituent.

2. The photoelectric conversion element according to claim 1, wherein the group represented by formula (A-1) is the group represented by formula (A-2). 【Chemistry 2】 In equation (A-2), * indicates the bonding position. C ２ This represents a ring containing three or more carbon atoms, which may have substituents. W ２ and W ３ These are, independently, an oxygen atom, a sulfur atom, and =NR Ｗ２ , or =CR Ｗ３ R Ｗ４ It represents. R Ｗ２ represents a hydrogen atom or a substituent. R Ｗ３ and R Ｗ４ These are, independently, a cyano group and -SO ２ R Ｗ５ , -COOR Ｗ６ or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ Each of these independently represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aromatic ring group, or an optionally substituted aliphatic heterocyclic group.

3. The photoelectric conversion element according to claim 2, wherein the group represented by formula (A-2) is the group represented by formula (C-1) or the group represented by formula (C-2).

4. The photoelectric conversion film further comprises an n-type organic semiconductor, The photoelectric conversion element according to any one of claims 1 to 3, wherein the photoelectric conversion film has a bulk heterostructure formed by mixing the compound represented by formula (1) and the n-type organic semiconductor.

5. The photoelectric conversion element according to claim 4, wherein the n-type organic semiconductor comprises fullerenes selected from the group consisting of fullerenes and their derivatives.

6. The photoelectric conversion element according to any one of claims 1 to 3, wherein the photoelectric conversion film further comprises a p-type organic semiconductor.

7. The photoelectric conversion element according to any one of claims 1 to 3, wherein the photoelectric conversion film further comprises a dye.

8. A photoelectric conversion element according to any one of claims 1 to 3, wherein the conductive film and the transparent conductive film are interposed between them, and one or more intermediate layers in addition to the photoelectric conversion film.

9. An image sensor having a photoelectric conversion element according to any one of claims 1 to 3.

10. A light sensor having a photoelectric conversion element according to any one of claims 1 to 3.

11. A method for manufacturing an image sensor, comprising the step of manufacturing a photoelectric conversion element according to any one of claims 1 to 3.

12. A compound represented by formula (1) or formula (2). 【Transformation 3】 In formula (1), R １ and R ２ Each of these independently represents a hydrogen atom or a substituent. X １ and X ２ Each of these is independently -CR ａ１ = or represents a nitrogen atom. R ａ１ represents a hydrogen atom or substituent. R ３ and R ４ Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 5 or fewer carbon atoms. A １ and A ２ Each of these independently represents a group represented by formula (A-1). In formula (A-1), * represents a bond position. In formula (A-1), C １ This represents a ring containing two or more carbon atoms, which may have substituents. W １ This consists of a sulfur atom, an oxygen atom, and =NR Ｗ２ or = CR Ｗ３ R Ｗ４ It represents. R Ｗ２ represents a hydrogen atom or a substituent. R Ｗ３ and R Ｗ４ These are, independently, a cyano group and -SO ２ R Ｗ５ , -COOR Ｗ６ or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ Each of these independently represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aromatic ring group, or an optionally substituted aliphatic heterocyclic group. In formula (2), R １ and R ２ Each of these independently represents a hydrogen atom or a substituent. Cy represents an aromatic ring containing two or more carbon atoms, which may have substituents. R ５ This represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aryl group, an optionally substituted heterocyclic group, a silyl group, or a halogen atom. R ６ represents a hydrogen atom or substituent. A １ and A ２ Each of these independently represents either the group represented by formula (C-1) or the group represented by formula (C-2). In equation (C-1), * indicates the bonding position. X ｃ１ and X ｃ２ These are, independently, an oxygen atom, a sulfur atom, or =C(CN) ２ It represents. C ３ This represents an aromatic ring that may have substituents. In equation (C-2), * indicates the bonding position. X ｃ３ ~X ｃ５ Each of these independently represents either an oxygen atom or a sulfur atom. R ｃ１ and R ｃ２ each independently represents a hydrogen atom or a substituent.

13. The compound according to claim 12, wherein the group represented by formula (A-1) is the group represented by formula (A-2). 【Chemistry 4】 In equation (A-2), * indicates the bonding position. C ２ This represents a ring containing three or more carbon atoms, which may have substituents. W ２ and W ３ each independently represents an oxygen atom, a sulfur atom, =NR Ｗ２ , or =CR Ｗ３ R Ｗ４ represents. R Ｗ２ represents a hydrogen atom or a substituent. R Ｗ３ and R Ｗ４ These are, independently, a cyano group and -SO ２ R Ｗ５ , -COOR Ｗ６ or -COR Ｗ７ Represents R Ｗ５ ~R Ｗ７ Each of these independently represents an optionally substituted aliphatic hydrocarbon group, an optionally substituted aromatic ring group, or an optionally substituted aliphatic heterocyclic group.

14. The compound according to claim 13, wherein the group represented by formula (A-2) is the group represented by formula (C-1) or the group represented by formula (C-2).

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