JP7202157B2 - Compound and photoelectric conversion element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a compound and a photoelectric conversion device using the compound.

A photoelectric conversion device is a device that includes at least a pair of electrodes including an anode and a cathode, and an active layer provided between the pair of electrodes. In a photoelectric conversion element, one of the electrodes is made of a transparent or semi-transparent material, and light is allowed to enter the active layer from the side of the transparent or semi-transparent electrode. Electric charges (holes and electrons) are generated in the active layer by the energy (hν) of light incident on 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 cathode are taken out of the device.

A photoelectric conversion element having effective sensitivity in the near-infrared wavelength region (wavelength 800 nm to 2500 nm) (hereinafter referred to as a near-infrared photoelectric conversion element) can detect near-infrared light, which is invisible light. , can be used as a near-infrared photodetector.

By using a near-infrared photoelectric conversion element as a near-infrared photodetector, information that cannot be obtained with the human eye can be obtained as an electric signal. And since the obtained electrical signal can be visualized by processing it with any suitable information processing technology, near-infrared photoelectric conversion can be applied to various fields such as 3D imaging and diagnosis based on biological information such as blood flow. Applications of conversion elements are expected (see, for example, Non-Patent Documents 1 and 2).

Further, as a material for the active layer of a near-infrared photoelectric conversion device, an attempt has been made to develop a material that has strong absorption in the near-infrared region and relatively small absorption in the visible region (see Patent Document 1). .

Japanese Patent Application Laid-Open No. 2008-308602

"One-shot measurement method of textured shape using near-infrared grid pattern" Image recognition and understanding symposium (MIRU2011) July 2011 P. 1494-1501. ``Visualization of living organisms using near-infrared rays,'' Medical Photonics No. 7 p. 53-57.

The photoelectric conversion element differs in the wavelength of light to be photoelectrically converted depending on the application of the mounted photodetector. For example, the photoelectric conversion element described in Patent Document 1 has a maximum absorption wavelength of 700 nm to 800 nm, but there are cases where a photoelectric conversion element having a maximum absorption wavelength of 800 nm or more is desired. Further, like the photoelectric conversion element described in Patent Document 1, a photoelectric conversion element with low absorption in the visible light region may be required depending on the application of the photodetector. Further, there is a demand for improvement in characteristics that affect photodetection sensitivity, such as photoelectric conversion efficiency and dark current. In this way, the photoelectric conversion element and the material of the active layer applied thereto have characteristics (transmittance in the visible light range, absorption at a specific wavelength, photoelectric conversion (efficiency, dark current, heat resistance, etc.) are required.

（式（１）および式（２）中、
Ａ_１、Ａ_２、Ａ_３、Ａ_４、Ａ_５、Ａ_６、Ａ_７、Ａ_８、Ａ_９、Ａ_１０、Ａ_１１、Ａ_１２、Ａ_１３およびＡ_１４は、互いに独立に、水素原子、置換基を有していてもよいアルキル基、置換基を有していてもよいアリール基または置換基を有していてもよい１価の芳香族複素環基を表す。
Ｘ_１およびＸ_２は、互いに独立に、置換基を有していてもよい炭素原子数３～２０の炭化水素環または置換基を有していてもよい炭素原子数２～２０複素環を表す。置換基同士が結合して環を形成していてもよい。
ｎは０または１を表す。）
［２］Ａ_１とＡ_６とが同一の基であり、Ａ_２とＡ_７とが同一の基であり、Ａ_３とＡ_８とが同一の基であり、Ａ_４とＡ_９とが同一の基であり、Ａ_５とＡ_１０とが同一の基であり、かつＸ_１とＸ_２とが同一の基である、［１］に記載の化合物。
［３］前記活性層が、ｐ型半導体材料およびｎ型半導体材料を含み、該ｐ型半導体材料が、［１］または［２］に記載の化合物である［１］または［２］に記載の光電変換素子。
［４］前記ｎ型半導体材料が、フラーレンである、［３］に記載の光電変換素子。
［５］前記ｎ型半導体材料が、Ｃ６０フラーレンである、［４］に記載の光電変換素子。
［６］光検出素子である、［１］～［５］のいずれか１つに記載の光電変換素子。
［７］［６］に記載の光電変換素子を備える、イメージセンサー。
［８］［１］または［２］に記載の式（１）または式（２）で表される化合物であって、式（１）におけるｎが１である化合物。
［９］［１］または［２］に記載の式（１）または式（２）で表される化合物であって、式（１）におけるｎが０であり、Ｘ_１またはＸ_２が、互いに独立に、芳香族炭化水素を含む環である化合物。 The present inventors have made intensive research to solve the above problems, and found that the above problems can be solved by a compound having a predetermined structure and a photoelectric conversion device using such a compound as a material for the active layer. The discovery led to the completion of the present invention. Accordingly, the present invention provides the following [1] to [9].
[1] comprising an anode, a cathode, and an active layer provided between the anode and the cathode, wherein the active layer comprises a compound represented by the following formula (1) or (2); Photoelectric conversion element.

(In formulas (1) and (2),
A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are each independently a hydrogen atom, It represents an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted monovalent aromatic heterocyclic group.
X ₁ and X ₂ each independently represent an optionally substituted hydrocarbon ring having 3 to 20 carbon atoms or an optionally substituted heterocyclic ring having 2 to 20 carbon atoms . The substituents may combine to form a ring.
n represents 0 or 1; )
[2] A ₁ and A ₆ are the same group, A ₂ and A ₇ are the same group, A ₃ and A ₈ are the same group, A ₄ and A ₉ are the same The compound according to [1], wherein A ₅ and A ₁₀ are the same group, and X ₁ and X ₂ are the same group.
[3] The active layer according to [1] or [2], wherein the active layer contains a p-type semiconductor material and an n-type semiconductor material, and the p-type semiconductor material is the compound according to [1] or [2]. Photoelectric conversion element.
[4] The photoelectric conversion device according to [3], wherein the n-type semiconductor material is fullerene.
[5] The photoelectric conversion device according to [4], wherein the n-type semiconductor material is C60 fullerene.
[6] The photoelectric conversion element according to any one of [1] to [5], which is a photodetector.
[7] An image sensor comprising the photoelectric conversion element according to [6].
[8] A compound represented by formula (1) or (2) described in [1] or [2], wherein n in formula (1) is 1.
[9] A compound represented by formula (1) or formula (2) described in [1] or [2], wherein n in formula (1) is 0, and X ₁ or X ₂ is A compound that is independently a ring containing aromatic hydrocarbon.

ADVANTAGE OF THE INVENTION According to this invention, the photoelectric conversion element which has the characteristic required for the use of the photodetector by which a near-infrared photoelectric conversion element is mounted, and the material using such a photoelectric conversion element can be provided.

FIG. 1 shows the solution absorption spectrum of compound P-22 and the film absorption spectrum of compound P-22. FIG. 2 shows the solution absorption spectrum of compound P-23 and the film absorption spectrum of compound P-23. FIG. 3 shows the solution absorption spectrum of compound P-24 and the film absorption spectrum of compound P-24.

Preferred embodiments of the present invention are described in detail below. First, terms commonly used in the description of the present embodiment will be described.

A "hydrogen atom" may be either a protium atom or a deuterium atom.

"Optionally having a substituent" means that all hydrogen atoms constituting the compound or group are unsubstituted, and one or more hydrogen atoms are partially or entirely substituted by a substituent. Both aspects are included.

Examples of "substituents" include halogen atoms, alkyl groups, halogenated alkyl groups, aryl groups, arylalkyl groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, monovalent heterocyclic groups, and substituted amino groups. , acyl groups, imine residues, amide groups, acid imide groups, substituted oxycarbonyl groups, alkenyl groups, alkynyl groups, cyano groups, and nitro groups.

A "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

An "alkyl group" may be linear, branched, or cyclic, unless otherwise specified. The alkyl group may have a substituent. The number of carbon atoms in the linear alkyl group is generally 1-50, preferably 1-30, more preferably 1-20, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched or cyclic alkyl group is generally 3 to 50, preferably 3 to 30, more preferably 4 to 20, not including the number of carbon atoms in substituents.

Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isoamyl, 2-ethylbutyl, 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-dimethyl Alkyl groups such as octyl group, 2-ethyloctyl group, 2-n-hexyl-decyl group, n-dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, trifluoromethyl group, pentafluoroethyl group, per fluorobutyl group, perfluorohexyl group, perfluorooctyl group, 3-phenylpropyl group, 3-(4-methylphenyl)propyl group, 3-(3,5-di-n-hexylphenyl)propyl group, 6- An alkyl group having a substituent such as an ethyloxyhexyl group can be mentioned.

"Aryl group" means an atomic group remaining after removing one hydrogen atom directly bonded to a carbon atom constituting a ring from an optionally substituted aromatic hydrocarbon.

The aryl group may have a substituent. Specific examples of aryl groups include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-pyrenyl, 2-pyrenyl, and 4-pyrenyl groups. , 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 2-phenylphenyl group, 3-phenylphenyl group, 4-phenylphenyl group, and these groups are alkyl groups, alkoxy groups, aryl groups, fluorine atoms groups having substituents such as

An "alkoxy group" may be linear, branched, or cyclic. The number of carbon atoms in the linear alkoxy group is usually 1-40, preferably 1-10, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched or cyclic alkoxy group is usually 3-40, preferably 4-10, not including the number of carbon atoms in the substituents.

The alkoxy group may have a substituent. Specific examples of alkoxy groups include methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, isobutyloxy, tert-butyloxy, n-pentyloxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, n-nonyloxy, n-decyloxy, 3,7-dimethyloctyloxy, and lauryloxy groups.

The number of carbon atoms in the "aryloxy group" is usually 6-60, preferably 6-48, not including the number of carbon atoms in the substituents.

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-anthryloxy group, a 9-anthryloxy group, a 1-pyrenyloxy group, and alkyl groups of these groups. , an alkoxy group, and a group having a substituent such as a fluorine atom.

The "alkylthio group" may be linear, branched, or cyclic. The number of carbon atoms in the straight-chain alkylthio group is generally 1-40, preferably 1-10, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched or cyclic alkylthio group is generally 3-40, preferably 4-10, not including the number of carbon atoms in the substituents.

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

The number of carbon atoms in the "arylthio group" is usually 6-60, preferably 6-48, not including the number of carbon atoms in the substituents.

The arylthio group may have a substituent. Examples of arylthio groups include a phenylthio group and a C1-C12 alkyloxyphenylthio group (where "C1-C12" indicates that the number of carbon atoms in the group immediately following it is 1-12. The same applies to other groups hereinafter.), C1-C12 alkylphenylthio groups, 1-naphthylthio groups, 2-naphthylthio groups, and pentafluorophenylthio groups.

A "hydrocarbon ring of 3 to 20 carbon atoms or heterocyclic ring of 2 to 20 carbon atoms" is a ring structure containing a carbon atom bonded to two nitrogen atoms. The substituents of the hydrocarbon ring having 3 to 20 carbon atoms or the heterocyclic ring having 2 to 20 carbon atoms may be combined to form a ring.
The "hydrocarbon ring having 3 to 20 carbon atoms" preferably has 4 to 16 carbon atoms, more preferably 5 to 10 carbon atoms.
The "heterocyclic ring having 2 to 20 carbon atoms" preferably has 3 to 16 carbon atoms, more preferably 4 to 10 carbon atoms. The heteroatom contained in the heterocyclic ring includes an oxygen atom, a nitrogen atom and a sulfur atom, preferably an oxygen atom or a nitrogen atom.
Hydrocarbon rings include, for example, rings containing alicyclic hydrocarbons and aromatic hydrocarbons.
Alicyclic hydrocarbons include, for example, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, norbornane ring, norbornene ring, decalin ring and adamantane ring.
Aromatic hydrocarbons include, for example, benzene, naphthalene and anthracene rings.
Examples of rings containing aromatic hydrocarbons include indane ring (benzocyclopentane ring), tetralin ring (benzocyclohexane ring), fluorene ring, dihydroanthracene ring and tetrahydroanthracene ring.
Examples of the "heterocyclic ring having 3 to 20 carbon atoms" include tetrahydropyran ring, tetrahydrofuran ring, piperidine ring, tetrahydrothiopyran ring and tetrahydrothiophene ring.

The term "monovalent heterocyclic group" refers to the remaining atomic group excluding one hydrogen atom among the hydrogen atoms directly bonded to the carbon atoms or heteroatoms constituting the ring from the heterocyclic compound. means. The monovalent heterocyclic group includes a "monovalent aromatic heterocyclic group". "Monovalent aromatic heterocyclic group" refers to the remaining atoms of an aromatic heterocyclic compound excluding one hydrogen atom directly bonded to a carbon atom or heteroatom constituting a ring. means group. The monovalent heterocyclic group and monovalent aromatic heterocyclic group may have a substituent. Examples of heteroatoms include nitrogen, oxygen, sulfur, phosphorus, chlorine, iodine, and bromine atoms.

Examples of substituents that the monovalent heterocyclic group and the monovalent aromatic heterocyclic group may have include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, and an arylthio group. , monovalent heterocyclic groups, substituted amino groups, acyl groups, imine residues, amide groups, acid imide groups, substituted oxycarbonyl groups, alkenyl groups, alkynyl groups, cyano groups, and nitro groups.

Aromatic heterocyclic compounds include compounds in which an aromatic ring is condensed with a heterocyclic ring that does not exhibit aromaticity, in addition to a compound that exhibits aromaticity in itself.

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

Among aromatic heterocyclic compounds, specific examples of compounds in which an aromatic ring is fused to a heterocyclic ring that does not exhibit aromaticity include phenoxazine, phenothiazine, dibenzoborole, dibenzosilole, and benzopyran. .

The number of carbon atoms in the monovalent heterocyclic group is usually 2-60, preferably 4-20, not including the number of carbon atoms in the substituents.

The monovalent heterocyclic group may have a substituent, and specific examples of the monovalent heterocyclic group include thienyl, pyrrolyl, furyl, pyridyl, piperidyl, quinolyl, An isoquinolyl group, a pyrimidinyl group, a triazinyl group, and groups in which these groups have a substituent such as an alkyl group or an alkoxy group.

A "substituted amino group" means an amino group having a substituent. Examples of substituents that the substituted amino group can have include alkyl groups, aryl groups, and monovalent heterocyclic groups. Preferred substituents are alkyl groups, aryl groups, and monovalent heterocyclic groups. The substituted amino group usually has 2 to 30 carbon atoms.

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

The "acyl group" usually has 2 to 20 carbon atoms, preferably 2 to 18 carbon atoms. Specific examples of acyl groups include acetyl, propionyl, butyryl, isobutyryl, pivaloyl, benzoyl, trifluoroacetyl, and pentafluorobenzoyl groups.

The term “imine residue” means an atomic group remaining after removing one hydrogen atom directly bonded to a carbon atom or a nitrogen atom constituting a carbon atom-nitrogen atom double bond from an imine compound. An "imine compound" means an organic compound having a carbon atom-nitrogen atom double bond in the molecule. Examples of imine compounds include aldimines, ketimines, and compounds in which a hydrogen atom bonded to a nitrogen atom constituting a carbon atom-nitrogen atom double bond in aldimines is substituted with an alkyl group or the like.

The imine residue usually has 2 to 20 carbon atoms, preferably 2 to 18 carbon atoms. Examples of imine residues include groups represented by the following structural formulas.

"Amido group" means an atomic group remaining after removing one hydrogen atom bonded to a nitrogen atom from amide. The amide group usually has 1 to 20 carbon atoms, preferably 1 to 18 carbon atoms. 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, and a dibenzamide group. , ditrifluoroacetamide groups, and dipentafluorobenzamide groups.

An "acid imide group" means an atomic group remaining after removing one hydrogen atom bonded to a nitrogen atom from an acid imide. The number of carbon atoms in the acid imide group is generally 4-20. Specific examples of acid imide groups include groups represented by the following structural formulas.

"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.

The substituted oxycarbonyl group usually has 2 to 60 carbon atoms, preferably 2 to 48 carbon atoms.

Specific examples of substituted oxycarbonyl groups include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a tert-butoxycarbonyl group, a pentyloxycarbonyl group, and a hexyloxycarbonyl group. group, cyclohexyloxycarbonyl group, heptyloxycarbonyl group, octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3,7-dimethyloctyloxycarbonyl group, dodecyloxycarbonyl group, tri fluoromethoxycarbonyl, pentafluoroethoxycarbonyl, perfluorobutoxycarbonyl, perfluorohexyloxycarbonyl, perfluorooctyloxycarbonyl, phenoxycarbonyl, naphthoxycarbonyl, and pyridyloxycarbonyl groups.

An "alkenyl group" may be linear, branched, or cyclic. The number of carbon atoms in the straight-chain alkenyl group is usually 2-30, preferably 3-20, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched or cyclic alkenyl group is usually 3 to 30, preferably 4 to 20, not including the number of carbon atoms in substituents.

The alkenyl group may have a substituent. Specific examples of alkenyl groups include vinyl, 1-propenyl, 2-propenyl, 2-butenyl, 3-butenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl and 5-hexenyl groups. , 7-octenyl groups, and groups in which these groups have substituents such as alkyl groups and alkoxy groups.

An "alkynyl group" may be linear, branched, or cyclic. The number of carbon atoms in the linear alkenyl group is usually 2 to 20, preferably 3 to 20, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched or cyclic alkenyl group is generally 4 to 30, preferably 4 to 20, not including the number of carbon atoms in substituents.

The alkynyl group may have a substituent. Specific examples of alkynyl groups include ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, 3-butynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl and 5-hexynyl groups. , and groups in which these groups have a substituent such as an alkyl group or an alkoxy group.

<Compound>
The compound of the present embodiment is a compound containing a core structure of squaric acid (squaric acid) type or pentagonal acid (croconic acid) type, and two condensed ring structures are bound to this core structure. In this embodiment, both of these two condensed ring structures contain a spiro structure. In the present embodiment, the two condensed ring structures preferably have the same structure from the viewpoint of facilitating production.

The compound of this embodiment has a maximum absorption wavelength (λmax) in the near-infrared wavelength region (wavelength 800 nm to 2500 nm).

The compound of the present embodiment has excellent heat resistance because both of the two condensed ring structures contained therein contain a spiro structure.

Examples of the compound of the present embodiment include compounds represented by the following formulas (1) and (2). Formulas (1) and (2) have syn- and anti-isomers, and any of them may be used.

Here, constituent elements that can be contained in the compounds represented by formulas (1) and (2) will be described.
A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are each independently a hydrogen atom, It represents an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted monovalent aromatic heterocyclic group.
X ₁ and X ₂ each independently represent an optionally substituted hydrocarbon ring having 3 to 20 carbon atoms or an optionally substituted heterocyclic ring having 2 to 20 carbon atoms . These rings contain a nitrogen atom and a carbon atom attached to the nitrogen atom. Moreover, the substituents may combine to form a ring.
n represents 0 or 1;

A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ and A ₁₀ are preferably hydrogen atoms, halogen atoms, alkyl groups and aryl groups, A hydrogen atom is more preferred.
A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are preferably methyl groups.

X ₁ and X ₂ are preferably a hydrocarbon ring or heterocyclic ring having 4 to 16 carbon atoms, more preferably a hydrocarbon ring or heterocyclic ring having 5 to 12 carbon atoms.
Hydrocarbon rings having 3 to 20 carbon atoms include cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, indane ring (benzocyclopentane ring), and tetralin ring (benzocyclohexane ring). , a fluorene ring, a dihydroanthracene ring or a tetrahydroanthracene ring are preferred.
The heterocyclic ring having 2 to 20 carbon atoms is preferably a tetrahydropyran ring or a piperidine ring.
X ₁ and X ₂ are cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, indane ring (benzocyclopentane ring), tetralin ring (benzocyclohexane ring), fluorene ring, dihydro It is preferably an anthracene ring, a tetrahydroanthracene ring, a tetrahydropyran ring or a piperidine ring, and from the viewpoint of lengthening the absorption wavelength, an indane ring (benzocyclopentane ring), a tetralin ring (benzocyclohexane ring), a fluorene ring, a dihydro Anthracene ring and tetrahydroanthracene ring are more preferable.

In formula (1) or formula (2), A ₁ and A ₆ are the same group, A ₂ and A ₇ are the same group, A ₃ and A ₈ are the same group, , A ₄ and A ₉ are the same group, A ₅ and A ₁₀ are the same group, and X ₁ and X ₂ are preferably the same group.

Specific examples of the compound represented by formula (1) include compound P-1 to compound P-21 represented by the following formula.
As the compound represented by formula (1), from the viewpoint of heat resistance of the photoelectric conversion device, compound P-1, compound P-4 to compound P-9, and compound P-19 are preferred.

As formula (1), compounds P-1, compounds P-4 to compounds P-9, and P-19 are preferable from the viewpoint of heat resistance of the photoelectric conversion device.

Specific examples of compounds represented by formula (1) in which n is 0 include compounds P-22 to P-42 represented by the following formulas.

Specific examples of the compound represented by formula (2) include compound P-43 to compound P-48 represented by the following formula.

In the near-infrared wavelength region, the compound of the present embodiment preferably exhibits high absorption in the wavelength range of 800 nm to 1200 nm, and more preferably exhibits high absorption in the wavelength range of 850 nm to 1100 nm. Further, the compound of the present embodiment preferably has high transmittance of light in the visible light wavelength range.

<Method for producing compound>
The compound of the present embodiment can be produced (synthesized), for example, with reference to the production method described in Dyes and Pigments, 2018, 154, 216-228. Hereinafter, the method for producing the compound of the present embodiment, which has already been described, will be described more specifically.

In the method for producing the compound of the present embodiment, a perimidine compound can be synthesized and used.

Specifically, first, 1,8-diaminonaphthalenes and cycloalkane-ones are condensed by heating under reflux in a solvent (for example, a mixed solvent of toluene and 1-propanol) in the presence of an acid catalyst. to synthesize a perimidine compound.

Examples of 1,8-diaminonaphthalenes include 1,8-diaminonaphthalenes optionally having an alkyl group, an aryl group, or a monovalent heterocyclic group as a substituent.

The cycloalkane-ones preferably have 3 to 22 carbon atoms. Examples of cycloalkane-ones include 1-tetralone, 2-sec-butylcyclohexan-1-one, and 4-tert-butylcyclohexan-1-one.

Suitable examples of acid catalysts include p-toluenesulfonic acid.
As the solvent, it is preferable to use a mixed solvent of an alcohol solvent and an aromatic hydrocarbon solvent because it is easy to ensure the solubility and because it is easy to promote the condensation reaction.

Suitable examples of alcoholic solvents include methanol, ethanol, propanol, butanol, and pentanol.

Suitable examples of aromatic hydrocarbon solvents include benzene, toluene, xylene, and chlorobenzene.

The mixing ratio (alcohol solvent:aromatic hydrocarbon solvent) in the mixed solvent is preferably 1:10 to 10:1, more preferably 1:5 to 5:1.

In synthesizing the perimidine compound, the reaction time (heating and refluxing time) is preferably 0.5 to 24 hours, more preferably 1 to 12 hours. The reaction temperature is preferably from 5°C to 200°C, more preferably from 80°C to 150°C, since the reaction is dehydration-condensation and it is preferable to heat the reaction.

After heating under reflux, the residue obtained by distilling off the solvent under reduced pressure is preferably dissolved in a solvent (eg, toluene), and the resulting solution is passed through a silica gel column to remove highly polar impurities.
Next, the solution from which impurities have been removed is distilled off under reduced pressure to obtain a perimidine compound as a precursor.

Subsequently, the resulting perimidine compound is condensed with squaric acid (squaric acid) or croconic acid (pentanoic acid) in a solvent (for example, a mixed solvent of toluene and 1-propanol) under reflux with heating.

After heating under reflux, the reaction solution is cooled to room temperature, and the resulting precipitate is filtered and washed with methanol to obtain the compound according to the present embodiment.

The equivalent amount of the precursor perimidine compound to squaric acid (squaric acid) or croconic acid (pentanoic acid) is determined to condense two molecules to one molecule of squaric acid (squaric acid) or croconic acid (pentanoic acid). , preferably 1.5 to 5.0 times the molar amount, more preferably 1.8 to 3.0 times the molar amount for condensation.

Since this condensation reaction is dehydration condensation, it is preferably carried out under heating conditions, and the reaction temperature is preferably 80°C to 150°C, more preferably 90°C to 130°C.

In this dehydration condensation reaction, a mixed solvent of an alcohol solvent and an aromatic hydrocarbon solvent is used because it is easy to ensure the solubility of the intermediate product iodonium salt, squaric acid (squaric acid) or croconic acid (pentagonal acid). is preferred because it facilitates the condensation reaction.

In this dehydration condensation reaction, it is preferable to use methanol, ethanol, propanol, butanol, pentanol, etc. as the alcohol solvent from the viewpoint of ease of removal by distillation under reduced pressure. Benzene, toluene, xylene, chlorobenzene and the like are preferably used.

<Photoelectric conversion element>
The photoelectric conversion element of this embodiment includes an anode, a cathode, and an active layer provided between the anode and the cathode, and the active layer is represented by formula (1) or formula (2) A photoelectric conversion device containing a compound.

The photoelectric conversion element of this embodiment exhibits excellent photoelectric conversion efficiency in the near-infrared wavelength region (wavelength 800 nm to 2500 nm).

In the photoelectric conversion device of the present embodiment, since the active layer contains the compound represented by formula (1) or (2), high photoelectric conversion efficiency is preferably obtained in the near-infrared wavelength region at a wavelength of 800 nm to 1200 nm. and more preferably high photoelectric conversion efficiency at wavelengths of 850 nm to 1100 nm. Since the compound represented by Formula (1) or Formula (2) can transmit light in the visible wavelength range, the photoelectric conversion element of the present embodiment reduces signals based on light in the visible wavelength range. In addition, it is possible to effectively detect light in the near-infrared wavelength range.

Here, the constituent elements that the photoelectric conversion element of this embodiment can have will be described.

(substrate)
A photoelectric conversion element is usually provided on a substrate (support substrate). Electrodes, including cathodes and anodes, may be formed on the substrate. A mode in which the anode is arranged so as to be bonded to the support substrate is called a forward lamination structure, and a mode in which the cathode is arranged so as to be bonded to the support substrate is called a reverse lamination structure. The photoelectric conversion element of this embodiment can take any form.

The material of the substrate is not particularly limited as long as it is a material that does not chemically change when the layer containing the organic compound is formed. Materials for the substrate include, for example, glass, plastic, polymer film, and silicon. In the case of an opaque substrate, it is preferable that the electrode on the side opposite to the electrode provided on the opaque substrate side (that is, the electrode on the far side from the substrate) be a transparent or translucent electrode.

(electrode)
Materials for transparent or translucent electrodes include, for example, conductive metal oxide films and semitransparent metal thin films. Specifically, indium oxide, zinc oxide, tin oxide, and their composites indium tin oxide (ITO), indium zinc oxide (IZO), conductive materials such as NESA, gold, platinum, silver, and copper. mentioned. ITO, IZO, and tin oxide are preferable as materials for transparent or translucent electrodes. Moreover, as the electrode, a transparent conductive film using an organic compound such as polyaniline and its derivatives, polythiophene and its derivatives as a material may be used. Transparent or translucent electrodes include dispersions such as emulsions, suspensions, and metal pastes containing nanoparticles of conductive materials, nanowires of conductive materials, or nanotubes of conductive materials. Alternatively, it may be formed by a coating method using a molten low melting point metal or the like. Examples of conductive substances include metals such as gold and silver, oxides such as ITO (indium tin oxide), carbon nanotubes, and the like. The electrode has a structure in which nanoparticles or nanofibers of a conductive substance are dispersed and arranged in a predetermined medium such as a conductive polymer, as described in Japanese Patent Application Publication No. 2010-525526. may be
The transparent or translucent electrode can be either the anode or the cathode. Further, the electrode provided so as to be bonded to the substrate (supporting substrate) may be either an anode or a cathode. If both electrodes are transparent, it is possible to obtain a photoelectric conversion element with high transmittance of light in the visible light wavelength range.

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

(active layer)
In the photoelectric conversion device of this embodiment, the active layer contains a p-type semiconductor material (electron-donating compound) and an n-type semiconductor material (electron-accepting compound), and the p-type semiconductor material has the formula (1) or the formula It is a compound represented by (2).

The active layer can take the form of a single layer or a laminate of multiple layers. The monolayer active layer contains an electron-accepting compound (n-type semiconductor material) and an electron-donating compound (p-type semiconductor material).

In the p-type semiconductor material and the n-type semiconductor material that the active layer may contain, which of the p-type semiconductor material and the n-type semiconductor material is relative to the HOMO or LUMO energy levels of the selected compounds. can be determined to

The active layer in which a plurality of layers are laminated is composed of, for example, a laminate obtained by laminating a first semiconductor layer containing a p-type semiconductor material and a second semiconductor layer containing an n-type semiconductor material. In this case, the first semiconductor layer is arranged closer to the anode than the second semiconductor layer.

The n-type semiconductor material used as the material for the active layer is not particularly limited, provided that it can be applied to the active layer forming process described below.

As the n-type semiconductor material, one or more selected from fullerenes and fullerene derivatives is preferable. In particular, when the active layer is formed by a vapor deposition method, it is preferable to use fullerene, and when it is formed by a coating method, it is preferable to use a fullerene derivative.

Examples of fullerenes include C60 fullerene, C70 fullerene, C76 fullerene, C78 fullerene, and C84 fullerene. Examples of fullerene derivatives include derivatives of these fullerenes. A fullerene derivative means a compound in which at least a part of fullerene is modified.

Examples of fullerene derivatives include compounds represented by the following formulas (N-1) to (N-4).

In formulas (N-1) to (N-4), R ^a represents an alkyl group, an aryl group, a monovalent heterocyclic group, or a group having an ester structure. A plurality of R ^a may be the same or different.

^Rb represents an alkyl group or an aryl group. A plurality of R ^b may be the same or different.

Examples of groups having an ester structure represented by R ^a include groups represented by the following formula (19).

In formula (19), u1 represents an integer of 1-6. u2 represents an integer from 0 to 6; R ^c represents an alkyl group, an aryl group, or a monovalent heterocyclic group.

Examples of C60 fullerene derivatives include the following compounds.

Examples of C70 fullerene derivatives include the following compounds.

Specific examples of fullerene derivatives include [6,6]-phenyl-C61 butyric acid methyl ester (C60PCBM, [6,6]-Phenyl C61 butyric acid methyl ester), [6,6]-phenyl-C71 butyric acid methyl ester ( C70PCBM, [6,6]-Phenyl C71 butyric acid methyl ester), [6,6"-phenyl-C85 butyric acid methyl ester (C84PCBM, [6,6]-Phenyl C85 butyric acid methyl ester), and [6,6 ]-Thienyl-C61 butyric acid methyl ester ([6,6]-Thienyl C61 butyric acid methyl ester).

The thickness of the active layer is generally preferably 1 nm to 100 μm, more preferably 2 nm to 1000 nm, even more preferably 5 nm to 500 nm, and particularly preferably 20 nm to 200 nm. When the photoelectric conversion element is, for example, a solar cell, the thickness of the active layer is preferably 500 nm to 1000 nm. When the photoelectric conversion element is, for example, a photodetection element, the thickness of the active layer is preferably 500 nm to 1000 nm.

(middle layer)
The photoelectric conversion element of the present embodiment includes additional components such as a charge transport layer (electron transport layer, hole transport layer, electron injection layer, hole injection layer) as further components for improving characteristics such as photoelectric conversion efficiency. An intermediate layer may be provided.

As a material used for such an intermediate layer, any suitable conventionally known material can be used. Materials for the intermediate layer include, for example, alkali metal or alkaline earth metal halides, such as lithium fluoride, and oxides.

Materials used for the intermediate layer include fine particles of inorganic semiconductors such as titanium oxide, and PEDOT (poly(3,4-ethylenedioxythiophene)) and PSS (poly(4-styrenesulfonate)). A mixture (PEDOT:PSS) may be mentioned.

The photoelectric conversion element of this embodiment may have 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.

A hole-transporting layer provided in contact with an anode may be particularly referred to as a hole-injecting layer. A hole transport layer (hole injection layer) provided in contact with the anode has a function of promoting injection of holes into the anode. The hole transport layer (hole injection layer) may be in contact with the active layer.

The hole-transporting layer contains a hole-transporting material. Examples of hole-transporting materials include polythiophene and its derivatives, aromatic amine compounds, polymeric compounds containing constitutional units having aromatic amine residues, CuSCN, CuI, NiO, and molybdenum oxide ( _MoO3 ). be done.

The photoelectric conversion device of this embodiment may have an electron transport 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.

The electron-transporting layer contains an electron-transporting material. Examples of electron-transporting materials include nanoparticles of zinc oxide, nanoparticles of gallium-doped zinc oxide, nanoparticles of aluminum-doped zinc oxide, and polyalkyleneimine as the backbone, with ethylene oxide attached to nitrogen atoms in the backbone. ethoxylated polyethylenimine (PEIE), which is a modified variant, and PFN-P2.

(sealing layer)
The photoelectric conversion element may contain a sealing layer. The sealing layer can be provided, for example, on the side of the electrode farther from the substrate. The sealing layer can be formed of a material having a property of blocking moisture (water vapor barrier property) or a property of blocking oxygen (oxygen barrier property).

(Use of photoelectric conversion element)
The photoelectric conversion element of the present embodiment can pass a photocurrent by irradiating light from the transparent or translucent electrode side in a state where a voltage is applied between the electrodes, and can be used as a light detection element (photosensor). can be operated. Moreover, it can also be used as an image sensor by integrating a plurality of optical sensors.

Moreover, the photoelectric conversion element of this embodiment can generate a photovoltaic force between the electrodes by being irradiated with light, and can be operated as a solar cell. A thin-film solar cell module can also be obtained by integrating a plurality of solar cells.

(Application example of photoelectric conversion element)
The photoelectric conversion device according to the present embodiment has a compound represented by formula (1) or formula (2), which has a particularly large absorption in the near-infrared wavelength region and a small absorption in the visible wavelength region, in the active layer. Since it is used as a material, it is useful as a near-infrared photodetector.

The photoelectric conversion element of the present embodiment can be suitably used as a photodetector and image sensor applied to devices for 3D imaging, VR (virtual reality), augmented reality (AR), and MR (mixed reality).

<Method for producing photoelectric conversion element>
The method for manufacturing the photoelectric conversion element of this embodiment is not particularly limited. The photoelectric conversion element of this embodiment can be manufactured by a forming method suitable for the materials selected for forming the constituent elements already described.

(Method of forming electrodes)
As a method for forming the electrodes, any suitable conventionally known forming method can be used. Methods of forming electrodes include, for example, a vacuum deposition method, a sputtering method, an ion plating method, and a plating method.

(Method for forming intermediate layer)
A method for manufacturing the intermediate layer is not particularly limited. When the intermediate layer is composed of the already-described inorganic material or low-molecular-weight material, it can be formed by any suitable method, such as a vacuum vapor deposition method or a vacuum heating vapor deposition method, depending on the material.

Further, when the functional layer such as the intermediate layer of the photoelectric conversion element of the present embodiment is composed of a material soluble in a solvent, particularly a polymer compound, it can be produced by a coating method using ink.

The coating method applied in the method for producing a photoelectric conversion element of the present embodiment includes a step (i) of obtaining a coating film by applying an ink containing a material and a solvent to an object to be coated, and removing the solvent from the coating film. and step (ii). Steps (i) and (ii) included in the coating method will be described below.

step (i)
Any suitable coating method can be used as a method for applying the ink to the coating object. The coating method is preferably a slit coating method, a knife coating method, a spin coating method, a micro gravure coating method, a gravure coating method, a bar coating method, an inkjet printing method, a nozzle coating method, or a capillary coating method. A coating method, a capillary coating method, or a bar coating method is more preferable, and a slit coating method or a spin coating method is even more preferable.

The ink is applied to an application target selected according to the photoelectric conversion element and its manufacturing method. The ink can be applied onto the substrate or the functional layer of the photoelectric conversion element in the manufacturing process of the photoelectric conversion element. Therefore, the ink application target differs depending on the layer structure and the order of layer formation of the photoelectric conversion element to be manufactured. For example, when the photoelectric conversion element has a layer structure of substrate/anode/hole transport layer/active layer/electron transport layer/cathode, and the layer described further to the left is formed first (forward lamination structure), and when the hole transport layer is formed by a coating method, the object to be coated with the ink is the anode. Further, for example, when the photoelectric conversion element has a layer structure of substrate/cathode/electron transport layer/active layer/hole transport layer/anode, and the layer described further to the left is formed first ( When the hole transport layer is formed by a coating method, the ink is applied to the active layer.

step (ii)
Any suitable method can be used as a method for removing the solvent from the coating film of the ink, that is, as a method for removing the solvent from the coating film to form a solidified film. Examples of methods for removing the solvent include drying methods such as direct heating using a hot plate, hot air drying, infrared heat drying, flash lamp annealing drying, and vacuum drying.

The step of forming the functional layer by the coating method may include other steps in addition to the steps (i) and (ii) provided that the objects and effects of the present invention are not impaired.

The ink used in the ink coating method may be a solution, or may be a dispersion liquid such as a dispersion liquid, an emulsion (emulsion), or a suspension (suspension). The ink of this embodiment is an ink for forming a predetermined functional layer, and may contain a selected functional material (p-type semiconductor material and/or n-type semiconductor material) and a solvent.

The ink may contain only one type of p-type semiconductor material and n-type semiconductor material, or may contain two or more types in combination at any ratio.

The solvent should be selected in consideration of the solubility of the selected material and the characteristics (boiling point, etc.) for coping with the drying conditions.
The solvent preferably contains an aromatic hydrocarbon (hereinafter simply referred to as aromatic hydrocarbon) optionally having a substituent (eg, alkyl group, halogen atom).

Examples of such aromatic hydrocarbons include toluene, xylene (eg, o-xylene, m-xylene, p-xylene), trimethylbenzene (eg, mesitylene, 1,2,4-trimethylbenzene (pseudocumene)). , butylbenzene (eg n-butylbenzene, sec-butylbenzene, tert-butylbenzene), methylnaphthalene (eg 1-methylnaphthalene), tetralin, indane, chlorobenzene and dichlorobenzene (o-dichlorobenzene). .

The solvent may contain only one aromatic hydrocarbon, or may contain two or more aromatic hydrocarbons. Preferably, the solvent contains only one aromatic hydrocarbon.

Solvents are preferably toluene, o-xylene, m-xylene, p-xylene, mesitylene, pseudocumene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, tetralin, indane, chlorobenzene and o-xylene. It contains one or more selected from the group consisting of dichlorobenzene, more preferably o-xylene, pseudocumene, tetralin, chlorobenzene or o-dichlorobenzene.

The solvent may further contain a solvent other than aromatic hydrocarbons. Examples of such solvents include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, and propiophenone, ethyl acetate, butyl acetate, phenyl acetate, ethyl cellosolve acetate, methyl benzoate, butyl benzoate, and benzyl benzoate. and other ester solvents.

In addition to a solvent, a p-type semiconductor material, and an n-type semiconductor material, the ink contains an ultraviolet absorber, an antioxidant, and a sensitizer to generate electric charges by absorbed light, as long as the objects and effects of the present invention are not impaired. Optional ingredients such as sensitizers to increase stability and light stabilizers to increase UV stability may also be included.

Preparation of Ink The ink can be prepared by a known method. For example, it can be prepared by mixing selected multiple types of solvents to prepare a mixed solvent, adding and mixing the materials already described to the mixed solvent, and dissolving or dispersing the materials. The solvent and material may be heated and mixed at a temperature below the boiling point of the solvent.

After mixing the solvent and materials, the resulting mixture may be filtered using a filter and the obtained filtrate may be used as an ink. As the filter, for example, a filter made of a fluororesin such as polytetrafluoroethylene (PTFE) can be used.

(Method of forming active layer)
The active layer of the photoelectric conversion device of the present embodiment is preferably manufactured using the compound represented by formula (1) or (2) as the p-type semiconductor material and fullerene as the n-type semiconductor material.

As a method for forming the active layer, any suitable conventionally known forming method can be used. The active layer may be formed by a coating method similar to the method for forming the intermediate layer already described.

As a method for forming the active layer, any suitable conventionally known forming method can be used. Suitable methods for forming the active layer of the present embodiment, which is formed using the materials already described, include, for example, a vacuum deposition method such as a resistance heating deposition method and an electron beam heating deposition method. More specifically, the active layer of the photoelectric conversion element of the present embodiment uses a compound represented by formula (1) or formula (2) and fullerene, and a co-evaporation method or flash vapor deposition in which these are simultaneously vacuum-deposited. It is preferably formed by a method.

Examples of the present invention will be described below. The invention is not limited to the following examples.

(I) NMR analysis NMR measurement was performed using a sample in which the compound to be measured was dissolved in deuterated chloroform, using an NMR device (400 MHz NMR device manufactured by JEOL, JNM-ECZ400S/L1).
(II) UV-vis absorption spectrum analysis 5 mg of the compound to be measured was dissolved in 0.995 g of chloroform to obtain solution I. A mixed solution II was obtained by mixing 0.16 g of the resulting solution and 0.84 g of chloroform. A mixed solution III obtained by mixing 0.1 g of the obtained mixed solution I and 4.9 g of chloroform was used as a measurement solution.
The absorption spectrum of the measurement solution was measured from 300 to 1200 nm using a measurement device (Cary 5E UV-VIS-NIR Spectrophotometer manufactured by Varian). The spectrum obtained is called a solution absorption spectrum.
A film of the solution I was formed on a glass substrate by spin coating to obtain a measurement sample. The absorption spectrum of the measurement sample was measured from 300 to 1200 nm using a measurement device (Cary 5E UV-VIS-NIR Spectrophotometer manufactured by Varian). The obtained spectrum is called a deposition absorption spectrum.

<Example 1> (Synthesis of compound P-1)
Dyes and Pigments 154 (2018) 216-228, except that croconic acid was used instead of squaric acid and a cyclic carbonyl compound was used instead of a linear carbonyl compound. Compound P-1 was synthesized according to the following scheme with reference to the description.

Specifically, 0.791 g (5.00 mmol) of 1,8-diaminonaphthalene, 0.765 g (5.25 mmol) of 1-tetralone and 0.095 g (0.50 mmol) of toluene-4-sulfonic acid monohydrate was added to 10 mL of 1-propanol and heated under reflux for 2 hours, after which the solvent 1-propanol was distilled off under reduced pressure.

Then, a toluene solution in which the resulting residue was dissolved in a small amount of toluene was filtered using silica gel. Colored impurities were adsorbed on the silica gel to obtain a toluene solution from which the colored impurities were removed. Toluene was distilled off from the resulting toluene solution under reduced pressure to quantitatively obtain 1.50 g (5.02 mmol) of a brown solid.

Subsequently, the total amount of the brown solid obtained was 1.50 g (5.02 mmol), and 0.357 g (2.51 mmol) of croconic acid was added to a mixed solvent of 12.6 mL of 1-propanol and 6.3 mL of toluene. In addition, the mixture was heated under reflux for 2 hours. After allowing the reaction solution to cool to room temperature, the solid obtained was filtered off and washed with methanol. The washed solid was vacuum-dried at 50° C. to obtain 1.21 g (71.2% yield over two steps) of compound P-1, which is a brown powdery p-type semiconductor material.
¹ H-NMR (ppm, DMF-d7): 10.9-10.1 (brs, -NH-), 10.1-9.4 (brs, -NH-), 8.8-8.2 ( br, aromatic ring), 8.2-6.0 (br, aromatic ring), 4.0-2.5 (br, —CH ₂ —), 2.5-1.5 (br, —CH ₂ — ).

<Example 2> Synthesis of compound P-2 Dyes and Pigments 154 (2018) 216-228, except that croconic acid was used instead of squaric acid and a cyclic carbonyl compound was used instead of a linear carbonyl compound. Compound P-2 was synthesized according to the following scheme with reference to the description.

Specifically, 0.791 g (5.00 mmol) of 1,8-diaminonaphthalene, 0.810 g (5.25 mmol) of 2-sec-butylcyclohexan-1-one, 0 toluene-4-sulfonic acid monohydrate 0.095 g (0.50 mmol) was added to 10 mL of 1-propanol and heated to reflux for 2 hours. Then, the solvent 1-propanol was distilled off under reduced pressure. The resulting residue was dissolved in a small amount of toluene and filtered through 5 g of silica gel. By eluting with 55 mL of toluene, the colored impurities were adsorbed on the silica gel, and a toluene solution from which the colored impurities were removed was obtained. Toluene was distilled off from the resulting toluene solution under reduced pressure to quantitatively obtain 1.497 g (5.04 mmol) of an oily component as a brown solid.

Subsequently, 1.497 g (5.04 mmol) of the obtained solid oily component and 0.358 g (2.52 mmol) of croconic acid were added to a mixed solvent of 12.6 mL of 1-propanol and 6.3 mL of toluene. The mixture was added and heated under reflux for 2 hours. After allowing the reaction solution to cool to room temperature, it was filtered and the obtained solid was washed with methanol. The washed solid was vacuum-dried at 50° C. to obtain 1.62 g (yield 93.0%) of compound P-2, which is a brown powder p-type semiconductor material.

<Example 3> Synthesis of compound P-3 Dyes and Pigments 154 (2018) 216-228, except that croconic acid was used instead of squaric acid and a cyclic carbonyl compound was used instead of a linear carbonyl compound. Compound P-3 was synthesized according to the following scheme with reference to the description.

Specifically, 0.791 g (5.00 mmol) of 1,8-diaminonaphthalene, 0.810 g (5.25 mmol) of 4-tert-butylcyclohexan-1-one and 0 toluene-4-sulfonic acid monohydrate 0.095 g (0.50 mmol) was added to 10 mL of 1-propanol and heated to reflux for 1 hour. The solvent 1-propanol was distilled off under reduced pressure. The resulting residue was dissolved in a small amount of toluene and filtered through 5 g of silica gel. By eluting with 55 mL of toluene, the colored impurities were adsorbed on the silica gel, and a toluene solution from which the colored impurities were removed was obtained. Toluene was distilled off from the resulting toluene solution under reduced pressure to obtain 1.384 g of pink solid oily component (yield 93.6%).

Subsequently, 1.384 g (4.70 mmol) of the obtained solid oily component and 0.334 g (2.35 mmol) of croconic acid were added to a mixed solvent of 11.8 mL of 1-propanol and 5.9 mL of toluene. The mixture was added and heated under reflux for 2 hours. The resulting reaction solution was allowed to cool to room temperature, separated, and the obtained solid was washed with methanol. The washed solid was vacuum-dried at 50° C. to obtain 1.03 g (63.5% yield) of compound P-3, which is a brown powdery p-type semiconductor material.
¹ H-NMR (ppm, DMF-d7): 10.1-9.5 (brs, -NH-), 8.5-6.1 (br, aromatic ring), 8.2-6.0 (br , aromatic ring), 2.1-1.1 (br, alkyl moiety).

<Comparative Example 1> Synthesis of compound CP-1 Dyes and Pigments 154 (2018) 216-228, except that croconic acid was used instead of squaric acid. Compound CP-1 was synthesized according to the following scheme with reference to.

Specifically, 3.16 g (20.0 mmol) of 1,8-diaminonaphthalene, 1.81 g (21.0 mmol) of 3-pentanone, and 0.380 g (2.0 mmol) of toluene-4-sulfonic acid monohydrate ) was added to 40 mL of 1-propanol and heated to reflux for 2 hours. 1 propanol as a solvent was distilled off under reduced pressure. The resulting residue was dissolved in 8 mL of toluene and filtered through 20 g of silica gel. By eluting with 220 mL of toluene, the colored impurities were adsorbed on the silica gel, and a toluene solution from which the colored impurities were removed was obtained. Toluene was distilled off from the obtained toluene solution under reduced pressure to quantitatively obtain 4.67 g (20.11 mmol) of an oily component as a brown solid.

Subsequently, 4.67 g (20.11 mmol) of the obtained solid oily component and 1.43 g (10.05 mmol) of croconic acid were added to a mixed solvent of 50 mL of 1-propanol and 25 mL of toluene, and the mixture was stirred for 2 hours. Heated to reflux. The reaction mixture was allowed to cool to room temperature, separated, and the obtained solid was washed with methanol. The washed solid was vacuum-dried at 50° C. to obtain 3.87 g (yield 68.9%) of compound CP-1, which is a p-type semiconductor material in the form of black-brown powder.
¹ H-NMR (ppm, DMSO-d ₆ ): 10.2-9.5 (br, -NH-), 7.7-6.3 (br, Ar), 2.6-2.2 (br , —CH ₂ —), 1.1-0.6 (br, —CH ₃ ).

<Example 4> (Synthesis of compound P-22)
Compound P-22 was synthesized according to the following scheme in the same manner as in Example 1, except that squaric acid was used instead of croconic acid.

^１Ｈ－ＮＭＲ（ｐｐｍ，ＤＭＳＯ－ｄ_６）：
１０．５（ｂｒｓ、－ＮＨ－）、７．９－６．９（ｍ、芳香環）、６．８（ｄｄ，芳香環）、６．５（ｄ，芳香環）、２．５－１．５（ｍ，－ＣＨ_２－）。

¹ H-NMR (ppm, DMSO-d ₆ ):
10.5 (brs, -NH-), 7.9-6.9 (m, aromatic ring), 6.8 (dd, aromatic ring), 6.5 (d, aromatic ring), 2.5-1 .5(m, —CH ₂ —).

A solution absorption spectrum of compound P-22 and a film absorption spectrum of P-22 were measured according to the method described in (II). The results are shown in FIG.

<Synthesis Example 1> (Synthesis of compound P-23)
Compound P-23 was synthesized according to the following scheme in the same manner as in Example 2, except that squaric acid was used instead of croconic acid.

^１Ｈ－ＮＭＲ（ｐｐｍ，ＤＭＳＯ－ｄ_６）：
１０．４－９．８（ｂｒ、－ＮＨ－）、８．２－６．４（ｍ、芳香環）、２．５－０．６（ｍ，脂肪族）。

¹ H-NMR (ppm, DMSO-d ₆ ):
10.4-9.8 (br, -NH-), 8.2-6.4 (m, aromatic ring), 2.5-0.6 (m, aliphatic).

A solution absorption spectrum of compound P-23 and a film absorption spectrum of P-23 were measured according to the method described in (II). The results are shown in FIG.

<Synthesis Example 2> (Synthesis of compound P-24)
Compound P-24 was synthesized according to the following scheme in the same manner as in Example 3, except that squaric acid was used instead of croconic acid.

^１Ｈ－ＮＭＲ（ｐｐｍ，ＤＭＳＯ－ｄ_６）：
１０．５－１０．２（ｂｒ、－ＮＨ－）、７．９－６．４（ｍ、芳香環）、２．４－１．０（ｍ，脂肪族）、０．９１（ｓ,－ＣＨ_３）。

¹ H-NMR (ppm, DMSO-d ₆ ):
10.5-10.2 (br, -NH-), 7.9-6.4 (m, aromatic ring), 2.4-1.0 (m, aliphatic), 0.91 (s, - _CH3 ).

A solution absorption spectrum of compound P-24 and a film absorption spectrum of P-24 were measured according to the method described in (II). The results are shown in FIG.

<Thermal Analysis of Compounds P-1 to P-3, Compounds P-22 to P-24, and Compound CP-1>
Compounds P-1 to P-3, Compounds P-22 to P-24, and Compound CP-1 were evaluated for heat resistance by TG-DTA (differential thermal analysis). Table 1 shows the results.

As the TG-DTA apparatus, "Thermal Analysis Apparatus TG-DTA6300" (manufactured by SII Nano Technology Co., Ltd.) was used. In a nitrogen atmosphere, the temperature was raised from 25° C. to 500° C. at a rate of 10° C./min, and the temperature at which the weight loss reached 5% was measured. By raising the temperature, the compound is decomposed and the weight of the compound is reduced. The higher the temperature at which the weight loss reaches 5%, the better the heat resistance.

The compounds obtained in Example 4, Synthesis Example 1, and Synthesis Example 2 were able to suppress weight loss due to temperature change, and had improved heat resistance.
The compounds obtained in Example 4, Synthesis Example 1, and Synthesis Example 2 exhibited strong absorption in the near-infrared wavelength region and relatively small absorption in the visible wavelength region.

<Example 5>
(Manufacturing of near-infrared photoelectric conversion element)
A near-infrared photoelectric conversion device is produced using the compound P-1 obtained in Synthesis Example 1 above. This embodiment includes an anode, a hole transport layer (electron blocking layer), an active layer, an electron transport layer (hole blocking layer) and a cathode.

Specifically, among the glass substrates provided with an ITO layer, the ITO layer is patterned to prepare a glass substrate as an anode, which is then subjected to acetone ultrasonic cleaning and then UV ozone cleaning.
Next, using a solution containing polyethyleneimine, the solution is applied to the side where the anode is provided by a spin coating method, and the applied film is dried by heating to form a hole transport layer.

Next, the compound P-1 obtained in Example 1 above and C60 fullerene, which is an n-type semiconductor material, are co-evaporated on the hole transport layer by a vacuum heating evaporation method to form an active layer.

Next, molybdenum oxide (MoO ₃ ) is vapor-deposited on the active layer by a vacuum heating vapor deposition method to form an electron transport layer.

Then, Ag is vapor-deposited on the electron-transporting layer to form a cathode, thereby producing a near-infrared photoelectric conversion device.

After forming the cathode, the glass substrate having each of the above layers is transferred into a glove box without being exposed to the atmosphere, and a glass plate coated with a UV-curable epoxy resin is bonded together and irradiated with UV light for UV curing. The mold epoxy resin is cured to seal the near-infrared photoelectric conversion element.

(Evaluation of near-infrared photoelectric conversion element)
In order to evaluate the photoelectric conversion characteristics in the near-infrared light wavelength region, the spectral sensitivity of the near-infrared photoelectric conversion element is evaluated using a spectral sensitivity measurement device (CEP2000, manufactured by Spectro Keiki Co., Ltd.).

<Example 6>
(Manufacturing of near-infrared photoelectric conversion element)
Using the compound P-1 obtained in Example 1 above, a near-infrared photoelectric conversion device is produced. In this example, the near-infrared photoelectric conversion device includes an anode, a hole transport layer, an active layer, an electron transport layer and a cathode.

Specifically, among the glass substrates provided with an ITO layer, the ITO layer is patterned to prepare a glass substrate as an anode, which is then subjected to acetone ultrasonic cleaning and then UV ozone cleaning.

Next, using a polyethyleneimine solution, the solution is applied to the side where the anode is provided by a spin coating method, and the applied film is dried by heating to form a hole transport layer.

Next, the compound P-1 obtained in Example 1 above and C60PCBM, which is an n-type semiconductor material, were placed on the hole transport layer at a weight ratio of 1:3 (p-type semiconductor material: n-type semiconductor material) in chloroform. is applied by spin coating to form a coating film, and the coating film is dried by heating to form an active layer.

Next, molybdenum oxide (MoO ₃ ) is vapor-deposited on the active layer by a vacuum heating vapor deposition method to form an electron transport layer.

Then, Ag is vapor-deposited on the electron-transporting layer to form a cathode, thereby producing a near-infrared photoelectric conversion device.

After forming the cathode, the glass substrate having each of the above layers is transferred into a glove box without being exposed to the atmosphere, and a glass plate coated with a UV-curable epoxy resin is bonded together and irradiated with UV light for UV curing. The mold epoxy resin is cured to seal the near-infrared photoelectric conversion element.

(Evaluation of near-infrared photoelectric conversion element)
In order to evaluate photoelectric conversion acceleration in the near-infrared light wavelength region, the spectral sensitivity of the near-infrared photoelectric conversion element is evaluated using a spectral sensitivity measurement device (CEP2000, manufactured by Spectroscopic Keiki Co., Ltd.).

<Example 7>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound P-2 obtained in Example 2 above was used instead of the compound P-1.
<Example 8>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound P-2 obtained in Example 2 above was used instead of the compound P-1.

<Example 9>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound P-3 obtained in Example 3 above was used instead of the compound P-1.

<Example 10>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound P-3 obtained in Synthesis Example 3 was used instead of the compound P-1.
<Example 11>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound P-22 obtained in Example 4 above was used instead of the compound P-1.

<Example 12>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound P-22 obtained in Example 4 above was used instead of the compound P-1.

<Example 13>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound P-23 obtained in Synthesis Example 1 was used instead of the compound P-1.

<Example 14>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound P-23 obtained in Synthesis Example 1 was used instead of the compound P-1.

<Example 15>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound P-24 obtained in Synthesis Example 2 was used instead of the compound P-1.

<Example 16>
(Manufacturing and Evaluation of Near Infrared Photoelectric Conversion Device)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound P-24 obtained in Synthesis Example 2 was used instead of the compound P-1.

<Comparative Example 2>
(Manufacturing and Evaluation of Photoelectric Conversion Elements)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 5 except that the compound CP-1 obtained in Comparative Synthesis Example 1 was used instead of the compound P-1.

<Comparative Example 3>
(Manufacturing and Evaluation of Photoelectric Conversion Elements)
A near-infrared photoelectric conversion device is produced and evaluated in the same manner as in Example 6 except that the compound CP-1 obtained in Comparative Synthesis Example 1 was used instead of the compound P-1.

The near-infrared photoelectric conversion elements of Examples 5 to 16 are superior to the near-infrared photoelectric conversion elements of Comparative Examples 2 and 3 in photoelectric conversion efficiency in the near-infrared wavelength region of 800 nm or more, and in the visible light region. Photoelectric conversion efficiency decreases.

Claims (9)

A photoelectric conversion device comprising an anode, a cathode, and an active layer provided between the anode and the cathode, wherein the active layer contains a compound represented by the following formula (1) or (2): .

(In formulas (1) and (2),
A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are each independently a hydrogen atom, It represents an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted monovalent aromatic heterocyclic group .
n represents 0 or 1;
X ₁ and X ₂ are
(a) when n in the formulas (1) and (2) is 0, independently of each other, indane ring (benzocyclopentane ring), tetralin ring (benzocyclohexane ring), fluorene ring, dihydroanthracene ring, or a tetrahydroanthracene ring, or
(b) when n in the formulas (1) and (2) is 1, independently of each other, an optionally substituted hydrocarbon ring having 3 to 20 carbon atoms or a substituent It represents a heterocyclic ring having 2 to 20 carbon atoms which may be substituted, and the substituents may be combined to form a ring. ) In formulas (1) and (2), A ₁ and A ₆ are the same group, A ₂ and A ₇ are the same group, and A ₃ and A ₈ are the same group; , A ₄ and A ₉ are the same group, A ₅ and A ₁₀ are the same group, and X ₁ and X ₂ are the same group. . 3. The active layer according to claim 1 or 2, wherein the active layer contains a p-type semiconductor material and an n-type semiconductor material, and the p-type semiconductor material is a compound represented by the formula (1) or the following formula (2) . Photoelectric conversion element. 4. The photoelectric conversion device according to claim 3, wherein said n-type semiconductor material is fullerene. 5. The photoelectric conversion device according to claim 4, wherein said n-type semiconductor material is C60 fullerene. 6. The photoelectric conversion device according to claim 1, which is a photodetector. An image sensor comprising the photoelectric conversion element according to claim 6 . A compound represented by the following formula (1) or (2).

A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are each independently a hydrogen atom, It represents an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted monovalent aromatic heterocyclic group.
X ₁ and X ₂ each independently represent an optionally substituted hydrocarbon ring having 3 to 20 carbon atoms or an optionally substituted heterocyclic ring having 2 to 20 carbon atoms . The substituents may combine to form a ring.
n represents 1; ) A compound represented by the following formula (1) or (2).

(In formulas (1) and (2),
A ₁ , A ₂ , A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , A ₈ , A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ are each independently a hydrogen atom, It represents an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted monovalent aromatic heterocyclic group.
n represents 0;
X ₁ and X ₂ are each independently an indane ring (benzocyclopentane ring), a tetralin ring (benzocyclohexane ring), a fluorene ring, a dihydroanthracene ring, or a tetrahydroanthracene ring. )

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