Compound, composition, ink, photoelectric conversion element, and optical sensor

Abstract

To provide a compound that absorbs long wavelength light.SOLUTION: The present invention relates to a compound represented by the formula (X) in the figure. In the formula (X), D represents an electron-donating divalent group, at least one of p1 or p2 is a divalent group comprising at least one unit represented by the formula (a) or (b) in the figure, p1 and p2 may be the same or different, and each A independently represents an electron-withdrawing monovalent group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to compounds, compositions, inks, photoelectric conversion elements, and optical sensors.

Background Art

[0002] Photoelectric conversion elements are extremely useful devices, for example, from the viewpoints of energy saving and reduction of carbon dioxide emissions, and have attracted attention.

[0003] A photoelectric conversion element is an element including at least a pair of electrodes composed of an anode and a cathode, and an active layer provided between the pair of electrodes. In the photoelectric conversion element, at least one of the pair of electrodes is made of a transparent or translucent material, and light is incident on the active layer from the transparent or translucent electrode side. Due to the energy (hν) of the light incident on the active layer, charges (holes and electrons) are generated in the active layer. The generated holes move toward the anode, and the electrons move toward the cathode. Then, the charges that have reached the anode and the cathode are taken out to the outside of the element.

[0004] As compounds used in photoelectric conversion elements, for example, non-fullerene acceptors (NFAs, Non-Fullerene Acceptors) having a specific structure as described in Non-Patent Documents 1 to 3 are known.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the development of a new compound that can be used in a photoelectric conversion element that absorbs light in the eye-safe band (wavelength: 1300 nm to 1400 nm), which is less harmful to the human eye and has a longer wavelength, is further desired. A photoelectric conversion element that absorbs light in the eye-safe band is expected to be applied to consumer use (e.g., security cameras and line-of-sight measurement), industrial use (e.g., agricultural robots and microscopic inspections), and in-vehicle use (e.g., in-vehicle sensors).

[0007] The present disclosure has been made in view of the above, and the present disclosure provides a compound, a composition, an ink, a photoelectric conversion element, and an optical sensor that absorb light of a long wavelength.

Means for Solving the Problems

[0008] Specific means for solving the above problems include the following aspects. <1> A compound represented by the following formula (X).

[0009]

Chemical formula

[0010] In formula (X), D represents an electron-donating divalent group, at least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different, A each independently represents an electron-withdrawing monovalent group.

[0011]

Chemical formula

[0012]

Chemical formula

[0013] In formulas (a) and (b), X 1 is an electron-donating group, and Y 1 is a hydrogen atom or an electron-withdrawing group, *1 is a bond to the D side, and *2 is a bond to the A side, In formula (b), n is an integer from 1 to 3. <2> X 1 are each independently, -R b , -OR b and -NR b 2 any electron-donating group selected from the group consisting of, Y 1 are each independently, a hydrogen atom, -CN and -CO 2 R b any group selected from the group consisting of, R b are each independently, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group and aromatic alkynyl group may have substituents and may be linear, branched or cyclic, The compound according to <1>. <3> The compound according to <1>, represented by the following formula (1) or the following formula (2).

[0014]

Chemical formula

[0015] In formulas (1) and (2), D represents an electron-donating divalent group, A each independently represents an electron-withdrawing monovalent group, X 1 and X 2are each independently an electron-donating group, and Y 1 and Y 2 are each independently a hydrogen atom or an electron-withdrawing group, In formula (2), n is each independently an integer from 1 to 3. <4> X 1 and X 2 are each independently, -R b , -OR b and -NR b 2 is any electron-donating group selected from the group consisting of, Y 1 and Y 2 are each independently a hydrogen atom, -CN, and -CO 2 R b is any group selected from the group consisting of, R b are each independently an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have substituents and may be linear, branched, or cyclic, the compound according to <3>. <5> A is each independently a group represented by the following formula (a-1) to formula (a-5), the compound according to any one of <1> to <4>.

[0016]

Chemical formula

[0017] In the above formula (a-1) to formula (a-5), T represents a carbocyclic ring which may have substituents, or a heterocyclic ring which may have substituents. The carbocyclic ring and the heterocyclic ring may be monocyclic or fused rings. When these rings have a plurality of substituents, the plurality of substituents may be the same or different. X 4 , X5 and X 6 each independently represents an oxygen atom, a sulfur atom, an alkylidene group, =C(-CN) 2 or =C(-CN)-CR a represents a group represented by, R a is an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic. <6> A composition comprising a p-type semiconductor material and an n-type semiconductor material, wherein the n-type semiconductor material contains the compound according to any one of <1> to <5>. <7> The composition according to <6>, wherein the p-type semiconductor material is a polymer compound containing at least one selected from the group consisting of a structural unit represented by the following formula (3) and a structural unit represented by the following formula (4).

[0018]

Chemical formula

[0019] In formula (3), Ar 1 and Ar 2 each independently represents a trivalent aromatic heterocyclic group which may have a substituent, and Z represents a group represented by the following formula (Z-1) to formula (Z-7).

[0020]

Chemical formula

[0021] In formulas (Z-1) to (Z-7), R is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, A cycloalkyl group which may have a substituent, An aryl group which may have a substituent, An alkyloxy group which may have a substituent, A cycloalkyloxy group which may have a substituent, An aryloxy group which may have a substituent, An alkylthio group which may have a substituent, A cycloalkylthio group which may have a substituent, An arylthio group which may have a substituent, A monovalent heterocyclic group which may have a substituent, A substituted amino group which may have a substituent, An acyl group which may have a substituent, An imine residue which may have a substituent, An amide group which may have a substituent, An acid imide group which may have a substituent, A substituted oxycarbonyl group which may have a substituent, An alkenyl group which may have a substituent, A cycloalkenyl group which may have a substituent, An alkynyl group which may have a substituent, A cycloalkynyl group which may have a substituent, A cyano group, A nitro group, A group represented by -C(=O)-R d1 or -SO 2 -R d2 represents a group represented by, R d1 and R d2 each independently represents A hydrogen atom, An alkyl group which may have a substituent, An aryl group which may have a substituent, An alkyloxy group which may have a substituent, An aryloxy group which may have a substituent, or A monovalent heterocyclic group which may have a substituent. In each of Formulas (Z-1) to (Z-7), when there are two Rs, the two Rs may be the same as or different from each other. In Formula (4), Ar 3 represents a divalent aromatic heterocyclic group. <8> An ink containing a compound according to any one of <1> to <5> and a solvent. <9> An anode, a cathode, and an active layer provided between the anode and the cathode and containing a p-type semiconductor material and an n-type semiconductor material, <10> A photoelectric conversion element containing, as the n-type semiconductor material, a compound according to any one of <1> to <5>. <10> The photoelectric conversion element according to <9>, which is a photodetector element. <11> A photosensor containing the photoelectric conversion element according to <10>. <12> A compound represented by the following formula (X) and having a calculated value of the wavelength λ corresponding to the energy band gap Eg by density functional theory of 800 nm or more.

[0022]

Chemical formula

[0023] (In Formula (X), D represents an electron-donating divalent group, at least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different, A each independently represents an electron-withdrawing monovalent group.)

[0024]

Chemical formula

[0025]

Chemical formula

[0026] (In Formula (a) and Formula (b), X 1 is an electron-donating group, and Y 1 is a hydrogen atom or an electron-withdrawing group, *1 is a bond to the D side, and *2 is a bond to the A side, In formula (b), n is an integer from 1 to 3.) <13> The compound according to <12>, wherein the formula (X) is represented by the following formula (1) or the following formula (2).

[0027]

Chemical formula

[0028] In formula (1) and formula (2), D represents an electron-donating divalent group, A each independently represents an electron-withdrawing monovalent group, X 1 and X 2 are each independently an electron-donating group, and Y 1 and Y 2 are each independently a hydrogen atom or an electron-withdrawing group, In formula (2), n is each independently an integer from 1 to 3.)

Advantages of the Invention

[0029] According to the present disclosure, a compound, a composition, an ink, a photoelectric conversion element, and a photosensor that absorb light of a long wavelength are provided.)

Brief Description of the Drawings

[0030]

Figure 1

Modes for Carrying Out the Invention

[0031] Hereinafter, the compounds of the present disclosure will be described, and further, the photoelectric conversion elements using the compounds of the present disclosure will be described with reference to the drawings. Note that the drawings only schematically show the shapes, sizes, and arrangements of the components to the extent that the invention can be understood. The present disclosure is not limited by the following description, and each component can be appropriately changed without departing from the gist of the present disclosure. Also, the configuration of the present disclosure is not necessarily manufactured or used in the arrangement shown in the drawings.

[0032] In the present disclosure, in the numerical range indicated by "~", the numerical values described before and after "~" are included as the lower limit value and the upper limit value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stepwise descriptions. Also, in the numerical range described in the text, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, the content rate of each component in the composition means the total content rate of the plurality of substances corresponding to each component in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified.

[0033] In the present disclosure, commonly used terms will be explained. In the description of the present disclosure, the following explanations apply unless otherwise individually specified.

[0034] The term "non-fullerene compound" refers to a compound that is neither fullerene nor a fullerene derivative.

[0035] The term "π-conjugated system" means a system in which π electrons are delocalized over a plurality of bonds.

[0036] The term "polymer compound" refers to a polymer having a molecular weight distribution and a number average molecular weight in terms of polystyrene of 1×10 3 or more and 1×10 8 or less. Note that the constituent units contained in the polymer compound are 100 mol% in total.

[0037] The "structural unit" means a residue derived from a raw material compound (monomer) that is present in one or more in a compound and a polymer compound.

[0038] The "hydrogen atom" may be a light hydrogen atom or a deuterium atom.

[0039] Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0040] The aspect of "optionally having a substituent" includes both aspects where all hydrogen atoms constituting a compound or a group are unsubstituted and where some or all of one or more hydrogen atoms are substituted by a substituent.

[0041]

[0042] In this specification, unless otherwise specified, the "alkyl group" may be linear, branched, or cyclic. The number of carbon atoms of a linear alkyl group, excluding the number of carbon atoms of the substituent, is usually preferably 1 to 50, more preferably 1 to 30, and still more preferably 1 to 20. The number of carbon atoms of a branched or cyclic alkyl group, excluding the number of carbon atoms of the substituent, is usually preferably 3 to 50, more preferably 3 to 30, and still more preferably 4 to 20.

[0043] ​Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isoamyl group, 2-ethylbutyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, cyclohexylethyl group, n-octyl group, 2-ethylhexyl group, 3-n-propylheptyl group, adamantyl group, n-decyl group, 3,7-dimethyloctyl group, 2-ethyloctyl group, 2-n-hexyl-decyl group, n-dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, and eicosyl group.

[0044] The alkyl group may have a substituent. The alkyl group having a substituent is, for example, a group in which a hydrogen atom in the above-exemplified alkyl group is substituted with a substituent such as an alkyloxy group, an aryl group, or a fluorine atom.

[0045] Specific examples of the alkyl having a substituent include trifluoromethyl group, pentafluoroethyl group, perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, 3-phenylpropyl group, 3-(4-methylphenyl)propyl group, 3-(3,5-dihexylphenyl)propyl group, and 6-ethyloxyhexyl group.

[0046] The "cycloalkyl group" may be a monocyclic group or a polycyclic group. The cycloalkyl group may have a substituent. The number of carbon atoms of the cycloalkyl group, excluding the carbon atoms of the substituent, is usually preferably 3 to 30, more preferably 12 to 19.

[0047] Examples of the cycloalkyl group include alkyl groups having no substituent such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and adamantyl group, and groups in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0048] Specific examples of the cycloalkyl group having a substituent include a methylcyclohexyl group and an ethylcyclohexyl group.

[0049] The "aryl hydrocarbon group" means a group formed by removing any number of hydrogen atoms directly bonded to the carbon atoms constituting the ring from an aromatic hydrocarbon which may have a substituent. The aryl hydrocarbon group may further have a substituent. The "aryl hydrocarbon ring" includes a structure in which two or more carbon rings (aromatic rings) are bridged by a group (substituent) containing a hetero atom, for example.

[0050] The "aryl group" is a monovalent aryl hydrocarbon group, and means a group formed by removing one hydrogen atom directly bonded to the carbon atom constituting the ring from an aromatic hydrocarbon which may have a substituent.

[0051] The aryl group may have a substituent. Specific examples of the aryl group include a phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 2-phenylphenyl group, 3-phenylphenyl group, 4-phenylphenyl group, and groups in which hydrogen atoms in these groups are substituted with substituents such as an alkyl group, an alkyloxy group, an aryl group, and a fluorine atom.

[0052] The "alkyloxy group" may be linear, branched, or cyclic. The number of carbon atoms of the linear alkyloxy group, excluding the number of carbon atoms of the substituent, is usually preferably 1 to 40, more preferably 1 to 10. The number of carbon atoms of the branched or cyclic alkyloxy group, excluding the number of carbon atoms of the substituent, is usually preferably 3 to 40, more preferably 4 to 10.

[0053] The alkyloxy group may have a substituent. Specific examples of the alkyloxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a tert-butyloxy group, an n-pentyloxy group, an n-hexyloxy group, a cyclohexyloxy group, an n-heptyloxy group, an n-octyloxy group, a 2-ethylhexyloxy group, an n-nonyloxy group, an n-decyloxy group, a 3,7-dimethyloctyloxy group, a 3-heptyldodecyloxy group, a lauryloxy group, and groups in which a hydrogen atom in these groups is substituted with an alkyloxy group, an aryl group, or a fluorine atom.

[0054] The cycloalkyl group of the "cycloalkyloxy group" may be a monocyclic group or a polycyclic group. The cycloalkyloxy group may have a substituent. The number of carbon atoms of the cycloalkyloxy group, excluding the number of carbon atoms of the substituent, is usually preferably 3 to 30, more preferably 12 to 19.

[0055] Examples of the cycloalkyloxy group include cycloalkyloxy groups having no substituent such as a cyclopentyloxy group, a cyclohexyloxy group, and a cycloheptyloxy group, and groups in which a hydrogen atom in these groups is substituted with a fluorine atom or an alkyl group.

[0056] The number of carbon atoms of the "aryloxy group", excluding the number of carbon atoms of the substituent, is usually preferably 6 to 60, more preferably 6 to 48.

[0057] The aryloxy group may have a substituent. Specific examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 1-anthracenyloxy group, a 9-anthracenyloxy group, a 1-pyrenyloxy group, and groups in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkyloxy group, or a fluorine atom.

[0058] The "alkylthio group" may be linear, branched, or cyclic. The number of carbon atoms in the linear alkylthio group, excluding the carbon atoms of the substituent, is usually preferably 1 to 40, more preferably 1 to 10. The number of carbon atoms in the branched and cyclic alkylthio groups, excluding the carbon atoms of the substituent, is usually preferably 3 to 40, more preferably 4 to 10.

[0059] The alkylthio group may have a substituent. Specific examples of the alkylthio group include methylthio group, ethylthio group, propylthio group, isopropylthio group, butylthio group, isobutylthio group, tert-butylthio group, pentylthio group, hexylthio group, cyclohexylthio group, heptylthio group, octylthio group, 2-ethylhexylthio group, nonylthio group, decylthio group, 3,7-dimethyloctylthio group, laurylthio group, and trifluoromethylthio group.

[0060] The cycloalkyl group of the "cycloalkylthio group" may be a monocyclic group or a polycyclic group. The cycloalkylthio group may have a substituent. The number of carbon atoms in the cycloalkylthio group, excluding the carbon atoms of the substituent, is usually preferably 3 to 30, more preferably 12 to 19.

[0061] An example of the cycloalkylthio group that may have a substituent is the cyclohexylthio group.

[0062] The number of carbon atoms in the "arylthio group", excluding the carbon atoms of the substituent, is usually preferably 6 to 60, more preferably 6 to 48.

[0063] The arylthio group may have a substituent. Examples of the arylthio group include a phenylthio group, a C1-C12 alkyloxyphenylthio group (C1-C12 indicates that the number of carbon atoms in the group described immediately after is 1 to 12. The same applies hereinafter), a C1-C12 alkylphenylthio group, a 1-naphthylthio group, a 2-naphthylthio group, and a pentafluorophenylthio group.

[0064] The "heterocyclic group" means a group remaining after removing any number of hydrogen atoms directly bonded to a carbon atom or a heteroatom constituting the ring from a heterocyclic compound which may have a substituent.

[0065] The heterocyclic group may further have a substituent. The number of carbon atoms in the heterocyclic group, excluding the number of carbon atoms in the substituent, is usually preferably 2 to 30, more preferably 2 to 6.

[0066] Examples of the substituent which the heterocyclic compound may have include, for example, a halogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, an alkylthio group, an arylthio group, a monovalent heterocyclic group, a substituted amino group, an acyl group, an imine residue, an amide group, an acid imide group, a substituted oxycarbonyl group, an alkenyl group, an alkynyl group, a cyano group, and a nitro group. The heterocyclic group includes an "aromatic heterocyclic group".

[0067] The "aromatic heterocyclic group" means a group remaining after removing any number of hydrogen atoms directly bonded to a carbon atom or a heteroatom constituting the ring from an aromatic heterocyclic compound which may have a substituent. The aromatic heterocyclic group may further have a substituent.

[0068] The aromatic heterocyclic compounds include, in addition to compounds in which the heterocyclic ring itself exhibits aromaticity, compounds in which the heterocyclic ring itself does not exhibit aromaticity but an aromatic ring is fused to the heterocyclic ring.

[0069] Among aromatic heterocyclic compounds, specific examples of compounds in which the heterocyclic ring itself exhibits aromaticity include oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, and dibenzophosphole.

[0070] Among aromatic heterocyclic compounds, specific examples of compounds in which the aromatic heterocyclic ring itself does not exhibit aromaticity and an aromatic ring is fused to the heterocyclic ring include phenoxazine, phenothiazine, dibenzoborole, dibenzosilole, and benzopyran.

[0071] The number of carbon atoms of the monovalent heterocyclic group, excluding the number of carbon atoms of the substituent, is usually preferably 2 to 60, more preferably 4 to 20.

[0072] The monovalent heterocyclic group may have a substituent. Specific examples of the monovalent heterocyclic group include, for example, a thienyl group, a pyrrolyl group, a furyl group, a pyridyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, a pyrimidinyl group, a triazinyl group, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, an alkyloxy group, or the like.

[0073] The "substituted amino group" means an amino group having a substituent. Examples of the substituent that the amino group has include an alkyl group, an aryl group, and a monovalent heterocyclic group, and an alkyl group, an aryl group, or a monovalent heterocyclic group is preferable. The number of carbon atoms of the substituted amino group is usually preferably 2 to 30.

[0074] Examples of the substituted amino group include dialkylamino groups such as dimethylamino group and diethylamino group; diarylamino groups such as diphenylamino group, bis(4-methylphenyl)amino group, bis(4-tert-butylphenyl)amino group, and bis(3,5-di-tert-butylphenyl)amino group.

[0075] The "acyl group" may have a substituent. The number of carbon atoms in the acyl group, excluding the number of carbon atoms in the substituent, is usually preferably 2 to 20, more preferably 2 to 18. Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a benzoyl group, a trifluoroacetyl group, and a pentafluorobenzoyl group.

[0076] The "imine residue" means the remaining atomic group obtained by removing one hydrogen atom directly bonded to the carbon atom or nitrogen atom constituting the carbon atom-nitrogen atom double bond from an imine compound. The "imine compound" means an organic compound having a carbon atom-nitrogen atom double bond in the molecule. Examples of the imine compound include aldimine, ketimine, and a compound in which the hydrogen atom bonded to the nitrogen atom constituting the carbon atom-nitrogen atom double bond in aldimine is substituted with an alkyl group or the like.

[0077] The imine residue usually preferably has 2 to 20 carbon atoms, more preferably 2 to 18 carbon atoms. Examples of the imine residue include groups represented by the following structural formulas. In the following structural formulas, Me represents a methyl group.

[0078]

Chemical formula

[0079] The "amide group" means the remaining atomic group obtained by removing one hydrogen atom bonded to the nitrogen atom from an amide. The number of carbon atoms in the amide group is usually preferably 1 to 20, more preferably 1 to 18. Specific examples of the amide group include a formamide group, an acetamide group, a propioamide group, a butyroamide group, a benzamide group, a trifluoroacetamide group, a pentafluorobenzamide group, a diformamide group, a diacetamide group, a dipropioamide group, a dibutyroamide group, a dibenzamide group, a ditrifluoroacetamide group, and a dipentafluorobenzamide group.

[0080] "Acid imide group" means the remaining atomic group after removing one hydrogen atom bonded to the nitrogen atom from acid imide. The number of carbon atoms in the acid imide group is usually preferably 4 to 20. Specific examples of the acid imide group include groups represented by the following structural formulas. In the following structural formulas, Me represents a methyl group.

[0081] [Chemical formula]

[0082] "Substituted oxycarbonyl group" means a group represented by R'-O-(C=O)-. Here, R' represents an alkyl group, an aryl group, an arylalkyl group, or a monovalent heterocyclic group.

[0083] The number of carbon atoms in the substituted oxycarbonyl group, excluding the number of carbon atoms in the substituent, is usually preferably 2 to 60, and more preferably 2 to 48.

[0084] Specific examples of the substituted oxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, isobutoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group, cyclohexyloxycarbonyl group, heptyloxycarbonyl group, octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3,7-dimethyloctyloxycarbonyl group, dodecyloxycarbonyl group, trifluoromethoxycarbonyl group, pentafluoroethoxycarbonyl group, perfluorobutoxycarbonyl group, perfluorohexyloxycarbonyl group, perfluorooctyloxycarbonyl group, phenoxycarbonyl group, naphthoxycarbonyl group, and pyridyloxycarbonyl group.

[0085] "Alkenyl group" may be linear, branched, or cyclic. The number of carbon atoms in a linear alkenyl group, excluding the number of carbon atoms in the substituent, is usually preferably 2 to 30, more preferably 3 to 20. The number of carbon atoms in a branched or cyclic alkenyl group, excluding the number of carbon atoms in the substituent, is usually preferably 3 to 30, more preferably 4 to 20.

[0086] The alkenyl group may have a substituent. Specific examples of the alkenyl group include a vinyl group, 1-propenyl group, 2-propenyl group, 2-butenyl group, 3-butenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5-hexenyl group, 7-octenyl group, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0087] "Cycloalkenyl group" may be a monocyclic group or a polycyclic group. The cycloalkenyl group may have a substituent. The number of carbon atoms in the cycloalkenyl group, excluding the number of carbon atoms in the substituent, is usually preferably 3 to 30, more preferably 12 to 19.

[0088] Examples of the cycloalkenyl group include cycloalkenyl groups having no substituent such as a cyclohexenyl group, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0089] Examples of the cycloalkenyl group having a substituent include a methylcyclohexenyl group and an ethylcyclohexenyl group.

[0090] "Alkynyl group" may be linear, branched, or cyclic. The number of carbon atoms in a linear alkynyl group, excluding the number of carbon atoms in the substituent, is usually preferably 2 to 20, more preferably 3 to 20. The number of carbon atoms in a branched or cyclic alkynyl group, excluding the number of carbon atoms in the substituent, is usually preferably 4 to 30, more preferably 4 to 20.

[0091] The alkynyl group may have a substituent. Specific examples of the alkynyl group include an ethynyl group, 1-propynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, 3-pentynyl group, 4-pentynyl group, 1-hexynyl group, 5-hexynyl group, and groups in which a hydrogen atom in these groups is substituted with an alkyloxy group, aryl group, or fluorine atom.

[0092] The "cycloalkynyl group" may be a monocyclic group or a polycyclic group. The cycloalkynyl group may have a substituent. The number of carbon atoms in the cycloalkynyl group, excluding the number of carbon atoms in the substituent, is usually preferably 4 to 30, more preferably 12 to 19.

[0093] Examples of the cycloalkynyl group include a cycloalkynyl group having no substituent such as a cyclohexynyl group, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, alkyloxy group, aryl group, or fluorine atom.

[0094] Examples of the cycloalkynyl group having a substituent include a methylcyclohexynyl group and an ethylcyclohexynyl group.

[0095] The "alkylsulfonyl group" may be linear or branched. The alkylsulfonyl group may have a substituent. The number of carbon atoms in the alkylsulfonyl group, excluding the number of carbon atoms in the substituent, is usually preferably 1 to 30. Specific examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a dodecylsulfonyl group.

[0096] The symbol "*" that can be attached to a chemical formula represents a bond.

[0097] "Ink" means a liquid substance used in a coating method and is not limited to a colored liquid. Also, the "coating method" includes methods of forming a film (layer) using a liquid substance. Examples include slot die coating, slit coating, knife coating, spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, gravure printing, flexographic printing, offset printing, inkjet coating, dispenser printing, nozzle coating, and capillary coating.

[0098] The ink may be a solution or a dispersion such as an emulsion or a suspension.

[0099] The "absorption peak wavelength" is a parameter specified based on the absorption peak of the absorption spectrum measured in a predetermined wavelength range, and refers to the wavelength of the absorption peak with the largest absorbance among the absorption peaks of the absorption spectrum.

[0100] The "external quantum efficiency", also referred to as EQE (External Quantum Efficiency), is a value indicating the ratio (%) of the number of electrons that could be extracted outside the photoelectric conversion element to the number of electrons generated with respect to the number of photons irradiated on the photoelectric conversion element.

[0101] ≪Compound≫ <Compound represented by formula (X)> The compound of the present disclosure is represented by the following formula (X).

[0102]

Chemical formula

[0103] In formula (X), D represents a divalent electron-donating group, At least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different. Each A independently represents an electron-withdrawing monovalent group.

[0104]

Chemical formula

[0105]

Chemical formula

[0106] In formula (a) and formula (b), X 1 is an electron-donating group, and Y 1 is a hydrogen atom or an electron-withdrawing group. *1 is a bond to the D side, and *2 is a bond to the A side. In formula (b), n is an integer from 1 to 3.

[0107] The compound of the present disclosure is represented by formula (X) and absorbs light with a long wavelength. Although the action of the compound of the present disclosure is not clear, it is presumed as follows. In the chemical structure of formula (X), the group represented by D is the core, the group represented by A is the acceptor, and the groups represented by p1 and p2 (that is, the groups located between D and A) are linkers. In the compound of the present disclosure, the linker contains a condensed ring structure, and in this condensed ring structure, X 1 is used as an electron-donating group, and Y 1 is used as a hydrogen atom or an electron-withdrawing group. X 1 has a great influence on the core in terms of the distribution of the HOMO orbital, so by using X 1 as an electron-donating group, the electron-donating property (that is, the core property) of the core can be increased. On the other hand, Y 1 has a great influence on the acceptor in terms of the distribution of the LUMO orbital, so Y 1By using a hydrogen atom or an electron-withdrawing group, the electron-withdrawing property (i.e., acceptor property) of the acceptor can be enhanced. That is, since the compound of the present disclosure has strong core property and strong acceptor property, the HOMO energy of the compound is high and the LUMO energy is low. That is, the compound of the present disclosure has a small HOMO-LUMO gap. From the above, the compound of the present disclosure is likely to absorb light of low energy, i.e., light of long wavelength. It should be noted that the present disclosure is not limited to the above estimation mechanism at all.

[0108] [Linker; p1 and p2] In the compound of the present disclosure, at least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different.

[0109]

Chemical formula

[0110]

Chemical formula

[0111] In formula (a) and formula (b), X 1 is an electron-donating group, Y 1 is a hydrogen atom or an electron-withdrawing group, *1 is a bond to the D side, and *2 is a bond to the A side, In formula (b), n is an integer from 1 to 3.

[0112] (Unit) In the compound of the present disclosure, the number of units represented by formula (a) or formula (b) in p1 or p2 is not particularly limited. p1 may be a divalent group containing a total of 0 to 3 units represented by formula (a) or the following formula (b), may be a divalent group containing a total of 0 to 2 units, or may be a divalent group containing a total of 0 or 1 unit. p2 may be a divalent group containing a total of 0 to 3 units represented by formula (a) or the following formula (b), may be a divalent group containing a total of 0 to 2 units, or may be a divalent group containing a total of 0 or 1 unit.

[0113] In the compound of the present disclosure, the core and the acceptor are π-conjugated via a linker. Here, for example, when there are a plurality of condensed ring structures (specifically, thienothiophene structures) represented by formula (a) or formula (b) in p1 or p2, the π-conjugation is further extended. Even when there are a plurality of condensed ring structures represented by formula (a) or formula (b), an electron-donating group X 1 is present at a site where the contribution to the HOMO energy is large, and an electron-withdrawing group Y 1 is present at a site where the contribution to the LUMO energy is large. And thereby, the electron-donating property (i.e., core property) of the core and the electron-withdrawing property (i.e., acceptor property) of the acceptor are enhanced, the HOMO-LUMO gap becomes small, and it becomes easy to absorb light of a long wavelength.

[0114] In the compound of the present disclosure, only p1 may be a divalent group containing at least one unit represented by formula (a) or formula (b), only p2 may be a divalent group containing at least one unit represented by formula (a) or formula (b), or both p1 and p2 may each independently be a divalent group containing at least one unit represented by formula (a) or formula (b). From the viewpoint that the compound easily absorbs light of a long wavelength, it is preferable that both p1 and p2 are each independently a divalent group containing at least one unit represented by formula (a) or formula (b).

[0115] In the compound of the present disclosure, at least one of p1 and p2 may be a divalent group containing at least one unit represented by formula (a), or at least one of p1 and p2 may be a divalent group containing at least one unit represented by formula (b). From the viewpoint of easy synthesis, it is preferable that both p1 and p2 are divalent groups containing at least one unit represented by formula (a).

[0116] p1 may be a divalent group that does not contain the unit represented by formula (a) or formula (b), may be a divalent group that contains one unit represented by formula (a) or formula (b), may be a divalent group that contains two units represented by formula (a) or formula (b), or may be a divalent group that contains one unit represented by formula (a) and one unit represented by formula (b). From the viewpoint of facilitating synthesis, p1 is preferably a divalent group that contains one unit represented by formula (a) or formula (b).

[0117] p2 may be a divalent group that does not contain the unit represented by formula (a) or formula (b), may be a divalent group that contains one unit represented by formula (a) or formula (b), may be a divalent group that contains two units represented by formula (a) or formula (b), or may be a divalent group that contains one unit represented by formula (a) and one unit represented by formula (b). From the viewpoint of facilitating synthesis, p2 is preferably a divalent group that contains one unit represented by formula (a) or formula (b).

[0118] p1 and p2 may be the same or different. That p1 and p2 may be the same or different means that when taking D in formula (X) as the center point, the chemical structure of p1 and the chemical structure of p2 may be point-symmetrical or may not be point-symmetrical. From the viewpoint of easy synthesis, p1 and p2 are preferably the same. That is, when taking D in formula (X) as the center point, the chemical structure of p1 and the chemical structure of p2 are preferably point-symmetrical.

[0119] In formula (a) and formula (b), *1 is a bond to the D side, and *2 is a bond to the A side. The bond to the D side may be a bond directly connecting to D, or may be a bond connecting to D through the unit represented by formula (a) or formula (b) or other structures outside the unit. The bond to the A side may be a bond directly connecting to A, or may be a bond connecting to A through the unit represented by formula (a) or formula (b) or other structures outside the unit.

[0120] {X 1} In formula (a) and formula (b), X 1 is an electron-donating group. When there are a plurality of X 1 in formula (X), X 1 may have the same structure or different structures from each other. From the viewpoint of making the synthesis of the compounds of the present disclosure easier, it is preferable that the plurality of X 1 are the same group.

[0121] From the viewpoint that the compound easily absorbs light of a long wavelength, X 1 is preferably any electron-donating group selected from the group consisting of -R b , -OR b and -NR b 2 . Here, each R b is independently an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group and aromatic alkynyl group may have substituents and may be linear, branched or cyclic. From the viewpoint that the compound easily absorbs light of a long wavelength, X 1 is more preferably an alkyloxy group, that is, -OR b , and it is even more preferable that it is -OR b and R b is an alkyl group having 1 to 30 carbon atoms.

[0122] {Y 1} In formula (a) and formula (b), Y 1 is a hydrogen atom or an electron-withdrawing group. When there are a plurality of Y 1 in formula (X), Y 1 may have the same structure or different structures from each other. From the viewpoint of making the synthesis of the compounds of the present disclosure easier, it is preferable that the plurality of Y 1 are the same group.

[0123] From the viewpoint that the compound is likely to absorb light of a long wavelength, Y 1 is preferably any group selected from the group consisting of a hydrogen atom, -CN, and -CO 2 R b is preferably any group selected from the group consisting of a hydrogen atom, -CN, and -CO. Note that R b is each independently an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic. From the viewpoint that the synthesis of the compound is easy, Y 1 is more preferably a hydrogen atom.

[0124] {n} In formula (b), n is an integer of 1 to 3. From the viewpoint of making the synthesis of the compound of the present disclosure easier, n is preferably 1 or 2, and more preferably 1. When a plurality of n are present in formula (X), n may be the same integer or different from each other. From the viewpoint of making the synthesis of the compound of the present disclosure easier, n is preferably the same integer.

[0125] (Configuration other than the unit) The configuration other than the unit represented by formula (a) or formula (b) that may be included in p1 or p2 is not particularly limited as long as the effects of the present disclosure are achieved. The configuration other than the unit represented by formula (a) or formula (b) that may be included in p1 or p2 is preferably an electron-donating group for the substituent adjacent to D in either p1 or p2 from the viewpoint that the compound is likely to absorb light of a long wavelength. Note that the substituent adjacent to D means the substituent closest to D among the substituents for the molecular chain that shortest connects A and D in p1 or p2 (when the molecular chain includes a ring structure, it means the substituent for the ring structure).

[0126] In the present disclosure, a configuration other than the unit represented by formula (a) or formula (b) that may be included in p1 or p2 is Ar p is defined as. In the compounds of the present disclosure, when there are a plurality of Ar p the plurality of Ar p may be the same as or different from each other.

[0127] For example, p1 is a group containing a divalent group containing at least one unit represented by formula (a) or formula (b) and a divalent group represented by Ar p and p2 may be a group containing a divalent group containing at least one unit represented by formula (a) or formula (b) and a divalent group represented by Ar p . Alternatively, p1 is a group composed of a divalent group containing at least one unit represented by formula (a) or formula (b) and a divalent group represented by Ar p and p2 may be a divalent group containing at least one unit represented by formula (a) or formula (b). Alternatively, p1 is a group composed of a divalent group containing at least one unit represented by formula (a) or formula (b) and a divalent group represented by Ar p and p2 may be a divalent group represented by Ar p .

[0128] Alternatively, p1 is a divalent group containing at least one unit represented by formula (a) or formula (b) and p2 may be a group composed of a divalent group containing at least one unit represented by formula (a) or formula (b) and a divalent group represented by Ar p . Alternatively, p1 is a divalent group containing at least one unit represented by formula (a) or formula (b) and p2 may be a divalent group represented by Ar p .

[0129] Alternatively, p1 is a divalent group represented by Ar p and p2 is a divalent group containing at least one unit represented by formula (a) or formula (b) and Ar pIt may also be a group composed of a divalent group represented by Alternatively, p1 is Ar p is a divalent group, and p2 may be a divalent group containing at least one unit represented by formula (a) or formula (b).

[0130] Ar p The structure of is not particularly limited, but Ar p is preferably a divalent aromatic carbon ring group which may have a substituent and in which a plurality of ring structures may be further condensed, or a divalent aromatic heterocyclic group which may have a substituent and in which a plurality of ring structures may be further condensed. The divalent aromatic carbon ring group and the divalent aromatic heterocyclic group preferably have 3 or less double bonds in the main chain, that is, the conjugated structure connecting the two bonds in the shortest way.

[0131] From the viewpoint of solubility, the divalent aromatic carbon ring group and the divalent aromatic heterocyclic group preferably have 2 double bonds in the conjugated structure connecting the two bonds in the shortest way.

[0132] Ar p preferably is a divalent aromatic heterocyclic group which contains a thiophene ring, may have a substituent, and in which a plurality of ring structures may be condensed.

[0133] Ar p The divalent aromatic carbon ring group (arylene group) represented by specifically means the remaining atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon which may have a substituent. Here, the aromatic hydrocarbon includes a compound having a condensed ring in which a plurality of ring structures are condensed.

[0134] Ar p The number of carbon atoms of the divalent aromatic carbon ring group represented by is usually 6 to 60, preferably 6 to 20, not including the number of carbon atoms of the substituent. The number of carbon atoms of the aromatic carbon ring group including the substituent is usually 6 to 100.

[0135] Ar pExamples of the divalent aromatic carbocyclic group represented by include divalent aromatic carbocyclic groups represented by the following formulae. The divalent aromatic carbocyclic groups represented by the following formulae may further have substituents. In the formulae, the symbol "*" indicates a bond.

[0136]

Chemical formula

[0137] Ar p The number of carbon atoms of the divalent aromatic heterocyclic group represented by is usually 2 to 60, preferably 4 to 60, and more preferably 4 to 20.

[0138] Ar p Examples of the substituents that the divalent aromatic heterocyclic group represented by may have include a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkyloxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent, an acyl group which may have a substituent, an imine residue which may have a substituent, an amide group which may have a substituent, an acid imide group which may have a substituent, a substituted oxycarbonyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, a cyano group, and a nitro group.

[0139] Ar p Specific examples of the divalent aromatic heterocyclic group represented by include divalent aromatic heterocyclic groups represented by the following formulae. These groups may further have substituents. In the formulae, the symbol "*" indicates a bond, and the bond to either the D side, the A side, formula (a), or formula (b) is not particularly limited.

[0140]

Chemical formula

[0141]

Chem.

[0142]

Chem.

[0143] Ar p As the divalent aromatic heterocyclic group represented by, the divalent aromatic heterocyclic group represented by the following formula is preferable. These groups may further have substituents.

[0144]

Chem.

[0145] Ar represented by the above formula p Preferable specific examples of the divalent aromatic heterocyclic group represented by include divalent groups represented by the following formula.

[0146]

Chem.

[0147] (Examples of linker) In the above, the preferred embodiments of p1 and p2, the preferred embodiments of the units represented by formula (a) and formula (b), and Ar p Although the preferred embodiments have been described, the combination of each preferred embodiment results in a more preferred linker embodiment. p1 and p2 are each independently preferably any group represented by the following formula (p12-1) to formula (p12-8), more preferably a group represented by the following formula (p12-1), formula (p12-3), formula (p12-4), or formula (p12-6), and even more preferably a group represented by the following formula (p12-1) or formula (p12-3).

[0148] In formula (p12-1) to formula (p12-8), X1 , Y 1 , and the definitions, examples, and preferred embodiments of n, etc. are as described above. When there are a plurality of Ys 1 in the formula, the Ys 1 may have the same structure or different structures from each other. When there are a plurality of ns in the formula, the ns may be the same integer or different integers from each other. In the formula, the definition, example, and preferred embodiment of Ar p are as described above. *1 is a bond to the D side, and *2 is a bond to the A side.

[0149]

Chemical formula

[0150] Specific examples of formula (p12-1) include groups represented by the following formulas. In each formula, *1 is a bond to the D side, and *2 is a bond to the A side.

[0151]

Chemical formula

[0152]

Chemical formula

[0153]

Chemical formula

[0154]

Chemical formula

[0155] Specific examples of formula (p12-2), formula (p12-3), and formula (p12-7) include groups represented by the following formulas. In each formula, *1 is a bond to the D side, and *2 is a bond to the A side.

[0156] [Chemistry]

[0157] Specific examples of formula (p12-4) include groups represented by the following formulas. In each formula, *1 is a bond to the D side and *2 is a bond to the A side.

[0158] [Chemistry]

[0159] [Chemistry]

[0160] Specific examples of formula (p12-5), formula (p12-6), and formula (p12-8) include groups represented by the following formulas. In each formula, *1 is a bond to the D side and *2 is a bond to the A side.

[0161] [Chemistry]

[0162] [Acceptor; A] A each independently represents an electron-withdrawing monovalent group. The two A's in formula (X) may be the same group or different groups from each other. From the viewpoint of making the synthesis of the compounds of the present disclosure easier, it is preferable that the two A's in formula (X) are the same group.

[0163] From the viewpoint that the compound is likely to absorb light of a long wavelength, the two A's in formula (X) are preferably each independently a group represented by the following formula (a-1) to formula (a-5), and more preferably a group represented by formula (a-1).

[0164] [Chemistry]

[0165] (T) In the above formulas (a-1) to (a-5), T represents a carbocyclic ring which may have a substituent or a heterocyclic ring which may have a substituent. The carbocyclic ring and the heterocyclic ring may be a monocyclic ring or a condensed ring. When these rings have a plurality of substituents, the plurality of substituents may be the same or different.

[0166] Examples of the carbocyclic ring which may have a substituent represented by T include aromatic carbocyclic rings, and preferably an aromatic carbocyclic ring. Specific examples of the carbocyclic ring which may have a substituent represented by T include benzene ring, naphthalene ring, anthracene ring, tetracene ring, pentacene ring, pyrene ring, and phenanthrene ring, preferably benzene ring, naphthalene ring, and phenanthrene ring, more preferably benzene ring and naphthalene ring, and still more preferably benzene ring. These rings may have a substituent.

[0167] Examples of the heterocyclic ring which may have a substituent represented by T include aromatic heterocyclic rings, and preferably an aromatic heterocyclic ring. Specific examples of the heterocyclic ring which may have a substituent represented by T include pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, thienothiophene ring, quinoline ring, quinoxaline ring, pyridopyrazine ring, and pyrazinopyrazine ring, preferably thiophene ring, and pyridine ring, pyrazine ring, thiazole ring, thienothiophene ring, quinoxaline ring, pyridopyrazine ring and pyrazinopyrazine ring, more preferably pyridine ring, pyrazine ring, quinoxaline ring, pyridopyrazine ring, and pyrazinopyrazine ring. These rings may have a substituent.

[0168] Examples of the substituent that the carbocycle or heterocycle represented by T may have include a halogen atom, an alkyl group, an alkyloxy group, an aryl group, a nitro group, a cyano group, and a monovalent heterocyclic group, and are preferably a fluorine atom, a chlorine atom, an alkyloxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms, a nitro group, or a cyano group, and more preferably a fluorine atom, a chlorine atom, a nitro group, or a cyano group.

[0169] (X 4 , X 5 , X 6 ) X 4 , X 5 , and X 6 each independently represent an oxygen atom, a sulfur atom, an alkylidene group, or a group represented by =C(-CN) 2 or =C(-CN)-CR a . It is preferable that X 4 , X 5 , and X 6 are each independently an oxygen atom or =C(-CN) 2 .

[0170] R a represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic.

[0171] (Example of A) Above, the preferred embodiment of T, the preferred embodiments of X 4 , X 5 , and X 6 , and the preferred embodiment of R a have been explained, but the combination of each of the preferred embodiments results in a more preferred embodiment of A. Examples of A include groups represented by the following formulas (a-1-1) to (a-1-22), (a-2-1), (a-2-2), and (a-3-1). In each formula, the symbol "*" indicates a bonding hand with a linker.

[0172] From the viewpoint that the compound is likely to absorb light of a long wavelength, the two A's in formula (X) are each independently preferably a group represented by the following formula (a-1-1), (a-1-6), (a-1-7), (a-1-14), (a-1-15), or (a-1-16), more preferably a group represented by the following formula (a-1-1), (a-1-15), or (a-1-16), and even more preferably a group represented by the following formula (a-1-1).

[0173] [Chemical formula]

[0174] [Chemical formula]

[0175] [Chemical formula]

[0176] In formulas (a-1-1) to (a-1-22), (a-2-1), (a-2-2), and (a-3-1), R a1 ~R a9 each independently represents a hydrogen atom or a substituent. R a1 ~R a9Each is independently preferably a hydrogen atom, a halogen atom, a cyano group, a linear alkyl group, a branched alkyl group, a silyl group, an ester group, an alkyloxy group, a thioalkyl group, a haloalkyl group, an alkene group, an alkyne group, a cyano-substituted alkyl group, a nitro-substituted alkyl group, a hydroxy-substituted alkyl group, or a keto-substituted alkyl group, more preferably each is independently a hydrogen atom, a halogen atom, an alkyloxy group, a cyano group or an alkyl group, and even more preferably each is independently a hydrogen atom, a fluorine atom, a chlorine atom, or a cyano group.

[0177] In addition, the linear alkyl group preferably has 1 to 30 carbon atoms, the branched alkyl group preferably has 3 to 30 carbon atoms, the silyl group preferably has 1 to 30 carbon atoms, the ester group preferably has 2 to 30 carbon atoms, the alkyloxy group preferably has 1 to 30 carbon atoms, the thioalkyl group preferably has 1 to 30 carbon atoms, the haloalkyl group preferably has 1 to 30 carbon atoms, the alkene group preferably has 2 to 30 carbon atoms, the alkyne group preferably has 2 to 30 carbon atoms, the cyano-substituted alkyl group preferably has 2 to 30 carbon atoms, the nitro-substituted alkyl group preferably has 1 to 30 carbon atoms, the hydroxy-substituted alkyl group preferably has 1 to 30 carbon atoms, and the keto-substituted alkyl group preferably has 3 to 30 carbon atoms.

[0178] Specific examples of A include groups represented by the following formulas. In each formula, the symbol "*" indicates a bond to the linker.

[0179]

Chemical formula

[0180] [Core; D] In formula (X), D represents an electron-donating divalent group. From the perspective that the compound is likely to absorb light of long wavelengths, D in formula (X) is preferably a group represented by the following formula (c-1) to formula (c-27), more preferably a group represented by formula (c-2) to formula (c-10), and even more preferably a group represented by formula (c-4). In the formula, the symbol "*" indicates a bond, and it is not particularly limited which of the two linkers that may exist in the compound of the present disclosure the bond is with.

[0181]

Chemical formula

[0182]

Chemical formula

[0183] (U, U 1 , U 2 ) In the above formula (c-1) to formula (c-27), U, U 1 , and U 2 are each O, S, or Se. It is preferable that U, U 1 , and U 2 are S.

[0184] (R c1 ) R c1 are each independently a hydrogen atom, a halogen atom, a cyano group, a linear alkyl group, a branched alkyl group, a silyl group, an ester group, an alkyloxy group, a thioalkyl group, a haloalkyl group, an alkene group, an alkyne group, a cyano-substituted alkyl group, a nitro-substituted alkyl group, a hydroxy-substituted alkyl group, or a keto-substituted alkyl group. R c1 are each independently preferably a linear alkyl group, a branched alkyl group, an alkene group or an alkyne group, more preferably a linear alkyl group or a branched alkyl group, and even more preferably a branched alkyl group.

[0185] In addition, the linear alkyl group preferably has 1 to 30 carbon atoms, the branched alkyl group preferably has 3 to 30 carbon atoms, the silyl group preferably has 1 to 30 carbon atoms, the ester group preferably has 2 to 30 carbon atoms, the alkyloxy group preferably has 1 to 30 carbon atoms, the thioalkyl group preferably has 1 to 30 carbon atoms, the haloalkyl group preferably has 1 to 30 carbon atoms, the alkene group preferably has 2 to 30 carbon atoms, the alkyne group preferably has 2 to 30 carbon atoms, the cyano-substituted alkyl group preferably has 2 to 30 carbon atoms, the nitro-substituted alkyl group preferably has 1 to 30 carbon atoms, the hydroxy-substituted alkyl group preferably has 1 to 30 carbon atoms, and the keto-substituted alkyl group preferably has 3 to 30 carbon atoms.

[0186] y is, independently of each other, an integer from 0 to 5. y is preferably an integer from 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0187] (Ar c1 ) Ar c1 is, independently of each other, a monocyclic or polycyclic aromatic ring or heteroaromatic ring group, which is unsubstituted or substituted with a halogen atom.

[0188] Ar c1 's aromatic ring has 4 to 30 cyclic carbon atoms, is preferably monocyclic or polycyclic, may contain a fused ring (more preferably 1, 2, 3, 4 or 5 fused rings) or a non-fused ring, and may optionally contain one or more halogen substituents. Ar c1 's heteroaromatic ring has 4 to 30 cyclic carbon atoms, one or more of the cyclic carbon atoms are heteroatoms (more preferably N, O, S, Si or substituents), is preferably monocyclic or polycyclic, may contain a fused ring (more preferably 1, 2, 3, 4 or 5 fused rings) or a non-fused ring, and may optionally contain one or more halogen substituents.

[0189] (Examples of D) In the above, U, U 1 and U 2 preferred embodiments, R c1 preferred embodiments, preferred embodiments of y, and Ar c1 preferred embodiments have been described, and combinations of the respective preferred embodiments result in more preferred embodiments of D. Examples of D include groups represented by the following formulas (c-3-1), (c-4-1), (c-5-1), (c-6-1) to (c-6-3), (c-7-1) to (c-7-3), (c-10-1), (c-17-1), (c-18-1) to (c-18-2), and (c-27-1). In each formula, the symbol "*" indicates a bond to the linker.

[0190] [Chemical formula]

[0191] In formulas (c-3-1), (c-4-1), (c-5-1), (c-6-1) to (c-6-3), (c-7-1) to (c-7-3), (c-10-1), (c-17-1), (c-18-1) to (c-18-2), and (c-27-1), R c1 is each independently a hydrogen atom, a halogen atom, a cyano group, a linear alkyl group, a branched alkyl group, a silyl group, an ester group, an alkyloxy group, a thioalkyl group, a haloalkyl group, an alkene group, an alkyne group, a cyano-substituted alkyl group, a nitro-substituted alkyl group, a hydroxy-substituted alkyl group, or a keto-substituted alkyl group. R c1 is each independently preferably a linear alkyl group, a branched alkyl group, an alkene group, or an alkyne group, more preferably a linear alkyl group or a branched alkyl group, and even more preferably a branched alkyl group.

[0192] In addition, the linear alkyl group preferably has 1 to 30 carbon atoms, the branched alkyl group preferably has 3 to 30 carbon atoms, the silyl group preferably has 1 to 30 carbon atoms, the ester group preferably has 2 to 30 carbon atoms, the alkyloxy group preferably has 1 to 30 carbon atoms, the thioalkyl group preferably has 1 to 30 carbon atoms, the haloalkyl group preferably has 1 to 30 carbon atoms, the alkene group preferably has 2 to 30 carbon atoms, the alkyne group preferably has 2 to 30 carbon atoms, the cyano-substituted alkyl group preferably has 2 to 30 carbon atoms, the nitro-substituted alkyl group preferably has 1 to 30 carbon atoms, the hydroxy-substituted alkyl group preferably has 1 to 30 carbon atoms, and the keto-substituted alkyl group preferably has 3 to 30 carbon atoms.

[0193] Specific examples of D include groups represented by the following formulas. In each formula, the symbol "*" indicates a bond to the linker, and it is not particularly limited which of the two linkers that may be present in the compound of the present disclosure the bond is to.

[0194]

Chemical formula

[0195] <Compound represented by formula (1) or formula (2)> The compound of the present disclosure is preferably represented by the following formula (1) or the following formula (2).

[0196]

Chemical formula

[0197] In formula (1) and formula (2), D represents an electron-donating divalent group, A each independently represents an electron-withdrawing monovalent group, X 1 and X 2 are each independently an electron-donating group, and Y 1 and Y 2 are each independently a hydrogen atom or an electron-withdrawing group, In formula (2), n is independently an integer of 1 to 3 respectively.

[0198] The compound represented by the above formula (1) or the above formula (2) also absorbs light with a long wavelength. Although the action of the compound represented by formula (1) or formula (2) is not clear, it is the same as the action in the compound represented by the above formula (X). X 1 and X 2 have a great influence on the core in terms of the distribution of the HOMO orbital, so X 1 and X 2 can increase the electron-donating property (i.e., core property) of the core by using them as electron-donating groups. On the other hand, Y 1 and Y 2 have a great influence on the acceptor in terms of the distribution of the LUMO orbital, so Y 1 and Y 2 can enhance the electron-withdrawing property (i.e., acceptor property) of the acceptor by using them as hydrogen atoms or electron-withdrawing groups. That is, since the compound represented by formula (1) or formula (2) has strong core property and strong acceptor property, the HOMO energy of the compound is high and the LUMO energy is low. That is, the compound represented by formula (1) or formula (2) has a small HOMO-LUMO gap. From the above, the compound represented by formula (1) or formula (2) easily absorbs light with low energy, that is, light with a long wavelength.

[0199] [Linker; a group located between D and A] (X 1 , X 2 ) In formula (1) and formula (2), X 1 and X 2 are each independently an electron-donating group. X 1 and X 2 may be the same group or different groups from each other. From the viewpoint of making the synthesis of the compound of the present disclosure easier, X 1 and X 2 are preferably the same group.

[0200] From the viewpoint that the compound easily absorbs light with a long wavelength, X1 and X 2 is, independently of one another, -R b , -OR b and -NR b 2 is preferably any electron-donating group selected from the group consisting of. Note that R b is, independently of one another, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic. From the viewpoint that the compound easily absorbs light of a long wavelength, X 1 and X 2 are, independently of one another, more preferably an alkyloxy group, i.e., -OR b , and it is even more preferable that it is -OR b and R b is an alkyl group having 1 to 30 carbon atoms.

[0201] (Y 1 , Y 2 ) In Formula (1) and Formula (2), Y 1 and Y 2 are, independently of one another, a hydrogen atom or an electron-withdrawing group. Y 1 and Y 2 may be the same group or different groups from each other. From the viewpoint of making the synthesis of the compound of the present disclosure easier, Y 1 and Y 2 are preferably the same group.

[0202] From the viewpoint that the compound easily absorbs light of a long wavelength, Y 1 and Y 2 are, independently of one another, preferably any group selected from the group consisting of a hydrogen atom, -CN, and -CO 2 R b Note that R bis, independently of each other, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group and aromatic alkynyl group may have a substituent and may be linear, branched or cyclic. From the viewpoint of easy synthesis of the compound, Y 1 and Y 2 are more preferably hydrogen atoms.

[0203] (n) In formula (2), n is independently an integer of 1 to 3. The two n's in formula (2) may be the same number or different numbers from each other. From the viewpoint of making the synthesis of the compound of the present disclosure easier, the two n's are preferably the same number. From the viewpoint of making the synthesis of the compound of the present disclosure easier, n is preferably 1 or 2, and more preferably 1.

[0204] (Examples of linker) In the above, X 1 and X 2 preferred embodiments, Y 1 and Y 2 preferred embodiments, and preferred embodiments of n have been described, but combinations of the respective preferred embodiments result in more preferred linker embodiments. Specific examples of the linker are the same as the specific examples in [Linker; p1 and p2] of <Compound represented by formula (X)> in the (Examples of linker) above.

[0205] [Acceptor; A] Regarding the definition, examples, and preferred embodiments of A in formula (1) and formula (2), etc., they are the same as those described in [Acceptor; A] in the aforementioned formula (X), including the definition, examples, and preferred embodiments, etc.

[0206] [Core; D] In Formula (1) and Formula (2), the definition, examples, and preferred embodiments of D are the same as those described for [Core; D] in the aforementioned Formula (X).

[0207] <Specific Examples of the Compounds of the Present Disclosure> Preferred specific examples of the compounds of the present disclosure include compounds represented by the following formula.

[0208] [Chemical Formula]

[0209] [Chemical Formula]

[0210] [Chemical Formula]

[0211] [Energy Difference (Eg) between the Energy Level of the Lowest Excited Singlet State and the Energy Level of the Ground State of the Compound] For the compounds of the present disclosure, the energy difference (Eg) between the energy level of the lowest excited singlet state and the energy level of the ground state calculated by computational science methods is preferably 1.55 eV or less. Computational science methods include, for example, methods calculated using quantum chemistry calculation programs. In the examples described later, the following method is used.

[0212] Using the quantum chemistry calculation program Gaussian 03, the structure optimization of the ground state is performed by the density functional theory at the B3LYP level. For the optimized structure, the value obtained by calculation using 6-31g* as the basis function is taken as the value of the energy level of the ground state. Subsequently, the energy level of the lowest excited singlet state is determined by TD DFT calculation using B3LYP as the functional and 6-31g* as the basis function. The difference between the energy level of the lowest excited singlet state and the energy level of the ground state is defined as the energy band gap (Eg).

[0213] When the energy band gap of the compound is 1.55 eV or less, the compound of the present disclosure is more likely to perform photoelectric conversion at longer wavelengths when used in a photoelectric conversion element.

[0214] More preferably, the energy band gap of the compound is 1.50 eV or less, even more preferably 1.45 eV or less, and particularly preferably 1.35 eV or less. The lower limit of the energy band gap of the compound is not particularly limited, but for example, it is 1.0 eV. In one embodiment of the present disclosure, the energy band gap of the compound is preferably 1.0 eV to 1.55 eV.

[0215] <Wavelength λ corresponding to the energy band gap Eg > In one embodiment of the present disclosure, for the compound of the present disclosure, the calculated value of the wavelength λ corresponding to the energy band gap Eg by density functional theory is 800 nm or more.

[0216] In one embodiment of the present disclosure, for the compound of the present disclosure, the calculated value of the wavelength λ corresponding to the energy band gap Eg by density functional theory is preferably 826 nm or more, more preferably 855 nm or more, and even more preferably 918 nm or more from the viewpoint that the compound is likely to absorb light of long wavelengths. The wavelength λ Eg corresponding to the energy band gap, the upper limit of the calculated value by density functional theory is not particularly limited, but for example, it is preferably 1500 nm or less, more preferably 1400 nm or less, and even more preferably 1240 nm or less. In one embodiment of the present disclosure, for the wavelength λ Eg corresponding to the energy band gap of the compound, the calculated value by density functional theory is preferably 826 nm to 1240 nm.

[0217] Wavelength λ EgThe calculated value by the density functional theory is obtained by the energy band gap (Eg) obtained above and the following (Equation 1). λ Eg = 1240 / Eg (Equation 1)

[0218] <The optical absorption edge wavelength (λth) of the solution> For the compound of the present disclosure, it is preferable that the optical absorption edge wavelength (λth) of the solution containing the compound is 1000 nm or more. The photoelectric conversion element containing the compound of the present disclosure is more likely to perform photoelectric conversion in light of a longer wavelength than before. From the viewpoint of utilizing light of a longer wavelength, the optical absorption edge wavelength (λth) is preferably a longer wavelength. The optical absorption edge wavelength is preferably 1000 nm or more, more preferably 1050 nm or more, still more preferably 1080 nm or more, even more preferably 1090 nm or more, still even more preferably 1100 nm or more, yet still even more preferably 1110 nm or more, particularly preferably 1120 nm or more, more particularly preferably 1130 nm or more, and even more particularly preferably 1150 nm or more. The upper limit value of the optical absorption edge wavelength is not particularly limited, and for example, it may be 1500 nm or less, 1400 nm or less, 1300 nm or less, or 1200 nm or less. In one embodiment of the present disclosure, the optical absorption edge wavelength is preferably 1000 nm to 1500 nm.

[0219] The optical absorption edge wavelength is represented as the wavelength value at the long-wavelength side end of the optical absorption wavelength. In the present disclosure, the numerical value of the optical absorption edge wavelength is specifically represented by the value obtained by the following method.

[0220] For the measurement of the optical absorption wavelength, a spectrophotometer (for example, the ultraviolet-visible-near-infrared spectrophotometer "Cary5E" manufactured by Varian) that operates in the wavelength regions of ultraviolet light, visible light, and near-infrared light is used. The compound is added to a mixed solvent of orthodichlorobenzene and 1,2-dimethoxybenzene (mixing ratio: orthodichlorobenzene / 1,2-dimethoxybenzene = 80% by mass / 20% by mass) so that the concentration becomes 0.5% by mass, and a solution for measurement is prepared.

[0221] The absorption spectrum of the solution is shown with the absorbance of the compound on the vertical axis and the wavelength on the horizontal axis. It is desirable to adjust the concentration of the solution so that the absorbance of the largest absorption peak is about 0.4 to 2.

[0222] The light absorption edge wavelength can be obtained from the intersection of the first reference line and the second reference line shown below.

[0223] - First reference line - In the entire absorption waveform (absorption spectrum), the absorbance of the absorption peak point (maximum value) closest to the longest wavelength is set to 100%.

[0224] Of the two intersections where a straight line parallel to the horizontal axis (wavelength axis) showing 50% of the absorbance of the above absorption peak point intersects the absorption waveform, the intersection closer to the longer wavelength than the above absorption peak point is taken as the first point.

[0225] Of the two intersections where a straight line parallel to the wavelength axis showing 44% of the absorbance of the above absorption peak point intersects the absorption waveform, the intersection closer to the longer wavelength than the above absorption peak point is taken as the second point. The straight line connecting the first point and the second point is taken as the first reference line.

[0226] - Second reference line - In the entire absorption waveform, the absorbance of the absorption peak point (maximum value) closest to the longest wavelength is set to 100%.

[0227] Of the two intersections where a straight line parallel to the wavelength axis showing an absorbance of 20% of the absorption peak point intersects with the absorption waveform, the wavelength of the intersection closer to the longer wavelength side than the absorption peak point is used as the reference point, and a point on the absorption waveform that is 200 nm longer in wavelength than the wavelength of the reference point is defined as the third point. Also, a point on the absorption waveform that is 250 nm longer in wavelength than the wavelength of the reference point is defined as the fourth point. A straight line connecting the third point and the fourth point is defined as the second reference line.

[0228] The value of the wavelength at the intersection of the first reference line and the second reference line is taken as the value of the optical absorption edge wavelength.

[0229] ≪Composition≫ The composition of the present disclosure includes a p-type semiconductor material and an n-type semiconductor material, and as the n-type semiconductor material, it is preferable to include the compound of the present disclosure.

[0230] The composition of the present disclosure may contain components other than the p-type semiconductor material and the n-type semiconductor material. Also, the composition of the present disclosure may contain only the compound of the present disclosure as the n-type semiconductor material, or may contain other compounds other than the compound of the present disclosure. Other compounds that can be included as the n-type semiconductor material may be low molecular weight compounds or high molecular weight compounds.

[0231] <n-type semiconductor material> Examples of low molecular weight compounds that can be included as the n-type semiconductor material include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorenone derivatives, diphenyldicyanoethylene and its derivatives, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and its derivatives, and phenanthrene derivatives such as bathocuproine.

[0232] Examples of the polymer compound that can be included as the n-type semiconductor material include, for example, polyvinylcarbazole and its derivatives, polysilane and its derivatives, polysiloxane derivatives having an aromatic amine structure in the side chain or main chain, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylene vinylene and its derivatives, polythienylene vinylene and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, and polyfluorene and its derivatives.

[0233] In addition, other compounds may be fullerene derivatives.

[0234] Here, the fullerene derivative refers to a compound in which at least a part of fullerene (C 60 fullerene, C 70 fullerene, C 76 fullerene, C 78 fullerene, and C 84 fullerene) is modified. In other words, it refers to a compound having one or more groups added to the fullerene skeleton. Hereinafter, the fullerene derivative of C 60 fullerene is referred to as "C 60 fullerene derivative", and the fullerene derivative of C 70 fullerene may be referred to as "C 70 fullerene derivative".

[0235] The fullerene derivative that can be included as the n-type semiconductor material is not particularly limited as long as it does not impair the object of the present disclosure.

[0236] Specific examples of the C 60 fullerene derivative that can be included as the n-type semiconductor material include the following compounds.

[0237]

Chemical formula

[0238] In the above formula, R is a hydrogen atom, A halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, an alkyloxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, a cycloalkylthio group which may have a substituent, an arylthio group which may have a substituent, a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent, an acyl group which may have a substituent, an imine residue which may have a substituent, an amide group which may have a substituent, an acid imide group which may have a substituent, a substituted oxycarbonyl group which may have a substituent, an alkenyl group which may have a substituent, a cycloalkenyl group which may have a substituent, an alkynyl group which may have a substituent, a cycloalkynyl group which may have a substituent, a cyano group, a nitro group, a group represented by -C(=O)-R d1 or -SO 2 -R d2 represents a group represented by, R d1 and R d2 each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkyloxy group which may have a substituent, An aryloxy group which may have a substituent, or represents a monovalent heterocyclic group which may have a substituent. In addition, when there are a plurality of Rs, the plurality of Rs may be the same as or different from each other.

[0239] C 70 Examples of the fullerene derivative include the following compounds.

[0240]

Chemical formula

[0241] <p-type semiconductor material> The p-type semiconductor material is preferably a polymer compound having a predetermined weight average molecular weight in terms of polystyrene.

[0242] Here, the weight average molecular weight in terms of polystyrene means the weight average molecular weight calculated using gel permeation chromatography (GPC) with a standard sample of polystyrene.

[0243] The weight average molecular weight in terms of polystyrene of the p-type semiconductor material is preferably 3000 or more and 500000 or less, particularly from the viewpoint of improving solubility in a solvent.

[0244] The p-type semiconductor material is preferably a π-conjugated polymer compound (also referred to as a D-A type conjugated polymer compound) containing a donor structural unit (also referred to as a D structural unit) and an acceptor structural unit (also referred to as an A structural unit). Note that which is the donor structural unit or the acceptor structural unit can be relatively determined from the energy levels of HOMO or LUMO.

[0245] Here, the donor structural unit is a structural unit with excessive π electrons, and the acceptor structural unit is a structural unit lacking π electrons.

[0246] In the present disclosure, the structural units that can constitute a p-type semiconductor material include structural units in which a donor structural unit and an acceptor structural unit are directly bonded, and further include structural units in which a donor structural unit and an acceptor structural unit are bonded via an arbitrarily suitable spacer (group or structural unit).

[0247] Examples of the p-type semiconductor material that is a polymer compound include polyvinylcarbazole and its derivatives, polysilane and its derivatives, polysiloxane derivatives containing an aromatic amine structure in the side chain or main chain, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylene vinylene and its derivatives, polythienylene vinylene and its derivatives, and polyfluorene and its derivatives.

[0248] The p-type semiconductor material is preferably a polymer compound containing at least one selected from the group consisting of the structural unit represented by the following formula (3) and the structural unit represented by the following formula (4). The structural unit represented by the following formula (3) is preferably usually a donor structural unit. The structural unit represented by the following formula (4) is preferably usually an acceptor structural unit.

[0249]

Chemical formula

[0250] -Formula (3)- In formula (3), Ar 1 and Ar 2 each independently represent a trivalent aromatic heterocyclic group which may have a substituent, and Z represents a group represented by the following formula (Z-1) to formula (Z-7).

[0251]

Chemical formula

[0252] In formula (Z-1) to formula (Z-7), the definition of R is C 60It is the same as the definition of R in the formula of the fullerene derivative. In each of Formula (Z-1) to Formula (Z-7), when there are two Rs, the two Rs may be the same as or different from each other.

[0253] Ar 1 and Ar 2 The aromatic heterocyclic rings that can form Ar and Ar include, in addition to monocyclic and condensed rings in which the heterocyclic ring itself exhibits aromaticity, rings in which an aromatic ring is condensed to the heterocyclic ring even if the heterocyclic ring itself that constitutes the ring does not exhibit aromaticity.

[0254] Ar 1 and Ar 2 The aromatic heterocyclic rings that can form Ar and Ar may each be a monocyclic ring or a condensed ring. When the aromatic heterocyclic ring is a condensed ring, the condensed ring may be a condensed ring in which all of the rings constituting the condensed ring have aromaticity, or a condensed ring in which only a part has aromaticity. When these rings have a plurality of substituents, these substituents may be the same as or different from each other.

[0255] Ar 1 and Ar 2 Specific examples of the aromatic carbon rings that can form Ar and Ar include benzene ring, naphthalene ring, anthracene ring, tetracene ring, pentacene ring, pyrene ring, and phenanthrene ring. Benzene ring and naphthalene ring are preferred, benzene ring and naphthalene ring are more preferred, and benzene ring is even more preferred. These rings may have substituents.

[0256] Specific examples of the aromatic heterocyclic ring include the ring structures of the compounds already described as aromatic heterocyclic compounds, such as an oxadiazole ring, a thiadiazole ring, a thiazole ring, an oxazole ring, a thiophene ring, a pyrrole ring, a phosphole ring, a furan ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a pyridazine ring, a quinoline ring, an isoquinoline ring, a carbazole ring, and a dibenzophosphole ring, as well as a phenoxazine ring, a phenothiazine ring, a dibenzoborole ring, a dibenzosilole ring, and a benzopyran ring. These rings may have substituents.

[0257] The structural unit represented by formula (3) is preferably a structural unit represented by the following formula (3-1), (3-2) or (3-3).

[0258]

Chemical formula

[0259] In formulae (3-1), (3-2) and (3-3), the definitions of Ar 1 , Ar 2 and R are as defined above.

[0260] Specific examples of the preferred structural unit represented by formula (3) include structural units represented by the following formulae.

[0261]

Chemical formula

[0262] In the above formulae, the definition of R is the same as the definition of R in the formula of the fullerene derivative. 60 When there are two Rs, the two Rs may be the same or different. When there are two Rs, the two Rs may be the same or different.

[0263] Examples of more specific preferred structural units represented by formula (3) include structural units represented by the following formulae.

[0264] [Chemical formula]

[0265] - Formula (4)- In Formula (4), Ar 3 represents a divalent aromatic heterocyclic group.

[0266] Ar 3 The divalent aromatic heterocyclic group represented by has preferably 2 to 60 carbon atoms, more preferably 4 to 60 carbon atoms, and still more preferably 4 to 20 carbon atoms.

[0267] Ar 3 The divalent aromatic heterocyclic group represented by may have a substituent. Ar 3 Examples of the substituent that the divalent aromatic heterocyclic group represented by may have include a halogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, an alkyloxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylthio group that may have a substituent, an arylthio group that may have a substituent, a monovalent heterocyclic group that may have a substituent, a substituted amino group that may have a substituent, an acyl group that may have a substituent, an imine residue that may have a substituent, an amide group that may have a substituent, an acid imide group that may have a substituent, a substituted oxycarbonyl group that may have a substituent, an alkenyl group that may have a substituent, an alkynyl group that may have a substituent, a cyano group, and a nitro group.

[0268] As the structural unit represented by Formula (4), the structural units represented by the following Formulas (4-1) to (4-10) are preferable.

[0269] [Chemical formula]

[0270] In Formulas (4-1) to (4-10), R is as defined above. X 3 and X4 Each independently represents an oxygen atom or a sulfur atom. Z 1 and Z 2 Each independently represents a group represented by =C(R)- or a nitrogen atom. When there are two Rs, the two Rs may be the same or different.

[0271] X in Formulas (4-1) to (4-10) 3 and X 4 From the viewpoint of availability of the starting compound, both are preferably sulfur atoms.

[0272] Note that the structural units represented by Formulas (4-1) to (4-10) can usually function as acceptor structural units as described above. However, it is not limited thereto, and in particular, the structural units represented by Formulas (4-4), (4-5), and (4-7) can also function as donor structural units.

[0273] The p-type semiconductor material preferably contains a structural unit containing a thiophene skeleton and is a π-conjugated polymer compound containing a π-conjugated system.

[0274] Ar 3 Specific examples of the divalent aromatic heterocyclic group represented by include groups represented by the following Formulas (101) to (191). These groups may further have substituents.

[0275]

Chemical formula

[0276]

Chemical formula

[0277]

Chemical formula

[0278]

Chemical formula

[0279] The polymer compound that is a p-type semiconductor material preferably is a π-conjugated polymer compound containing a structural unit represented by formula (3) as a donor structural unit and a structural unit represented by formula (4) as an acceptor structural unit.

[0280] In the polymer compound that is a p-type semiconductor material, the polymer compound that is a p-type semiconductor material may contain, as a structural unit, a structure in which the structural unit represented by formula (3) already described and the structural unit appearing in the following formula (4) are linked.

[0281] The polymer compound that is a p-type semiconductor material may contain two or more structural units represented by formula (3), and may also contain two or more structural units represented by formula (4).

[0282] For example, from the viewpoint of improving solubility in a solvent, the polymer compound that is a p-type semiconductor material may contain a structural unit represented by the following formula (5).

[0283]

Chemical formula

[0284] In formula (5), Ar 4 represents an arylene group.

[0285] Ar 4 The arylene group represented by means the atomic group remaining after removing two hydrogen atoms from an aromatic hydrocarbon which may have a substituent. The aromatic hydrocarbon includes compounds having a condensed ring, compounds in which two or more selected from the group consisting of an independent benzene ring and a condensed ring are directly bonded or bonded via a divalent group such as a vinylene group.

[0286] Examples of the substituent that the aromatic hydrocarbon may have include the same substituents as those exemplified as the substituent that the heterocyclic compound may have.

[0287] Ar 4 The number of carbon atoms of the arylene group represented by Ar, excluding the carbon atoms of the substituent, is usually preferably 6 to 60, more preferably 6 to 20. The number of carbon atoms of the arylene group including the substituent is usually preferably 6 to 100.

[0288] Ar 4 Examples of the arylene group represented by Ar include a phenylene group (e.g., the following Formula 1 to Formula 3), a naphthalene-diyl group (e.g., the following Formula 4 to Formula 13), an anthracene-diyl group (e.g., the following Formula 14 to Formula 19), a biphenyl-diyl group (e.g., the following Formula 20 to Formula 25), a terphenyl-diyl group (e.g., the following Formula 26 to Formula 28), a condensed ring compound group (e.g., the following Formula 29 to Formula 35), a fluorene-diyl group (e.g., the following Formula 36 to Formula 38), and a benzofluorene-diyl group (e.g., the following Formula 39 to Formula 46).

[0289]

Chemical formula

[0290]

Chemical formula

[0291]

Chemical formula

[0292]

Chemical formula

[0293]

Chemical formula

[0294]

Chemical formula

[0295]

Chem.

[0296]

Chem.

[0297] In the formula, the definition of R is the same as the definition of R in the formula of the fullerene derivative. A plurality of Rs may be the same or different. 60 The definition of R in the formula of the fullerene derivative is the same. A plurality of Rs may be the same or different.

[0298] The structural unit represented by formula (5) is preferably a structural unit represented by the following formula (5-1) and formula (5-2).

[0299]

Chem.

[0300] In formula (5), the definition of R is the same as the definition of R in the formula of the fullerene derivative. Two Rs may be the same or different. 60 The definition of R in the formula of the fullerene derivative is the same. Two Rs may be the same or different.

[0301] The structural unit constituting the polymer compound which is a p-type semiconductor material may be a structural unit in which two or more structural units selected from the above structural units are combined and linked.

[0302] When the polymer compound as the p-type semiconductor material contains the structural unit represented by formula (3) and / or the structural unit represented by formula (4), the total amount of the structural unit represented by formula (3) and the structural unit represented by formula (4) is usually preferably 20 mol% to 100 mol%, more preferably 40 mol% to 100 mol%, and still more preferably 50 mol% to 100 mol% based on 100 mol% of the amount of all the structural units contained in the polymer compound, from the viewpoint of improving the charge transport property as the p-type semiconductor material.

[0303] Specific examples of the polymer compound that is a p-type semiconductor material include polymer compounds represented by the following formulas (P-1) to (P-19).

[0304]

Chemical formula

[0305]

Chemical formula

[0306]

Chemical formula

[0307]

Chemical formula

[0308]

Chemical formula

[0309]

Chemical formula

[0310]

Chemical formula

[0311]

Chemical formula

[0312] In the above formulas, the definition of R is the same as the definition of R in the formula of the fullerene derivative. A plurality of Rs may be the same as or different from each other. 60 The definition of R in the formula of the fullerene derivative is the same. A plurality of Rs may be the same as or different from each other.

[0313] When the above-exemplified polymer compound is used as the p-type semiconductor material, it is possible to suppress a decrease in EQE with respect to heat treatment in the manufacturing process of the photoelectric conversion element or the incorporation process into a device to which the photoelectric conversion element is applied, or to further improve the EQE, and it is possible to improve the heat resistance of the photoelectric conversion element.

[0314] ≪Ink≫ The ink of the present disclosure preferably contains the compound of the present disclosure and a solvent. Further, the ink of the present disclosure preferably contains the p-type semiconductor material, the n-type semiconductor material, and the solvent of the present disclosure. Since the compound of the present disclosure is included as the n-type semiconductor material, the ink of the present disclosure is preferably an ink for forming an active layer of a photoelectric conversion element, and more preferably an ink for forming a bulk heterojunction type active layer.

[0315] According to the ink of the present disclosure, by including the p-type semiconductor material and the compound of the present disclosure, it is possible to suppress a decrease in EQE with respect to heat treatment in the manufacturing process of the photoelectric conversion element or the incorporation process into a device to which the photoelectric conversion element is applied, or to further improve the EQE, and it is possible to improve the heat resistance.

[0316] As the solvent, for example, a mixed solvent in which a first solvent and a second solvent described later are combined can be used. Specifically, when the ink contains two or more solvents, it preferably contains a main solvent (first solvent) as a main component and other additive solvents (second solvents) added for improving solubility or the like. The solvent may be only the first solvent.

[0317] Hereinafter, the first solvent and the second solvent that can be preferably used for the ink for forming the active layer and combinations thereof will be described.

[0318] <First Solvent> As the first solvent, a solvent in which the p-type semiconductor material is soluble is preferable. The first solvent is preferably an aromatic hydrocarbon.

[0319] Examples of the aromatic hydrocarbon include toluene, xylene (e.g., o-xylene, m-xylene, p-xylene), chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, trimethylbenzene (e.g., mesitylene, 1,2,4-trimethylbenzene (pseudocumene)), butylbenzene (e.g., n-butylbenzene, sec-butylbenzene, tert-butylbenzene), methylnaphthalene (e.g., 1-methylnaphthalene), 1-chloronaphthalene, bromobenzene, tetralin, and indane.

[0320] The first solvent may be composed of one type of aromatic hydrocarbon or two or more types of aromatic hydrocarbons. Preferably, the first solvent is composed of one type of aromatic hydrocarbon.

[0321] The first solvent is preferably at least one selected from the group consisting of toluene, o-xylene, m-xylene, p-xylene, mesitylene, chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, 1-chloronaphthalene, bromobenzene, tetralin, and indane, and more preferably toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, o-dichlorobenzene, mesitylene, 1,2,4-trichlorobenzene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, 1-chloronaphthalene, bromobenzene, tetralin, or indane.

[0322] <Second Solvent> The second solvent is preferably selected from the perspective of facilitating the implementation of the manufacturing process and further improving the characteristics of the photoelectric conversion element. Examples of the second solvent include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, and propiophenone; ester solvents such as ethyl acetate, butyl acetate, phenyl acetate, ethyl cellosolve acetate, methyl benzoate, butyl benzoate, and benzyl benzoate; ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and 1-methoxynaphthalene; 1,2,4-trimethylbenzene, 1,2,4-trichlorobenzene, tetralin, 2-isopropylphenol, 2-isopropyl-5-methylanisole, and bromobenzene.

[0323] The second solvent is preferably acetophenone, propiophenone, butyl benzoate, or methyl benzoate, for example, from the perspective of further reducing the dark current.

[0324] <Combination of the first solvent and the second solvent> Examples of suitable combinations of the first solvent and the second solvent include combinations of tetralin and ethyl benzoate, tetralin and propyl benzoate, tetralin and butyl benzoate, o-dichlorobenzene and 1,2-dimethoxybenzene, o-dichlorobenzene and methyl benzoate, more preferably combinations of tetralin and butyl benzoate, and o-dichlorobenzene and 1,2-dimethoxybenzene.

[0325] <Mass ratio of the first solvent and the second solvent> The mass ratio of the first solvent (the main solvent) to the second solvent (the additive solvent) (first solvent: second solvent) is preferably in the range of 50:50 to 99:1 from the perspective of further improving the solubility of the p-type semiconductor material and the n-type semiconductor material.

[0326] <Any other solvent> The solvent may contain any other solvent other than the first solvent and the second solvent. When the total mass of all the solvents contained in the ink is 100% by mass, the content of any other solvent is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass or less. As any other solvent, a solvent having a boiling point higher than that of the second solvent is preferred.

[0327] In addition to the first solvent, the second solvent, the p-type semiconductor material, and the n-type semiconductor material, the ink may contain any components such as a surfactant, an ultraviolet absorber, an antioxidant, a sensitizer for enhancing the function of generating charges by the absorbed light, and a light stabilizer for enhancing the stability against ultraviolet rays, as long as the objects and effects of the present disclosure are not impaired.

[0328] The concentrations of the p-type semiconductor material and the n-type semiconductor material in the ink can be set to any suitable concentrations within a range that does not impair the object of the present disclosure, taking into account the solubility in the solvent and the like.

[0329] The mass ratio of the "p-type semiconductor material" to the "n-type semiconductor material" in the ink is usually preferably in the range of 1 / 0.1 to 1 / 10, more preferably in the range of 1 / 0.5 to 1 / 2, and still more preferably 1 / 1.5.

[0330] The total content of the "p-type semiconductor material" and the "n-type semiconductor material" in the ink is usually preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and still more preferably 0.25% by mass or more. Also, the total content of the "p-type semiconductor material" and the "n-type semiconductor material" in the ink is usually preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 7.50% by mass or less.

[0331] The content of the "p-type semiconductor material" in the ink is usually preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.10% by mass or more. Also, the content of the "p-type semiconductor material" in the ink is usually preferably 10% by mass or less, more preferably 5.00% by mass or less, and even more preferably 3.00% by mass or less.

[0332] The content of the "n-type semiconductor material" in the ink is usually preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.15% by mass or more. Also, the content of the "n-type semiconductor material" in the ink is usually preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 4.50% by mass or less.

[0333] The ink can be prepared by known methods. For example, a method of preparing a mixed solvent by mixing a first solvent or a first solvent and a second solvent, and adding a p-type semiconductor material and an n-type semiconductor material to the obtained mixed solvent, a method of adding a p-type semiconductor material to a first solvent and adding an n-type semiconductor material to a second solvent, and then mixing the first solvent and the second solvent to which each material has been added, etc. can be used for preparation.

[0334] The first solvent and the second solvent and the p-type semiconductor material and the n-type semiconductor material may be heated and mixed to a temperature below the boiling point of the solvent.

[0335] After mixing the first solvent and the second solvent with the p-type semiconductor material and the n-type semiconductor material, the obtained mixture may be filtered using a filter, and the obtained filtrate may be used. As the filter, for example, a filter formed of a fluororesin such as polytetrafluoroethylene (PTFE) can be used.

[0336] ≪Photovoltaic conversion element≫ The photoelectric conversion element of the present disclosure includes an anode, a cathode, and an active layer provided between the anode and the cathode and containing a p-type semiconductor material and an n-type semiconductor material. As the n-type semiconductor material, it is preferable to include the compound of the present disclosure. Preferred embodiments of the p-type semiconductor material and the n-type semiconductor material are as described above.

[0337] According to the photoelectric conversion element of the present disclosure, by having the above configuration, a decrease in the external quantum efficiency with respect to heat treatment in the manufacturing process of the photoelectric conversion element or the process of incorporating the photoelectric conversion element into a device to which the photoelectric conversion element is applied can be suppressed, and the heat resistance can be effectively improved.

[0338] Here, a configuration example that the photoelectric conversion element of the present disclosure can take will be described. FIG. 1 is a diagram schematically showing the configuration of the photoelectric conversion element of the present disclosure.

[0339] As shown in FIG. 1, the photoelectric conversion element 10 is provided on a support substrate 11. The photoelectric conversion element 10 includes an anode 12 provided so as to be in contact with the support substrate 11, a hole transport layer 13 provided so as to be in contact with the anode 12, an active layer 14 provided so as to be in contact with the hole transport layer 13, an electron transport layer 15 provided so as to be in contact with the active layer 14, and a cathode 16 provided so as to be in contact with the electron transport layer 15. In this configuration example, a sealing member 17 is further provided so as to be in contact with the cathode 16.

[0340] As another configuration example of the photoelectric conversion element, it includes a cathode provided so as to be in contact with a support substrate, an electron transport layer provided so as to be in contact with the cathode, an active layer provided so as to be in contact with the electron transport layer, a hole transport layer provided so as to be in contact with the active layer, and an anode provided so as to be in contact with the hole transport layer. In this configuration example, a sealing member is further provided so as to be in contact with the anode.

[0341] Hereinafter, the components that can be included in the photoelectric conversion element of the present disclosure will be specifically described.

[0342] <Substrate> A photoelectric conversion element is usually formed on a substrate (support substrate). Further, it may be sealed by another substrate (sealing substrate). Usually, one of a pair of electrodes consisting of an anode and a cathode is formed on the substrate. The material of the substrate is not particularly limited as long as it does not chemically change when forming a layer containing an organic compound in particular.

[0343] Examples of the material of the substrate include glass, plastic, polymer film, and silicon. When an opaque substrate is used, the electrode on the side opposite to the electrode provided on the opaque substrate side (in other words, the electrode far from the opaque substrate) is preferably a transparent or translucent electrode.

[0344] <Electrode> A photoelectric conversion element includes an anode and a cathode which are a pair of electrodes. Among the anode and the cathode, at least one of the electrodes is preferably a transparent or translucent electrode for allowing light to be incident.

[0345] Examples of the material of the transparent or translucent electrode include a conductive metal oxide film and a translucent metal thin film. Specifically, indium oxide, zinc oxide, tin oxide, and composites thereof such as indium tin oxide (ITO), indium zinc oxide (IZO), and NESA, and conductive materials such as gold, platinum, silver, and copper can be mentioned. As the material of the transparent or translucent electrode, ITO, IZO, and tin oxide are preferable. Further, as the electrode, a transparent conductive film using an organic compound such as polyaniline and its derivatives, polythiophene and its derivatives, etc. may be used as the material. The transparent or translucent electrode may be an anode or a cathode.

[0346] If one of the pair of electrodes is transparent or translucent, the other electrode may be an electrode with low light transmittance. Examples of materials for the electrode with low light transmittance include metals and conductive polymers. Specific examples of materials for the electrode with low light transmittance include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, etc., alloys of two or more of these, or alloys of one or more of these metals and one or more metals selected from the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin, graphite, graphite intercalation compounds, polyaniline and its derivatives, polythiophene and its derivatives. Examples of alloys include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

[0347] <Active layer> The active layer included in the photoelectric conversion element of the present disclosure is assumed to have a bulk heterojunction structure, includes a p-type semiconductor material and an n-type semiconductor material, and the active layer includes the compound of the present disclosure as the n-type semiconductor material.

[0348] The thickness of the active layer is not particularly limited. The thickness of the active layer can be any suitable thickness in consideration of the balance between suppression of dark current and extraction of the generated photocurrent. From the viewpoint of further reducing dark current in particular, the thickness of the active layer is preferably 100 nm or more, more preferably 150 nm or more, and still more preferably 200 nm or more. Also, the thickness of the active layer is preferably 10 μm or less, more preferably 5 μm or less, and still more preferably 1 μm or less.

[0349] <Intermediate layer> As shown in FIG. 1, the photoelectric conversion element of the present disclosure preferably includes an intermediate layer (buffer layer) such as a charge transport layer (electron transport layer, hole transport layer, electron injection layer, hole injection layer), etc., as a component for improving characteristics such as photoelectric conversion efficiency.

[0350] Examples of materials used for the intermediate layer include metals such as calcium, inorganic oxide semiconductors such as molybdenum oxide and zinc oxide, and a mixture of PEDOT (poly(3,4-ethylenedioxythiophene)) and PSS (poly(4-styrenesulfonate)) (PEDOT:PSS).

[0351] As shown in FIG. 1, the photoelectric conversion element preferably includes a hole transport layer between the anode and the active layer. The hole transport layer has a function of transporting holes from the active layer to the electrode.

[0352] The hole transport layer provided in contact with the anode is sometimes particularly referred to as a hole injection layer. The hole transport layer (hole injection layer) provided in contact with the anode has a function of promoting the injection of holes into the anode. The hole transport layer (hole injection layer) may be in contact with the active layer.

[0353] The hole transport layer contains a hole transporting material. Examples of hole transporting materials include polythiophene and its derivatives, aromatic amine compounds, polymer compounds containing a structural unit having an aromatic amine residue, CuSCN, CuI, NiO, tungsten oxide (WO 3 ) and molybdenum oxide (MoO 3 ). Examples of hole transporting material products include P-10 and P-21 from Avantama.

[0354] The intermediate layer can be formed by any conventionally known suitable formation method. The intermediate layer can be formed by a vacuum evaporation method or a coating method similar to the method for forming the active layer.

[0355] The photoelectric conversion element of the present disclosure preferably has a structure in which the intermediate layer is an electron transport layer, and a substrate (support substrate), an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode are laminated in this order so as to be in contact with each other.

[0356] As shown in FIG. 1, the photoelectric conversion element of the present disclosure preferably includes an electron transport layer as an intermediate layer between the cathode and the active layer. The electron transport layer has a function of transporting electrons from the active layer to the cathode. The electron transport layer may be in contact with the cathode. The electron transport layer may be in contact with the active layer.

[0357] The electron transport layer provided in contact with the cathode is sometimes particularly referred to as an electron injection layer. The electron transport layer (electron injection layer) provided in contact with the cathode has a function of promoting the injection of electrons generated in the active layer into the cathode.

[0358] The electron transport layer contains an electron transporting material. Examples of the electron transporting material include polyalkyleneimine and its derivatives, polymer compounds containing a fluorene structure, metals such as calcium, and metal oxides.

[0359] Examples of polyalkyleneimine and its derivatives include alkyleneimines having 2 to 8 carbon atoms such as ethyleneimine, propyleneimine, butyleneimine, dimethylethyleneimine, pentyleneimine, hexyleneimine, heptyleneimine, and octyleneimine, particularly polymers obtained by polymerizing one or more alkyleneimines having 2 to 4 carbon atoms by a conventional method, and polymers chemically modified by reacting them with various compounds. As polyalkyleneimine and its derivatives, polyethyleneimine (PEI) and ethoxylated polyethyleneimine (PEIE) are preferred.

[0360] Examples of the polymer compound containing a fluorene structure include poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-ortho-2,7-(9,9'-dioctylfluorene)] (PFN) and PFN-P2.

[0361] Examples of the metal oxide include zinc oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, titanium oxide, and niobium oxide. As the metal oxide, a metal oxide containing zinc is preferable, and zinc oxide is particularly preferable. Examples of the metal oxide products include Avantama's N-10, N-11, N-12, N-13, N-20X, N-21X, Infinity PV's ZnO, ZnO(2.8%), ZnO(5.6%), and Doped ZnO.

[0362] Examples of other electron transporting materials include poly(4-vinylphenol) and perylene diimide.

[0363] <Sealing member> The photoelectric conversion element of the present disclosure further includes a sealing member, and it is preferable to form a sealed body sealed by such a sealing member. As the sealing member, any suitable conventionally known member can be used. Examples of the sealing member include a combination of a glass substrate (sealing substrate) as a substrate and a sealing material (adhesive) such as a UV curable resin.

[0364] The sealing member may be a sealing layer having a layer structure of one or more layers. Examples of the layers constituting the sealing layer include a gas barrier layer and a gas barrier film.

[0365] The sealing layer is preferably formed of a material having a property of blocking moisture (water vapor barrier property) or a property of blocking oxygen (oxygen barrier property). Examples of suitable materials as the material of the sealing layer include organic materials such as polytetrafluoroethylene, polychlorotrifluoroethylene (PCTFE), polyimide, polycarbonate, polyethylene terephthalate, alicyclic polyolefin, and ethylene-vinyl alcohol copolymer, and inorganic materials such as silicon oxide, silicon nitride, aluminum oxide, and diamond-like carbon.

[0366] The sealing member is usually composed of a material that can withstand the heat treatment performed when the photoelectric conversion element is incorporated into a device, for example, the following application examples, to which the photoelectric conversion element is applied.

[0367] <Dark current> The dark current of the encapsulant of the photoelectric conversion element containing the compound of the present disclosure is 5×10 -4 A / cm 2 The following is preferable, and 1×10 -4 A / cm 2 The following is more preferable, and 5×10 -5 A / cm 2 The following is even more preferable. When the photoelectric conversion element is adopted as a photodetector element, from the viewpoint of detection sensitivity, the smaller the value of the dark current, the more preferable.

[0368] The dark current is measured by the following method. 1. Mix 1.3% by mass of the target compound to be measured, 1.3% by mass of the polymer compound P-1 described below, and the remaining amount of the solvent (a mixed solvent of 1,2,4-trimethylbenzene and 1,2-dimethoxybenzene (mixing ratio: 1,2,4-trimethylbenzene / 1,2-dimethoxybenzene = 97% by mass / 3% by mass)) that makes up 100% by mass of the entire ink, and stir at 60°C for 8 hours. The obtained mixed solution is filtered using a filter to obtain an ink.

[0369] Prepare a glass substrate on which a thin film (anode) of ITO with a thickness of 45 nm is formed by sputtering, and perform ozone UV treatment on this glass substrate as a surface treatment.

[0370] Next, the cleaned glass substrate is spin-coated with a solution obtained by diluting an 80% ethoxylated aqueous solution of polyethyleneimine (manufactured by Sigma-Aldrich, 37% by mass aqueous solution) 500 times with water to form a coating film, and then placed on a hot plate and dried in the atmosphere at 120°C for 10 minutes to make the coating film an electron transport layer.

[0371] Next, the obtained ink was applied onto the electron transport layer by spin coating to form a coating film, and then heat-treated for 5 minutes using a hot plate heated to 70 °C under the atmosphere to dry it (pre-bake process). Subsequently, it was heat-treated at 100 °C for 10 minutes on a hot plate under a nitrogen atmosphere (post-bake process) to form an active layer. The thickness of the formed active layer is set to be about 400 nm.

[0372] Next, a molybdenum oxide (MoO 3 ) layer was formed to a thickness of about 30 nm to serve as a hole transport layer.

[0373] Next, a silver (Ag) layer was formed to a thickness of about 60 nm on the formed hole transport layer to serve as a cathode. Through the above steps, a photoelectric conversion element is manufactured on a glass substrate.

[0374] Next, a UV curable sealant, which is a sealing material, was applied to the outer periphery of a glass substrate that is a sealing substrate, and the glass substrate that is a sealing substrate was bonded to the center of a glass substrate that is a support substrate. After that, by irradiating with UV light, the photoelectric conversion element was sealed in the gap between the support substrate and the sealing substrate to obtain a sealed body of the photoelectric conversion element. The planar shape when viewed from the thickness direction of the photoelectric conversion element sealed in the gap between the support substrate and the sealing substrate is a square of 2 mm × 2 mm. The obtained sealed body is used as a sample.

[0375] For the sample manufactured as described above, in the dark state where no light is irradiated, the current value when a reverse bias voltage of -3 V measured using a known method is applied is obtained as the value of the dark current (Jd).

[0376] <Applications of the photoelectric conversion element> Examples of the applications of the photoelectric conversion element of the present disclosure include a photodetection element and a solar cell. More specifically, the photoelectric conversion element of the present disclosure can generate a photocurrent by irradiating light from the transparent or translucent electrode side while applying a voltage (reverse bias voltage) between the electrodes, and can operate as a photodetector (photosensor). Further, by integrating a plurality of photodetectors, it can also be used as an image sensor. Thus, the photoelectric conversion element of the present disclosure can be particularly preferably used as a photodetector.

[0377] In addition, when the photoelectric conversion element of the present disclosure is irradiated with light, it can generate a photoelectromotive force between the electrodes and can operate as a solar cell. By integrating a plurality of photoelectric conversion elements, a solar cell module can also be formed.

[0378] The photoelectric conversion element of the present disclosure can be preferably applied as a photodetector to detection units provided in various electronic devices such as workstations, personal computers, portable information terminals, access control systems, digital cameras, and medical devices.

[0379] The photoelectric conversion element of the present disclosure can be preferably applied to an image detection unit (for example, an image sensor such as an X-ray sensor) for solid-state imaging devices such as X-ray imaging devices and CMOS image sensors, a detection unit of a biometric authentication device that detects predetermined features of a part of a living body such as a fingerprint detection unit, a face detection unit, a vein detection unit, and an iris detection unit (for example, a near-infrared sensor), a detection unit of an optical biosensor such as a pulse oximeter, etc., which are provided in the above-exemplified electronic devices.

[0380] The photoelectric conversion element of the present disclosure can also be preferably applied as an image detection unit for solid-state imaging devices, and further to a Time-of-flight (TOF) type distance measurement device (TOF type ranging device).

[0381] Since the compound of the present disclosure is included in the photoelectric conversion element of the present disclosure, it is driven at a longer wavelength than before.

[0382] <Method for manufacturing a photoelectric conversion element> The manufacturing method of the photoelectric conversion element of the present disclosure is not particularly limited. The photoelectric conversion element of the present disclosure can be manufactured by combining formation methods suitable for the materials selected for forming the components.

[0383] Hereinafter, a manufacturing method of a photoelectric conversion element having a configuration in which a substrate (support substrate), an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode are in contact with each other in this order will be described.

[0384] (Step of preparing a substrate) In this step, for example, a support substrate provided with an anode is prepared. Further, a substrate provided with a conductive thin film formed of the electrode material already described is obtained from the market, and if necessary, the conductive thin film is patterned to form an anode, whereby a support substrate provided with an anode can be prepared.

[0385] In the manufacturing method of the photoelectric conversion element of the present disclosure, the method for forming the anode when forming the anode on the support substrate is not particularly limited. The anode can be formed on a configuration (e.g., support substrate, active layer, hole transport layer) on which the anode is to be formed by any conventionally known suitable method such as a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, a coating method, etc. using the materials already described.

[0386] (Step of forming a hole transport layer) The manufacturing method of the photoelectric conversion element may include a step of forming a hole transport layer (hole injection layer) provided between the active layer and the anode.

[0387] The method for forming the hole transport layer is not particularly limited. From the viewpoint of making the step of forming the hole transport layer simpler, it is preferable to form the hole transport layer by any conventionally known suitable coating method. The hole transport layer can be formed, for example, by a coating method using a coating solution containing the material and solvent of the hole transport layer already described or by a vacuum evaporation method.

[0388] (Step of forming an active layer) In the method for manufacturing a photoelectric conversion element of the present disclosure, an active layer is formed on a hole transport layer. The active layer, which is a main component, can be formed by any suitable conventionally known forming process. The active layer is preferably manufactured by a coating method using ink (coating liquid). Preferred embodiments of the ink are as described above.

[0389] Hereinafter, steps (i) and (ii) included in the forming process of the active layer, which is a main component of the present disclosure, will be described.

[0390] Step (i) As a method for applying ink to an object to be coated, any suitable coating method can be used. Preferred coating methods include a slit coating method, a knife coating method, a spin coating method, a microgravure coating method, a gravure coating method, a bar coating method, an inkjet printing method, a nozzle coating method, or a capillary coating method. More preferred are the slit coating method, the spin coating method, the capillary coating method, or the bar coating method. Even more preferred are the slit coating method or the spin coating method.

[0391] The ink for forming the active layer is applied to an object to be coated selected according to the photoelectric conversion element and its manufacturing method. The ink for forming the active layer can be applied to a functional layer of the photoelectric conversion element in the manufacturing process of the photoelectric conversion element, where the active layer may exist. Therefore, the object to be coated with the ink for forming the active layer varies depending on the layer configuration and the order of layer formation of the photoelectric conversion element to be manufactured. For example, when the photoelectric conversion element has a layer configuration in which a substrate, an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode are laminated, and the layers described more to the left are formed first, the object to be coated with the ink for forming the active layer is the hole transport layer. Also, for example, when the photoelectric conversion element has a layer configuration in which a substrate, a cathode, an electron transport layer, an active layer, a hole transport layer, and an anode are laminated, and the layers described more to the left are formed first, the object to be coated with the ink for forming the active layer is the electron transport layer.

[0392] Step (ii) As a method for removing the solvent from the ink coating film, that is, a method for removing the solvent from the coating film and solidifying it, any suitable method can be used. Examples of the method for removing the solvent include a method of directly heating using a hot plate in an inert gas atmosphere such as nitrogen gas, a hot air drying method, an infrared heating drying method, a flash lamp annealing drying method, a drying method such as a vacuum drying method, and the like.

[0393] In the method for manufacturing a photoelectric conversion element of the present disclosure, step (ii) is a step for volatilizing and removing the solvent, and is also referred to as a pre-bake step (first heat treatment step).

[0394] Regarding the implementation conditions of the pre-bake step and the post-bake step, that is, conditions such as the heating temperature and the heat treatment time, any suitable conditions can be set in consideration of the composition of the ink used, the boiling point of the solvent, and the like.

[0395] In the method for manufacturing a photoelectric conversion element of the present disclosure, specifically, for example, the pre-bake step and the post-bake step can be carried out using a hot plate in a nitrogen gas atmosphere.

[0396] The thickness of the active layer can be set to any desired thickness by appropriately adjusting the solid content concentration in the coating solution and the conditions of step (i) and / or step (ii).

[0397] The step of forming the active layer may include other steps on the condition that the objects and effects of the present disclosure are not impaired, in addition to step (i) and step (ii).

[0398] The method for manufacturing a photoelectric conversion element of the present disclosure may be a method for manufacturing a photoelectric conversion element including a plurality of active layers, or may be a method in which step (i) and step (ii) are repeated a plurality of times.

[0399] The method for manufacturing a photoelectric conversion element of the present disclosure includes a step of forming an electron transport layer (electron injection layer) provided on the active layer.

[0400] The method for forming the electron transport layer is not particularly limited. From the viewpoint of making the formation process of the electron transport layer simpler, it is preferable to form the electron transport layer by any conventionally known and suitable vacuum evaporation method.

[0401] (Cathode formation step) The method for forming the cathode is not particularly limited. The cathode can be formed on the electron transport layer by any conventionally known and suitable method such as a coating method, a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, etc. using the materials of the electrodes exemplified above. Through the above steps, the photoelectric conversion element of the present disclosure is manufactured.

[0402] (Sealing body formation step) In forming the sealing body, any conventionally known and suitable sealing material (adhesive) and substrate (sealing substrate) are used. Specifically, after applying a sealing material such as a UV curable resin on a support substrate so as to surround the periphery of the manufactured photoelectric conversion element, and then bonding them together without gaps with the sealing material, the photoelectric conversion element is sealed in the gap between the support substrate and the sealing substrate using a method suitable for the selected sealing material such as irradiation with UV light, whereby a sealing body of the photoelectric conversion element can be obtained.

[0403] <Photo-detection element> The photoelectric conversion element of the present disclosure, particularly the photo-detection element (photo sensor), can function when incorporated into an image sensor, a biometric authentication device (fingerprint authentication device, vein authentication device) as described above.

Examples

[0404] Hereinafter, examples are shown to explain the present disclosure in more detail. The present disclosure is not limited to the examples described below.

[0405] A photoelectric conversion element was fabricated using a p-type semiconductor material and an n-type semiconductor material.

[0406] <p-type semiconductor material> The p-type semiconductor material is an electron-donating compound. As the p-type semiconductor material, the polymer compound P-1 was synthesized with reference to the method described in International Publication No. WO 2011 / 052709. The chemical structure of the polymer compound P-1 is as shown in Table 1 below.

[0407]

Table 1

[0408] <n-type semiconductor material> The n-type semiconductor material is an electron-accepting compound. As the n-type semiconductor materials, the following Compound N-1 and Compound N-2 were synthesized. The chemical structures of Compound N-1 and Compound N-2 are as shown in Table 2 below.

[0409]

Table 2

[0410] Compound N-1 and Compound N-2 were synthesized as follows.

[0411] <Synthesis of Compound N-1> Compound 2 was synthesized using Compound 1.

[0412]

Chemical formula

[0413] A 500 mL four-necked flask was charged with sodium methoxide (69.59 g, 1.29 mol) and methanol (290 mL), and stirred at room temperature for 2 hours. Then, compound 1 (15.95 g, 68.5 mmol), copper(II) oxide (11.38 g, mmol, 143.1 mmol), and potassium iodide (0.58 g, 3.5 mmol) were added. After heating to 90 °C, the mixture was stirred for 4.5 hours. The reaction solution was cooled to room temperature, diluted with ethyl acetate, and separated with water once. It was dehydrated with magnesium sulfate, magnesium sulfate was removed by filtration, and then concentrated on a rotary evaporator. 157 mL of heptane was added to the obtained crude product, and after heating to 50 °C, the insoluble components were removed by filtration. The filtrate was left to cool overnight at 3 °C, and the precipitated solid was filtered to obtain 6.20 g (yield 53%) of the target product as a yellow solid. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 7.37 (1H), 7.17 (1H), 6.28 (1H), 3.93 (3H)

[0414] Compound 3 was synthesized using compound 2.

[0415]

Chemical Structure

[0416] Compound 2 (5.50 g, 32.3 mmol), toluene (206 mL), ethylhexyl alcohol (17.1 mL, 109.3 mmol), p-TsOH·H 2O (1.84 g, 9.7 mmol) was charged, and the reaction vessel was placed in an oil bath heated to 117 °C and heated under reflux for 3 hours. The reaction solution was cooled to room temperature, diluted with toluene, and separated with water once. After drying over magnesium sulfate and removing magnesium sulfate by filtration, the crude product was obtained by concentration using a rotary evaporator. The obtained crude product was purified by silica gel column (developing solvent: heptane = 100 wt%) to obtain 8.26 g (yield 95%) of the target product as a yellow oil. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 7.36 (1H), 7.17 (1H), 6.26 (1H), 3.97 (2H), 1.77 (1H), 1.20 - 1.55 (8H), 0.80 - 1.00 (6H)

[0417] Compound 4 was synthesized using Compound 3.

[0418]

Chemical formula

[0419] Compound 3 (4.00 g, 14.9 mmol) and chloroform (27 ml) were charged into a 100 mL four-necked flask and cooled to 2 °C in an ice bath. Then, N-bromosuccinimide (2.62 g, 14.8 mmol) was added and stirred for 1.5 hours. The reaction solution was quenched with an aqueous sodium sulfite solution, and the organic layer was extracted with chloroform and then washed with water. After drying over magnesium sulfate and removing magnesium sulfate by filtration, the crude product was obtained by concentration using a rotary evaporator. The crude product was dissolved in heptane, and the filtrate obtained by celite filtration was concentrated to obtain 5.1 g (yield 99%) of the target product as a brown oil. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1H-NMR (300 MHz, CHLOROFORM-D) δ 7.37 (1H), 7.12 (1H), 4.17 (2H), 1.70 (1H), 1.20―1.65 (8H), 0.80―1.00 (6H)

[0420] Compound 6 was synthesized using Compound 4 and Compound 5.

[0421]

Chemical Structure

[0422] A 100 mL four-necked flask was charged with Compound 5 (1.03 g, 1.31 mmol) (synthesized by the method described in WO2014 / 112656), Compound 6 (1.00 g, 2.88 mmol), and THF (10 mL). After nitrogen bubbling for 30 minutes, Pd 2 (dba) 3 (0.0599 g, 0.13 mmol), [(tBu) 3 PH]BF 4 (0.038 g, 0.13 mmol), and 3M K 3 PO 4 aqueous solution (2.42 g) were added, and the temperature was raised to 60°C. After maintaining the temperature for 2 hours, the reaction solution was cooled to room temperature, diluted with toluene, and washed twice with water. It was dried over magnesium sulfate, and after removing the magnesium sulfate by filtration, it was concentrated using a rotary evaporator to obtain a crude product. The obtained crude product was purified on silica gel (developing solvent: heptane / ethyl acetate = 100 / 1 to 50 / 1 (volume ratio)) to obtain 0.86 g (yield 62%) of the target product as a reddish-brown oil. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 7.31 (2H), 7.15 (2H), 6.84 (1H), 6.80 (1H), 4.32 (4H), 1.90 (6H), 1.15―1.75 (56H), 0.80―1.10 (18H)

[0423] Compound 7 was synthesized using Compound 6.

[0424]

Chemical Structure

[0425] Compound 6 (0.800 g, 0.75 mmol), chloroform (14 ml), and (chloromethylene)dimethyliminium chloride (0.288 g, 2.26 mmol) were charged into a 100 mL four-necked flask and stirred in an oil bath at 60 °C for 2.5 hours. After removing it from the oil bath and allowing it to cool to room temperature, it was quenched by pouring water (7 ml) and 5% aqueous sodium carbonate solution (14 ml). After removing the aqueous layer by liquid separation, it was dried over magnesium sulfate. Magnesium sulfate was removed by filtration, and the crude product was obtained by concentration using a rotary evaporator. The obtained crude product was purified on silica gel (developing solvent: heptane / ethyl acetate = 5 / 1 (volume ratio)), and 0.36 g (yield 43%) of the target product was obtained as a reddish-purple viscous solid. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 9.92 (2H), 7.78 (2H), 6.95(1H), 6.89(1H), 4.36 (4H), 1.87 (6H),1.15―1.75(56H), 0.80―1.10(18H)

[0426] Compound N-1 was synthesized using Compound 7.

[0427]

Chemical Structure

[0428] In a 50 mL three-necked flask, compound 7 (0.360 g, 0.321 mmol), compound 8 (0.235 g, 0.964 mmol) (synthesized according to the method described in International Publication No. 2020 / 109823), magnesium sulfate (0.180 g), p-toluenesulfonic acid monohydrate (0.185 g, 0.964 mmol), toluene (7.2 g), and ethanol (3.2 g) were charged, and the mixture was kept warm in an oil bath at 65 °C for 2 hours. The reaction solution was cooled to room temperature, magnesium sulfate was removed by filtration, and the solution was concentrated. The concentrate was dissolved in chloroform (12.6 g), and methanol (40.5 g) was added for reprecipitation, followed by filtration to obtain a crude product. The obtained crude product was purified by silica gel (developing solvent: chloroform = 100 wt%) to obtain 0.133 g (yield 26%) of the target product. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 8.96(2H).8.88 (2H),8.23(2H), 7.98 (2H),7.09(1H), 6.98(1H), 4.53 (4H), 1.92 (4H),0.80―1.80(76H)

[0429] <Synthesis of Compound N-2> Compound 9 was synthesized using compound 5.

[0430] [Chemical formula]

[0431] In a 100 mL three-necked flask, compound 5 (1.00 g, 12.7 mmol) (synthesized by the method described in WO2014 / 112656), 5-Bromo-4-((2-ethylhexyl)oxy)thiophene-2-carbaldehyde (0.934 g, 29.3 mmol) (manufactured by JiangSu GR-Chem), and THF (9 g) were charged, and nitrogen bubbling was carried out for 30 minutes. Pd 2 (dba) 3 (0.058 g, 0.06 mmol), P(tBu 3 )HBF4 (0.037 g, 0.13 mmol), 3M K 3 PO 4 aq (2.36 g) were charged in this order, and then the temperature was raised to 60 °C. After stirring for 2 hours, it was cooled to room temperature. It was diluted with toluene, washed twice with water, dehydrated with magnesium sulfate, the magnesium sulfate was removed by filtration, and then the whole amount was concentrated with a rotary evaporator. The obtained crude product was purified by a silica gel column (developing solvent: heptane / toluene = 80 / 20 to 0 / 100 (mass ratio)) to obtain 0.53 g (yield 41%) of the target product as a blue-violet solid. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 9.75 (2H), 7.46 (2H), 7.09 (1H), 6.99 (1H), 4.09 (4H), 1.78 - 1.95 (m, 6H), 1.22 - 1.64 (m, 56H), 0.84 - 1.02 (m, 18H)

[0432] Compound N-2 was synthesized using Compound 9.

[0433]

Chemical Structure

[0434] Compound 9 (0.266 g, 0.264 mmol), Compound 8 (0.194 g, 0.793 mmol), p-toluenesulfonic acid monohydrate (0.151 g, 0.0793 mmol), ethanol (2.4 g), toluene (5.3 g), and magnesium sulfate (0.13 g) were charged into a 30 mL three-necked flask, and it was placed in an oil bath heated to 65 °C and kept warm. After stirring for 2 hours, it was taken out of the oil bath and allowed to cool to room temperature, and MgSO 4After removal, the precipitate was washed while dissolving it in chloroform. After concentration using an evaporator, the crude product was obtained by repulping and washing with methanol. The obtained crude product was purified by silica gel column (developing solvent: chloroform = 100 wt%) to obtain 0.265 g (yield 72.1%, 0.182 mmol) of the target product as a blue-greenish black solid. The NMR spectrum of the obtained target product was analyzed. The results are as follows. 1 H-NMR (300 MHz, CHLOROFORM-D) δ 8.96 (1H), 8.78 (2H), 8.67 (1H), 8.17 (2H), 7.54 (1H), 7.46 (2H), 7.13 (1H), 4.24 (4H), 1.94 - 2.05 (m, 6H), 1.23 - 1.76 (m, 56H), 0.84 - 1.12 (m, 18H)

[0435] <Measurement of the light absorption end wavelength of the solution> Compound N-1 and Compound N-2 were each added to a mixed solvent of orthodichlorobenzene and 1,2-dimethoxybenzene (mixing ratio: orthodichlorobenzene / 1,2-dimethoxybenzene = 80 mass% / 20 mass%) so that the concentration became 0.5 mass%, and UV-Vis spectrum measurement was performed to determine the light absorption end wavelength.

[0436]

Table 3

[0437] <Preparation of ink> (Ink Example 1: Preparation of Ink (I-1)) The following components were mixed and stirred at 60 °C for 8 hours. Note that p-type semiconductor material / n-type semiconductor material = 1 / 1. The obtained mixed solution was filtered using a filter to obtain Ink (I-1). · p-type semiconductor material: Polymer compound P-1 … 1.3 mass% · n-type semiconductor material: Compound N-1 … 1.3 mass% · Solvent: A mixed solvent of 1,2,4-trimethylbenzene and 1,2-dimethoxybenzene (mixing ratio: 1,2,4-trimethylbenzene / 1,2-dimethoxybenzene = 97% by mass / 3% by mass) … The remaining amount that makes up 100% by mass of the entire ink

[0438] (Ink Comparative Example 1: Preparation of Ink (I-2)) Ink (I-2) was prepared in the same manner as in Example 1 for the preparation of the ink, except that compound N-2 was used as the n-type semiconductor material.

[0439]

Table 4

[0440] <Example 11> [Manufacture of Photovoltaic Conversion Element and Its Encapsulated Body] A glass substrate on which a thin film (anode) of ITO was formed with a thickness of 45 nm by sputtering was prepared, and this glass substrate was subjected to ozone UV treatment as a surface treatment.

[0441] Next, the cleaned glass substrate was spin-coated with a solution obtained by diluting an 80% ethoxylated aqueous solution of polyethyleneimine (manufactured by Sigma-Aldrich, 37% aqueous solution) 500-fold with water to form a coating film, and then placed on a hot plate and dried in the air at 120 °C for 10 minutes to make the coating film an electron transport layer.

[0442] Next, Ink (I-1) was spin-coated on the electron transport layer to form a coating film, and then heat-treated and dried for 5 minutes using a hot plate heated to 70 °C under the atmosphere (pre-bake process). Then, heat treatment was performed on the hot plate at 100 °C for 10 minutes under a nitrogen atmosphere (post-bake process) to form an active layer. The thickness of the formed active layer was about 400 nm.

[0443] Next, a molybdenum oxide (MoO 3 ) layer was formed with a thickness of about 30 nm to serve as a hole transport layer.

[0444] Next, a silver (Ag) layer was formed with a thickness of about 60 nm on the formed hole transport layer to serve as a cathode. Through the above steps, a photoelectric conversion element was manufactured on a glass substrate.

[0445] Next, a UV curable sealant, which is a sealing material, was applied to the outer periphery of a glass substrate that is a sealing substrate, and after a glass substrate that is a sealing substrate was bonded to the center of a glass substrate that is a support substrate, by irradiating UV light, the photoelectric conversion element was sealed in the gap between the support substrate and the sealing substrate to obtain a sealed body of the photoelectric conversion element. The planar shape when viewed from the thickness direction of the photoelectric conversion element sealed in the gap between the support substrate and the sealing substrate was a square of 2 mm × 2 mm. The obtained sealed body was designated as Sample 1.

[0446] [Evaluation of Dark Current of Photoelectric Conversion Element] For Sample 1 manufactured as described above, in a dark state without light irradiation, the current value when a reverse bias voltage of -3V was applied, measured using a known method, was obtained as the value of the dark current (Jd). The results are shown in Table 5 below.

[0447] <Comparative Example 11> A sealed body (Sample 2) of a photoelectric conversion element was manufactured in the same manner as for Ink (I-1), except that Ink (I-1) was changed to Ink (I-2). The value of the dark current (Jd) was obtained in the same manner as in Example 11, except that Sample 1 was changed to Sample 2. The results are shown in Table 5 below.

[0448]

Table 5

[0449] As shown in Table 3, it was found that the compound of the present disclosure absorbed up to a longer wavelength compared with conventional n-type semiconductor materials. As shown in Table 5, it was found that the photoelectric conversion element using the compound of the present disclosure as an n-type semiconductor material reduced the dark current compared with the photoelectric conversion element using a conventional n-type semiconductor material.

[0450] [Evaluation of the Energy Band Gap of Compounds] The energy band gaps (Eg) of the above-mentioned compounds N-1 to N-2 and compounds N-3 to N-20, which are n-type semiconductor materials in the present disclosure, were calculated using computational science methods.

[0451] Specifically, using the quantum chemistry calculation program Gaussian 03, the ground state structure optimization was performed by the density functional theory at the B3LYP level. For the optimized structure, the value obtained by calculation using 6-31g* as the basis function was taken as the value of the ground state energy level. Subsequently, the energy level of the exciton singlet state was obtained by TD DFT calculation using B3LYP as the functional and 6-31g* as the basis function. The difference between the energy level of the exciton singlet state and the energy level of the ground state was taken as the energy band gap (Eg). The wavelength λ Eg corresponding to the energy band gap was obtained by (Equation 1). λ Eg = 1240 / Eg (Equation 1)

[0452] The results are shown in Tables 6 to 11 below. In calculating the energy band gap, for the alkyl group that may be included in the structure of the compound, as a representative, the propyl group (-CH 2 -CH 2 -CH 3 ) was taken as an example for calculation. The calculated values are almost the same for the compound before changing the alkyl group to a propyl group and the compound after changing the alkyl group to a propyl group.

[0453] [Table 6]

[0454] [Table 7]

[0455]

Table 8

[0456]

Table 9

[0457]

Table 10

[0458]

Table 11

[0459] As described above, the compounds of Calculation Examples 1 to 8 have a smaller energy band gap (Eg) and a longer wavelength λ corresponding to the energy band gap (Eg) than the compounds of the corresponding Calculation Comparative Examples 1 to 13. Eg was shown to have a longer wavelength.

Explanation of Reference Signs

[0460] 10 Photoelectric conversion element 11 Support substrate 12 Anode 13 Hole transport layer 14 Active layer 15 Electron transport layer 16 Cathode 17 Sealing member

Claims

1. A compound represented by the following formula (X): 【Chemistry 1】 (In formula (X), D represents an electron-donating divalent group; At least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different: Each A independently represents an electron-withdrawing monovalent group. 【Chemistry 2】 【Chemistry 3】 (In formula (a) and formula (b), X １ is an electron donating group, Y １ is a hydrogen atom or an electron-withdrawing group, *1 is a bond to the D side, *2 is a bond to the A side, In formula (b), n is an integer of 1 to 3.

2. X １ are each independently -R ｂ , -OR ｂ and -NR ｂ ２ is an electron donating group selected from the group consisting of Y １ each independently represents a hydrogen atom, -CN, or -CO ２ R ｂ is any group selected from the group consisting of R ｂ each independently represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, wherein the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic; The compound of claim 1.

3. The compound according to claim 1, represented by the following formula (1) or the following formula (2): 【Chemistry 4】 (In formula (1) and formula (2), D represents an electron-donating divalent group; Each A independently represents an electron-withdrawing monovalent group, X １ and X ２ are each independently an electron donating group; Y １ and Y ２ are each independently a hydrogen atom or an electron-withdrawing group, In formula (2), n is independently an integer of 1 to 3.

4. X １ and X ２ are each independently -R ｂ , -OR ｂ and -NR ｂ ２ is an electron donating group selected from the group consisting of Y １ and Y ２ each independently represents a hydrogen atom, -CN, or -CO ２ R ｂ is any group selected from the group consisting of R ｂ each independently represents an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, wherein the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic; The compound according to claim 3.

5. The compound according to claim 1 or claim 3, wherein A is each independently a group represented by the following formula (a-1) to formula (a-5): 【Chemistry 5】 (In the above formulas (a-1) to (a-5), T represents a carbocycle which may have a substituent, or a heterocycle which may have a substituent. The carbocyclic ring and the heterocyclic ring may be a single ring or a condensed ring. When these rings have a plurality of substituents, the plurality of substituents may be the same or different. X ４ , X ５ , and X ６ are each independently an oxygen atom, a sulfur atom, an alkylidene group, ═C(—CN) ２ or =C(-CN)-CR ａ represents a group represented by R ａ is an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aromatic alkyl group having 5 to 30 carbon atoms, an aromatic alkenyl group having 5 to 30 carbon atoms, or an aromatic alkynyl group having 5 to 30 carbon atoms, and the alkyl group, alkenyl group, alkynyl group, aromatic alkyl group, aromatic alkenyl group, and aromatic alkynyl group may have a substituent and may be linear, branched, or cyclic.

6. A composition comprising a p-type semiconductor material and an n-type semiconductor material, the n-type semiconductor material comprising the compound according to claim 1 or 3.

7. The composition according to claim 6, wherein the p-type semiconductor material is a polymer compound containing at least one selected from the group consisting of a structural unit represented by the following formula (3) and a structural unit represented by the following formula (4): 【Chemistry 6】 (In formula (3), Ar １ and Ar ２ each independently represents a trivalent aromatic heterocyclic group which may have a substituent, and Z represents a group represented by the following formulae (Z-1) to (Z-7). 【Chemistry 7】 In formulas (Z-1) to (Z-7), R is Hydrogen atoms, Halogen atoms, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an optionally substituted aryl group, an alkyloxy group which may have a substituent; a cycloalkyloxy group which may be substituted; an optionally substituted aryloxy group, an optionally substituted alkylthio group, a cycloalkylthio group which may be substituted; an optionally substituted arylthio group; a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent; an optionally substituted acyl group, an imine residue which may have a substituent; an amide group which may have a substituent; an acid imide group which may have a substituent; a substituted oxycarbonyl group which may have a substituent; an alkenyl group which may have a substituent; a cycloalkenyl group which may have a substituent, an optionally substituted alkynyl group, a cycloalkynyl group which may be substituted, Cyano group, Nitro group, -C(=O)-R ｄ１ or -SO ２ -R ｄ２ represents a group represented by R ｄ１ and R ｄ２ are each independently Hydrogen atoms, an alkyl group which may have a substituent, an optionally substituted aryl group, an alkyloxy group which may have a substituent; an optionally substituted aryloxy group, or represents a monovalent heterocyclic group which may have a substituent, In each of formulas (Z-1) to (Z-7), when there are two R's, the two R's may be the same or different from each other, In formula (4), Ar ３ represents a divalent aromatic heterocyclic group.

8. An ink comprising the compound according to claim 1 or 3 and a solvent.

9. an anode, a cathode, and an active layer provided between the anode and the cathode and including a p-type semiconductor material and an n-type semiconductor material; A photoelectric conversion element comprising the compound according to claim 1 or 3 as the n-type semiconductor material.

10. The photoelectric conversion element according to claim 9 , which is a photodetection element.

11. An optical sensor comprising the photoelectric conversion element according to claim 10.

12. The wavelength λ corresponding to the energy band gap is represented by the following formula (X): Ｅｇ The compound has a calculated value of 800 nm or more according to density functional theory. 【Chemistry 8】 (In formula (X), D represents an electron-donating divalent group; At least one of p1 and p2 is a divalent group containing at least one unit represented by the following formula (a) or the following formula (b), and p1 and p2 may be the same or different: Each A independently represents an electron-withdrawing monovalent group. 【Chemistry 9】 【Chemistry 10】 (In formula (a) and formula (b), X １ is an electron donating group, Y １ is a hydrogen atom or an electron-withdrawing group, *1 is a bond to the D side, *2 is a bond to the A side, In formula (b), n is an integer of 1 to 3.

13. The compound according to claim 12, wherein the formula (X) is represented by the following formula (1) or the following formula (2): 【Chemistry 11】 (In formula (1) and formula (2), D represents an electron-donating divalent group; Each A independently represents an electron-withdrawing monovalent group, X １ and X ２ are each independently an electron donating group; Y １ and Y ２ are each independently a hydrogen atom or an electron-withdrawing group, In formula (2), n is independently an integer of 1 to 3.

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