JP2005223038A - Optoelectric transducer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optoelectric transducer having the high efficiency of a photoelectric conversion, even if a solid is used as an electrolyte, and to provide a manufacturing method for the optoelectric transducer. <P>SOLUTION: The optoelectric transducer 10 has a laminated constitution in which a hole-transporting high-molecular electrolyte film (an electrolyte film 14) between an n-type semiconductor electrode 13, in which a pigment is attracted to a surface, and to an electronic conductive electrode 15. In the optoelectric transducer 10, the hole-transporting high-molecular electrolyte film contains a conjugate conductive high molecules and a fibrous conductor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dye-sensitized photoelectric conversion element and a method for producing the same.

  Solar cells equipped with photoelectric conversion elements are attracting attention as a power generation system with less environmental pollution, and silicon-based photoelectric conversion elements have been put into practical use, but silicon-based photoelectric conversion elements are expensive to manufacture, In recent years, a dye-sensitized photoelectric conversion element with a low manufacturing cost has been studied.

FIG. 1 shows an example of a dye-sensitized photoelectric conversion element. The dye-sensitized photoelectric conversion element 10 includes a transparent substrate 11, a transparent electrode 12 formed on the transparent substrate 11, an n-type semiconductor electrode 13 formed on the transparent electrode 12 and adsorbed with a dye, n An electrolyte film 14 formed on the type semiconductor electrode 13 and an electron conductive electrode 15 formed on the electrolyte film 14 are included. Here, the n-type semiconductor electrode 13 is an electrode that captures electrons of the dye by light irradiation and generates holes on the dye, and the electrolyte film is a film that can transport holes generated in the n-type semiconductor electrode. is there.
In the dye-sensitized photoelectric conversion element 10, the light irradiated on the transparent substrate 11 reaches the n-type semiconductor electrode 13, and holes are generated in the n-type semiconductor electrode 13 by the light energy (electrons are generated in the conduction band). Excited). The holes generated in the n-type semiconductor electrode 13 are transported by the electrolyte film 14 and reach the electron conductive electrode 15. As a result, an electromotive force is generated between the transparent electrode 12 and the electron conductive electrode 15 to generate power.

As the electrolyte of the electrolyte membrane 14, a liquid material such as iodine / iodine ions has been used. However, since the photoelectric conversion element is heated by its light energy when irradiated with sunlight, the liquid electrolyte may expand and leak due to heating or damage the photoelectric conversion element.
Then, in order to suppress the expansion | swelling by sunlight, using the solid conjugated system conductive polymer as an electrolyte is examined (for example, refer patent document 1, 2).
JP 2003-142168 A JP 2003-243681 A

If the electrolyte is solid, expansion due to heating is small, and leakage of the electrolyte and damage to the photoelectric conversion element can be prevented. However, since the n-type semiconductor electrode is porous or has irregularities on the surface, when the solid electrolyte is used, the solid electrolyte does not enter the pores or the recesses, and the contact with the n-type semiconductor electrode does not occur. Sometimes it was incomplete. As a result, there was a problem that the photoelectric conversion efficiency was lower when the solid electrolyte was used than when the liquid electrolyte was used.
This invention is made | formed in view of the said situation, and it aims at providing a photoelectric conversion element with high photoelectric conversion efficiency, and its manufacturing method, even if it uses a solid thing as an electrolyte.

The photoelectric conversion element of the present invention is a photoelectric conversion element having a laminated structure in which a hole transporting polymer electrolyte membrane is interposed between an n-type semiconductor electrode having a dye adsorbed on the surface and an electron conductive electrode.
The hole transporting polymer electrolyte membrane includes a conjugated conductive polymer and a fibrous conductor.
In the photoelectric conversion element of the present invention, the fibrous conductor is preferably a material having a sulfonic acid group.
In the photoelectric conversion element of the present invention, the hole transporting polymer electrolyte membrane preferably contains an inorganic p-type semiconductor.
In the photoelectric conversion device of the present invention, the conjugated conductive polymer is preferably doped with a dopant having a sulfonic acid group.
Furthermore, in the photoelectric conversion element of this invention, it is preferable that the said hole transportable polymer electrolyte membrane is a coating film apply | coated on the n-type semiconductor electrode.
In the method for producing a photoelectric conversion element of the present invention, a conjugated conductive polymer is dispersed or dissolved in a solvent and a solution containing a fibrous conductor is applied onto an n-type semiconductor, and the solvent is removed to form a coating film. After the film is formed, an electron conductive electrode is formed on the coating film.

The photoelectric conversion element of the present invention can prevent electrolyte leakage and damage even when heated by sunlight. In addition, according to the photoelectric conversion element of the present invention, since the obtained solid hole transporting polymer electrolyte membrane has high conductivity and low internal resistance, the photoelectric conversion efficiency is high.
According to the method for producing a photoelectric conversion element of the present invention, the production of the photoelectric conversion element is simple.

  An embodiment of a photoelectric conversion element and a method for producing the same according to the present invention will be described. The photoelectric conversion element of the present embodiment has the same configuration as that shown in FIG. 1, and includes a transparent substrate 11, a transparent electrode 12, an n-type semiconductor electrode 13, an electrolyte film 14, and an electron conductive electrode 15. Yes. In the photoelectric conversion element of this embodiment, the electrolyte membrane 14 is made of a specific hole transporting polymer electrolyte membrane.

Below, each structure of a photoelectric conversion element is demonstrated.
The transparent substrate 11 has high light transmittance and mechanical properties that can protect the transparent electrode 12. For example, a glass plate, polyethylene terephthalate, polycarbonate, polyphenylene sulfide, polysulfone, polyester sulfone, Examples thereof include resin sheets having excellent transparency such as etherimide and polycycloolefin.
The thickness of the transparent substrate is preferably 20 to 2000 μm, and more preferably 50 to 500 μm. The light transmittance is preferably 50% or more.

As the transparent electrode 12, a well-known transparent conductive film such as tin oxide, indium oxide doped with tin (ITO), or indium oxide doped with fluorine (FTO) can be used.
The thickness of the transparent electrode 12 is preferably 0.01 to 0.5 μm, and the surface resistance value is preferably 500Ω or less. Here, the surface resistance value is a value measured according to JIS K 6911.

The n-type semiconductor electrode 13 is a layer composed of an n-type semiconductor compound and a dye. Examples of the n-type semiconductor compound include titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum oxide, cadmium, zinc, lead, silver, Antimony, bismuth sulfide and the like.
The dye has a photosensitizing action, and examples thereof include organometallic complex dyes, methine dyes, porphyrin dyes, and phthalocyanine dyes. This dye is formed in layers on the n-type semiconductor compound.
The thickness of the n-type semiconductor electrode 13 is preferably 2 to 50 μm.

The hole transporting polymer electrolyte membrane as the electrolyte membrane 14 is a membrane containing a conjugated conductive polymer and a fibrous conductor.
Here, examples of the conjugated conductive polymer include conjugated hetero 5-membered ring polymers composed of two or more elements in a 5-membered ring. Specifically, polypyrroles, polythiophenes, And copolymers thereof.
Conjugated conductive polymers can provide good hole transport properties even if they are not substituted, but they are effective for addition to other organic resin components, dispersion or dissolution in solvents, so alkyl groups, carboxyl groups It is more preferable to introduce a functional group such as a sulfonic acid group, an alkoxyl group, an ester group, a hydroxy group, or a cyano group.

  Specific examples include polypyrrole, poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), poly (3-butylpyrrole), poly (3-octylpyrrole). , Poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3-carboxylpyrrole), poly (3-methyl -4-carboxylpyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-methyl-4-hexyloxypyrrole), poly (thiol Phen), poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-heptylthiophene) , Poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly (3-hydroxythiophene) , Poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxy Thiophene), poly (3-hexyloxythiophene), poly (3-heptyloxythiophene), poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly ( 3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-methoxythiophene), poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene), poly (3,4-dioctyloxythiophene), poly (3,4 Didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4 -Ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4 -Ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene) , Polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid) and the like.

The conjugated conductive polymer is preferably doped with a dopant in order to further increase the conductivity. As the dopant, a halogen compound, a Lewis acid, a proton acid, an organic cyano compound, an organometallic compound, or the like can be used.
Examples of the halogen compound include chlorine (Cl ₂ ), bromine (Br ₂ ), iodine (I ₂ ), iodine chloride (ICl), iodine bromide (IBr), and iodine fluoride (IF).
Examples of the Lewis acid include PF ₅ , AsF ₅ , SbF ₅ , BF ₃ , BCl ₃ , BBr ₃ , SO _{3 and the} like.
Examples of the protic acid include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, borohydrofluoric acid, hydrofluoric acid, and perchloric acid, and organic acids such as organic carboxylic acid and sulfonic acid.
As the organic carboxylic acid, those containing one or more carbonyl groups in aliphatic, aromatic, cycloaliphatic and the like can be used. For example, formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, And triphenylacetic acid.

  As the organic sulfonic acid, aliphatic, aromatic, cycloaliphatic, etc. containing one or more sulfonic acid groups and polymers containing sulfonic acid groups can be used. Examples of those containing one sulfonic acid group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, and 1-octanesulfone. Acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-dodecanesulfonic acid, 1-tetradecanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, Trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, colistin methanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5 -Naphthol-7-sulfonic acid, 3-aminopropanes Phosphonic acid, N-cyclohexyl-3-aminopropanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzene Sulfonic acid, heptylbenzenesulfonic acid, octylbenzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4 -Dimethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, 4-amino-2-chloro Toluene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenzenesulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfone Acid, 4-chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butylnaphthalenesulfonic acid, pentylnaphthalenesulfonic acid, 4-amino-1-naphthalenesulfone Acid, 8-chloronaphthalene-1-sulfonic acid, etc. The

As one containing at least one sulfonic acid group, for example, ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, o-benzenedisulfonic acid, m-benzenedisulfonic acid, p-benzenedisulfonic acid, toluenedisulfonic acid Xylene disulfonic acid, chlorobenzene disulfonic acid, fluorobenzene disulfonic acid, dimethylbenzene disulfonic acid, diethylbenzene disulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 3,4-dihydroxy-1,3 -Benzenedisulfonic acid, naphthalene disulfonic acid, methyl naphthalene disulfonic acid, ethyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1 Acetamide-8-hydroxy-3,6-naphthalenedisulfonic acid, 2-amino-1,4-benzenedisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5-naphthalenedisulfonic acid, 4-acetamido-4′-isothio-cyanotostilbene-2,2′-disulfonic acid, 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid, 4-acetamido-4′-maleimi And distilbene-2,2′-disulfonic acid.
As the polymer having a sulfonic acid group, any polymer having an anion group in the side chain can be used. Examples of the main chain include polyalkylene composed of repeating methylene, polyalkenylene composed of structural units containing one vinyl group in the main chain, and the like. Specific examples include polyvinyl sulfonic acid, polymethallyl sulfonic acid, polyallyl sulfonic acid, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylamide-t-butyl sulfonic acid, polymethallyloxybenzene sulfonic acid, and the like. It is done.

As the fibrous conductor, any fibrous electrical conductor can be used. For example, a carbon-based fiber material, a metal-based fiber material, or a metal oxide-based fiber material can be used.
Examples of the carbon-based fiber material include polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, rayon-based carbon fiber, glassy carbon, carbon nanotube, and these carbon fibers subjected to surface treatment.
Examples of the metallic fibrous material include fibrous metals manufactured from gold, silver, nickel, platinum and the like, fibrous metal alloys, fibrous metal composites, and surface-treated metal fibers. be able to.
The metal oxide-based fibrous materials, _{e.g., InO 2, InO 2 Sn,} SnO 2, ZnO, SnO 2 -Sb 2 O 4, SnO 2 -V 2 O 5, TiO 2 (Sn / Sb) O 2, Metal oxide fibers, metal oxide composite fibers manufactured from SiO ₂ (Sn / Sb) O ₂ , K ₂ O—nTiO ₂ — (Sn / Sb) O ₂ , K ₂ O—nTiO ₂ —C, and the like, and These metal oxide fibers subjected to surface treatment, these metal-coated fibers subjected to surface treatment, and the like can be mentioned.
Among these, a carbon fiber material, a metal oxide fiber material, a surface treatment material, or the like that hardly corrodes is more preferable.
The fiber diameter (minor axis) of the fibrous conductor is preferably 1 μm or less, and the fiber length (major axis) is preferably 1 to 100 μm (where fiber length / 2 ≧ fiber diameter).

The fibrous conductor is preferably a material having a sulfonic acid group. Examples of the material having a sulfonic acid group include a carbon fiber material into which a sulfonic acid group is introduced, a metal fiber material or a metal oxide fiber material into which a sulfonic acid is introduced into the surface treatment layer.
If the fibrous conductor is a material having a sulfonic acid group, the sulfonic acid group on the surface of the fibrous conductor interacts with the conjugated conductive polymer in the bipolaron state, and the conductive composite has a lower resistance. Is obtained.

The hole transporting polymer electrolyte membrane preferably contains an inorganic p-type semiconductor because the photoelectric conversion efficiency becomes higher. An inorganic p-type semiconductor has a redox potential 0.1 to 0.9 V lower than the oxidation potential of the dye, is composed of a stable reversible redox pair, and transports charges between electrodes at a sufficient rate. A material that can be produced is desirable.
The reversible redox pair is preferably composed of a halogen molecule such as an I ⁻ / I ₃ ⁻ pair and a halogen compound. In such a reversible redox pair, a reducing species such as I ⁻ receives holes from the oxidized dye and becomes an oxidizing species such as I ₃ ⁻ , and this oxidizing species is capable of transporting holes. Holes can be transported to the electron conductive electrode 15 by moving through the polymer electrolyte membrane.

Examples of the halogen molecule include chlorine, bromine and iodine.
Examples of the halogen compound include metal halides such as alkali metals, alkaline earth metals, and transition metals, halogenated quaternary ammonium compounds, and halogenated molten salts.
Specifically, as the metal _{halide, LiI, NaI, KI, CsI} , CaI 2, MgI 2, AlI 3, PbI 2, SnI 2, SnI 4, GeI 4, GaI 3, TiI 4, NiI 2, CoI ^{_{2, ZnI 2, MgI 2,}} CuI 2, RuI 3, PtI 4, MnI 2, OsCl 3, IrBr 3, RhI 3, PdI 2, GaI 4, FeI 2, CaCl 2, ZnCl 2, MgCl 2, BCl 3, _{PCl 3, LiBr, NaBr, KBr} , CsBr, CaBr 2, ScBr 3, SiI 4, such as TiBr ₄ and the like.
Examples of halogenated quaternary ammonium compounds include tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, tetrahexylammonium salt, trimethylphenylammonium salt, triethylphenylammonium salt, trimethylbenzylammonium salt, acetylcholine salt Benzoylcholine salt and the like.
Examples of the halogenated molten salt include halogen compounds such as pyridinium and imidazolium. For example, pyridinium halogen compounds include 1-acetonylpyridinium chloride, 1-aminopyridinium iodide, 4-bromopyridine hydrobromide, 4-bromopyridine hydrochloride, 1-n-butylpyridine bromide, ethylpyridinium bromide, ethyl Examples include pyridinium chloride, chloromethylpyridine hydrochloride, 2-chloro-methylpyridinium iodide, hexadecylpyridinium bromide, hexadecylpyridinium chloride, 1,1′-dimethyl-4,4′-bipyridinium dichloride.
Examples of halogen compounds of imidazolium include 1,1-dimethylimidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1-methyl-3-pentylimidazolium iodide, 1-methyl-3-isopentyl. Imidazolium iodide, 1-methyl-3-hexylimidazolium iodide, 1-methyl-3-isohexyl (branched) imidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1,2-dimethyl- Examples include 3-propylimidazole iodide, 1-ethyl-3-isopropylimidazolium iodide, 1-propyl-3-propylimidazolium iodide, pyrrolidinium iodide, and the like.

The hole transporting polymer electrolyte membrane is preferably a coating film applied on the n-type semiconductor electrode. If the coating film is formed by simple and suitable application for mass production, the cost can be reduced. When a coating film is formed by coating, a conjugated conductive polymer obtained by a chemical oxidative polymerization method is used. This chemical oxidative polymerization method is a method in which a monomer is polymerized with an oxide in a solvent, so that it can be easily produced in large quantities. As another method for obtaining a conjugated conductive polymer, an electrolytic polymerization method is known. In this method, a polymer is polymerized in a film form on an n-type semiconductor electrode or an electron conductive electrode. This is not suitable for mass production.
The thickness of the hole transporting polymer electrolyte membrane is preferably 0.1 to 100 μm.
If necessary, the inorganic p-type semiconductor layer may be interposed between the hole-transporting polymer electrolyte membrane and the n-type semiconductor electrode.

The electron conductive electrode 15 is an electrode made of a material having high electron conductivity such as platinum, gold, silver, copper, an alloy, or a carbon material.
The thickness of the electron conductive electrode 15 is preferably 0.05 to 100 μm.

In the photoelectric conversion element 10 having the above configuration, the light irradiated to the transparent substrate 11 reaches the n-type semiconductor electrode 13 and generates holes in the n-type semiconductor electrode 13 by the light energy. The holes generated in the n-type semiconductor electrode 13 are transported by the hole transporting polymer electrolyte membrane which is the electrolyte membrane 14 and reach the electron conductive electrode 15. As a result, an electromotive force is generated between the transparent electrode 12 and the electron conductive electrode 15 to generate power.
In this photoelectric conversion element 10, the hole transporting polymer electrolyte membrane as the electrolyte membrane 14 contains not only a conjugated conductive polymer but also a fibrous conductor, and the fibrous conductor is conductive. Since it is high, the conductivity in the hole transporting polymer electrolyte membrane is improved. As a result, the internal resistance of the photoelectric conversion element 10 is reduced, and the photoelectric conversion efficiency can be increased. Moreover, since the electrolyte is solid, expansion due to heating is small, and leakage of the electrolyte and damage to the photoelectric conversion element can be prevented.

Next, the manufacturing method of this photoelectric conversion element is demonstrated.
First, a transparent conductive film is formed on a transparent substrate by vapor deposition, sputtering, or the like, and an n-type semiconductor electrode is formed on the transparent conductive film. Here, as a method for forming an n-type semiconductor electrode, a dispersion liquid in which an n-type semiconductor compound is dispersed in a solvent is applied or printed on a transparent conductive film to form a coating film, and then the coating film is dyed The method of immersing in the solution containing this is mentioned. Furthermore, examples of the coating method of the dispersion liquid in which an n-type semiconductor compound is dispersed in a solvent include a doctor blade method, a roll coating method, a spray coating method, a spin coating method, and the printing methods include a screen printing method and an inkjet method. Examples thereof include a printing method, an offset printing method, and a gravure printing method.

Next, a conjugated conductive polymer and, if necessary, a polyanion and / or an electron-withdrawing functional group-containing polymer are dispersed or dissolved in a solvent, and a fibrous conductor is added to the solvent. A conjugated conductive polymer solution is prepared by adding a p-type semiconductor. Then, the conjugated conductive polymer solution is applied onto the n-type semiconductor electrode, and the solvent is removed to form a coating film (hole transporting polymer electrolyte membrane). Then, an electron conductive electrode is formed on the hole transporting polymer electrolyte membrane by vapor deposition, sputtering, coating, or the like to obtain a photoelectric conversion element.
Alternatively, a photoelectric conversion element may be obtained by forming a p-type semiconductor layer on an n-type semiconductor electrode and further forming a hole transporting polymer electrolyte film thereon.

  In the above-described production method, the solvent for dispersing or dissolving the conjugated conductive polymer may be any solvent that can dissolve or disperse the conjugated conductive polymer. For example, water, N-methyl-2-pyrrolidone , N, N′-dimethylformamide, N, N′-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide and other polar solvents, cresol, phenol, xylenol and other phenols, methanol, ethanol, propanol, butanol and other alcohols Ketones such as acetone and methyl ethyl ketone, hydrocarbons such as hexane, benzene and toluene, carboxylic acids such as formic acid and acetic acid, carbonate compounds such as ethylene carbonate and propylene carbonate, ether compounds such as dioxane and diethyl ether, ethyl Chain ethers such as glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile And nitrile compounds such as benzonitrile. These solvents may be used alone or as a mixture of two or more kinds, or a mixture with other organic solvents, if necessary.

  Moreover, in the manufacturing method mentioned above, it is preferable to dope the conjugated conductive polymer with a polyanion and / or an electron-withdrawing functional group-containing polymer. If the conjugated conductive polymer is doped with a polyanion and / or an electron-withdrawing functional group-containing polymer, the conjugated conductive polymer is solubilized in a solvent, which makes it suitable for mass production. When the conjugated conductive polymer is doped with a polyanion and / or electron-withdrawing functional group-containing polymer, the hole-transporting polymer electrolyte membrane has a polyanion and / or electron-withdrawing functional group-containing polymer. Is included.

As said polyanion, what introduce | transduced the anion group which can produce dope to the said conjugated system conductive polymer can be used. Examples of the anion group include groups such as —O—SO ₃ X, —O—PO (OX) ₂ , —COOX, —SO ₃ X (in each formula, X represents a hydrogen atom or an alkali metal atom). Can be mentioned. From the viewpoint of the doping effect on the conjugated conductive polymer, —SO ₃ X and —O—SO ₃ X are preferable (X has the same meaning as described above).
The polyanion may be a polymer composed only of an anionic polymerizable monomer, but is preferably a copolymer of an anionic polymerizable monomer and another polymerizable monomer.

As the anionic polymerizable monomer, an anionic group such as —O—SO ₃ X, —O—PO (OX) ₂ , —COOX, —SO ₃ X or the like (X is as described above) at an appropriate site of the polymerizable monomer. The same meaning is used.) Can be used. For example, substituted or unsubstituted ethylene sulfonic acid compounds, substituted or unsubstituted styrene sulfonic acid compounds, substituted heterocyclic sulfonic acid compounds, substituted acrylamide sulfonic acid compounds, substituted or unsubstituted cyclovinylene sulfonic acid compounds, substituted or unsubstituted Examples thereof include butadiene sulfonic acid compounds and vinyl aromatic sulfonic acid compounds.

  Specific examples of the substituted or unsubstituted ethylene sulfonic acid compound include vinyl sulfonic acid, vinyl sulfonate, allyl sulfonic acid, allyl sulfonate, methallyl sulfonic acid, methallyl sulfonate, 4-sulfobutyl methacrylate, Examples include 4-sulfobutyl methacrylate salt, methallyloxybenzene sulfonic acid, methallyloxybenzene sulfonate, allyloxybenzene sulfonic acid, and allyloxybenzene sulfonate.

Specific examples of the substituted or unsubstituted styrene sulfonic acid compound include styrene sulfonic acid, styrene sulfonate, α-methyl styrene sulfonate, α-methyl styrene sulfonate, and the like.
Specific examples of the substituted acrylamide sulfonic acid compound include acrylamide-t-butyl sulfonic acid, acrylamide-t-butyl sulfonic acid salt, 2-acrylamido-2-methylpropane sulfonic acid, and 2-acrylamido-2-methylpropane sulfonic acid salt. Etc.
Specific examples of the substituted or unsubstituted cyclovinylene sulfonic acid compound include cyclobutene-3-sulfonic acid, cyclobutene-3-sulfonate, and the like.

Specific examples of the substituted or unsubstituted butadiene sulfonic acid compound include isoprene sulfonic acid, isoprene sulfonate, 1,3-butadiene-1-sulfonic acid, 1,3-butadiene-1-sulfonate, 1-methyl -1,3-butadiene-2-sulfonic acid, 1-methyl-1,3-butadiene-3-sulfonate, 1-methyl-1,3-butadiene-4-sulfonic acid, 1-methyl-1,3 -Butadiene-4-sulfonic acid salt etc. are mentioned.
Among these, vinyl sulfonate, styrene sulfonate, styrene sulfonate, isoprene sulfonate, isoprene sulfonate and the like can be shown as preferred examples, and isoprene sulfonate and isoprene sulfonate are more preferred examples. Can be mentioned.

  Other polymerizable monomers that copolymerize with anionic polymerizable monomers include substituted or unsubstituted ethylene compounds, substituted acrylic acid compounds, substituted or unsubstituted styrene, substituted or unsubstituted vinylamines, and unsaturated group-containing heterocycles. Compound, substituted or unsubstituted acrylamide compound, substituted or unsubstituted cyclovinylene compound, substituted or unsubstituted butadiene compound, substituted or unsubstituted vinyl aromatic compound, substituted or unsubstituted divinylbenzene compound, substituted vinylphenol compound , Arbitrary substituted silyl styrene, arbitrary substituted phenol compounds and the like.

  Specifically, ethylene, propene, 1-butene, 2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, styrene, p-methylstyrene, p-ethylstyrene, p-butyl Styrene, 2,4,6-trimethylstyrene, p-methoxystyrene, 2-vinylnaphthalene, 6-methyl-2-vinylnaphthalene, 1-vinylimidazole, vinylpyridine, vinyl acetate, acrylic aldehyde, acrylonitrile, N-vinyl- 2-pyrrolidone, acrylamide, N, N-dimethylacrylamide, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, isooctyl acrylate, isononyl butyl acrylate, allyl acrylate, ethyl methacrylate , Acrylic acid hydroxy Ethyl, methoxyethyl acrylate, methoxybutyl acrylate, stearyl acrylate, acrylate ester, acryloylmorpholine, vinylamine, N, N-dimethylvinylamine, N, N-diethylvinylamine, N, N-dibutylvinylamine, N , N-di-t-butylvinylamine, N, N-diphenylvinylamine, N-vinylcarbazole, vinyl alcohol, vinyl chloride, vinyl fluoride, vinyl ether, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, 2-methylcyclohexene, vinylphenol, 1,3-butadiene, 1-methyl-1,3-butadiene, 2-methyl-1,3-butadiene, 1,4-dimethyl-1,3-butadiene, 1,2- Dimethyl-1, -Butadiene, 1,3-dimethyl-1,3-butadiene, 1-octyl-1,3-butadiene, 2-octyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 2-phenyl-1 , 3-butadiene, 1-hydroxy-1,3-butadiene, 2-hydroxy-1,3-butadiene, allyl acrylate, acrylamide allyl, divinyl ether, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, etc. Can be illustrated. Among these, 1-butene, vinylphenol, butyl acrylate, N-vinyl-2-pyrrolidone, 1,3-butadiene and the like can be exemplified as preferable ones.

The polyanion can be obtained by a chemical oxidative polymerization method in the presence of the anionic polymerizable monomer or the other polymerizable monomer and an oxidizing agent and / or an oxidative polymerization catalyst.
Examples of oxidizing agents include peroxodisulfates such as ammonium peroxodisulfate, sodium peroxodisulfate, and potassium peroxodisulfate, transition metal compounds such as ferric chloride, ferric sulfate, and cupric chloride, and oxidation. Metal oxides such as silver and cesium oxide, peroxides such as hydrogen peroxide and ozone, organic peroxides such as benzoyl peroxide, oxygen, and the like can be used.
Among the polyanions described above, polyisoprene sulfonic acid, a copolymer of isoprene sulfonic acid, polystyrene sulfonic acid, and a copolymer of polystyrene sulfonic acid are preferable.

  As the electron-withdrawing functional group-containing polymer, any electron-withdrawing functional group such as cyano group, halogen such as fluorine, chlorine or bromine, carbonyl group, hydroxyl group or the like is introduced into the polymer. Polymers can also be used. In particular, from the viewpoint of electron withdrawing property and solvent solubility, the electron withdrawing functional group is preferably a cyano group, fluorine, or carbonyl group. Specific examples of preferable electron-withdrawing functional group-containing polymers include polyacrylonitrile, polyvinylidene fluoride, polybalavanic acid, and the like.

  In the method of manufacturing a photoelectric conversion element described above, a hole transporting polymer electrolyte membrane that is a solid electrolyte is formed by applying a solution containing a conjugated conductive polymer and a fibrous conductor onto an n-type semiconductor electrode. It is easy to form.

Examples of the present invention will be specifically described below, but the present invention is not limited to the examples.
(Preparation of hole transporting polymer electrolyte solution I)
Dissolve 1.02 g of pyrrole, 2.37 g of polyisoprene sulfonic acid and 0.7 g of sulfonated carbon nanotubes in 300 ml of distilled water, keep this solution at 0 ° C. and stir into 40 ml of distilled water. A dissolved solution of 3.4 g ammonium persulfate and 0.6 g ferric sulfate was slowly added and stirred for 3 hours.
400 ml of ion-exchanged water is added to the obtained reaction solution, and after removing iron sulfate and ammonium sulfate ions using an ultrafiltration method, the solution is concentrated under reduced pressure, and a conductive polymer solution having a solid content of 10% by mass. And an equal mass of acetonitrile was added to prepare a 5 mass% hole-transporting polymer electrolyte solution I.
(Preparation of hole transporting polymer electrolyte solution II)
After adding 0.475 g of tetrapropylammonium iodide dissolved in 15 g of acetonitrile and 0.025 g of iodine to 20 g of the above hole transporting polymer electrolyte solution I, and stirring well, 0.2 g of carbon nanotubes were added. The mixture was added and further stirred to prepare a 4.8 mass% hole-transporting polymer electrolyte solution II.

(Example 1)
Formation of titanium dioxide layer: A commercially available ultrafine titanium oxide aqueous solution (trade name: PASOL-HPA-15R, Catalyst Chemical Industry Co., Ltd.) was applied to a transparent fluorine-doped SnO ₂ glass substrate by a doctor blade method, After preliminarily drying for 60 minutes in an atmosphere, firing was performed for 90 minutes in an atmosphere at 450 ° C. Furthermore, said application | coating, preliminary drying, and baking were performed on the baking film | membrane, and the titanium dioxide porous layer with a film thickness of 13-15 micrometers was produced.
Formation of dye layer: The above-mentioned dioxide dioxide was added to a dye solution having a concentration of 3 × 10 ⁻⁴ mol / l in ethanol of a sensitizing dye (ruthenium organic complex, Kojima Chemical Co., Ltd.) having a structure represented by the following formula (1). The substrate with the titanium porous layer was immersed at 60 ° C. for 5 hours to form a dye layer.
Preparation of hole transporting polymer electrolyte layer: The above hole transporting polymer electrolyte solution I is applied onto the titanium dioxide substrate on which the dye layer is formed by a doctor blade method, and dried in a vacuum to increase the hole transporting property. A molecular electrolyte layer was formed to obtain a photoelectric conversion element I.

(Example 2)
A photoelectric conversion element II was obtained in the same manner as in Example 1 except that the hole transporting polymer electrolyte solution II was used instead of the hole transporting polymer electrolyte solution I.
(Example 3)
Platinum was vapor-deposited on the hole transporting polymer electrolyte layer obtained by the method of Example 2 to obtain a photoelectric conversion element III.

The photoelectric conversion elements of Examples 1 to 3 were irradiated with light having an irradiation intensity of 100 mW / cm ² and the open circuit voltage (Voc), short circuit current (Isc), and photoelectric conversion efficiency were measured. The conversion element also showed high photoelectric conversion efficiency. The results are shown in Table 1.

It is sectional drawing of an example of a dye-sensitized photoelectric conversion element.

Explanation of symbols

10 Photoelectric conversion element (dye-sensitized photoelectric conversion element)
13 n-type semiconductor electrode 14 electrolyte membrane (hole transporting polymer electrolyte membrane)
15 Electron conductive electrode

Claims (6)

In a photoelectric conversion element having a laminated structure in which a hole transporting polymer electrolyte membrane is interposed between an n-type semiconductor electrode having a dye adsorbed on the surface and an electron conductive electrode,
The hole-transporting polymer electrolyte membrane contains a conjugated conductive polymer and a fibrous conductor.   The photoelectric conversion element according to claim 1, wherein the fibrous conductor is a material having a sulfonic acid group.   The photoelectric conversion element according to claim 1, wherein the hole transporting polymer electrolyte membrane contains an inorganic p-type semiconductor.   The photoelectric conversion element according to claim 1, wherein the conjugated conductive polymer is doped with a dopant having a sulfonic acid group.   The photoelectric conversion element according to claim 1, wherein the hole transporting polymer electrolyte membrane is a coating applied on an n-type semiconductor electrode. After a conjugated conductive polymer is dispersed or dissolved in a solvent and a solution containing a fibrous conductor is applied onto an n-type semiconductor, the solvent is removed and a coating film is formed. A process for producing a photoelectric conversion element comprising a step of forming an electron conductive electrode.

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