JP6284822B2 - Picene derivative, photoelectric conversion material and photoelectric conversion element - Google Patents

Description

  The present invention relates to a novel p-type organic semiconductor material having a specific structure, a photoelectric conversion material, and a photoelectric conversion element using the same.

In recent years, solar cells (solar power generation) that can be used continuously, do not deplete resources, and have low environmental pollution have been actively studied. Solar cells are roughly classified into Si-based and non-Si-based inorganic solar cells, and dye-sensitized and organic thin-film organic solar cells. Inorganic solar cells generally have high photoelectric conversion efficiency, but have a drawback of high manufacturing cost because high vacuum is required or high-temperature heat treatment is required. On the other hand, since the organic solar cell can be formed by a coating method, a printing method, or the like, the manufacturing cost is low and the film can be formed in a large area. Another advantage is that the device is lighter than inorganic solar cells. In particular, organic thin-film solar cells are excellent in printing methods and can be easily formed into a film or the like, so that flexible solar cells are also easy.
However, since many organic solar cells have low photoelectric conversion efficiency, increasing the photoelectric conversion efficiency is a problem.

  Currently, P3HT [poly (3-hexylthiophene)], which is a p-type organic semiconductor material, and PCBM [[6, 6], which is an n-type organic semiconductor material, as materials having high photoelectric conversion efficiency in organic thin-film solar cells. ] -Phenyl-C61-butyric acid methyl ester] and a bulk heterojunction made of a mixed material (see Non-Patent Document 1, etc.). In addition, a low molecular compound such as pentacene may be used as the p-type organic semiconductor material. However, it is generally considered that a high molecular weight material is more suitable for device manufacturing by coating, which can reduce cost and increase the screen size. It is considered easy.

A characteristic required for the p-type organic semiconductor material is that the material has a highly planar π-conjugated plane. This is because high π-π interaction and high carrier transport efficiency can be expected, and as a result, high photovoltaic power can be provided.
Patent Documents 1 to 3 disclose a polymer-type p-type organic semiconductor.

JP 2008-042107 A JP 2009-155891 A Special table 2011-116962 gazette

F. Padinger, et al., Adv. Funct. Mater., 13, 85 (2003)

Accordingly, an object of the present invention is to provide a p-type organic semiconductor material that is easy to manufacture and has high planarity in a polymer skeleton.
Another object of the present invention is to provide a photoelectric conversion layer, a photoelectric conversion element, and an organic thin film solar cell having high photoelectric conversion efficiency using the p-type organic semiconductor material.

  As a result of intensive studies, the inventors of the present invention can easily produce a photoelectric conversion layer when a picene derivative having at least one structural unit represented by the following general formula (1) is used as a p-type organic semiconductor material. I found out that I can do it. As a result of further investigation, it has been found that the photoelectric conversion element having the photoelectric conversion layer exhibits high carrier mobility and can solve the above-described problems.

  The present invention has been made based on the above findings, and provides a novel picene derivative (hereinafter also referred to as a picene derivative) having at least one structural unit represented by the following general formula (1).

(In the formula, A ¹ and A ² each independently represent a single ring,
The hydrogen atom in the structural unit represented by the general formula (1) has a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ⁵ R ⁶ group, a substituent, or is unsubstituted. Or a group represented by -SiR ¹ R ² R ³ , or unsubstituted or substituted, and R ¹ , R ² , R ³ , R ⁵ or R ⁶ are each independently a hydrogen atom or It represents a substituted or unsubstituted hydrocarbon group. )

  The present invention also provides a photoelectric conversion material comprising (A) the above-mentioned picene derivative as a p-type organic semiconductor material and (B) an n-type organic semiconductor material.

  Moreover, this invention provides the photoelectric converting layer obtained by forming into a film the said photoelectric converting material.

  Moreover, this invention provides the photoelectric conversion element which has the said photoelectric converting layer.

  Moreover, this invention provides the organic thin film solar cell which has the said photoelectric conversion element.

  According to the present invention, a novel picene derivative useful as an organic semiconductor material can be provided. When the photoelectric conversion material of the present invention containing the compound is used, high performance of the device can be realized due to high carrier mobility.

FIG. 1A is a cross-sectional view showing an example of the configuration of the photoelectric conversion element of the present invention, FIG. 1B is a cross-sectional view showing another example of the configuration of the photoelectric conversion element of the present invention, FIG.1 (c) is sectional drawing which shows another example of a structure of the photoelectric conversion element of this invention.

  Hereinafter, the picene derivative, photoelectric conversion material, photoelectric conversion layer, and organic thin-film solar cell of the present invention will be described in detail based on preferred embodiments.

<Picene derivative>
The picene derivative of the present invention is a compound having at least one structural unit represented by the general formula (1). In addition, * in the said General formula (1) means that group represented by these formulas couple | bonds with adjacent group in * part (the following is same).

The monocycle represented by A ¹ and A ² in the above general formula is not particularly limited, but is preferably an aromatic monocycle, and specific examples include a benzene ring, a furan ring, a thiophene ring, and a selenophene. And a ring, a tellurophen ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring, an imidazole ring, and a pyrazole ring. Among these, a heterocyclic ring containing a sulfur atom, a selenium atom, or a tellurium atom is preferable because it improves the characteristics of the device.

The hydrogen atom in the general formula (1) is a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ⁵ R ⁶ group, a substituted or unsubstituted hydrocarbon group, Or substituted by a group represented by -SiR ¹ R ² R ³ or unsubstituted, and R ¹ , R ² , R ³ , R ⁵ and R ⁶ each independently have a hydrogen atom or a substituent. Or an unsubstituted hydrocarbon group.
In the present invention, the halogen atom includes fluorine, chlorine, bromine, iodine and the like,
Examples of the hydrocarbon group include an aromatic hydrocarbon group, an aromatic hydrocarbon group substituted with an aliphatic hydrocarbon, and an aliphatic hydrocarbon group, and those having 1 to 40 carbon atoms, particularly 4 to 22 carbon atoms. Preferably
Examples of the aromatic hydrocarbon group include phenyl, naphthyl, cyclohexylphenyl, biphenyl, terphenyl, fluoryl, thiophenylphenyl, furanylphenyl, 2′-phenyl-propylphenyl, benzyl, naphthylmethyl, and the like.
Examples of the aliphatic hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, isobutyl, amyl, isoamyl, t-amyl, hexyl, heptyl, isoheptyl, t-heptyl, n. -Linear, branched and cyclic alkyl groups such as octyl, isooctyl, t-octyl, nonyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc., and these aliphatic hydrocarbon groups Is interrupted by —O—, —COO—, —OCO—, —CO—, —S—, —SO—, —SO ₂ —, —NR ¹⁵ —, —HC═CH— or —C≡C—. (Note that the interruption may interrupt the portion to which the aliphatic hydrocarbon group is bonded), and R ¹⁵ has a substituent. Represents an unsubstituted or unsubstituted hydrocarbon group, and examples of the substituted or unsubstituted hydrocarbon group include the same groups as described above, and among them, perfluoroalkyl is preferable.
Examples of the aromatic hydrocarbon group substituted with the aliphatic hydrocarbon include phenyl, naphthyl, benzyl and the like substituted with the aliphatic hydrocarbon group.
Examples of the group that may substitute these hydrocarbon groups include a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, and a —NR′R ″ group, and R ′ and R ″ are It represents a substituted or unsubstituted hydrocarbon group, and examples of the substituted or unsubstituted hydrocarbon group include the same groups as described above.

  Among picene derivatives, those having 2 or more and 100 or less structural units represented by the above general formula (1) are preferable because of excellent film forming properties. The picene derivative may have a structural unit other than the structural unit represented by the general formula (1) (hereinafter also referred to as other structural unit). When a picene derivative contains other structural units, it is preferable that the structural unit of the said General formula (1) is 5-100 mol%, It is more preferable that it is 10-90 mol%, 20-80 mol% It is particularly preferred that

  Among the picene derivatives represented by the general formula (1), those having at least one structural unit represented by the following general formula (1-1) or (1-2) are preferable because they are easy to produce. .

(Wherein, A ³ and A ⁴ represent what a 6-membered ring of the monocyclic exemplified in the description of the A ¹ and A ^2, A ⁵ and A ⁶ are, in the A ¹ and A ² This represents a 5-membered ring in the single rings exemplified in the description, and the hydrogen atom in the formula may be substituted in the same manner as the hydrogen atom in the general formula (1).

Among the picene derivatives having the structural units represented by the general formulas (1-1) and (1-2), A ³ and A ⁴ in the general formula (1-1) are the same 6-membered ring. Or those in which A ⁵ and A ⁶ in the above general formula (1-2) are the same 5-membered ring are preferable because the production is easier.

  The other structural unit is not particularly limited as long as it is a π-conjugated group, but examples include structural units selected from the following group Y or group Z. From the viewpoint of durability and light resistance of the material, (Y− A structural unit selected from 2), (Y-3), (Y-4) or group Z is preferred.

Wherein X ¹ and X ⁴ represent S, O or NR ⁴ ; k represents an integer of 1 to 4; R ⁴ represents a substituted or unsubstituted hydrocarbon group; The hydrogen atom in the structural unit is a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ¹⁰ R ¹¹ group, a substituted or unsubstituted hydrocarbon group or a substituted group. Or may be substituted with an unsubstituted or substituted heterocyclic group, and R ¹⁰ and R ¹¹ represent a substituted or unsubstituted hydrocarbon group.)

Wherein X ² represents S or NR ⁷ , X ³ represents S, NR ⁷ , CR ⁸ R ⁹ or SiR ⁸ R ⁹ , X ⁵ represents S, O or NR ⁷ , R ⁷ , R ⁸ and R ⁹ represent a substituted or unsubstituted hydrocarbon group, and the hydrogen atom in the structural unit represented by group Z is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, thiol group , —NR ¹⁰ R ¹¹ group, substituted or unsubstituted hydrocarbon group or substituted or unsubstituted heterocyclic group, R ¹⁰ and R ¹¹ may be substituted. Or it represents an unsubstituted hydrocarbon group.)

A hydrocarbon group that may substitute a hydrogen atom in the structural unit represented by group Y or group Z, or a substituted or unsubstituted hydrocarbon group represented by R ¹⁰ and R ¹¹ in —NR ¹⁰ R ¹¹ ; And NR ⁴ representing X ¹ and X ⁴ in group Y, NR ⁷ representing X ² and X ⁵ in group Z, and NR ⁷ representing X ³ , R ⁴ in CR ⁸ R ⁹ and SiR ⁸ R ⁹ , Examples of the substituted or unsubstituted hydrocarbon group represented by R ⁷ , R ⁸ and R ⁹ include the same groups as the substituted or unsubstituted hydrocarbon group in the general formula (1).

  When the picene derivative includes a structural unit of the group Y or group Z, the picene derivative is represented by the following general formula (1 ′), and each of o, p, or q structural units in the general formula (1 ′) The arrangement is not particularly limited, and the effects of the present invention are achieved. Moreover, as a preferable ratio of each structural unit, when o which is a structural unit of Formula (1) is 1, p or q which is a structural unit of the group Y or the group Z is 1-10. The value of p is more preferably 0 to 8 and still more preferably 1 to 5 from the viewpoint of high light absorption efficiency in the long wavelength region. Further, a more preferable value of q is 0 to 2, more preferably 1 or 2, particularly preferably 1, from the viewpoint of high light absorption efficiency in the long wavelength region.

(The hydrogen atom in the formula may be substituted in the same manner as in the general formula (1), Y represents a group selected from the group Y, Z represents a group selected from the group Z, and o represents 1 represents an integer of 1 to 1000, and p and q represent an integer of 0 to 1000.)

  A preferred example of the picene derivative is a compound represented by the following general formula (2).

(In the formula, A ¹ and A ² represent the same group as in the above formula (1), and the hydrogen atom in the picene-derived group having A ¹ and A ² is substituted in the same manner as in the above formula (1). You can,
Y ¹ and Y ² are a single bond or a group connected by combining 1 to 5 groups selected from the following (Y-1) to (Y-8),
Z ¹ represents a single bond or a group selected from the following (Z-1) to (Z-21), and n represents an integer of 1 to 1,000. )

(Wherein X ¹ and X ⁴ represent S, O or NR ⁴ , k represents an integer of 1 to 4, R ⁴ represents a substituted or unsubstituted hydrocarbon group, (Y-1 ) To (Y-4) and (Y-6) to (Y-8) include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ¹⁰ R ¹¹ group, R ¹⁰ and R ¹¹ may be substituted with a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, and R ¹⁰ and R ¹¹ represent a substituted or unsubstituted hydrocarbon group. Represents.)

Wherein X ² represents S or NR ⁷ , X ³ represents S, NR ⁷ , CR ⁸ R ⁹ or SiR ⁸ R ⁹ , X ⁵ represents S, O or NR ⁷ , R ⁷ , R ⁸ and R ⁹ represent a substituted or unsubstituted hydrocarbon group, and the hydrogen atom in the structural unit represented by group Z is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, thiol group , —NR ¹⁰ R ¹¹ group, substituted or unsubstituted hydrocarbon group or substituted or unsubstituted heterocyclic group, R ¹⁰ and R ¹¹ may be substituted. Or it represents an unsubstituted hydrocarbon group.)

Among the compounds represented by the general formula (2), a compound in which at least one of Y ¹ , Y ^2, or Z ¹ is not a single bond is preferable because of excellent characteristics as a photoelectric conversion element.

  Specific examples of picene derivatives include the following Nos. 1-No. 21 is mentioned, but it is not particularly limited to these. Note that n in the following formula is the same as that in the general formula (2). In the formula, Hex represents a hexyl group, and 2-EH represents a 2-ethylhexyl group.

  Any of the picene derivatives of the present invention is not limited to the production method thereof, and can be obtained by a method using a known general reaction. As an example, the picene derivative represented by the general formula (2) can be produced by synthesis of a picene derivative and subsequent polycondensation reaction as shown below. This will be specifically described below.

<Synthesis of picene derivatives>
First, as shown below, 1,4-dibromo-2,3-diiodobenzene (3) is replaced with (Z) -alkenylboronic acid ester (4), a metal catalyst, preferably a transition metal compound and tri-substituted. A picene precursor (5) is synthesized by reacting with a catalyst comprising phosphine in the presence of a base, and then a picene derivative (6) is synthesized from the precursor (5) by dehydrohalogenation. To do.

In the above reaction formula, A represents either A ¹ or A ^{2 in} the general formula (1).

<Polycondensation reaction>
Next, as shown below, the picene derivative (2) of the present invention is subjected to a polycondensation reaction between the picene derivative (6) obtained above and a halogenated π-conjugated group (7) obtained by a known synthesis method. ) Can be obtained.

In the above reaction formula, A ¹ , A ² , X, Y ¹ , Y ² , Z ¹ and n have the same meaning as in the general formula (2).

<Photoelectric conversion material>
The photoelectric conversion material of the present invention contains (A) a p-type organic semiconductor material containing at least one picene derivative, and (B) an n-type organic semiconductor material.

  (A) As a p-type organic-semiconductor material, it is sufficient if it contains at least one picene derivative, and other known materials can be used together. For example, phthalocyanine pigments, indigo or thioindigo pigments, quinacridone pigments, triarylmethane derivatives, triarylamine derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, pyrazoline derivatives, polysilane derivatives, polyphenylene vinylene and derivatives thereof (for example, polyphenylene vinylene) [2-Methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene]: MEH-PPV, poly [2-methoxy-5- (3 ′, 7′-dimethyloctyloxy) -1,4 -Phenylene vinylene]), polythiophene and derivatives thereof (for example, poly (3-dodecylthiophene), poly (3-hexylthiophene): P3HT, poly (3-octylthiophene)), poly-N-vinylcarbazole derivatives, and the like. It is done.

  When other known materials are used as the (A) p-type organic semiconductor material, the content of the picene derivative is preferably 1 to 99 mass%, more preferably 1 to 80 mass% in the (A) p-type organic semiconductor material. %.

  (B) As an n-type organic semiconductor material, a perylene pigment, a perinone pigment, a polycyclic quinone pigment, an azo pigment, C60 fullerene, C70 fullerene, and a derivative thereof can be used. For example, tris (8-quinolinolato) aluminum, bis (10-benzo [h] quinolinolato) beryllium, beryllium salt of 5-hydroxyflavone, aluminum salt of 5-hydroxyflavone], oxadiazole derivative [for example, 1,3- Bis [5 ′-(p-tert-butylphenyl) -1,3,4-oxadiazol-2′-yl] benzene], triazole derivatives [eg 3- (4′-tert-butylphenyl) -4 -Phenyl-5- (4 ''-biphenyl) -1,2,4-triazole], phenanthroline derivatives [e.g. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine, BCP)], triazine derivatives, quinoline derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorenone derivatives, thiopyrandioxide derivatives, etc. It can also be used. (B) Among n-type organic semiconductor materials, C60 fullerene, C70 fullerene, and derivatives thereof are preferable because they have high carrier mobility as n-type materials and / or high charge separation efficiency. In addition, the compound quoted as an example as an n-type organic-semiconductor material may be used independently, or may be used together.

  Examples of the C60 fullerene, C70 fullerene, and derivatives thereof include the following C1 to C6 compounds. Among them, C1 PCBM (phenyl) is preferable because it has excellent electronic level matching and is easily available. -C61-butyric acid methyl ester) is preferably used.

  In the photoelectric conversion material of the present invention, the weight ratio of the component (A) to the component (B) (the former: the latter) is 10:90 to 90:10, preferably 10:90 to 70:30, and more preferably Is 20: 80-50: 50.

  Moreover, the photoelectric conversion material of this invention may contain a 1 type, or 2 or more types of solvent as needed.

  The solvent is not particularly limited as long as it can dissolve or disperse the component (A) and the component (B). For example, water, alcohol solvent, diol solvent, ketone solvent, ester solvent, ether Examples thereof include an aliphatic solvent, an aliphatic or alicyclic hydrocarbon solvent, an aromatic hydrocarbon solvent, a hydrocarbon solvent having a cyano group, a halogenated hydrocarbon solvent, and other solvents. A photoelectric conversion material using a solvent can be used as a coating solution.

  Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, 1-butanol, isobutanol, 2-butanol, tertiary butanol, pentanol, isopentanol, 2-pentanol, neopentanol, and third. Pentanol, hexanol, 2-hexanol, heptanol, 2-heptanol, octanol, 2-ethylhexanol, 2-octanol, cyclopentanol, cyclohexanol, cycloheptanol, methylcyclopentanol, methylcyclohexanol, methylcycloheptanol , Benzyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl Ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, 2- (N, N-dimethylamino) ethanol, 3 (N, N-dimethylamino) propanol, etc. Can be mentioned.

  Examples of the diol solvent include ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, isoprene glycol ( 3-methyl-1,3-butanediol), 1,2-hexanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,2-octanediol, octanediol (2-ethyl) -1,3-hexanediol), 2-butyl-2-ethyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol 1,4-cyclohexanedimethanol and the like.

  Examples of the ketone solvent include acetone, ethyl methyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl hexyl ketone, ethyl butyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, and methyl. Examples include amyl ketone, cyclohexanone, and methylcyclohexanone.

  Examples of the ester solvent include methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, second butyl acetate, third butyl acetate, amyl acetate, isoamyl acetate, and third amyl acetate. , Phenyl acetate, methyl propionate, ethyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, sec-butyl propionate, tert-butyl propionate, amyl propionate, isoamyl propionate, amyl propionate, Phenyl propionate, methyl 2-ethylhexanoate, ethyl 2-ethylhexanoate, propyl 2-ethylhexanoate, isopropyl 2-ethylhexanoate, butyl 2-ethylhexanoate, methyl lactate, ethyl lactate, methyl methoxypropionate Methyl ethoxypropionate, ethyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol mono Butyl ether acetate, ethylene glycol mono secondary butyl ether acetate, ethylene glycol mono isobutyl ether acetate, ethylene glycol mono tertiary butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl Pyrether acetate, Propylene glycol monoisopropyl ether acetate, Propylene glycol monobutyl ether acetate, Propylene glycol mono secondary butyl ether acetate, Propylene glycol monoisobutyl ether acetate, Propylene glycol mono tertiary butyl ether acetate, Butylene glycol monomethyl ether acetate, Butylene glycol monoethyl Ether acetate, butylene glycol monopropyl ether acetate, butylene glycol monoisopropyl ether acetate, butylene glycol monobutyl ether acetate, butylene glycol mono sec-butyl ether acetate, butylene glycol monoisobutyl ether acetate, butylene glycol mono Examples include tertiary butyl ether acetate, methyl acetoacetate, ethyl acetoacetate, methyl oxobutanoate, ethyl oxobutanoate, γ-lactone, dimethyl malonate, dimethyl succinate, propylene glycol diacetate, and δ-lactone.

  Examples of the ether solvent include tetrahydrofuran, tetrahydropyran, morpholine, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol dimethyl ether, dibutyl ether, diethyl ether, and dioxane.

  Examples of the aliphatic or alicyclic hydrocarbon solvents include pentane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, heptane, octane, decalin, solvent naphtha, turpentine oil, D-limonene, pinene, and minerals. Spirit, Swazol # 310 (Cosmo Matsuyama Oil Co., Ltd., Solvesso # 100 (Exxon Chemical Co., Ltd.)) and the like.

  Examples of the aromatic hydrocarbon solvent include benzene, toluene, ethylbenzene, xylene, mesitylene, diethylbenzene, cumene, isobutylbenzene, cymene, and tetralin.

  Examples of the hydrocarbon solvent having a cyano group include acetonitrile, 1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyanocyclohexane, cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, , 6-dicyanohexane, 1,4-dicyanocyclohexane, 1,4-dicyanobenzene and the like.

  Examples of the halogenated hydrocarbon solvent include carbon tetrachloride, chloroform, dichloromethane, trichloroethylene, chlorobenzene, dichlorobenzene, and trichlorobenzene.

  Examples of the other organic solvents include N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, aniline, triethylamine, pyridine, and carbon disulfide.

  Among these, preferable solvents include chloroform, dichloromethane, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene and the like.

  When the above-described solvent is contained in the photoelectric conversion material of the present invention, the content is not particularly limited as long as it does not hinder the formation of a photoelectric conversion layer using the photoelectric conversion material. It is preferable that the total amount of the component (A) and the component (B) is 0.1 to 20 parts by weight when it is 100 parts by weight, more preferably 1 to 10 parts by weight, particularly preferably. Is preferably selected from the range of 3 to 7 parts by weight.

<Photoelectric conversion layer>
Next, the photoelectric conversion layer of the present invention will be described. The photoelectric conversion layer of the present invention is obtained by forming the photoelectric conversion material of the present invention into a film. The film forming method is not particularly limited. For example, vapor deposition method, physical vapor deposition method (PVD), chemical vapor deposition method (CVD), atomic layer deposition method (ALD), atomic layer epitaxy method (ALE). ), Dry processes such as molecular beam epitaxy (MBE), vapor phase epitaxy (VPE), sputtering, plasma polymerization, etc .; dip coating, casting, air knife coating, curtain coating, roller coating, wire Forming a coating on a support by wet processes such as bar coating, gravure coating, spin coating, LB, offset printing, screen printing, flexographic printing, dispenser printing, ink jet, and extrusion coating The method of doing is mentioned.

  Although the film thickness of the said photoelectric converting layer is not specifically limited, Generally, it is preferable to set to about 5 nm-5 micrometers, and heat processing, such as annealing, may be performed.

  The photoelectric conversion layer is used for an element in which p-type and n-type organic semiconductor materials are mixed. In addition to the organic bulk heterojunction element which is a preferred embodiment, a super hierarchical nanostructure junction element, a hybrid heterojunction type, pi Used for the i layer and the like in an -n junction type element.

<Photoelectric conversion element and organic thin film solar cell>
The photoelectric conversion element of this invention is comprised similarly to a conventionally well-known photoelectric conversion element except having at least one photoelectric conversion layer of this invention. For example, taking FIG. 1A as an example, the support 1, the electrode 2, the charge transfer layer 3, the photoelectric conversion layer 4, and the electrode 5 are sequentially stacked. Further, a structure excluding the charge transfer layer 3 as shown in FIG. 1B or a structure further having a charge transfer layer 6 as shown in FIG. 1C may be used.

  In the photoelectric conversion element of the present invention, light needs to reach the photoelectric conversion layer 4 from the support 1. In order to allow irradiation light to reach the photoelectric conversion layer 4 from the support 1, the electrode 2 and the charge transfer layer 3, the support 1, the electrode 2 and the charge transfer layer 3 are formed of a light transmissive material, and the light transmittance Is preferably set to be 70% or more.

  As long as the support 1 can stably hold the electrode 2 on the surface, the support 1 is not limited by the material and thickness, but needs to have transparency. Therefore, the shape of the support may be plate or film. Transparency refers to the property of transmitting light in a predetermined wavelength region used in a photoelectric conversion element, for example, visible light region at a high rate. For the support 1, for example, glass, transparent polymer film (polyethylene terephthalate (PET), tetraacetyl cellulose (TAC), polycarbonate, polyethylene naphthalate, polyphenylene sulfide, polyester sulfone, syndiotactic polystyrene) or the like can be used. The photoelectric conversion element of the present invention is preferably formed on the surface of the support 1. However, when the electrode 2 itself has a certain degree of hardness and is self-supporting, the structure in which the electrode 2 also serves as the support 1. In this case, the support 1 may be omitted.

  In the present invention, the work functions of a pair of electrodes (electrode 2 and electrode 5) arranged opposite to each other may have a relatively large relationship with each other (that is, the work functions are different from each other). Therefore, it is sufficient that the work function of the electrode 2 is relatively larger than that of the electrode 5. In this case, the work function difference between the two electrodes is preferably 0.5 V or more. In addition, when a buffer layer is provided between each electrode and the semiconductor layer and the compound of the buffer layer on the electrode and the electrode are chemically bonded, these restrictions may be relaxed.

  Examples of the electrodes 2 and 5 include noble metals such as gold, platinum, and silver, metals such as zinc oxide, indium oxide, tin oxide (NESA), tin-doped indium oxide (ITO), and fluorine-doped tin oxide (FTO). Oxide, lithium, lithium-indium alloy, sodium, sodium-potassium alloy, calcium, magnesium, magnesium-silver alloy, magnesium-indium alloy, indium, ruthenium, titanium, manganese, yttrium, aluminum, aluminum-lithium alloy, aluminum- In addition to calcium alloys, aluminum-magnesium alloys, chromium, graphite thin films, organic conductive compounds such as PEDOT-PSS can be used as appropriate. These electrode materials may be used alone or in combination. Since the electrode 2 needs to have transparency, a transparent material such as zinc oxide, NESA, ITO, FTO, and PEDOT-PSS is used. The electrode 2 and the electrode 5 can be formed by using a dry process or a wet process using these electrode materials in the same manner as the photoelectric conversion layer 4. Further, it may be formed by firing by a sol-gel method or the like. Moreover, although the thickness of an electrode is based also on the material of the electrode substance to be used, both the electrode 2 and the electrode 5 are generally set to about 5-1000 nm, More preferably, about 10-500 nm.

The charge transfer layers 3 and 6 prevent the electrode material from entering and reacting with the photoelectric conversion layer, and prevent recombination of charges separated by the photoelectric conversion layer, thereby efficiently transferring the charge to the electrodes 2 and 5. There is a role such as letting. Examples of the material include charge transfer materials such as PEDOT: PSS, PEO, V ₂ O ₅ , zinc oxide, lithium fluoride, TiOx, and naphthalenetetracarboxylic acid anhydride. The charge transfer layer 3 needs to have transparency. When the photoelectric conversion layer 4 is a P3HT: PCBM bulk hetero type, PEDOT: PSS is often used for the charge transfer layer 3, and LiF is often used for the charge transfer layer 6. The charge transfer layers 3 and 6 can be formed using these charge transfer materials by a dry process method or a wet process method in the same manner as the photoelectric conversion layer 4. The thickness of the charge transfer layers 3 and 6 is generally set to 0.01 to 100 nm, more preferably about 0.1 to 50 nm.

  The photoelectric conversion element of this invention can be used for a photodiode, a photodetector, etc. other than the organic thin-film solar cell of this invention.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited by the following examples.

Example 1 Compound No. 1 Synthesis of 12 (Step 1) Synthesis of 2-[(Z) -2- (3-enylti) ethenyl] boronic acid pinacol ester (2a)
In a 200 mL two-necked insulator flask, cyclooctadiene rhodium chloride dimer (270 mg, 0.54 mmol), cyclohexane (65 mL), triisopropylphosphine (350 mL, 2.16 mmol), dehydrated triethylamine (19 mL, 140 mmol) And pinacol borane (3.9 mL, 27 mmol) was added, and it stirred at 15 degreeC for 30 minutes. Thereafter, 3-thienylethyne (1a) (4.3 g, 40 mmol) was added, and the mixture was stirred at room temperature for 1.5 hours. Thereafter, methanol was poured into the reaction solution to stop the reaction. Celite filtration was performed to remove the catalyst, and the mixture was concentrated on a rotary evaporator. Subsequently, the objective compound 2a was obtained as an orange transparent liquid by Kugel distillation in a yield of 79% (5.0 g, 21 mmol). Kugel distillation was carried out at 120 ° C / 1.2 Torr. It was confirmed by the following <Identification result> that the obtained orange transparent liquid was the target compound 2a.
<Identification results>
FT-IR (neat, cm-1): 2978 (s), 1614 (s), 1443 (m), 1335 (s), 1260 (s), 1144 (s), 812 (m), 673 (m) .
¹ H NMR (300 MHz, 25 ° C, CDCl ₃ ): δ 1.32 (s, 12H), 5.47 (d, J = 15.3 Hz, 1H), 7.17 (d, J = 15.3 Hz, 1H), 7.23 (dd, J = 5.1, 2.7 Hz, 1H), 7.55-7.57 (m, 1H), 7.66 (d, J = 2.7 Hz, 1H).
¹³ C [1H] NMR (75 MHz, 25 ° C., CDCl ₃ ): δ 24.9, 83.5, 124.9, 126.2, 128.6, 140.6, 141.9.
MS (EI, m / z (relative intensity)): 236 (M ⁺ , 70), 178 (30), 163 (83), 151 (24), 150 (29), 137 (54), 136 (100) , 135 (86), 120 (52), 111 (43).
Anal. Calcd for C12H17BO2S: C, 61.04; H, 7.26%. Found: C, 60.99; H, 7.29%.

(Step 2) Synthesis of 1,4-dichlorobis-2,3-[(Z) -2- (3thienylethynyl)] benzene (4a)
To a 20 mL Schlenk tube, 1,4-dichloro-2,3-diiodobenzene (compound 3a) (40 mg, 0.10 mmol), PEPPSI-IPr (6.8 mg, 0.010 mmol), compound 2a (61 mg, 0.26) mmol), potassium hydroxide (34 mg, 0.60 mmol), toluene (0.5 mL) and water (0.1 mL) were added, and the mixture was stirred at 110 ° C. for 12 hours. Thereafter, 1.0 M hydrochloric acid was poured into the reaction solution to stop the reaction, followed by separation and extraction with diethyl ether. The organic phase was dehydrated with a saturated aqueous sodium chloride solution and then dehydrated with anhydrous magnesium sulfate. After filtering the mixed solution, the solvent was distilled off using a rotary evaporator. The obtained brown liquid was purified by silica gel column chromatography (Rf = 0.12, hexane) to obtain the target compound 4a as an orange liquid in a yield of 48% (17 mg, 0.048 mmol). It was confirmed by the following <Identification result> that the obtained orange liquid was the target compound 4a.
<Identification results>
FT-IR (neat, cm ^-1 ): 2926 (s), 1724 (s), 1634 (w), 1435 (s), 1281 (s), 1265 (m), 1125 (s), 870 (m) , 797 (s), 773 (m).
¹ H NMR (300 MHz, 25 ° C, CDCl ₃ ): δ 6.08 (d, J = 12.0 Hz, 2H), 6.56-6.60 (m, 4H),
6.91 (d, J = 2.4 Hz, 2H), 7.09-7.11 (m, 2H), 7.37 (s, 1H).
¹³ C [1H] NMR (75 MHz, 25 ° C, CDCl ₃ ): δ 124.0, 124.3, 125.4, 126.4, 127.0, 129.4, 132.3, 137.8, 138.0
MS (EI, m / z (relative intensity)): 363 (M ⁺ , 11), 362 (15), 280 (11), 278 (16), 267 (17), 265 (25), 258 (11) , 208 (14), 179 (40), 97 (100).

(Step 3) Synthesis of phenanthro [1,2-b: 8,7-b '] dithiophene (5a)
To a 50 mL Schlenk tube, weigh tricyclohexylphosphine (210 mg, 0.75 mmol) under an argon atmosphere, and add PdCl ₂ (PhCN) ₂ (140 mg, 0.37 mmol) and dimethylacetamide (8.5 mL) at room temperature. For 10 minutes. Then, cesium carbonate (1.2 g, 3.7 mmol), 2.0 mL dimethylacetamide solution of compound 4a (680 mg, 1.9 mmol) and pivalic acid (77 mg, 0.75 mmol) were added, and the mixture was stirred at 150 ° C. for 12 hours. Thereafter, 1.0 M hydrochloric acid was poured into the reaction solution to stop the reaction, followed by separation and extraction with chloroform. The organic phase was dehydrated with a saturated aqueous sodium chloride solution and then dehydrated with anhydrous magnesium sulfate. After filtering the mixed solution, the solvent was distilled off using a rotary evaporator. The resulting black solid was purified by silica gel column chromatography (Rf = 0.44, hexane / CHCl ₃ = 4/1) to give the target compound 5a as a pale yellow solid, yield 38% (200 mg, 0.70 mmol) I got it. Further purification was performed using high performance liquid chromatography. It was confirmed by the following <Identification result> that the obtained yellowish white solid was the target compound 5a.
<Identification results>
mp 242-248 ℃
FT-IR (KBr, cm-1): 1564 (w), 1385 (w), 1292 (s), 1088 (m), 814 (s), 802 (s), 687 (s), 590 (w) .
¹ H NMR (300 MHz, 25 ° C, CDCl3): δ 7.56 (dd, J = 12.9, 5.4 Hz 4H), 8.06 (d, J = 9.0 Hz, 2H), 8.23 (s, 2H), 8.69 (d, J = 9.0 Hz, 2H).
¹³ C [1H] NMR (150 MHz, 25 ° C, CDCl3): δ 120.4, 122.7, 123.7, 125.1, 125.8, 127.1, 127.7, 137.8, 138.9.
MS (EI, m / z (relative intensity)): 290 (M ⁺ , 98), 289 (36), 258 (59), 243 (28), 209 (20), 207 (21), 145 (100) , 127 (25), 99 (22), 82 (21).
Anal. Calcd for C18H10S2: C, 74.45; H, 3.47%. Found: C, 74.52; H, 3.47%.

(Step 4) Synthesis of 3,6-dithiophen-2-yl-2,5-dihydropyrrolo [3,4-c] pyrrole-1,4-dione (6a)
To a 200 mL two-necked flask, add potassium tert-butoxide (8.0 g, 72 mmol), 2-methyl-2-butanol (50 mL) and 2-cyanothiophene (5.6 mL, 60 mmol) at 110 ° C. Stir with. A solution of dimethyl succinate in 2-methyl-2-butanol (2.6 mL, 20 mmol in 16 mL 2-methyl-2-butanol) was slowly added dropwise over 2 hours, and then stirred at 110 ° C. for 4 hours. After cooling to 65 ° C. and diluting with acidic methanol (100 mL MeOH and 5 mL conc. HCl), a black purple precipitate was formed. After further stirring at 65 ° C. for 10 minutes, the precipitate was filtered and washed with warm methanol and water. Thereafter, the desired compound 6a was obtained as a black purple solid in a crude yield of 92% (5.5 g, 18 mmol). The product was used for the next reaction directly without purification.

(Step 5) Synthesis of 2,5-diethylhexyl-3,6-dithiophen-2-ylpyrrolo [3,4-c] pyrrole-1,4-dione (7a)
In a 100 mL two-necked flask, compound 6a (1.5 g, 5 mmol), potassium carbonate (2.8 g, 20 mmol), 18-crown-6 (66 mg, 0.25 mmol) and dehydrated dimethylformamide (15 mL) were added. In addition, the mixture was stirred at 100 ° C for 30 minutes. Then, 2-ethylhexyl bromide (2.1 mL, 12 mmol) was added and stirred at 100 ° C. for 36 hours. Thereafter, the reaction solution was cooled to room temperature, poured into water to stop the reaction, and then separated and extracted with chloroform. The organic phase was dehydrated with a saturated aqueous sodium chloride solution and then dehydrated with sodium sulfate. After filtering the mixed solution, the solvent was distilled off using a rotary evaporator. The resulting purple solid was purified by silica gel column chromatography (Rf = 0.07 CHCl ₃ / hexane = 1/1), and further purified using Kugel distillation and high performance liquid chromatography to obtain the desired compound 7a as a purple solid. Obtained in 30% yield (0.79 g, 1.5 mmol). It was confirmed by the following <Identification result> that the obtained purple solid was the target compound 7a.
<Identification results>
¹ H NMR (300 MHz, 25 ° C, CDCl ₃ ): δ 8.89 (dd, J = 4.2, 1.2 Hz, 2H) 7.63 (dd, J = 1.2, 5.1 Hz, 2H) 7.27 (d, J = 0.9 Hz , 2H) 4.02 (m, 4H) 1.85 (m, 2H) 1.35-1.24 (m, 16H) 0.86 (m, 12H)

(Step 6) Synthesis of 2,5-diethylhexyl-3,6-bis (5-bromothiophen-2-yl) pyrrolo [3,4-c] pyrrole-1,4-dione (8a)
To a 50 mL Schlenk tube, compound 7a (0.44 g, 0.83 mmol), N-bromosuccinimide (0.30 g, 1.7 mmol) and chloroform (20 mL) were added and stirred at room temperature for 40 hours. Thereafter, methanol was poured into the reaction solution to stop the reaction, followed by filtration and drying to obtain the target compound 8a as a purple solid in a yield of 67% (0.38 g, 0.56 mmol). It was confirmed by the following <Identification result> that the obtained purple solid was the target compound 8a.
<Identification results>
¹ H NMR (300 MHz, 25 ° C, CDCl ₃ ): δ8.65 (d, J = 4.2 Hz, 2H) 7.23 (d, J = 4.2 Hz, 2H) 3.94 (m, 4H) 1.84 (m, 2H) 1.38-1.25 (m, 16H) 0.88 (m, 12H)

(Step 7) Poly (2,9′-phenanthro [1,2-b: 8,7-b ′] dithiophene-alt-5-diethylhexyl-3,6-bis (5-bromothiophen-2-yl) Synthesis of pyrrolo [3,4-c] pyrrole-1,4-dione) (Compound No. 12)
To a 20 mL Schlenk tube, compound 5a (46 mg, 0.15 mmol), compound 8a (102 mg, 0.15 mmol), palladium acetate (0.7 mg, 0.003 mmol), pivalic acid (4.6 mg, 0.05 mmol) and dehydrated dimethylacetamide (1.5 mL) was added, and the mixture was stirred at 100 ° C. for 24 hours. Thereafter, the mixture was cooled to room temperature, poured into a saturated aqueous solution of sodium ethylenediaminetetraacetate to stop the reaction, and the resulting precipitate was stirred at room temperature for 12 hours. Then, it refine | purified by reprecipitation from chloroform / methanol. The precipitate was filtered and the target compound No. 12 was obtained as a blue solid in a crude yield of 47% (58 mg, 0.07 mmol). When the obtained blue solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 2300, the weight average molecular weight (Mw) was 2900, and Mw / Mn was 1.24.

Example 2 Compound No. Synthesis of Step 13 (Step 1) Synthesis of 3,6-bis (4-bromophenyl) -2,5-dihydropyrrolo- [3,4-c] pyrrole-1,4-dione (9a)
To a 200 mL two-necked flask, potassium tert-butoxide (8.0 g, 72 mmol), 2-methyl-2-butanol (50 mL) and 4-bromobenzonitrile (10.8 g, 60 mmol) were added. Stir at ° C. A solution of dimethyl succinate in 2-methyl-2-butanol (2.6 mL, 20 mmol in 16 mL 2-methyl-2-butanol) was slowly added dropwise over 2 hours, followed by stirring at 110 ° C for 4 hours. . After cooling to 65 ° C and diluting with acidic methanol (100 mL MeOH and 5 mL conc. HCl), a dark red precipitate formed. After further stirring at 65 ° C. for 10 minutes, the precipitate was filtered and washed with warm methanol and water. Thereafter, the desired compound 9a was obtained as a dark red solid with a crude yield of 86% (7.7 g, 18 mmol). The product was used for the next reaction directly without purification.

(Step 2) Synthesis of 2,5-diethylhexyl-3,6-bis (4-bromophenyl) pyrrolo [3,4-c] pyrrole-1,4-dione (10a)
In a 100 mL two-necked flask, compound 9a (2.2 g, 5 mmol), potassium carbonate (2.8 g, 20 mmol), 18-crown-6 (66 mg, 0.25 mmol) and dehydrated dimethylformamide (15 mL) were added. In addition, the mixture was stirred at 100 ° C. for 30 minutes. Then, 2-ethylhexyl bromide (2.1 mL, 12 mmol) was added and stirred at 100 ° C. for 36 hours. Thereafter, the reaction solution was cooled to room temperature, poured into water to stop the reaction, and then separated and extracted with chloroform. The organic phase was dehydrated with a saturated aqueous sodium chloride solution and then dehydrated with sodium sulfate. After filtering the mixed solution, the solvent was distilled off using a rotary evaporator. The obtained orange solid was purified by silica gel column chromatography (Rf = 0.06 CHCl ₃ / hexane = 1/1), and further purified using Kugel distillation and high performance liquid chromatography to obtain the target compound 10a as an orange solid. Yield 10% (0.34 g, 0.5 mmol). It was confirmed by the following <Identification result> that the obtained orange solid was the target compound 10a.
<Identification results>
¹ H NMR (300 MHz, 25 ° C, CDCl3): δ7.66 (s, 7.66, 8H) 3.71 (d, J = 6.9 Hz, 4H) 1.47 (m, 2H) 1.19-1.08 (m, 16H) 0.79 ( t, J = 6.9 Hz, 6H) 0.71 (t, J = 7.5Hz, 6H)

(Step 3) Poly (2,9′-phenanthro [1,2-b: 8,7-b ′] dithiophene-alt-5-diethylhexyl-3,6-bis (4-bromophenyl) pyrrolo [3, Synthesis of 4-c] pyrrole-1,4-dione (Compound No. 13)
In a 20 mL Schlenk tube, compound 5a (29 mg, 0.1 mmol), compound 10a (67 mg, 0.1 mmol), palladium acetate (0.45 mg, 0.002 mmol), pivalic acid (3 mg, 0.05 mmol) and dehydrated dimethylacetamide (1.5 mL) was added, and the mixture was stirred at 100 ° C. for 24 hours. Thereafter, the mixture was cooled to room temperature, poured into a saturated aqueous solution of sodium ethylenediaminetetraacetate to stop the reaction, and the resulting precipitate was stirred at room temperature for 12 hours. Then, it refine | purified by reprecipitation from chloroform / methanol. The precipitate was filtered to obtain the target compound No. 13 as a red solid in a crude yield of 77% (62 mg, 0.08 mmol). When the obtained red solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 3,200, the weight average molecular weight (Mw) was 4,400, and Mw / Mn was 1.38.

Example 3 Synthesis of Compound No. 14 (PPD-DT) (Step 1) 2,9-bis (trimethylstannyl) -phenanthro [1,2-b: 8,7-b ′] dithiophene (11a) Synthesis of
Compound 5a (1.0 g, 3.43 mmol) and THF (100 mL) were added to a 300 ml two-necked flask, and 6.45 mL (10.3 mmol) of 1.6M n-butyllithium hexane solution was added dropwise at -78 ° C. Thereafter, the mixture was warmed to room temperature and stirred for 1 hour. Subsequently, trimethylstannyl chloride (2.75 g, 13.7 mmol) was added at −78 ° C., and the mixture was stirred at room temperature for 3 hours. The reaction was stopped by adding water, extracted with dichloromethane, dried, concentrated with a rotary evaporator, and the obtained crystals were washed with hexane to obtain 2.07 g (98%) of the intended compound 11a as a white solid. It was confirmed by the following <Identification result> that the obtained white solid was the target compound 11a.
<Identification results>
¹ HNMR (600 MHz, 25 ° C., CDCl ₃ ): δ0.49 (s, 18H), 7.61 (s, 2H), 8.03 (d, J = 9.0 Hz, 2H), 8.25 (s, 2H), 8.65 (d , J = 9.0Hz, 2H).
¹³ C [ ¹ H] NMR (150 MHz, 25 ° C., CDCl ₃ ): δ 143.8, 139.6, 139.2, 133.1, 127.3, 126.9, 124.0, 122.0, 120.3, -8.1.
Anal.CalcdforC ₂₄ H ₂₆ S ₂ Sn ₂ : C, 46.79; H, 4.25% .Found: C, 46.88; H, 4.11%.

(Step 2) Synthesis of Compound No. 14 (PPD-DT)
After adding Compound 11a (30.8 mg, 0.05 mmol), Compound 12a (56.5 mg, 0.05 mmol) and Pd (PPh ₃ ) ₂ Cl ₂ (0.7 mg, 1.0 μmol) to a 5 mL reaction vessel, argon gas was added. The reaction vessel was sealed. Toluene (2.5 mL) was then added to the reaction vessel and stirred at 140 ° C for 15 minutes in a microwave reactor. The reaction mixture was cooled to room temperature, poured into a mixed solution of methanol (100 mL) and concentrated hydrochloric acid (2 mL), and stirred at room temperature for 1 hour. After filtering the precipitate, Soxhlet extraction was performed in the order of methanol, hexane, chloroform, and chlorobenzene. The solution extracted with chloroform and chlorobenzene was concentrated and reprecipitated with methanol, and then filtered and dried under reduced pressure to obtain the target compound No. 14 with 9.2 mg (14 mg %), 14.2 mg (23%) of a component soluble in chlorobenzene was obtained as a purple solid having a metallic luster. When the obtained purple solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 24500, the weight average molecular weight (Mw) was 69200, and Mw / Mn was 2.82.

[Example 4] Synthesis of Compound No. 15 (PPB-DT)
In a 5 mL reaction vessel, compound 11a (61.6 mg, 0.1 mmol), compound 13a (113.1 mg, 0.1 mmol) and Pd (PPh ₃ ) ₄ (2.3 mg, 2.0 μmol) were added, and then argon gas was added. The reaction vessel was sealed. Thereafter, toluene (2.5 mL) was added to the reaction vessel, followed by stirring at 180 ° C. for 40 minutes in a microwave reactor. The reaction mixture was cooled to room temperature, poured into a mixed solution of methanol (100 mL) and concentrated hydrochloric acid (5 mL), and stirred at room temperature for 4 hours. After filtering the precipitate, Soxhlet extraction was performed in the order of methanol, hexane, chloroform, and chlorobenzene. Each of the solutions extracted with chlorobenzene was concentrated and reprecipitated with methanol, and then filtered and dried under reduced pressure to obtain the target compound No. 15 as a component soluble in chlorobenzene, 64.0 mg (51%) Was obtained as a purple solid with metallic luster. When the obtained purple solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 36300, the weight average molecular weight (Mw) was 65700, and Mw / Mn was 1.81.

[Example 5] Synthesis of Compound No. 16 (PPI2T-12OD)
After adding Compound 11a (30.8 mg, 0.05 mmol), Compound 14a (74.1 mg, 0.05 mmol) and Pd (PPh ₃ ) ₄ (1.2 mg, 1.0 μmol) to a 5 mL reaction vessel, put argon gas, The reaction vessel was sealed. Thereafter, toluene (2.5 mL) was added to the reaction vessel, followed by stirring at 180 ° C. for 40 minutes in a microwave reactor. The reaction mixture was cooled to room temperature, poured into a mixed solution of methanol (100 mL) and concentrated hydrochloric acid (5 mL), and stirred at room temperature for 5 hours. After filtering the precipitate, Soxhlet extraction was performed in the order of methanol, hexane, chloroform, and chlorobenzene. Each solution extracted with chlorobenzene was concentrated, reprecipitated with methanol, filtered and dried under reduced pressure to obtain 28.0 mg (35%) of the target compound No. 16 soluble in chlorobenzene. Obtained as a black solid with metallic luster. When the obtained black solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 9000, the weight average molecular weight (Mw) was 11600, and Mw / Mn was 1.28.

Example 6 Synthesis of Compound No. 17
Compound 11a (20.0 mg, 0.03 mmol), compound 15a (40.3 mg, 0.03 mmol), tetrakis (triphenylphosphine) palladium (0.75 mg, 0.0007 mmol), and toluene (1.7 ml) were added to a 5 mL reaction vessel, respectively. It was. The vessel was sealed and reacted at 180 ° C. for 40 minutes using a microwave synthesizer. After cooling to room temperature, the reaction solution was poured into a mixed solution of methanol (30 ml), H ₂ O (3 ml) and hydrochloric acid (1.5 ml) for reprecipitation. The precipitate was washed with Soxhlet using methanol, hexane, and chloroform, extracted with Soxhlet using chlorobenzene, reprecipitated with methanol, and dried to obtain the target polymer compound No. 17 (6.1 mg, 14%) was obtained as a dark green solid. The number average molecular weight (Mn) of the polymer compound No. 17 was 9956, the weight average molecular weight (Mw) was 40163, and Mw / Mn was 4.03.

Example 7 Synthesis of Compound No. 18
Compound 11a (30.0 mg, 0.05 mmol), compound 16a (20.6 mg, 0.05 mmol), tetrakis (triphenylphosphine) palladium (1.1 mg, 0.001 mmol) and toluene (4.5 ml) were added to a 5 ml reaction vessel, respectively. . The vessel was sealed and reacted at 180 ° C. for 1 hour using a microwave synthesizer. After cooling to room temperature, the reaction solution was poured into methanol (40 ml) and reprecipitated. The precipitate was washed with Soxhlet with methanol and hexane, dissolved in chloroform, and filtered through radiolite. The filtrate was concentrated under reduced pressure and reprecipitated with methanol to obtain the target compound No. 18 (16.8 mg, 62%) as a red solid. When the obtained red solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 4,300, the weight average molecular weight (Mw) was 14,300, and Mw / Mn was 3.33.

[Example 8] Synthesis of Compound No. 19
Compound 11a (30.0 mg, 0.05 mmol), compound 17a (26.1 mg, 0.05 mmol), tetrakis (triphenylphosphine) palladium (1.1 mg, 0.001 mmol) and toluene (4.5 ml) were added to a 5 ml reaction vessel, respectively. . The vessel was sealed and reacted at 180 ° C. for 2 hours using a microwave synthesizer. After cooling to room temperature, the reaction solution was poured into methanol (40 ml) and reprecipitated. The precipitate was washed with Soxhlet with methanol and hexane, dissolved in chloroform, and filtered through radiolite. The filtrate was concentrated under reduced pressure and reprecipitated with methanol to obtain the target compound No. 19 (16.8 mg, 49%) as a red solid. When the obtained red solid was analyzed by GPC (o-DCB, 130 ° C.), the number average molecular weight (Mn) was 5600, the weight average molecular weight (Mw) was 22000, and Mw / Mn was 3.93.

[Example 9] Synthesis of Compound No. 20
Compound 11a (30.0 mg, 0.05 mmol), compound 18a (26.1 mg, 0.05 mmol), tetrakis (triphenylphosphine) palladium (1.1 mg, 0.001 mmol) and toluene (4.5 ml) were added to a 5 ml reaction vessel, respectively. . The vessel was sealed and reacted at 180 ° C. for 2 hours using a microwave synthesizer. After cooling to room temperature, the reaction solution was poured into methanol (40 ml) and reprecipitated. The precipitate was washed with Soxhlet with methanol and hexane, dissolved in chloroform, and filtered through radiolite. The filtrate was concentrated under reduced pressure and reprecipitated with methanol to obtain the target compound 20 (12.8 mg, 34%) as a red solid. The target compound No. 20 had a number average molecular weight (Mn) of 8858, a weight average molecular weight (Mw) of 37513, and Mw / Mn of 4.24.

[Example 10] Synthesis of Compound No. 21
In a nitrogen atmosphere, in a 5 ml reaction vessel, compound 19a (13.9 mg, 0.03 mmol), compound 20a (200.0 mg, 0.3 mmol), compound 21a (128.4 mg, 0.28 mmol), bis (dibenzylideneacetone) palladium (28.5 mg) , 0.03 mmol), tri (o-tolyl) phosphine (37.8 mg, 0.1 mmol), tetraethylammonium hydroxide 20% aqueous solution (1.1 ml) and toluene (5.1 ml) were heated to 84 ° C., After reacting for hours, bromobenzene (4.9 mg, 0.03 mmol) was added and reacted for 1 hour, and phenylboronic acid (3.8 mg, 0.03 mol) was further added and reacted for 8 hours. The reaction mixture is poured into a mixed solution of methanol (200 ml) and H ₂ O (20 ml) and reprecipitated. The precipitate is washed with Soxhlet using acetone, hexane, toluene and dichloromethane, and then subjected to Soxhlet extraction with chloroform. To give the desired compound No. 21 (65 mg, 25%) as a dark purple solid. The number average molecular weight (Mn) of the target compound No. 21 was 21276, the weight average molecular weight (Mw) was 63699, and Mw / Mn was 2.99.

[Example 11] Fabrication of bulk heterojunction solar cell element ITO substrate (Geomatec, film thickness: 150 nm, resistivity: <12 Ω / □, transmittance: (λ = 550 nm) ≥ 85%) Each was ultrasonically cleaned for 10 minutes using detergent, ion-exchanged water, acetone and isopropanol. Thereafter, isopropanol containing the substrate was boiled for 10 minutes, dried, and then subjected to UV-ozone cleaning for 20 minutes. A 0.45 μm PVDF syringe filter with an aqueous solution of poly (3,4-ethylene-dioxythiophene): poly (styrenesulfonate) (PEDOT: PSS, Clevious P VP AI 4083) as the anode buffer layer on the cleaned substrate And spin coated at 5000 rpm for 30 seconds. After drying on a hot plate at 120 ° C. for 10 minutes, it was immediately carried into a glove box. A soluble fullerene derivative (PC ₆₁ BM) was added to an anhydrous o-dichlorobenzene solution of Compound No. 14 (PPD-DT) at a concentration of 12.5 g / L to a weight ratio of 1: 2, and the mixture was kept at 100 ° C. The active layer was formed on the substrate coated with (PEDOT: PSS) by spin coating at 400 rpm for 30 seconds and then 1000 rpm for 5 seconds. In addition, a solution obtained by adding PC ₆₁ BM to an anhydrous chlorobenzene solution of Compound No. 15 (PPB-DT) at a concentration of 7.5 g / L to a weight ratio of 1: 1, Compound No. 16 at a concentration of 4 g / L. (PPI2T-12OD) in an anhydrous chlorobenzene solution with PC ₆₁ BM added to a weight ratio of 1: 1, and a 4 g / L concentration of Compound No. 21 in an anhydrous chlorobenzene solution with a weight ratio of 1: 4 In this way, a solution containing PC ₇₁ BM was prepared, and an active layer was prepared under the same conditions as described above. After drying at room temperature, it is transferred to a vacuum evaporation system and activated by vacuum deposition of 10 nm calcium as a cathode buffer layer and then 80 nm aluminum as a cathode through a shadow mask under a reduced pressure of about 3 × 10 ^-5 Pa. A bulk heterojunction solar cell element with an area of 0.16 cm ^-2 was fabricated. Table 1 shows the photoelectric conversion characteristics of the fabricated solar cell element in a solar simulator (AM 1.5 G, 100 mW · cm ⁻² ) under an inert atmosphere at room temperature.

  When the picene derivative of this invention obtained by the said Example was used as a p-type organic semiconductor, it has confirmed that high photoelectric conversion efficiency was shown.

DESCRIPTION OF SYMBOLS 1 Support body 2 Electrode 3 Charge transfer layer 4 Photoelectric conversion layer 5 Electrode 6 Charge transfer layer

Claims (7)

And at least one structural unit represented by the following general formula (1), picene derivatives having at least one, a structural unit selected from the following group Z.
(In the formula, A ¹ and A ² each independently represent a single ring, and the hydrogen atom in the structural unit represented by the general formula (1) is a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, or a thiol. A group, a —NR ⁵ R ⁶ group, a substituted or unsubstituted hydrocarbon group, or a group represented by —SiR ¹ R ² R ³ , or unsubstituted, R ¹ , R ² , R ³ , R ⁵ or R ⁶ each independently represents a hydrogen atom, a substituted or unsubstituted hydrocarbon group, wherein * in the general formula (1) This means that the structural unit represented by the formula is bonded to the adjacent structural unit at the * part.
Wherein X ² represents S or NR ⁷ , X ³ represents S, NR ⁷ , CR ⁸ R ⁹ or SiR ⁸ R ⁹ , X ⁵ represents S, O or NR ⁷ , R ⁷ , R ⁸ and R ⁹ represent a substituted or unsubstituted hydrocarbon group, and the hydrogen atom in the structural unit represented by group Z is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, thiol group , —NR ¹⁰ R ¹¹ group, substituted or unsubstituted hydrocarbon group or substituted or unsubstituted heterocyclic group, R ¹⁰ and R ¹¹ may be substituted. Alternatively, it represents an unsubstituted hydrocarbon group, where * represents that the structural unit represented by these formulas is bonded to an adjacent structural unit at the * portion. The invention has at least one constitutional unit represented by the general formula (1), at least one constitutional unit selected from the above-mentioned group Z, and at least one constitutional unit selected from the following group Y. The picene derivatives described.
Wherein X ¹ and X ⁴ represent S, O or NR ⁴ ; k represents an integer of 1 to 4; R ⁴ represents a substituted or unsubstituted hydrocarbon group; The hydrogen atom in the structural unit is a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ¹⁰ R ¹¹ group, a substituted or unsubstituted hydrocarbon group or a substituted group. May be substituted with an unsubstituted or unsubstituted heterocyclic group, and R ¹⁰ and R ¹¹ represent a substituted or unsubstituted hydrocarbon group, where * denotes a formula in these formulas This means that the structural unit represented is bonded to an adjacent structural unit at the * part. The picene derivative according to claim 1 or 2, which has at least one structural unit represented by the following general formula (2).
(In the formula, A ¹ and A ² represent the same group as in the general formula (1), and the hydrogen atom in the picene-derived group having A ¹ and A ² is substituted in the same manner as in the general formula (1). May have been
Y ¹ and Y ² are a single bond or a group connected by combining 1 to 5 groups selected from the following (Y-1) to (Y-8),
Z ¹ represents a single bond or a group selected from the following (Z-1) to (Z-21), and n represents an integer of 1 to 1,000. )
(Wherein X ¹ and X ⁴ represent S, O or NR ⁴ , k represents an integer of 1 to 4, R ⁴ represents a substituted or unsubstituted hydrocarbon group, (Y-1 ) To (Y-4) and (Y-6) to (Y-8) include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, a thiol group, a —NR ¹⁰ R ¹¹ group, R ¹⁰ and R ¹¹ may be substituted with a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, and R ¹⁰ and R ¹¹ represent a substituted or unsubstituted hydrocarbon group. Note that * in the formula means that the structural unit represented by these formulas is bonded to an adjacent structural unit at the * portion. )
Wherein X ² represents S or NR ⁷ , X ³ represents S, NR ⁷ , CR ⁸ R ⁹ or SiR ⁸ R ⁹ , X ⁵ represents S, O or NR ⁷ , R ⁷ , R ⁸ and R ⁹ represent a substituted or unsubstituted hydrocarbon group, and the hydrogen atom in the structural unit represented by group Z is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, thiol group , —NR ¹⁰ R ¹¹ group, substituted or unsubstituted hydrocarbon group or substituted or unsubstituted heterocyclic group, R ¹⁰ and R ¹¹ may be substituted. Alternatively, it represents an unsubstituted hydrocarbon group, where * represents that the structural unit represented by these formulas is bonded to an adjacent structural unit at the * portion.   (A) A photoelectric conversion material comprising the picene derivative according to any one of claims 1 to 3 as a p-type organic semiconductor material and (B) an n-type organic semiconductor material.   A photoelectric conversion layer obtained by forming the photoelectric conversion material according to claim 4 into a film.   A photoelectric conversion element comprising the photoelectric conversion layer according to claim 5. An organic thin film solar cell comprising the photoelectric conversion element according to claim 6.