Photoelectric conversion elements, imaging elements, optical sensors, compounds

Abstract

The present invention provides a photoelectric conversion element that has excellent manufacturing suitability and excellent photoelectric conversion efficiency with respect to light in a wide wavelength range. The present invention also provides an imaging element, a photosensor, and a compound. This photoelectric conversion element has an electroconductive film, a photoelectric conversion film, and a transparent electroconductive film in the stated order, the photoelectric conversion film containing a compound represented by formula (1).

Description

[Technical Field]

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

[0002] In recent years, development of elements having a photoelectric conversion film has progressed. For example, Patent Document 1 discloses a photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, in which the photoelectric conversion film contains a compound represented by the following formula (1):

[0003] [ka] [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 013246 Summary of the Invention [Problem to be solved by the invention]

[0005] There are various characteristics required for photoelectric conversion elements. For example, in recent years, there has been a demand for photoelectric conversion films that have good photoelectric conversion characteristics for light in a wide wavelength range. The present inventors prepared a photoelectric conversion element using the compound disclosed in Patent Document 1, evaluated the obtained photoelectric conversion element, and found that there was room for improvement in the photoelectric conversion efficiency for light in a wide wavelength range (for example, 500 to 600 nm). Furthermore, due to requirements in product manufacturing, photoelectric conversion elements are required to have excellent manufacturability so that the photoelectric conversion characteristics do not deteriorate even when the deposition rate is increased when forming the photoelectric conversion film.

[0006] In view of the above circumstances, an object of the present invention is to provide a photoelectric conversion element that has excellent photoelectric conversion efficiency for light in a wide wavelength range and is easy to manufacture. Another object of the present invention is to provide an imaging element and an optical sensor including the photoelectric conversion element, and a compound applicable to the photoelectric conversion element. [Means for solving the problem]

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a compound having a predetermined structure in a photoelectric conversion film, and have thus completed the present invention. Specifically, the present invention has been completed by adopting the following configuration.

[0008] [1] A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, The photoelectric conversion element, wherein the photoelectric conversion film contains a compound represented by formula (1). [ka] In formula (1), Ar represents an aromatic ring which may have a substituent. R 1 and R 2 each independently represents a hydrogen atom or a substituent. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by formula (Q1). In formula (Q1), * represents a bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q B represents a nitrogen atom, a group represented by formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. A 1 is a molecule consisting of two carbon atoms and Q B and represents a ring which may have a substituent and contains at least one of the following. B 1 is one carbon atom and Q A and Q B and represents a ring which may have a substituent and contains at least one of the following. [ka] In formula (C), * C1 ~* C3 represents the binding position. [2] The photoelectric conversion element according to [1], wherein the compound represented by the formula (1) is a compound represented by the formula (2). [ka] In formula (2), R 1 and R 2 each independently represents a hydrogen atom or a substituent. R a1 and R a2each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1). X 1 ~X 4 each independently represents a nitrogen atom or -CR c1 = represents. R c1 represents a hydrogen atom or a substituent. R c1 If there are multiple R c1 may be bonded to each other to form a ring. [3] The photoelectric conversion element according to [1] or [2], wherein the compound represented by the formula (1) is a compound represented by the formula (3). [ka] In formula (3), R 1 ~R 4 each independently represents a hydrogen atom or a substituent. R 3 and R 4 may be bonded to each other to form a ring. R a1 and Ra2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1). [4] The photoelectric conversion element according to any one of [1] to [3], wherein the compound represented by the formula (1) is a compound represented by the formula (4). [ka] In formula (4), R 1 , R 2 , R 5 , and R 6 each independently represents a hydrogen atom or a substituent. R 5 and R 6 may be bonded to each other to form a ring. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~RL3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1). E 1 is a nitrogen atom or -CR E1 = R E1 represents a hydrogen atom or a substituent. E 2 is a nitrogen atom or -CR E2 = R E2 represents a hydrogen atom or a substituent. [5] The photoelectric conversion element according to any one of [1] to [4], wherein Q represents a group represented by formula (Q2). [ka] In formula (Q2), * represents the bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q B represents a nitrogen atom, a group represented by the above formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. Q Z represents a hydrogen atom or a substituent. B 1 is one carbon atom and Q A and Q Band represents a ring which may have a substituent and contains at least one of the following. [6] The photoelectric conversion element according to any one of [1] to [5], wherein Q represents a group represented by formula (Q3). [ka] In formula (Q3), * represents the bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q Z represents a hydrogen atom or a substituent. B 2 is one carbon atom, one nitrogen atom and Q A and represents a ring which may have a substituent and contains at least one of the following. [7] the photoelectric conversion film further contains an n-type organic semiconductor, The photoelectric conversion element according to any one of [1] to [6], wherein the photoelectric conversion film has a bulk heterostructure formed by mixing the compound represented by formula (1) with the n-type organic semiconductor. [8] The photoelectric conversion element according to [7], wherein the n-type organic semiconductor contains a fullerene selected from the group consisting of fullerenes and derivatives thereof. [9] The photoelectric conversion element according to [7] or [8], wherein the photoelectric conversion film further contains a p-type organic semiconductor.

[10] The photoelectric conversion element according to any one of [1] to [9], further comprising one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film.

[11] An imaging device having the photoelectric conversion element according to any one of [1] to

[10] .

[12] An optical sensor having the photoelectric conversion element according to any one of [1] to

[10] .

[13] A compound represented by formula (1). [ka] In formula (1), Ar represents an aromatic ring which may have a substituent. R 1 and R 2 each independently represents a hydrogen atom or a substituent. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by formula (Q1). In formula (Q1), * represents a bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q B represents a nitrogen atom, a group represented by formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. A 1 is a molecule consisting of two carbon atoms and Q B and represents a ring which may have a substituent and contains at least one of the following. B1 is one carbon atom and Q A and Q B and represents a ring which may have a substituent and contains at least one of the following. [ka] In formula (C), * C1 ~* C3 represents the binding position.

[14] The compound according to

[13] , wherein the compound represented by formula (1) is a compound represented by formula (2). [ka] In formula (2), R 1 and R 2 each independently represents a hydrogen atom or a substituent. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1). X 1 ~X 4each independently represents a nitrogen atom or -CR c1 = represents. R c1 represents a hydrogen atom or a substituent. R c1 If there are multiple R c1 may be bonded to each other to form a ring.

[15] The compound according to

[13] or

[14] , wherein the compound represented by formula (1) is a compound represented by formula (3). [ka] In formula (3), R 1 ~R 4 each independently represents a hydrogen atom or a substituent. R 3 and R 4 may be bonded to each other to form a ring. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1).

[16] The compound according to any one of

[13] to

[15] , wherein the compound represented by the formula (1) is a compound represented by the formula (4). [ka] In formula (4), R 1 , R 2 , R 5 , and R 6 each independently represents a hydrogen atom or a substituent. R 5 and R 6 may be bonded to each other to form a ring. R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the above formula (Q1). E 1 is a nitrogen atom or -CR E1 = R E1 represents a hydrogen atom or a substituent. E 2 is a nitrogen atom or -CR E2 = R E2 represents a hydrogen atom or a substituent.

[17] The compound according to any one of

[13] to

[16] , wherein Q represents a group represented by formula (Q2). [ka] In formula (Q2), * represents the bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q B represents a nitrogen atom, a group represented by the above formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. Q Z represents a hydrogen atom or a substituent. B 1 is one carbon atom and Q A and Q B and represents a ring which may have a substituent and contains at least one of the following.

[18] The compound according to any one of

[13] to

[17] , wherein Q represents a group represented by formula (Q3). [ka] In formula (Q3), * represents the bonding position. Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. Q Z represents a hydrogen atom or a substituent. B 2 is one carbon atom, one nitrogen atom and Q A and represents a ring which may have a substituent and contains at least one of the following. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a photoelectric conversion element that has excellent photoelectric conversion efficiency for light in a wide wavelength range and is easy to manufacture. The present invention also provides an imaging element and an optical sensor including the photoelectric conversion element, and a compound applicable to the photoelectric conversion element. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view showing a configuration example of a photoelectric conversion element. [Figure 2] FIG. 2 is a cross-sectional view showing a configuration example of a photoelectric conversion element. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the photoelectric conversion element of the present invention will be described below.

[0012] In this specification, unless otherwise specified, examples of the "substituent" include the groups exemplified as the substituent W described below.

[0013] (substituent W) The substituent W in this specification will be described. Examples of the substituent W include a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (including a cycloalkyl group, a bicycloalkyl group, or a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), an alkynyl group, an aryl group, a heteroaryl group (which may also be called a heterocyclic group), a cyano group, a nitro group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, a diaryloxy group, a cycloalkyl group, a cycloalkenyl group, a cycloalkyl group, a bicycloalkenyl group, a cycloalkyl group, a cycloalkenyl group, a bicycloalkenyl group, a cycloalkyl ... Examples of the W substituent include primary or tertiary amino groups (including anilino groups), alkylthio groups, arylthio groups, heterocyclic thio groups, alkyl or arylsulfinyl groups, alkyl or arylsulfonyl groups, acyl groups, aryloxycarbonyl groups, alkoxycarbonyl groups, aryl or heterocyclic azo groups, imido groups, phosphino groups, phosphinyl groups, phosphinyloxy groups, phosphinylamino groups, phosphono groups, silyl groups, carboxy groups, phosphate groups, sulfonic acid groups, hydroxy groups, thiol groups, acylamino groups, carbamoyl groups, ureido groups, boronic acid groups, and primary amino groups. Each of the above groups may further have a substituent (e.g., one or more of the above groups) if possible. For example, an alkyl group that may have a substituent is also included as one form of the substituent W. 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. It is also preferable that the specific compound does not have 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 a primary amino group as a substituent.

[0014] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0015] In this specification, unless otherwise specified, the alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms. 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 i-propyl group, an n-butyl group, a t-butyl group, an n-hexyl group, and a cyclopentyl group. The alkyl group may be, for example, a cycloalkyl group, a bicycloalkyl group, or a tricycloalkyl group, and may have these cyclic structures as partial structures. In the alkyl group which may have a substituent, the substituent which the alkyl group may have is not particularly limited, and examples thereof include the substituent W, and 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.

[0016] In this specification, unless otherwise specified, the alkyl group moiety in an alkoxy group is preferably the above-mentioned alkyl group, and the alkyl group moiety in an 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 substituents 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 substituents in the alkyl group which may have a substituent.

[0017] 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 which the alkenyl group may have include the same as the substituent 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 which the alkynyl group may have are the same as those of the substituent in the alkyl group which may have a substituent.

[0018] In this specification, unless otherwise specified, an optionally substituted silyl group is, for example, —Si(R S1 )(R S2 )(R S3 ) is an example of a group represented by R S1 , R S2 , and R S3 each independently represents a hydrogen atom or a substituent, and preferably represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkylthio group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent.

[0019] In this specification, unless otherwise specified, the aromatic ring may be monocyclic or polycyclic (for example, 2 to 6 rings). A monocyclic aromatic ring is an aromatic ring having only one aromatic ring structure as a ring structure. A polycyclic (for example, 2 to 6 rings) aromatic ring is an aromatic ring having a plurality of (for example, 2 to 6) condensed aromatic ring structures as a ring structure. The aromatic ring preferably has 5 to 15 ring atoms. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. 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, and a phenanthrene ring. Examples of the aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring (such as a 1,2,3-triazine ring, a 1,2,4-triazine ring, or a 1,3,5-triazine ring), a tetrazine ring (such as 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 3H-pyrrolidine ring, a pyrroloimidazole ring (such as a 5H-pyrrolo[1,2-a]imidazole ring), an imidazooxazole ring (such as an imidazo[2,1-b]oxazole ring), and the like. thiazolo ring, etc.), thienothiazole ring (thieno[2,3-d]thiazole ring, etc.), benzothiadiazole ring, benzodithiophene ring (benzo[1,2-b:4,5-b']dithiophene ring, etc.), thienothiophene ring (thieno[3,2-b]thiophene ring, etc.), thiazolothiazole ring (thiazolo[5,4-d]thiazole ring, etc.), naphthodithiophene ring (naphtho[2,3-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. In the aromatic ring which may have a substituent, the type of the substituent which the aromatic ring may have is not particularly limited, and examples thereof include a substituent W. When the aromatic ring has a substituent, the number of the substituents may be 1 or more (for example, 1 to 4). In this specification, the term "aromatic ring group" refers to, for example, a group obtained by removing one or more (for example, 1 to 5) hydrogen atoms from the above-mentioned aromatic ring. In this specification, the term "aryl group" includes, for example, a group obtained by removing one hydrogen atom from a ring that corresponds to an aromatic hydrocarbon ring among the above aromatic rings. In this specification, the term "heteroaryl group" refers to, for example, a group obtained by removing one hydrogen atom from a ring corresponding to an aromatic heterocycle among the above aromatic rings. In this specification, the term "arylene group" refers to, for example, a group obtained by removing two hydrogen atoms from a ring corresponding to an aromatic hydrocarbon ring among the above aromatic rings. As used herein, the term "heteroarylene group" refers to, for example, a group formed by removing two hydrogen atoms from a ring corresponding to an aromatic heterocycle among the above aromatic rings. In the aromatic ring group which may have a substituent, the aryl group which may have a substituent, the heteroaryl group which may have a substituent, the arylene group which may have a substituent, and the heteroarylene group which may have a substituent, the type of substituent that these groups may have is not particularly limited, and examples thereof include the substituent W. When these groups which may have a substituent have a substituent, the number of the substituents may be 1 or more (for example, 1 to 4).

[0020] In this specification, when a formula (general 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 same symbols may be the same or different, unless otherwise specified. In this specification, when a formula (general formula) showing a chemical structure contains a plurality of groups of the same type (such as alkyl groups), the specific details of the plurality of groups of the same type are independent of each other, and the specific details of the groups of the same type may be the same or different.

[0021] The bonding direction of a divalent group (e.g., -CO-O-) represented herein is not limited unless otherwise specified. For example, when Y in a compound represented by the general formula "XYZ" is -CO-O-, the compound may be "XO-CO-Z" or "X-CO-OZ."

[0022] In this specification, with respect to a compound 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.

[0023] In addition, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower limit and upper limit.

[0024] In this specification, when there are a plurality of substituents, linking groups, etc. (hereinafter referred to as "substituents, etc.") represented by a specific symbol, or when a plurality of substituents, etc. are simultaneously specified, it 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.

[0025] In this specification, the hydrogen atom may be a protium atom (normal hydrogen atom) or a deuterium atom (such as a deuterium atom).

[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 a compound represented by formula (1) described below (hereinafter also referred to as a "specific compound"). The mechanism by which the photoelectric conversion element of the present invention having such a configuration can solve the above problems is not entirely clear, but the present inventors speculate as follows. That is, the specific compound has a relatively large substituent (R in formula (1)) on a predetermined nitrogen atom. a1 and R a2) bonded to the specific compound, crystallization of the specific compound can be suppressed even when heated. Therefore, even when the deposition rate is increased when producing a photoelectric conversion film, there is little deterioration in photoelectric conversion efficiency, which is thought to have improved manufacturability. In addition, because the acceptor portion (the group represented by Q in formula (1)) of the specific compound has a specific structure, it is possible for it to absorb light of a wide wavelength range, and it is thought that this has also improved photoelectric conversion efficiency for light of a wide wavelength range. Furthermore, the photoelectric conversion element of the present invention has good response. Hereinafter, a photoelectric conversion element having better photoelectric conversion efficiency for light in a wide wavelength range, better manufacturability, and / or better responsiveness will also be referred to as having "better effects of the present invention."

[0027] FIG. 1 shows a cross-sectional view of one embodiment of the photoelectric conversion element of the present invention. The photoelectric conversion element 10a shown in Figure 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 described later, 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.

[0028] In the photoelectric conversion element 10a (or 10b), it is preferable that light be 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 -5 ~1×10 7From the viewpoint of performance and power consumption, it is preferable to apply a voltage of 1×10 V / cm. -4 ~1×10 7 V / cm is more preferable, and 1×10 -3 ~5×10 6 V / cm is more preferred. 1 and 2, the voltage is preferably applied so that the electron blocking film 16A side serves as the cathode and the photoelectric conversion film 12 side serves as the anode. When the photoelectric conversion element 10a (or 10b) is used as an optical sensor 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.

[0029] 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 film is a film containing a specific compound. The specific compounds are described in detail below.

[0031] <Compound represented by formula (1) (specific compound)> The photoelectric conversion film of the photoelectric conversion element of the present invention contains a specific compound. The specific compound is a compound represented by formula (1).

[0032] [ka]

[0033] In formula (1), R 1 and R 2 each independently represents a hydrogen atom or a substituent. R 1 and R 2 are each independently preferably a hydrogen atom.

[0034] In formula (1), R a1 and R a2each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent.

[0035] The aryl group is preferably a phenyl group, a naphthyl group, or a fluorenyl group, and more preferably a phenyl group or a naphthyl group. When the aryl group is a phenyl group, the phenyl group preferably has a substituent, and the substituents are each independently an alkyl group (preferably having 1 to 3 carbon atoms). When the aryl group is a phenyl group, the phenyl group preferably has 1 to 5 substituents, more preferably 2 or 3 substituents.

[0036] -C(R L1 )(R L2 )(R L3 ) in R L1 ~R L3 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R L1 ~R L3 At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. L1 ~R L3 The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. For example, alkyl groups which may have substituents may be bonded to each other to form a ring. Substituents in an aryl group which may have substituents and alkyl groups which may have substituents may be bonded to each other to form a ring. Substituents in a heteroaryl group which may have substituents and alkyl groups which may have substituents may be bonded to each other to form a ring. Substituents in an aryl group which may have substituents and substituents in another aryl group which may have substituents may be bonded to each other to form a ring. Substituents in an aryl group which may have substituents and substituents in a heteroaryl group which may have substituents may be bonded to each other to form a ring. Substituents in a heteroaryl group which may have substituents and substituents in another heteroaryl group which may have substituents may be bonded to each other to form a ring. The ring thus formed may further have a substituent, or a substituent on the formed ring may be bonded to another alkyl group which may have a substituent, a substituent on another aryl group which may have a substituent, or a substituent on another heteroaryl group which may have a substituent to form a further ring. As described above, the group formed by bonding a substituent to another substituent (for example, a substituent in an aryl group which may have a substituent and a substituent in a heteroaryl group which may have a substituent) may be a single bond. In addition, R L1 ~R L3 When an optionally substituted alkyl group, an optionally substituted aryl group, and an optionally substituted heteroaryl group are bonded to each other to form a ring, -C(R L1 )(R L2 )(R L3 ) is preferably other than an aryl group or a heteroaryl group.

[0037] R L1 ~R L3 The alkyl groups represented by R may each independently be linear, branched, or cyclic. L1~R L3 In the alkyl group represented by the formula: wherein two alkyl groups are preferably bonded to each other to form a ring. More specifically, for example, R L1 and an alkyl group represented by R L2 and an alkyl group represented by R L1 and an alkyl group represented by R L2 and a substituent on a ring (such as a monocyclic cycloalkane ring) formed by bonding together alkyl groups represented by R L3 and alkyl groups represented by the following formula (I) may be bonded to each other to form a polycycle (eg, a polycyclic cycloalkane ring). That is, -C(R L1 )(R L2 )(R L3 ) may be a cycloalkyl group (preferably a cyclohexyl group) which may have a substituent. The cycloalkyl group preferably has 3 to 12 membered rings, more preferably 5 to 8 membered rings, and even more preferably 6 membered rings. The cycloalkyl group may be monocyclic (such as a cyclohexyl group) or polycyclic (such as a 1-adamantyl group). The cycloalkyl group preferably has a substituent. When the cycloalkyl group has a substituent, the carbon atom directly bonded to the nitrogen atom (i.e., "-C(R L1 )(R L2 )(R L3 Preferably, the carbon atom adjacent to the "C" atom specified in ")" has a substituent. Examples of the substituent that the cycloalkyl group may have include alkyl groups (preferably having 1 to 3 carbon atoms). Substituents on the cycloalkyl group may be bonded to each other to form a ring, and the ring formed by bonding the substituents to each other may be a ring other than a cycloalkane ring.

[0038] R a1 and R a2 are each independently a group represented by formula (X), -C(R L1 )(R L2)(R L3 ), a polycyclic aryl group which may have a substituent, or a polycyclic heteroaryl group which may have a substituent. Among these, R is preferred because it has better manufacturing suitability for the photoelectric conversion element of the present invention. a1 and R a2 are each independently a group represented by formula (X), -C(R L1 )(R L2 )(R L3 ), or a polycyclic aryl group which may have a substituent. The group represented by formula (X) is preferably a group represented by formula (Z) described later, and more preferably a group represented by formula (ZB) described later.

[0039] The group represented by formula (X) is the group shown below.

[0040] [ka] In formula (X), C 1 is R d1 represents a monocyclic aromatic ring which may have a substituent other than the above. R d1 represents an alkyl group, a silyl group, an alkoxy group, an alkylthio group, a cyano group, a halogen atom, an aryl group, a heteroaryl group, an alkenyl group, or an alkynyl group. If possible, these groups may further have a substituent.

[0041] Examples of the monocyclic aromatic ring include a monocyclic aromatic hydrocarbon ring and a monocyclic aromatic heterocycle. Examples of the aromatic hydrocarbon ring include a benzene ring. Examples of the aromatic heterocycle include a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, and a thiazole ring. Among these, aromatic hydrocarbon rings are preferred, and benzene rings are more preferred, in that the heat resistance of the photoelectric conversion element is superior.

[0042] R d1The alkyl group represented by the formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. R d1 The silyl group represented by the following formula preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and further preferably 3 carbon atoms. R d1 The alkoxy group represented by the following formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. R d1 The alkylthio group represented by the following formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. R d1 Examples of the halogen atom represented by the formula (I) include a fluorine atom, an iodine atom, a bromine atom, and a chlorine atom. R d1 The alkenyl group represented by the following formula (I) preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 or 3 carbon atoms. R d1 The alkynyl group represented by the following formula preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 or 3 carbon atoms.

[0043] R d1 and C 1 may be bonded to each other to form a non-aromatic ring. * indicates the bond position. 1 The aromatic ring of is directly bonded to the nitrogen atom specified in formula (1).

[0044] The group represented by formula (X) is preferably a group represented by formula (Z).

[0045] [ka]

[0046] In formula (Z), T 1 ~T 4 are each independently -CR e12 = or nitrogen atom (=N-). e12 represents a hydrogen atom or a substituent.

[0047] "T 1 ~T 4 At least one of the is -CR e12 = and R e12 represents a substituent group," and "at least one of T 4 Ga-CR e12 = and T 4 R in e12 represents an alkyl group, an aryl group, or a heteroaryl group. R e12 The substituent represented by the formula (I) is preferably an alkyl group, an aryl group, a heteroaryl group, a silyl group, a halogen atom, or a cyano group. These groups may further have a substituent (for example, a halogen atom such as a fluorine atom). R e12 The alkyl group represented by the formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. R e12 The silyl group represented by the formula: d1 Examples of the silyl group include the silyl groups described above as the silyl group represented by the following formula: R e12 Examples of the halogen atom represented by the formula (I) include a fluorine atom, an iodine atom, a bromine atom, and a chlorine atom. In addition, R in formula (Z) e12 If there are multiple e12 may be the same or different from each other.

[0048] In formula (Z), R f2 represents an alkyl group, a silyl group, an alkoxy group, an alkylthio group, a cyano group, a halogen atom, an aryl group, a heteroaryl group, an alkenyl group, or an alkynyl group, and R in formula (X) d1 The same applies to the preferable conditions. Also, R f2 And, T 1 R in e12 may be bonded to each other to form a non-aromatic ring. R f2The alkyl group represented by the formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms.

[0049] The group represented by formula (X) is more preferably a group represented by formula (ZB). [ka]

[0050] In formula (ZB), T 1 ~T 3 are each independently -CR e12 = or nitrogen atom. R e12 represents a hydrogen atom or a substituent. R in formula (ZB) e12 is R in formula (Z). e12 is the same as:

[0051] In formula (ZB), R f3 and R f4 each independently represents an alkyl group, an aryl group, or a heteroaryl group. If possible, these groups may further have a substituent. * indicates the bond position. R f3 and R f4 The alkyl group represented by the formula (I) preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms.

[0052] The number of rings constituting the polycyclic aryl group which may have a substituent and the polycyclic heteroaryl group which may have a substituent is 2 or more, preferably 2 to 4, more preferably 2 to 3, and still more preferably 2. The polycyclic aryl group which may have a substituent and the substituent which the polycyclic heteroaryl group which may have a substituent may contain a non-aromatic ring. A preferred example of the polycyclic aryl group which may have a substituent is a naphthyl group which may have a substituent.

[0053] In formula (1), Ar represents an aromatic ring which may have a substituent. Among these, Ar is preferably an aromatic heterocycle, more preferably a quinoxaline ring or a pyrazine ring. The substituent that the aromatic ring represented by Ar may have is preferably an alkyl group which may have a substituent, a chlorine atom, a fluorine atom, or a cyano group.

[0054] In formula (1), Q represents a group represented by formula (Q1).

[0055] [ka]

[0056] In formula (Q1), * represents a bonding position. That is, the compound represented by formula (1) is the same as the compound represented by formula (1a). Each symbol in the following formula (1a) has the same meaning as the corresponding symbol in formula (1) and formula (Q1).

[0057] [ka]

[0058] In formula (Q1), Q A is a nitrogen atom (-N=) or -CQ X = represents Q X represents a hydrogen atom or a substituent. Among them, Q A is preferably a nitrogen atom.

[0059] In formula (Q1), Q B is a nitrogen atom (-N<), a group represented by formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. Among them, Q B is preferably a nitrogen atom or a group represented by formula (C), more preferably a nitrogen atom.

[0060] [ka] In formula (C), * C1 ~* C3 represents the binding position. Among them, * C1 But Q in equation (Q1) A and the carbon atom bonded to it by a double bond (A 1 and B 1 and a carbon atom which is a member atom of both rings) are preferably bonded to the ring. Also,* C2 However, A, which will be described later 1 and B 1 and * is the bonding position to one of the ring atoms in the ring represented by C3 However, A, which will be described later 1 and B 1 Preferably, the bond is to the other ring atom in the ring represented by the formula:

[0061] In formula (Q1), A 1 is a molecule consisting of two carbon atoms and Q B The two carbon atoms represent the carbon atoms specified in the formula. A 1 The ring represented by the formula (I) may be a monocyclic ring or a polycyclic ring, an aromatic ring or a non-aromatic ring, or a ring formed by condensing an aromatic ring and a non-aromatic ring. A 1 The number of ring atoms in the ring represented by the formula: is preferably 5 to 15, more preferably 5 to 9, and still more preferably 5. A 1 The ring represented by the formula (I) may have heteroatoms (nitrogen atoms, oxygen atoms, and / or sulfur atoms, etc.) as ring member atoms, and preferably has 1 to 5 heteroatoms, more preferably 1 to 2 heteroatoms, and even more preferably 2 heteroatoms. The number of heteroatoms here is Q B This number also includes the number of nitrogen atoms that can be expressed as:

[0062] Among them, A 1The ring represented by the formula (II) is preferably a ring containing a linking group represented by the formula (AA) or (AB), and more preferably a ring containing a linking group represented by the formula (AA). * V -CR Q1 =N-* W (AA) * V -Arylene group-* W (AB) In formulas (AA) and (AB), * V represents the bonding position relative to the root carbon atom in formula (Q1). The root carbon atom is R 1 means the carbon atom in formula (Q1) that is double bonded to the carbon atom bonded to In formulas (AA) and (AB), * W Q B represents the bonding position relative to In formula (AA), R Q1 represents a hydrogen atom or a substituent. Q1 The substituent represented by the formula (I) is preferably a fluorine atom, a chlorine atom, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. The arylene group in formula (AB) is preferably a group obtained by removing hydrogen atoms from two adjacent ring atoms of an aromatic hydrocarbon ring. The arylene group may have a substituent. The arylene group is preferably a 1,2-phenylene group.

[0063] In formula (Q2), B 1 is one carbon atom and Q A and Q B and represents a ring which may have a substituent and contains at least one of the following. B 1 The ring represented by the formula (I) may be a monocyclic ring or a polycyclic ring, an aromatic ring or a non-aromatic ring, or a ring formed by condensing an aromatic ring and a non-aromatic ring. B 1 The number of ring atoms in the ring represented by the formula (I) is preferably 5 to 15, more preferably 5 to 9, and even more preferably 5 or 6. B 1The ring represented by the formula (I) may have heteroatoms (nitrogen atoms, oxygen atoms, and / or sulfur atoms, etc.) as ring member atoms, and preferably has 1 to 5 heteroatoms, more preferably 2 to 3 heteroatoms. A and Q B This number also includes the number of nitrogen atoms that can be expressed as:

[0064] Among them, B 1 The ring represented by the formula (I) is preferably a ring containing a linking group represented by the formula (BA) or (BB) below. However, when the linking group is a linking group represented by formula (BA), Q B is a nitrogen atom or -CQ Y < When the linking group is a linking group represented by formula (BB), Q B is a group represented by the above formula (C). * X -(CO) m -T-(CO) n -* Y (BA) * X -X=YZ=* Y (BB) In formulas (BA) and (BB), * X Q A represents the bonding position relative to In formulas (BA) and (BB), * Y Q B represents the bonding position relative to In formula (BA), m and n each independently represent 0 or 1. In formula (BA), T is -CR Q2 =CR Q2 -, -CR Q2 =N-, -N=N-, -NR Q2 -, -O-, or -C(R Q2 )2-. R Q2 represents a hydrogen atom or a substituent. Q2 The substituent represented by the formula (I) is preferably a cyano group, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group. Q2=CR Q2 -Two R's in Q2 may be bonded to each other to form a ring (for example, an aromatic ring). -CR Q2 The nitrogen atom (=N-) in =N- is * X * Y It may be present on the side. In formula (BB), X, Y, and Z each independently represent -CR Q3 = or -N=, -CR Q3 = is preferred. R Q3 represents a hydrogen atom or a substituent. Q3 The substituent represented by the formula (I) is preferably a fluorine atom, a chlorine atom, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent.

[0065] Q in formula (1) preferably represents a group represented by formula (Q2).

[0066] [ka]

[0067] In formula (Q2), * represents the bonding position. In formula (Q2), Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. In formula (Q2), Q B represents a nitrogen atom, a group represented by formula (C), or -CQ Y < Q Y represents a hydrogen atom or a substituent. The group represented by formula (C) is as described above. In the group represented by formula (Q2), Q B is a group represented by formula (C), * in formula (C) C2 is B 1 The bond position is relative to a ring atom in the ring represented by the formula: In formula (Q2), B 1 is one carbon atom and QA and Q B The one carbon atom represents a ring containing at least one of the following groups, which may have a substituent: A and Q B It means the carbon atom sandwiched between and. Q in equation (Q2) A , Q B , and B 1 is Q in equation (Q1) A , Q B , and B 1 The same applies to the preferred conditions. In formula (Q2), Q Z represents a hydrogen atom or a substituent. Q Z The substituent represented by the formula (I) is preferably a fluorine atom, a chlorine atom, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent.

[0068] More preferably, Q in formula (1) represents a group represented by formula (Q3).

[0069] [ka]

[0070] In formula (Q3), * represents the bonding position. In equation (Q3), Q A is a nitrogen atom or -CQ X = represents Q X represents a hydrogen atom or a substituent. In equation (Q3), Q Z represents a hydrogen atom or a substituent. Q in equation (Q3) A is Q in equation (Q1) A The same applies to the preferable conditions. Q in equation (Q3) Z is Q in equation (Q2) Z The same applies to the preferable conditions. In formula (Q3), B 2is one carbon atom, one nitrogen atom and Q A The one carbon atom is a ring having at least one carbon atom, and may have a substituent, as specified in formula (Q3). A and a nitrogen atom. The one nitrogen atom is a carbon atom sandwiched between B 2 The nitrogen atom constituting the ring represented by the formula: B 2 The ring represented by the formula (I) may be a monocyclic ring or a polycyclic ring, an aromatic ring or a non-aromatic ring, or a ring formed by condensing an aromatic ring and a non-aromatic ring. B 2 The number of ring atoms in the ring represented by the formula (I) is preferably 5 to 15, more preferably 5 to 9, and even more preferably 5 or 6. B 2 The ring represented by the formula (Q3) preferably has 1 to 5 heteroatoms (nitrogen atoms, oxygen atoms, and / or sulfur atoms, etc.) as ring member atoms, and more preferably has 2 to 3 heteroatoms. The number of heteroatoms referred to here is the number of the nitrogen atoms and the oxygen atoms specified in the formula (Q3). A This number also includes the number of nitrogen atoms that can be expressed as: Among them, B in formula (Q3) 2 is preferably a ring containing a linking group represented by the above formula (BA). Y is the bond position to the nitrogen atom. Y The nitrogen atom bonded by Q in formula (Q1) B It is a nitrogen atom in the form of

[0071] The specific compound is preferably a compound represented by formula (2).

[0072] [ka]

[0073] In formula (2), R 1 and R 2 each independently represents a hydrogen atom or a substituent. In formula (2), R a1 and R a2each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. In formula (2), Q represents a group represented by the above formula (Q1). In formula (2), R 1 , R 2 , R a1 , R a2 , and Q is R in formula (1). 1 , R 2 , R a1 , R a2 , and Q, respectively, and the preferred conditions are also the same. In formula (2), X 1 ~X 4 are each independently a nitrogen atom (-N=) or -CR c1 = represents. R c1 represents a hydrogen atom or a substituent. R c1 If there are multiple R c1 may be bonded to each other to form a ring. For example, X 1 and X 2 Both are -CR c1 = and these R c1 may be bonded to each other to form a ring. 2 and X 3 Both are -CR c1 = and these R c1 may be bonded to each other to form a ring. 3 and X 4 Both are -CR c1 = and these R c1 may be bonded to each other to form a ring. Multiple Rs c1 The ring formed by bonding together may be an aromatic ring (such as a benzene ring) or a non-aromatic ring, may have one or more (for example, 1 to 6) heteroatoms, and may further have a substituent. c1may be bonded to each other to form a ring, and a plurality of substituents in the ring may be bonded to each other to form a further ring (a ring which may have a substituent).

[0074] The specific compound is more preferably a compound represented by formula (3).

[0075] [ka]

[0076] In formula (3), R 1 and R 2 each independently represents a hydrogen atom or a substituent. In formula (3), R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. In formula (3), Q represents a group represented by the above formula (Q1). In equation (3), R 1 , R 2 , R a1 , R a2 , and Q is R in formula (1). 1 , R 2 , R a1 , R a2 , and Q, respectively, and the preferred conditions are also the same. In formula (3), R 3 and R 4 each independently represents a hydrogen atom or a substituent. R 3 and R 4 may be bonded to each other to form a ring. R 3 and R 4 The ring formed by bonding together may be an aromatic ring or a non-aromatic ring, may have one or more (for example, 1 to 6) heteroatoms, and may further have a substituent. 3 and R 4may be bonded to each other to form a ring, and a plurality of substituents in the ring may be bonded to each other to form a further ring (a ring which may have a substituent).

[0077] The specific compound is more preferably a compound represented by formula (4).

[0078] [ka]

[0079] In formula (4), R 1 and R 2 each independently represents a hydrogen atom or a substituent. In formula (4), R a1 and R a2 each independently represents an optionally substituted aryl group, —C(R L1 )(R L2 )(R L3 ), or a heteroaryl group which may have a substituent. In formula (4), Q represents a group represented by the above formula (Q1). In equation (4), R 1 , R 2 , R a1 , R a2 , and Q is R in formula (1). 1 , R 2 , R a1 , R a2 , and Q, respectively, and the preferred conditions are also the same. In formula (4), E 1 is a nitrogen atom or -CR E1 = R E1 represents a hydrogen atom or a substituent. In formula (4), E 2 is a nitrogen atom or -CR E2 = R E2 represents a hydrogen atom or a substituent. The substituent R E1 and the substituent R E2are each independently preferably an alkoxy group, a silyl group, a chlorine atom, a fluorine atom, a cyano group, or an alkyl group, and more preferably an alkoxy group having 1 to 3 carbon atoms in the alkyl group moiety, a chlorine atom, a fluorine atom, a cyano group, or an alkyl group having 1 to 4 carbon atoms. In formula (4), R 5 and R 6 each independently represents a hydrogen atom or a substituent. The substituent R 5 and the substituent R 6 are each independently preferably an alkoxy group, a silyl group, a chlorine atom, a fluorine atom, a cyano group, or an alkyl group, and more preferably an alkoxy group having 1 to 3 carbon atoms in the alkyl group moiety, a chlorine atom, a fluorine atom, a cyano group, or an alkyl group having 1 to 4 carbon atoms. R 5 and R 6 may be bonded to each other to form a ring. R 5 and R 6 The ring formed by bonding together may be an aromatic ring (such as a benzene ring) or a non-aromatic ring, may have one or more (for example, 1 to 6) heteroatoms, and may further have a substituent. 5 and R 6 may be bonded to each other to form a ring, and a plurality of substituents in the ring may be bonded to each other to form a further ring (a ring which may have a substituent).

[0080] Examples of specific compounds are shown below.

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] The molecular weight of the specific compound is not particularly limited, but is preferably 400 to 1200. If the molecular weight is 1200 or less, the deposition temperature does not become high and decomposition of the compound does not occur easily. If the molecular weight is 400 or more, the glass transition point of the deposited film does not become low and the heat resistance of the photoelectric conversion element is improved.

[0089] The specific compound is particularly useful as a material for a photoelectric conversion film used in an imaging device, a photosensor, or a photovoltaic cell. The specific compound usually functions as a p-type organic semiconductor 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 agent material.

[0090] The specific compound is preferably a compound having 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.

[0091] The maximum absorption wavelength of the specific compound is not particularly limited, but is preferably in the range of 500 to 600 nm, and more preferably in the range of 530 to 580 nm. The maximum absorption wavelength is a value measured in the state of a film of the specific compound (for example, a vapor-deposited film of the specific compound).

[0092] The particular compound may be purified if necessary. The method for purifying the specific compound is not particularly limited, but sublimation purification is preferred. The purity of the specific compound after sublimation purification (for example, purity measured by HPLC or GC) is not particularly limited, but is preferably 95% or more, more preferably 98% or more, and even more preferably 99% or more.

[0093] Before the specific compound is purified by sublimation, the specific compound may be purified by other methods. For example, the specific compound is preferably subjected to purification using silica gel column chromatography, purification using GPC (Gel Permeation Chromatography), reslurry washing, reprecipitation purification, purification using an adsorbent such as activated carbon, and recrystallization purification. The purity of the specific compound before sublimation purification (for example, purity measured by HPLC or GC) is not particularly limited, but is preferably 95% or more, more preferably 98% or more, and even more preferably 99% or more. The solvent used for recrystallization purification (recrystallization solvent) is not particularly limited, and examples thereof include methanol, ethanol, isopropanol, butanol, toluene, xylene, anisole, 1,2-dimethoxybenzene, tetralin, chlorobenzene, dichlorobenzene, hexane, heptane, octane, acetonitrile, benzonitrile, acetic acid, chloroform, dichloromethane, ethyl acetate, butyl acetate, tetrahydrofuran, 4-methyltetrahydropyran, and cyclopentyl methyl ether. The recrystallization solvent may be a mixture of multiple solvents.

[0094] The amount of residual solvent contained in the crude product containing the specific compound to be subjected to sublimation purification is not particularly limited, but the amount of residual solvent is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably 2 mol % or less, relative to the total molar amount of the specific compound in the crude product.

[0095] Impurities contained in the crude product containing the specific compound to be subjected to sublimation purification and containing elements that do not constitute the specific compound (for example, Li, Na, K, Mg, Ca, Al, Si, P, Sn, transition metal elements, etc.) are not particularly limited, but are preferably 1000 mass ppm or less, more preferably 100 mass ppm or less, and still more preferably 10 mass ppm or less with respect to the total mass of the crude product. As a method for measuring the above elements, ICP (inductively coupled plasma) emission spectrometry can be mentioned.

[0096] The specific compound can be synthesized by a known method. In order to improve the purity of the specific compound, the purity of the raw materials used in the synthesis of the specific compound containing the intermediate (for example, the measured purity by HPLC or GC) is not particularly limited, but is preferably 97% or more, more preferably 98% or more, and still more preferably 99% or more. When the purity of commercially available raw materials and synthetic intermediates is low, those purified by a known method may be used.

[0097] The content of the specific compound in the photoelectric conversion film (= film thickness in terms of a single layer of the specific compound / film thickness of the photoelectric conversion film × 100) is preferably 15 to 75% by volume, more preferably 20 to 60% by volume, and still more preferably 25 to 50% by volume. The specific compound may be used alone or in combination of two or more.

[0098] <n-type organic semiconductor> The photoelectric conversion film preferably contains an n-type organic semiconductor as other components in addition to the specific compound described above. The n-type organic semiconductor is an acceptor-type organic semiconductor material (compound), and refers to an organic compound having a property of easily accepting electrons. More specifically, the n-type organic semiconductor refers to the organic compound having a larger electron affinity when two organic compounds are brought into contact and used. Therefore, as the acceptor-type organic semiconductor, any organic compound can be used as long as it is an organic compound having 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 (for example, 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 of a nitrogen atom, an oxygen atom, and a sulfur atom (for example, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imine, diphenylquinone derivatives; bathocuproine, bathophenanthroline, and derivatives thereof; triazole compounds; distyrylarylene derivatives; metal complexes having a nitrogen-containing heterocyclic compound as a ligand; silole compounds; and the compounds described in paragraphs

[0056] and

[0057] of JP 2006-100767 A.

[0099] Among these, the n-type organic semiconductor (compound) preferably contains a fullerene selected from the group consisting of fullerene and its derivatives. Examples of fullerenes include fullerene C60, fullerene C70, fullerene C76, fullerene C78, ​​fullerene C80, fullerene C82, fullerene C84, fullerene C90, fullerene C96, fullerene C240, fullerene C540, and mixed fullerenes. The fullerene derivative may be, for example, a compound in which a substituent is added to the above-mentioned fullerene. The substituent is preferably an alkyl group, an aryl group, or a heterocyclic group. The fullerene derivative is preferably a compound described in JP-A-2007-123707.

[0100] An organic dye may be used as the n-type organic semiconductor. 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, squarium 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, acridinone dyes, diphenylamine dyes, quinophthalone dyes, phenoxazine dyes, phthaloperylene dyes, dioxane dyes, porphyrin dyes, chlorophyll dyes, phthalocyanine dyes, subphthalocyanine dyes, and metal complex dyes.

[0101] The molecular weight of the n-type organic semiconductor is preferably 200 to 1,200, more preferably 200 to 900.

[0102] It is also desirable that the n-type organic semiconductor be colorless or have a maximum absorption wavelength and / or absorption waveform similar to that of a specific compound. Specifically, 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.

[0103] The photoelectric conversion film preferably has a bulk heterostructure formed by mixing a specific compound with an n-type organic semiconductor. The bulk heterostructure is a layer in the photoelectric conversion film in which the specific compound and the 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.

[0104] When the photoelectric conversion film contains an n-type organic semiconductor, the content of the n-type organic semiconductor in the photoelectric conversion film (=film thickness of n-type organic semiconductor in terms of a single layer / film thickness of photoelectric conversion film × 100) is preferably 15 to 75% by volume, more preferably 20 to 60% by volume, and even more preferably 25 to 50% by volume. The n-type semiconductor material may be used alone or in combination of two or more.

[0105] Furthermore, when the n-type semiconductor material contains fullerenes, the content of the fullerenes relative to the total content of the n-type semiconductor material (=film thickness of fullerenes converted into a single layer / total film thickness of each n-type semiconductor material converted into a single layer × 100) is preferably 50 to 100% by volume, and more preferably 80 to 100% by volume. The fullerenes may be used singly or in combination of two or more.

[0106] The difference in electron affinity between the specific compound and the n-type organic semiconductor is preferably 0.1 eV or more.

[0107] From the viewpoint of the responsiveness 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 of the specific compound in terms of a single layer / (film thickness of the specific compound in terms of a single layer+film thickness of the n-type organic semiconductor in terms of a single layer)×100) is preferably 20 to 80% by volume, and more preferably 40 to 80% by volume. Furthermore, when the photoelectric conversion film contains a p-type organic semiconductor described later, the content of the specific compound (=film thickness of the specific compound in terms of a single layer / (film thickness of the specific compound in terms of a single layer + film thickness of the n-type organic semiconductor in terms of a single layer + film thickness of the p-type organic semiconductor in terms of a single layer) × 100) is preferably 15 to 75 vol %, more preferably 30 to 75 vol %. It is preferable that the photoelectric conversion film is substantially composed of the specific compound, the n-type organic semiconductor, and the optionally contained p-type organic semiconductor. "Substantially" means that the total content of the specific compound, the n-type organic semiconductor, and the optionally contained p-type organic semiconductor is 90 to 100% by volume (preferably 95 to 100% by volume, more preferably 99 to 100% by volume) relative to the total mass of the photoelectric conversion film.

[0108] <p-type organic semiconductor> Also, the photoelectric conversion film may contain a p-type organic semiconductor. Among them, it is preferable that the photoelectric conversion film further contains a p-type organic semiconductor in addition to the specific compound and the n-type organic semiconductor. Examples of the p-type organic semiconductor include the compounds shown below. Here, the p-type organic semiconductor refers to a p-type organic semiconductor that is a different compound from the specific compound.

[0109] The p-type organic semiconductor is a donor-type organic semiconductor material (compound), which refers to an organic compound having a property of easily donating electrons. More specifically, the p-type organic semiconductor refers to the organic compound with a smaller ionization potential when two organic compounds are brought into contact and used. Examples of p-type organic semiconductors include triarylamine compounds (e.g., 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

[0052] to

[0063] of JP-A No. 2011-225544, compounds described in paragraphs

[0119] to

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

[0119] to

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

[0128] to

[0148] of JP-A No. 2011-22861 ... compounds described in paragraphs

[0044] to

[0051] of JP 015-153910 A and compounds described in paragraphs

[0086] to

[0090] of JP 2012-094660 A), 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]thiophene (BTBT) derivatives, thieno[3,2-f:4,5-f']bis[1]benzothiophene compounds described in paragraphs

[0031] to

[0036] of JP 2018-014474 A; compounds described in paragraphs

[0043] to

[0045] of WO 2016-194630 A; compounds described in paragraphs

[0025] to

[0037] and

[0099] to

[0109] of WO 2017-159684 A; compounds described in paragraphs

[0029] to

[0034] of JP 2017-076766 A; compounds described in paragraphs

[0015] to

[0025] of WO 2018-207722 A; and paragraph

[0045] of JP 2019-054228 A. 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 JP2019-080052A, 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,The compounds of paragraphs

[0033] to

[0036] of JP 2018-206878 A, the compounds of paragraphs

[0038] of JP 2018-190755 A, the compounds of paragraphs

[0019] to

[0021] of JP 2018-026559 A, the compounds of paragraphs

[0031] to

[0056] of JP 2018-170487 A, the compounds of paragraphs

[0036] to

[0041] of JP 2018-078270 A, the compounds of paragraphs

[0036] to

[0041] of JP 2018-166200 A Compounds of

[0055] to

[0082] , compounds of paragraphs

[0041] to

[0050] of JP 2018-113425 A, compounds of paragraphs

[0044] to

[0048] of JP 2018-85430 A, compounds of paragraphs

[0041] to

[0045] of JP 2018-056546 A, compounds of paragraphs

[0042] to

[0049] of JP 2018-046267 A, compounds of paragraphs

[0031] to

[0036] of JP 2018-014474 A 】, the compounds described in paragraphs

[0036] to

[0046] of WO2018-016465, the compounds described in paragraphs

[0045] to

[0048] of JP2020-010024A, etc.), cyanine compounds, oxonol compounds, polyamine compounds, indole compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, fused aromatic carbocyclic compounds (for example, 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 compounds with 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 semiconductor compounds are given below.

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] The difference in ionization potential between the specific compound and the p-type organic semiconductor is preferably 0.1 eV or more.

[0115] When the photoelectric conversion film contains a p-type organic semiconductor, the content of the p-type organic semiconductor in the photoelectric conversion film (=film thickness of p-type organic semiconductor in single layer equivalent / film thickness of photoelectric conversion film × 100) is preferably 15 to 75% by volume, more preferably 20 to 60% by volume, and even more preferably 25 to 50% by volume. The p-type semiconductor material may be used alone or in combination of two or more.

[0116] 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 is intended to mean a film having a luminescence quantum efficiency of 1% or less, preferably 0.5% or less, and more preferably 0.1% or less.

[0117] <Film formation method> The photoelectric conversion film can be formed mainly by a dry film formation method. 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. Among these, vacuum deposition is 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.

[0118] The thickness of the photoelectric conversion film is preferably from 10 to 1000 nm, more preferably from 50 to 800 nm, still more preferably from 50 to 500 nm, and particularly preferably from 50 to 300 nm.

[0119] 〔electrode〕 The electrodes (upper electrode (transparent conductive film) 15 and lower electrode (conductive film) 11) are made of a conductive material. Examples of the conductive material include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Since light is incident through the upper electrode 15, the upper electrode 15 is preferably transparent to the light to be detected. Examples of materials constituting the upper electrode 15 include conductive metal oxides such as antimony- or fluorine-doped tin oxide (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); thin metal 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. Among these, conductive metal oxides are preferred from the viewpoints of high conductivity and transparency.

[0120] Typically, reducing the thickness of a conductive film below a certain range results in a rapid increase in resistance. However, in a solid-state imaging device incorporating a photoelectric conversion element according to this embodiment, the sheet resistance is preferably 100 to 10,000 Ω / □, allowing for a wide range of film thicknesses. Furthermore, the thinner the upper electrode (transparent conductive film) 15, the less light it absorbs, and generally the higher its light transmittance. Increased 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 of the thin film, and the increase in transmittance that accompany thinning, the film thickness of the upper electrode 15 is preferably 5 to 100 nm, and more preferably 5 to 20 nm.

[0121] Depending on the application, the lower electrode 11 may be made transparent or non-transparent and light-reflective. Examples of materials constituting the lower electrode 11 include conductive metal oxides such as antimony- or fluorine-doped tin oxide (ATO, FTO), 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, and conductive compounds such as oxides or nitrides of these metals (one example is titanium nitride (TiN)); mixtures or laminates of these metals and conductive metal oxides; and organic conductive materials such as polyaniline, polythiophene, and polypyrrole.

[0122] The method for forming the electrodes is not particularly limited and 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 of methods include an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (such as a sol-gel method), and coating of a dispersion of indium tin oxide.

[0123] [Charge blocking film: electron blocking film, hole blocking film] The photoelectric conversion element of the present invention preferably has one or more intermediate layers between the conductive film and the transparent conductive film in addition to the photoelectric conversion film. Examples of the intermediate layer include a charge-blocking film. If the photoelectric conversion element has this film, the resulting photoelectric conversion element will have better properties (such as photoelectric conversion efficiency and responsiveness). Examples of the charge-blocking film include an electron-blocking film and a hole-blocking film. Each of these films will be described in detail below.

[0124] <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. Furthermore, polymeric materials can also be used as the electron blocking film. Examples of polymeric materials include polymers of phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, as well as derivatives thereof.

[0125] The electron blocking film may be made up of multiple films. The electron blocking film may be composed of an inorganic material. Generally, 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 photoelectric conversion 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.

[0126] <Hole-blocking film> The hole-blocking film is an acceptor organic semiconductor material (compound), and the above-mentioned n-type semiconductor can be used. The hole blocking film may be made up of multiple films.

[0127] The method for producing the charge blocking film is not particularly limited, and examples thereof include dry film formation methods and wet film formation methods. Examples of dry film formation methods include vapor deposition and sputtering. Vapor deposition methods may be either physical vapor deposition (PVD) or chemical vapor deposition (CVD), with physical vapor deposition methods 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 from the perspective of high-precision patterning.

[0128] The thickness of each of the charge blocking films (electron blocking film and hole blocking film) is preferably 3 to 200 nm, more preferably 5 to 100 nm, and even more preferably 5 to 30 nm.

[0129] 〔substrate〕 The photoelectric conversion element may further include a substrate. The type of the substrate to be used is not particularly limited, but examples thereof include a semiconductor substrate, a glass substrate, and a plastic substrate. The position of the substrate is not particularly limited, but typically, a conductive film, a photoelectric conversion film, and a transparent conductive film are laminated in this order on the substrate.

[0130] [Sealing layer] The photoelectric conversion element may further have a sealing layer. The performance of photoelectric conversion materials can be significantly degraded by the presence of degrading factors such as water molecules. Therefore, the entire photoelectric conversion film can be covered and sealed with a sealing layer made of ceramics such as dense metal oxide, metal nitride, or metal nitride oxide, or diamond-like carbon (DLC), which does not allow water molecules to penetrate, to prevent the above-mentioned degradation. The sealing layer may be made of a material selected and manufactured in accordance with the description in paragraphs

[0210] to

[0215] of JP-A-2011-082508, for example.

[0131] [Image sensor, optical sensor] One example of an application of a photoelectric conversion element is an image sensor. An image sensor 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. Each photoelectric conversion element (pixel) converts the optical signal into an electrical signal, and the electrical signal is output from the image sensor sequentially for each pixel. For this reason, each pixel is composed of one or more photoelectric conversion elements and one or more transistors. The imaging device is mounted on an imaging device of a digital camera, a digital video camera, or the like, an electronic endoscope, an imaging module of a mobile phone, or the like.

[0132] The photoelectric conversion element of the present invention is also preferably used in an optical sensor having the photoelectric conversion element of the present invention. The optical sensor may use the photoelectric conversion element 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 planarly.

[0133] [Compound] The present invention also includes inventions of compounds, including the specific compounds described above. [Example]

[0134] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures 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 following examples.

[0135] [Compound (evaluation compound)] <Synthesis of Compound (D-1)> A specific compound, compound (D-1), was synthesized according to the following scheme.

[0136] [ka]

[0137] To a mixture of 2,6-xylidine (300 g, 2.48 mol) and isopropanol (300 mL), 30% hydrochloric acid (288 mL, 2.73 mol) was added dropwise, and the resulting reaction mixture was stirred under reflux for 1 hour. The mixture was cooled to 2°C, and the resulting crystals were filtered. The resulting crystals were washed with isopropanol and then hexane to obtain 2,6-xylidine hydrochloride (350 g, 90% yield). Subsequently, 50% aqueous sodium hydroxide solution (199 g, 2.48 mol) was added dropwise to a mixture of 2,6-xylidine hydrochloride (300 g, 1.90 mol) and water (600 mL), and the resulting reaction mixture was stirred at room temperature (25°C) for 1 hour. The resulting mixture was transferred to a separatory funnel, washed with hexane (150 mL), and the aqueous phase was removed. The resulting organic phase was concentrated under reduced pressure to obtain 2,6-xylidine (200 g, 87%).

[0138] To a mixture of 2,3-dichloroquinoxaline (8.0 g, 40.2 mmol), a 35% tetrahydrofuran solution of sodium hexamethyldisilazane (1.9 mol / L) (90.4 mL, 181 mol), and tetrahydrofuran (80 mL), the 2,6-xylidine (11 mL, 88.2 mmol) obtained above was added dropwise to obtain a mixed solution. The mixed solution was stirred at 60°C for 1 hour and then allowed to cool to room temperature (25°C). Water (40 mL) was added dropwise to the mixed solution. 80 mL of 20% by mass brine was added to the mixed solution, and the organic phase of the mixed solution was extracted. The organic phase obtained was dried over magnesium sulfate and then filtered. The filtrate obtained was concentrated under reduced pressure. The crude product obtained (residue after concentration under reduced pressure) was purified by recrystallization using toluene / 2-propanol to obtain intermediate (D-1-1) (9.95 g, yield 67%).

[0139] p-Toluenesulfonic acid monohydrate (9.3 g, 48.9 mmol), acetic anhydride (16 mL), and intermediate (D-1-1) (6.0 g, 16.3 mmol) were mixed, and the resulting reaction solution was stirred at 130 °C for 1 hour. The reaction solution was allowed to cool to room temperature (25 °C) and added dropwise to a mixture of 50 w / v% aqueous sodium hydroxide (48 mL) and ice (143 g). The mixture was stirred for 30 minutes to obtain a reaction mixture. Acetic acid was added to the reaction mixture, and the pH of the reaction mixture (pH at 25 °C) was adjusted to 8. The mixture was stirred for an additional 20 minutes. The precipitate formed in the reaction mixture was filtered, and the resulting filter cake was washed sequentially with water and methanol. The resulting crude product (filter cake after washing) was purified by reprecipitation using dichloromethane / methanol to obtain intermediate (D-1-2) (6.2 g, yield 98%).

[0140] To a mixture of (chloromethylene)dimethyliminium chloride (5.87 g, 45.9 mmol) and acetonitrile (60 mL), intermediate (D-1-2) (6.0 g, 15.3 mmol) was added, and the resulting reaction solution was stirred at 50 °C for 2 hours. The reaction solution was allowed to cool to room temperature (25 °C) and added dropwise to a mixture of 1 mol / L aqueous sodium hydroxide solution (90 mL) and ice (90 g), and the resulting mixture was stirred for 1 hour. The precipitate formed in the mixture was filtered, and the resulting filter cake was washed with water and then methanol. The resulting crude product (filter cake after washing) was purified by reprecipitation using dichloromethane / acetonitrile to obtain intermediate (D-1-3) (4.4 g, yield 68%).

[0141] Intermediate (D-1-4) was synthesized with reference to a known method (for example, the method described in paragraphs

[0260] to

[0265] of JP-A-2009-235382).

[0142] Intermediate (D-1-3) (0.50 g, 1.19 mmol), intermediate (D-1-4) (0.31 g, 1.55 mmol), and acetic anhydride (7.5 mL) were mixed, and the resulting reaction solution was stirred at 110°C for 24 hours. After the reaction solution was allowed to cool to room temperature (25°C), the precipitate formed in the reaction solution was filtered, and the resulting filter cake was washed with methanol. The resulting crude product (filter cake after washing) was purified by silica gel chromatography (eluent (volume ratio): dichloromethane / ethyl acetate = 100:0 to dichloromethane / ethyl acetate = 85:15) to obtain compound (D-1) (0.49 g, yield 68%).

[0143] Other specific compounds were also synthesized with reference to the above synthesis methods. The specific compounds used in the test and the comparative compounds are shown below. In the following, compounds (D-1) to (D-16) are specific compounds. Hereinafter, the specific compound and the comparative compound will be collectively referred to as the evaluation compound. The evaluation compound was used to prepare a photoelectric conversion element as described below.

[0144] [ka]

[0145] [n-type organic semiconductor] Fullerene C 60 (C60) was used as an n-type organic semiconductor for evaluation in the production of a photoelectric conversion element, which will be described later.

[0146] [p-type organic semiconductor] The p-type organic semiconductors shown below were used as p-type organic semiconductors for evaluation in the production of photoelectric conversion elements, which will be described later.

[0147] [ka]

[0148] [evaluation] <Fabrication of photoelectric conversion element> A photoelectric conversion element having the configuration shown in Fig. 1 was fabricated using an evaluation compound (specific compound or comparative compound). Here, the photoelectric conversion element comprises a lower electrode 11, an electron blocking film 16A, a photoelectric conversion film 12, and an upper electrode 15. Specifically, amorphous ITO was deposited on a glass substrate by sputtering to form a lower electrode 11 (thickness: 30 nm), and the following compound (EB-1) was further deposited on the lower electrode 11 by vacuum thermal evaporation to form an electron blocking film 16A (thickness: 30 nm). Furthermore, with the substrate temperature controlled at 25°C, the evaluation compound and the n-type organic semiconductor (fullerene (C 60 )) and, if desired, a p-type organic semiconductor were co-deposited by vacuum evaporation to form a film of 80 nm in monolayer equivalent. This resulted in the formation of a photoelectric conversion film 12 with a bulk heterostructure of 160 nm (240 nm when a p-type organic semiconductor was also used). The film formation rate of the photoelectric conversion film 12 was 1.0 Å / sec. Furthermore, an upper electrode 15 (transparent conductive film) (thickness: 10 nm) was formed by sputtering amorphous ITO on the photoelectric conversion film 12. After forming an SiO film as a sealing layer on the upper electrode 15 by vacuum deposition, an aluminum oxide (Al2O3) layer was formed thereon by atomic layer chemical vapor deposition (ALCVD), thereby producing a photoelectric conversion element. The photoelectric conversion elements obtained in the respective Examples and Comparative Examples are collectively referred to as element (A).

[0149] [ka]

[0150] <Evaluation of photoelectric conversion efficiency (external quantum efficiency)> The operation of each of the obtained photoelectric conversion elements (element (A)) was confirmed. 5A voltage was applied to achieve an electric field strength of 1000 V / cm. Light was then irradiated from the upper electrode (transparent conductive film) side, and IPCE (incident photon-to-current conversion efficiency) measurements were performed to extract the photoelectric conversion efficiency (external quantum efficiency) at 500 nm and 600 nm. The photoelectric conversion efficiency was measured using an Optel constant energy quantum efficiency measurement device. The irradiated light intensity was 50 μW / cm. 2 When the photoelectric conversion efficiency of the photoelectric conversion element of Example 1 was normalized to 1, the photoelectric conversion efficiency of each photoelectric conversion element was determined, and the elements were evaluated according to the following criteria based on the determined photoelectric conversion efficiency. AA: 1.1 or higher A: 0.9 or more and less than 1.1 B: 0.8 or more and less than 0.9 C: 0.7 or more and less than 0.8 D: 0.6 or more and less than 0.7 E: Less than 0.6 For both wavelengths of 500 nm and 600 nm, it is preferable that the optical fiber has a refractive index of C or higher, and most preferably AA. Furthermore, it was confirmed that the photoelectric conversion elements (element (A)) of each example or comparative example all exhibited a photoelectric conversion efficiency of 40% or more at measurement wavelengths of 500 nm and 600 nm, and had an external quantum efficiency of a certain level or higher as photoelectric conversion elements.

[0151] <Evaluation of responsiveness> The response of each of the obtained photoelectric conversion elements (element (A)) was evaluated. 5 A voltage was applied to achieve an intensity of 1000 V / cm. Then, 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 580 nm was measured with an oscilloscope to measure the rise time from 0 (when no irradiation was performed) to 97% signal intensity. Next, the rise time of each photoelectric conversion element was determined when the rise time of the photoelectric conversion element of Example 1 was normalized to 1 at a wavelength of 580 nm, and the responsiveness of each photoelectric conversion element was evaluated based on the determined rise time in the following categories. AA: Less than 0.9 A: 0.9 or more and less than 2.0 B: 2.0 or more and less than 3.0 C: 3.0 or more and less than 4.0 D: 4.0 or more and less than 5.0 E: Less than 5.0 In practical terms, C or higher is preferred, and AA is most preferred.

[0152] <Evaluation of manufacturing suitability (photoelectric conversion efficiency during high-speed film formation)> Photoelectric conversion elements (elements (B)) of each example or comparative example were produced in the same manner as for element (A), except that the deposition rate of the photoelectric conversion film 12 was set to 3.0 Å / second. Using the obtained elements (B), the photoelectric conversion efficiency (external quantum efficiency) was evaluated in the same manner as described in the section <Evaluation of photoelectric conversion efficiency (external quantum efficiency)>. The photoelectric conversion efficiencies of element (A) and element (B) of the same Example or Comparative Example were compared, and the value of "photoelectric conversion efficiency of element (B) / photoelectric conversion efficiency of element (A)" was calculated. The obtained value was used to evaluate the manufacturing suitability of each photoelectric conversion element in light of the following criteria. A: 0.9 or higher B: Less than 0.9

[0153] The table below shows the types and characteristics of compounds used to prepare the photoelectric conversion film in each photoelectric conversion element (element (A) or element (B)) in each example or comparative example. The test results are shown in the table below. In the table, the column "Formula (4)" indicates whether the specific compound used in the preparation of the photoelectric conversion film corresponds to the compound represented by formula (4). If this requirement is met, it is marked "A", and if not, it is marked "B". The column "Q" indicates which of the groups represented by formulas (Q1) to (Q3) corresponds to the group corresponding to Q in formula (1) in the specific compound used to prepare the photoelectric conversion film. If it corresponds to the group represented by formula (Q3), it is marked "Q3." If it does not correspond to the group represented by formula (Q3) and corresponds to the group represented by formula (Q2), it is marked "Q2." If it corresponds only to the group represented by formula (Q1), it is marked "Q1." The column "B1" indicates the B in formula (1) in the specific compound used to prepare the photoelectric conversion film. 1 represents the number of ring atoms in the ring corresponding to the ring represented by

[0154] [Table 1]

[0155] From the results shown in the table, it was confirmed that the photoelectric conversion element of the present invention has excellent photoelectric conversion efficiency and manufacturability over a wide range of wavelengths, and further has excellent responsiveness.

[0156] In particular, it was confirmed that the effects of the present invention are more excellent when the specific compound is a compound represented by formula (4) (see, for example, a comparison of the results of Examples 1 and 10).

[0157] It was confirmed that when the group represented by Q is a group represented by formula (Q2) or a group represented by formula (Q3), the effects of the present invention are superior, and when it is a group represented by formula (Q3), the effects of the present invention are even superior (see comparison of the results of Examples 1, 8, and 9, etc.).

[0158] B 1 It was confirmed that the effects of the present invention are even more excellent when the number of ring atoms in the ring represented by the formula is 5 to 6 (see comparison of the results of Examples 1 to 7, etc.).

[0159] It was confirmed that the effects of the present invention are more excellent when the photoelectric conversion film further contains a p-type organic semiconductor (see comparison of the results of Examples 1, 13, and 14, etc.). [Explanation of symbols]

[0160] 10a, 10b Photoelectric conversion element 11 Conductive film (bottom electrode) 12 Photoelectric conversion film 15 Transparent conductive film (upper electrode) 16A Electron Blocking Film 16B Hole-blocking film 20a Image sensor 22 Blue photoelectric conversion element 24 Red photoelectric conversion element

Claims

1. A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, The photoelectric conversion element, wherein the photoelectric conversion film contains a compound represented by formula (3): 【Chemistry 1】 In formula (3), R １ ~R ４ each independently represents a hydrogen atom or a substituent. R ３ and R ４ may be bonded to each other to form a ring. R ａ１ and R ａ２ each independently represents an optionally substituted aryl group, —C(R Ｌ１ ) (R Ｌ２ ) (R Ｌ３ ), or a heteroaryl group which may have a substituent. R Ｌ１ ~R Ｌ３ each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R Ｌ１ ~R Ｌ３ At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. Ｌ１ ~R Ｌ３ The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by formula (Q1). In formula (Q1), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｂ represents a nitrogen atom, a group represented by formula (C), or -CQ Ｙ < represents. Q Ｙ represents a hydrogen atom or a substituent. A １ is composed of two carbon atoms and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following. B １ is one carbon atom and Q Ａ and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following. 【Chemistry 2】 In formula (C), *C1 to *C3 represent bonding positions.

2. The photoelectric conversion element according to claim 1 , wherein the compound represented by formula (3) is a compound represented by formula (4): 【Transformation 5】 In formula (4), R １ , R ２ , R ５ , and R ６ each independently represents a hydrogen atom or a substituent. R ５ and R ６ may be bonded to each other to form a ring. R ａ１ and R ａ２ each independently represents an optionally substituted aryl group, —C(R Ｌ１ ) (R Ｌ２ ) (R Ｌ３ ), or a heteroaryl group which may have a substituent. R Ｌ１ ~R Ｌ３ each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, or a hydrogen atom; R Ｌ１ ~R Ｌ３ At least two of R independently represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. Ｌ１ ~R Ｌ３ The optionally substituted alkyl group, the optionally substituted aryl group, and the optionally substituted heteroaryl group represented by the following formula (I) may be bonded to each other to form a ring. Q represents a group represented by the formula (Q1). E １ is a nitrogen atom or -CR Ｅ１ = represents. R Ｅ１ represents a hydrogen atom or a substituent. E ２ is a nitrogen atom or -CR Ｅ２ = represents. R Ｅ２ represents a hydrogen atom or a substituent.

3. The photoelectric conversion element according to claim 1 or 2, wherein Q represents a group represented by formula (Q2): 【Transformation 6】 In formula (Q2), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｂ represents a nitrogen atom, a group represented by the formula (C), or -CQ Ｙ < represents. Q Ｙ represents a hydrogen atom or a substituent. Q Ｚ represents a hydrogen atom or a substituent. B １ is one carbon atom and Q Ａ and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following.

4. 4. The photoelectric conversion element according to claim 1, wherein Q represents a group represented by formula (Q3): 【Transformation 7】 In formula (Q3), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｚ represents a hydrogen atom or a substituent. B ２ is one carbon atom, one nitrogen atom and Q Ａ and represents a ring which may have a substituent and contains at least one of the following.

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

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

7. The photoelectric conversion element according to claim 5 , wherein the photoelectric conversion film further contains a p-type organic semiconductor.

8. 8. The photoelectric conversion element according to claim 1, further comprising one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film.

9. An imaging device comprising the photoelectric conversion element according to any one of claims 1 to 8.

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

11. A compound represented by formula (3): 【Transformation 8】 In formula (3), R １ ~R ４ each independently represents a hydrogen atom or a substituent. R ３ and R ４ may be bonded to each other to form a ring. R ａ１ and R ａ２ each independently represents an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. Q represents a group represented by formula (Q1). In formula (Q1), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｂ represents a nitrogen atom, a group represented by formula (C), or -CQ Ｙ < represents. Q Ｙ represents a hydrogen atom or a substituent. A １ is composed of two carbon atoms and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following. B １ is one carbon atom and Q Ａ and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following. 【Chemistry 9】 In formula (C), * Ｃ１ ~* Ｃ３ represents the binding position.

12. The compound according to claim 11, wherein the compound represented by formula (3) is a compound represented by formula (4): 【Chemistry 10】 In formula (4), R １ , R ２ , R ５ , and R ６ each independently represents a hydrogen atom or a substituent. R ５ and R ６ may be bonded to each other to form a ring. R ａ１ and R ａ２ each independently represents an aryl group which may have a substituent, or a heteroaryl group which may have a substituent. Q represents a group represented by the formula (Q1). E １ is a nitrogen atom or -CR Ｅ１ = represents. R Ｅ１ represents a hydrogen atom or a substituent. E ２ is a nitrogen atom or -CR Ｅ２ = represents. R Ｅ２ represents a hydrogen atom or a substituent.

13. The compound according to claim 11 or 12, wherein Q represents a group represented by formula (Q2). 【Chemistry 11】 In formula (Q2), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｂ represents a nitrogen atom, a group represented by the formula (C), or -CQ Ｙ < represents. Q Ｙ represents a hydrogen atom or a substituent. Q Ｚ represents a hydrogen atom or a substituent. B １ is one carbon atom and Q Ａ and Q Ｂ and represents a ring which may have a substituent and contains at least one of the following.

14. The compound according to any one of claims 11 to 13, wherein Q represents a group represented by formula (Q3): 【Chemistry 12】 In formula (Q3), * represents a bonding position. Q Ａ is a nitrogen atom, or -CQ Ｘ = represents. Q Ｘ represents a hydrogen atom or a substituent. Q Ｚ represents a hydrogen atom or a substituent. B ２ is one carbon atom, one nitrogen atom and Q Ａ and represents a ring which may have a substituent and contains at least one of the following.

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