JP4376511B2 - Photoelectric cell - Google Patents

Description

【図面の簡単な説明】
【図１】 図１は、本発明に係る光電気セルの一実施例を示す概略断面図である。
【符号の説明】
１・・・透明電極層
２・・・半導体膜
３・・・電極層
４・・・電解質層
５・・・基板
６・・・基板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoelectric cell having high photoelectric conversion efficiency, durability, and the like.
[0002]
[Prior art]
The photoelectric conversion material is a material that can continuously extract light energy as electric energy, and is a material that converts light energy into electric energy using an electrochemical reaction between electrodes. When the photoelectric conversion material is irradiated with light, electrons are generated on one electrode side, move to the counter electrode, and the electrons moved to the counter electrode move as ions in the electrolyte and return to the one electrode. Thus, since energy conversion is continuous, it is utilized for a solar cell etc., for example.
[0003]
In general solar cells, first a semiconductor film for photoelectric conversion material is formed on a support such as a glass plate coated with a transparent conductive film to form an electrode, and then another transparent conductive film is formed as a counter electrode. A support such as a coated glass plate is provided, and an electrolyte is sealed between these electrodes.
When the spectral sensitizing dye adsorbed on the photoelectric conversion material semiconductor is irradiated with sunlight, the spectral sensitizing dye absorbs light in the visible region and is excited. The electrons generated by this excitation move to the semiconductor, then move to the transparent conductive glass electrode, move to the counter electrode through the conducting wire connecting the two electrodes, and the electrons transferred to the counter electrode are oxidized in the electrolyte. Reduce the reduction system. On the other hand, the spectral sensitizing dye having electrons transferred to the semiconductor is in an oxidant state, but this oxidant is reduced by the redox system in the electrolyte and returns to its original state. Thus, since electrons flow continuously, it functions as a solar cell using a semiconductor for photoelectric conversion materials.
[0004]
The electrolyte used by being sealed between the electrodes is sealed between the electrodes as an electrolyte mixed with a solvent depending on the type of the electrolyte, and is used by sealing the side surface of the electric cell with a resin or the like.
Solvents used at this time include water, alcohols, oligoethers, carbonates such as propion carbonate, phosphate esters, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-vinylpyrrolidone, sulfolane 66 sulfur compounds, carbonic acid Examples include ethylene, acetonitrile, and lactone.
[0005]
However, when the electrolyte is used in this way, the solvent molecules are altered, the solvent molecules are decomposed, the low-boiling-point solvent escapes, and the electrolyte (solvent and / or electrolyte) leaks from the seal portion during long-term use. The photoelectric conversion efficiency performance may decrease due to the above. In other words, there was a drawback of poor long-term stability.
Further, depending on the electrolyte used in the electrolytic solution, there is a hygroscopic effect, and the electrolyte and the photosensitizer are decomposed by the moisture absorbed, so that the performance is deteriorated and the long-term stability may be insufficient.
[0006]
For this reason, in order to improve long-term stability, it has been proposed to use a solid or gel solid electrolyte layer as the electrolyte. However, there is a drawback that the diffusibility and the moving speed of such solid electrolyte ions are lowered, and the photoelectric conversion efficiency is lowered.
As a result of intensive studies, the present inventors have found that photoelectric conversion efficiency is improved when silica-based particles having a surface hydroxyl group are blended in a solid electrolyte layer, and the present invention has been completed.
[0007]
OBJECT OF THE INVENTION
It is an object of the present invention to provide a photoelectric cell with improved ion diffusivity, moving speed, that is, ionic conductivity, and thus high photoelectric conversion efficiency, and no leakage of electrolyte, etc., and excellent long-term stability. It is said.
[0008]
SUMMARY OF THE INVENTION
The photovoltaic cell according to the present invention comprises:
A substrate having an electrode layer (1) on the surface and a semiconductor film (2) having a photosensitizer adsorbed on the surface of the electrode layer (1);
A substrate having an electrode layer (3) on the surface,
The electrode layer (1) and the electrode layer (3) are arranged so as to face each other,
In the photoelectric cell in which the electrolyte layer is provided between the semiconductor film (2) and the electrode layer (3),
The electrolyte layer is composed of an electrolyte and silica-based particles, and the content of silica-based particles in the electrolyte layer is in the range of 1 to 60% by weight,
It is characterized in that at least one of the substrate and the electrode layer has transparency.
[0009]
The silica-based particles have surface OH groups, and the amount of OH groups is 0.01 to 5 nm.^-2It is preferable that the average particle diameter of the silica-based particles is in the range of 0.5 to 100 nm.
It is desirable that the electrolyte layer further contains a hydrolyzate of an organosilicon compound having ion conductivity.
[0010]
The organosilicon compound having ion conductivity is preferably at least one selected from organosilicon compounds represented by the following formula (1).
R_nSiX_4-n             (1)
[However, R: an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different. X: C1-C4 alkoxy group, silanol group, halogen, hydrogen, n: 0-3]
R is preferably a substituted hydrocarbon group and is preferably a ring-opening functional group containing oxygen.
[0011]
In the present invention, it is desirable that the electrolyte layer further contains water, and the content of water in the electrolyte layer is in the range of 0.01 to 10% by weight.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described.
[Photoelectric cell]
The photovoltaic cell according to the present invention comprises:
A substrate having an electrode layer (1) on the surface and a semiconductor film (2) having a photosensitizer adsorbed on the surface of the electrode layer (1);
A substrate having an electrode layer (3) on the surface,
The electrode layer (1) and the electrode layer (3) are arranged so as to face each other,
In the photoelectric cell in which the electrolyte layer is provided between the semiconductor film (2) and the electrode layer (3),
The electrolyte layer is composed of an electrolyte and silica particles, and the content of silica particles in the electrolyte layer is in the range of 1 to 60% by weight,
It is characterized in that at least one of the substrate and the electrode layer has transparency.
[0013]
An example of such a photoelectric cell is shown in FIG.
FIG. 1 is a schematic cross-sectional view showing an embodiment of a photoelectric cell according to the present invention, which has a transparent electrode layer 1 on the surface and adsorbs a photosensitizer on the surface of the transparent electrode layer 1 (metal). Oxide) a substrate 5 on which a semiconductor film 2 is formed;
A substrate 6 having an electrode layer 3 having a catalytic reduction ability on the surface;
The electrode layers 1 and 3 are arranged to face each other,
Further, an electrolyte layer 4 in which an electrolyte is sealed is provided between the (metal oxide) semiconductor film 2 and the transparent electrode layer 3.
[0014]
As the transparent substrate 5, a transparent and insulating substrate such as a glass substrate or an organic polymer substrate such as PET can be used.
Further, the substrate 6 is not particularly limited as long as it has enough strength to withstand use. In addition to an insulating substrate such as an organic polymer substrate such as a glass substrate or PET, metal titanium, metal aluminum, metal copper, metal A conductive substrate such as nickel can be used.
[0015]
The transparent electrode layer 1 formed on the surface of the transparent substrate 5 includes tin oxide, tin oxide doped with Sb, F or P, indium oxide doped with Sn and / or F, antimony oxide, zinc oxide, noble metal, etc. Conventionally known electrodes such as can be used.
Such a transparent electrode layer 1 can be formed by a conventionally known method such as a thermal decomposition method or a CVD method.
[0016]
In addition, the electrode layer 3 formed on the surface of the substrate 6 is not particularly limited as long as it has a reduction catalytic ability, and may be an electrode material such as platinum, rhodium, ruthenium metal, ruthenium oxide, tin oxide, Conventionally known electrodes such as tin electrodes doped with Sb, F or P, electrodes obtained by plating or vapor-depositing the electrode materials on the surface of conductive materials such as indium oxide and Sn and / or F doped with antimony oxide, and carbon electrodes. An electrode can be used.
[0017]
The electrode layer 3 is formed by directly coating, plating, or vapor-depositing the electrode on the substrate 6 and forming a conductive layer from a conductive material by a conventionally known method such as a thermal decomposition method or a CDV method. The electrode material can be formed on the layer by a conventionally known method such as plating or vapor deposition.
The substrate 6 may be transparent like the transparent substrate 5, and the electrode layer 3 may be a transparent electrode like the transparent electrode layer 1.
[0018]
The visible light transmittance of the transparent substrate 5 and the transparent electrode layer 1 is preferably higher, specifically 50% or more, and particularly preferably 90% or more. When the visible light transmittance is less than 50%, the photoelectric conversion efficiency may be lowered.
The resistance values of the transparent electrode layer 1 and the electrode layer 3 are 100 Ω / cm, respectively.²The following is preferable. The resistance value of the electrode layer is 100Ω / cm²When the value exceeds the value, the photoelectric conversion efficiency may be lowered.
[0019]
The semiconductor film 2 may be formed on the electrode layer 3 formed on the substrate 6. The thickness of the semiconductor film 2 is preferably in the range of 0.1 to 50 μm.
As the semiconductor film, an inorganic semiconductor film formed from an inorganic semiconductor material, an organic semiconductor film formed from an organic semiconductor material, an organic-inorganic hybrid semiconductor film, or the like can be used.
[0020]
Examples of the organic semiconductor material include conventionally known compounds such as phthalocyanine, phthalocyanine-bisnaphthalocyanine, polyphenol, polyanthracene, polysilane, and polypyrrole.
The semiconductor film 2 of the present invention is preferably an inorganic semiconductor film formed from an inorganic semiconductor material. Among these, the use of a metal oxide as the inorganic semiconductor material is preferable because a porous metal oxide semiconductor having a high photosensitizer adsorption amount can be obtained.
[0021]
As such a metal oxide semiconductor film, a metal composed of at least one metal oxide selected from titanium oxide, lanthanum oxide, zirconium oxide, niobium oxide, tungsten oxide, strontium oxide, zinc oxide, tin oxide, and indium oxide. An oxide semiconductor film can be given.
Such a metal oxide semiconductor film is usually composed of metal oxide particles, and the metal oxide particles can be produced by a conventionally known method. Specifically, using an inorganic compound salt or an organometallic compound of the above metal, for example, after adding an acid or alkali to a hydrous metal oxide gel or sol obtained by a sol-gel method, It can be produced by a conventionally known method such as aging.
[0022]
The metal oxide is preferably spherical particles, and the average particle diameter is preferably in the range of 1 to 600 nm.
The particle size of the spherical particles can be measured with a laser Doppler particle size measuring device (manufactured by Nikkiso Co., Ltd .: Microtrack).
When the average particle diameter of the spherical particles is less than 1 nm, the formed metal oxide semiconductor film is likely to crack, and it becomes difficult to form a thick film without cracks having a film thickness described later with a small number of times. In addition, the pore diameter and pore volume of the metal oxide semiconductor film may decrease, and the amount of adsorption of the photosensitizer may decrease. In addition, when the average particle diameter of the spherical particles exceeds 600 nm, the strength of the metal oxide semiconductor film may be insufficient.
[0023]
Such metal oxide spherical particles are preferably made of crystalline titanium oxide, and particularly preferably made of one or more of anatase type titanium oxide, brookite type titanium oxide, and rutile type titanium oxide. Crystalline titanium oxide has a high band gap and a high dielectric constant, and the adsorption amount of the photosensitizer is higher than other metal oxide particles, and further, stability, safety, film formation, etc. are easy. Has excellent properties.
[0024]
Such crystalline titanium oxide particles are added to a hydrous titanic acid gel or sol obtained by a sol-gel method or the like by adding an acid or alkali as necessary, followed by heating and aging. Obtainable.
Further, the crystalline titanium oxide particles used in the present invention are obtained by adding hydrogen peroxide to a hydrous titanic acid gel or sol to dissolve the hydrous titanic acid to form peroxotitanic acid, and then adding the peroxotitanic acid to an alkali. Alternatively, it can be obtained by adding ammonia and / or an organic base to make it alkaline, and heating and aging in a temperature range of 80 to 350 ° C. Moreover, after adding the obtained crystalline titanium oxide particles as seed particles to peroxotitanic acid, the above step may be repeated.
[0025]
Furthermore, it can be fired at a high temperature of 350 ° C. or higher as necessary.
The metal oxide semiconductor film 2 preferably contains a titanium oxide binder component together with the crystalline titanium oxide particles.
Examples of such a titanium oxide binder component include a hydrous titanic acid gel obtained by a sol-gel method or the like, a titanium oxide composed of a sol, or a hydrous titanic acid gel or sol to which hydrogen peroxide is added to dissolve the hydrous titanic acid. Examples include a decomposition product of luoxotitanic acid.
[0026]
Of these, a decomposition product of peroxotitanic acid is particularly preferably used.
Such a titanium oxide binder component forms a dense and uniform adsorption layer on the surface of the crystalline titanium oxide particles. For this reason, the metal oxide semiconductor film obtained can improve adhesiveness with an electrode. Furthermore, when such a titanium oxide binder component is used, the contact between the crystalline titanium oxide particles changes from point contact to surface contact, it is possible to improve electron mobility, and the adsorption amount of the photosensitizer is increased. Can be increased.
[0027]
The ratio between the titanium oxide binder component and the crystalline titanium oxide particles in the metal oxide semiconductor film 2 is TiO 2.₂It is desirable that the weight ratio in terms of conversion (titanium oxide binder component / crystalline titanium oxide particles) is in the range of 0.05 to 0.50, preferably 0.1 to 0.3. When the weight ratio is less than 0.05, the absorption of light in the visible light region is insufficient, and the amount of adsorption of the photosensitizer may not increase. If the weight ratio is higher than 0.50, a porous semiconductor film may not be obtained, and the photosensitizer adsorption amount may not be improved.
[0028]
The metal oxide semiconductor film 2 preferably has a pore volume of 0.05 to 0.8 ml / g and an average pore diameter of 2 to 250 nm. When the pore volume is smaller than 0.05 ml / g, the adsorption amount of the photosensitizer is low, and when it is higher than 0.8 ml / g, the electron mobility in the film is lowered and the photoelectric conversion efficiency is improved. May decrease. Further, when the average pore diameter is less than 2 nm, the adsorption amount of the photosensitizer decreases, and when it exceeds 250 nm, the electron mobility decreases and the photoelectric conversion efficiency may decrease.
[0029]
Such a metal oxide semiconductor film 2 can be produced using, for example, a conventionally known coating liquid for forming a metal oxide semiconductor film for photoelectric cells as follows.
For example, a coating solution for forming a metal oxide semiconductor film for photoelectric cells, which comprises the metal oxide particles and a dispersion medium and contains a binder component precursor as required, can be used.
[0030]
A metal oxide semiconductor film for photoelectric cells can be produced by applying a coating liquid for forming a metal oxide semiconductor film for photoelectric cells on a substrate, drying and then curing.
The coating solution is preferably applied such that the final formed metal oxide semiconductor film has a thickness in the range of 0.1 to 50 μm. As a coating method of the coating solution, it can be applied by a conventionally known method such as a dipping method, a spinner method, a spray method, a roll coater method, flexographic printing, and screen printing.
[0031]
The drying temperature may be any temperature that can remove the dispersion medium.
In the present invention, the coating film can be further cured by irradiating with ultraviolet rays as necessary. By irradiating with ultraviolet rays, the precursor of the binder component can be decomposed and cured. In addition, when the film forming aid is contained in the coating liquid, the film forming aid may be decomposed by heat treatment after the coating film is cured.
[0032]
The thickness of the metal oxide semiconductor film thus obtained is preferably in the range of 0.1 to 50 μm.
In the present invention, the semiconductor film 2 adsorbs the photosensitizer.
The photosensitizer is not particularly limited as long as it absorbs and excites light in the visible light region and / or infrared light region. For example, organic dyes, metal complexes, and the like can be used.
[0033]
As the organic dye, a conventionally known organic dye having a functional group such as a carboxyl group, a hydroxyalkyl group, a hydroxyl group, a sulfone group, or a carboxyalkyl group in the molecule can be used. Specific examples include metal-free phthalocyanine, cyanine dyes, methocyanine dyes, triphenylmethane dyes, and xanthene dyes such as uranin, eosin, rose bengal, rhodamine B, and dibromofluorescein. These organic dyes have a characteristic that the adsorption rate to the metal oxide semiconductor film is fast.
[0034]
Examples of the metal complex include metal phthalocyanines such as copper phthalocyanine and titanyl phthalocyanine described in JP-A-1-220380 and JP-A-5-504023, chlorophyll, hemin, ruthenium-tris (2,2 ′ -Bispyridyl-4,4'-dicarboxylate), cis- (SCN^-Ruthenium- such as) -bis (2,2'-bipyridyl-4,4'-dicarboxylate) ruthenium, ruthenium-cis-diaqua-bis (2,2'-bipyridyl-4,4'-dicarboxylate) Examples thereof include complexes of ruthenium, osmium, iron, zinc and the like, such as cis-diaqua-bipyridyl complexes, porphyrins such as zinc-tetra (4-carboxyphenyl) porphine, and iron-hexacyanide complexes. These metal complexes are excellent in the effect of spectral sensitization and durability.
[0035]
The organic dye or metal complex as the above-mentioned photosensitizer may be used alone, or may be used by mixing two or more kinds of organic dyes or metal complexes. Further, the organic dye and the metal complex are used in combination. Also good.
The adsorption method of such a photosensitizer is not particularly limited, and a solution obtained by dissolving the photosensitizer in a solvent is absorbed into the metal oxide semiconductor film by a method such as a dipping method, a spinner method, a spray method, Then, a general method such as drying can be employed.
[0036]
As the solvent for dissolving the photosensitizer, any solvent that dissolves the photosensitizer can be used. Specifically, water, alcohols, toluene, dimethylformamide, chloroform, ethyl cellosolve, N-methylpyrrolidone, Tetrahydrofuran or the like can be used.
The amount of photosensitizer adsorbed on the metal oxide semiconductor film is 1 cm of the specific surface area of the metal oxide semiconductor film.²It is preferably 50 μg or more per unit. When the amount of the photosensitizer is less than 50 μg, the photoelectric conversion efficiency may be insufficient.
[0037]
In the photovoltaic cell, the metal oxide semiconductor film 2 and the transparent electrode layer 3 are disposed so as to face each other, the side surfaces are sealed with a resin or the like, and the electrolyte layer 4 is formed in the gap between the semiconductor film 2 and the transparent electrode layer 3. In the present invention, silica-based particles are contained in the electrolyte layer.
The electrolyte layer 4 may be a solid electrolyte or a liquid electrolyte. The solid electrolyte includes hard ones and soft ones such as gel, gel and jelly.
[0038]
As an electrolyte contained in such an electrolyte layer, a mixture of an electrochemically active salt and at least one compound that forms a redox system is used.
Examples of the electrochemically active salt include quaternary ammonium salts such as tetrapropylammonium iodide and imidazolium salts such as 1-propyl-2,3-dimethylimidazolium oxide. Compounds that form redox systems include quinone, hydroquinone, iodine (I^-/ I^- _Three), Potassium iodide, bromine (Br^-/ Br^- _Three), Potassium bromide, copper iodide and the like. In some cases, these may be used in combination.
[0039]
The amount of such an electrolyte used varies depending on the type of electrolyte and the type of solvent used as necessary, but the concentration in the electrolyte solution, which is a mixture of the electrolyte and the solvent (in the case of a solid electrolyte, the electrolyte layer) The amount in the volume is preferably in the range of about 0.1 to 5 mol / liter.
It is preferable that the content of silica particles is in the range of 1 to 60% by weight, preferably 5 to 50% by weight.
[0040]
When such silica-based particles are included, the ion diffusibility and ion transfer speed of the electrolyte layer are increased, and the photoelectric conversion efficiency and heat resistance are improved. In the case of a liquid electrolyte, ions move in the liquid, and in the case of a solid electrolyte, for example, move on the surface of solid particles.
When silica-based particles are included, the electrolyte is taken into the electric double layer formed with the zeta potential on the silica particle surface, and ions and holes can move more quickly on the surface of the silica-based particles in contact with each other. Thus, when the solid electrolyte is formed, leakage of the electrolyte and escape of the solvent are eliminated, so that high ion mobility can be expressed and maintained.
[0041]
When the content of silica-based particles in the electrolyte layer is less than 1% by weight, the contact between the silica-based particles becomes insufficient, and ions move rapidly on the surface of the silica-based particles, improving the hole conductivity in the electrolyte layer. The effect of improving the photoelectric conversion efficiency is not sufficiently obtained, and depending on the electrolyte used, the electrolyte layer is maintained in a solid state or a gel state, and it is stable for a long time by preventing leakage of the electrolyte and the solvent used as necessary. The effect of expressing sex may not be obtained.
[0042]
If the content of silica-based particles in the electrolyte layer exceeds 60% by weight, ions and ionic conductivity will not be further improved, and depending on the electrolyte, the viscosity will increase and it will not be possible to diffuse into the pores of the semiconductor film. The conductivity of ions and holes may be reduced.
The silica-based particles used in the present invention have a surface OH group content of 0.01 to 5 nm.^-2Furthermore, 0.1 to 5 nm^-2It is preferable that it exists in the range.
[0043]
Silica-based particles have a surface OH group content of 0.01 nm^-2If it is less than the above, the electrolyte doubles into the electric double layer as described above, and the ion diffusibility may not be sufficiently exhibited, and the ion conductivity becomes insufficient, so that the ions rapidly move on the surface of the silica-based particle. The effect of improving the photoelectric conversion efficiency may not be obtained sufficiently.
[0044]
Surface OH group content is 5 nm^-2It is difficult to obtain silica particles exceeding 1, and even if obtained, it already has OH groups with sufficient density, and OH groups are adjacent to each other, so that proton / hole conductivity / conductivity is further improved. I don't have to.
If the surface OH group amount of the silica-based particles is in the above range, the surface OH groups are in a dissociated state and have ionicity as compared with water molecules, etc. As a result, the ionic conductivity of the electrolyte layer is improved, and the photoelectric conversion efficiency can be improved.
[0045]
In the present invention, the silica particles may be silica alone or silica-based composite oxides such as silica-alumina, silica-titania, silica-zirconia, silica-tungsten oxide, and the like.
In the present invention, the determination of the surface OH groups of the silica-based particles can be performed, for example, by converting the silica particles into_ThreeIt can be determined by treating with MgI, reacting with surface OH groups and methylating, and then quantifying CH4 gas. For convenience, H when heated at 600 ° C. for 2 hours is used.₂The amount of O desorption can be measured and converted into the amount of OH.
[0046]
Such silica-based particles preferably have an average particle size in the range of 0.5 to 100 nm, more preferably 2 to 80 nm.
When the average particle diameter of the silica-based particles is less than 0.5 nm, it may combine with the titanium oxide of the semiconductor film to reduce the electron conductivity on the surface of the titanium oxide, and thus the photoelectric conversion efficiency may be reduced.
[0047]
When the average particle diameter of silica-based particles exceeds 100 nm, the number of particles that cannot enter the pores of the semiconductor film increases, and the effect of rapidly moving electrons from the semiconductor film to the electrolyte layer (while preventing back current) Becomes insufficient, and the effect of improving the photoelectric conversion efficiency may not be sufficiently obtained.
Furthermore, in the present invention, it is preferable that the electrolyte layer 4 contains a hydrolyzate of an organosilicon compound having ion conductivity. When such a hydrolyzate of an organosilicon compound is contained, the electrolyte layer becomes solid or gel-gel, and a solid electrolyte layer can be formed. When such a solid electrolyte layer is formed, there is no leakage of the electrolyte, and a photoelectric cell with excellent durability can be obtained.
[0048]
The organic silicon compound having ion conductivity is preferably at least one selected from organic silicon compounds represented by the following formula (1).
R_nSiX_4-n             (1)
[However, R: an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different. X: C1-C4 alkoxy group, silanol group, halogen, hydrogen, n: 0-3]
Specific examples of the organosilicon compound represented by the formula (1) include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, Phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3, 3,3-trifluoropropyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxytripropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxyp Pyrtriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ -Aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltri Ethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, trimethylsilanol, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethyl chloride Roshiran, phenyl trichlorosilane, diphenyl dichlorosilane, vinyl trichlorosilane, trimethylbromosilane, diethylsilane, and the like.
[0049]
Among these, it is preferable that an organic silicon compound in which the substituted hydrocarbon group is a ring-opening functional group containing oxygen is included. Specifically, γ-glycidoxytripropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltri Methoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-mercaptopropyltri And methoxysilane.
[0050]
Such an organic silicon compound having a ring-opening functional group containing oxygen generates a OH group by opening a substituted hydrocarbon group containing oxygen, so that a solid polymer electrolyte membrane having high ion conductivity can be obtained.
As a hydrolyzate of an organic silicon compound having ion conductivity, a hydrolyzate (partial) obtained by adding water to an organic solvent solution of the above-described organosilicon compound, adding an acid or an alkali as necessary, and hydrolyzing it. Hydrolysates and hydrolyzed / polycondensed products) may be washed, aged, etc., if necessary.
[0051]
The content of the organosilicon compound hydrolyzate in the electrolyte layer is R_nSiO_{(4-n) / 2}(Or as a solid content) in the range of 1 to 70% by weight, preferably 2 to 30% by weight. When the hydrolyzate of the organosilicon compound is included in the above range, the hydrolyzate of the organosilicon compound has a three-dimensional network structure due to the siloxane bond, and the electrolyte layer becomes a solid polymer electrolyte membrane. An OH group is present at the terminal of this, and ionic conductivity is expressed by this OH group, and the photoelectric conversion efficiency is improved.
[0052]
The electrolyte layer used in the present invention may further contain water. The water content in the electrolyte layer is preferably in the range of 0.01 to 10% by weight, more preferably 0.1 to 5% by weight. Thus, when water is contained, the dissociation of the electrolyte is increased, and the photoelectric conversion efficiency can be increased.
When the content of water in the electrolyte layer is less than 0.01% by weight, dissociation of the electrolyte may be insufficient, and the photoelectric conversion efficiency may be insufficient.
[0053]
Even if the content of water in the electrolyte layer exceeds 10% by weight, the ionic conductivity is not further improved, and the electrolyte layer may freeze when the cell is exposed to a low temperature.
Moreover, if it mixes with the said electrolyte and a solvent, it will become a liquid electrolyte solution. The solvent used at this time is preferably a solvent having a low photosensitizer solubility so that the photosensitizer adsorbed on the metal oxide semiconductor film does not desorb and dissolve. Specific examples of solvents include water, alcohols, oligoethers, carbonates such as propion carbonate, phosphate esters, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-vinylpyrrolidone, sulfolane 66, sulfur compounds, and carbonic acid. Examples include ethylene, acetonitrile, and γ-butyrolactone.
[0054]
In the case of an electrolytic solution, the electrolyte layer is sealed as it is. In the case of a solid electrolyte, the gel-like or gel-like one can be transferred to the electrolyte layer and sealed as it is, and once fluidized by diluting and dispersing with a solvent (water, acetonitrile, etc.). May be applied to the electrolyte layer, and the solvent may be removed by heating or drying under reduced pressure to solidify, followed by encapsulation.
[0055]
【The invention's effect】
According to the present invention, since the electrolyte layer contains silica particles having a surface OH group, the ionic conductivity of the electrolyte layer is high, and thus a photoelectric cell with high photoelectric conversion efficiency can be provided. In addition, when used as a solid electrolyte (including solidified and gelled state), the ionic conductivity is high, so there is no leakage of electrolyte or solvent, high photoelectric conversion efficiency, and excellent durability. Can be provided.
[0056]
【Example】
Hereinafter, although an example explains, the present invention is not limited by these examples.
[0057]
[referenceExample 1]
Preparation of titanium oxide particles for semiconductor films
  Suspend 5 g of titanium hydride in 1 liter of pure water, add 400 g of hydrogen peroxide solution with a concentration of 5% by weight over 30 minutes, then heat to 80 ° C to dissolve to prepare a solution of peroxotitanic acid. did. 90% by volume was taken from the total amount of this solution, adjusted to pH 9 by adding concentrated aqueous ammonia, placed in an autoclave, hydrothermally treated at 250 ° C. for 5 hours under saturated vapor pressure, and titania colloidal particles (A) Was prepared.
[0058]
The obtained titania colloidal particles were anatase type titanium oxide having high crystallinity by X-ray diffraction. The average particle diameter of the anatase-type titanium oxide particles was 40 nm.
Preparation of coating solution for semiconductor film formation
The titania colloidal particles (A) obtained above are concentrated to a concentration of 10%, the peroxotitanic acid solution is mixed, and the titanium in the mixture is converted to TiO2.₂Convert TiO₂Hydroxypropyl cellulose was added as a film forming aid so as to be 30% by weight of the weight to prepare a coating solution for forming a semiconductor film.
[0059]
Formation of metal oxide semiconductor film
The coating solution is applied onto a transparent glass substrate on which fluorine-doped tin oxide is formed as an electrode layer, air-dried, and then 6000 mJ / cm using a low-pressure mercury lamp.²The ultraviolet rays were irradiated to decompose the peroxoacid and the coating was cured. The coating film was heated at 300 ° C. for 30 minutes to decompose and anneal the hydroxypropyl cellulose to form a metal oxide semiconductor film.
[0060]
The obtained metal oxide semiconductor film had a thickness of 12 μm, a pore volume determined by a nitrogen adsorption method of 0.6 ml / g, and an average pore diameter of 18 nm.
Spectral sensitizing dye adsorption
As a spectral sensitizing dye, cis- (SCN^-) -Bis (2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium (II)^-FourA mol / liter ethanol solution was prepared. This spectral sensitizing dye solution was applied onto a metal oxide semiconductor film using a rpm 100 spinner and dried. This coating and drying process was performed five times. The absorption amount of the spectral sensitizing dye of the obtained metal oxide semiconductor film is 200 μg / cm.²Met.
[0061]
Photoelectric cell (1) Create
Electrolyte containing silica-based particles (1) Preparation of
To an electrolytic solution in which tetrapropylammonium iodide was dissolved in a solvent in which acetonitrile and ethylene carbonate were mixed at a volume ratio of 1: 4 as a solvent so that 0.46 mol / liter of iodine and 0.06 mol / liter of iodine were dissolved. Silica particles obtained by freeze-drying silica sol (manufactured by Catalyst Chemical Industries, Ltd .: SN-30, average particle size 12 nm) as silica-based particles (surface OH group content 3 nm)^-2) Was mixed so that the content of silica particles in the electrolyte tank was 30% by weight to prepare an electrolytic solution (1) containing silica particles.
[0062]
Next, the electrode prepared as above is used as one electrode, and fluorine doped tin oxide is formed as the other electrode as an electrode, and a transparent glass substrate carrying platinum thereon is placed facing it, and the side surface is made of resin. Sealing was performed, and the electrolyte solution (1) containing the above silica particles was sealed between the electrodes, and the electrodes were connected by lead wires to produce a photoelectric cell (1).
[0063]
Photoelectric cell (A) is a solar simulator, 100 W / m²Is irradiated at an incident angle of 90 ° (90 ° with the cell surface), the voltage in the open circuit state (Voc), the density of the current that flows when the circuit is short-circuited (Joc), the fill factor (FF) and Conversion efficiency (η) was measured. Further, the photoelectric cell (1) was treated in a dryer at 75 ° C. for 500 hours to observe the presence or absence of liquid leakage, and the conversion efficiency (η) was similarly measured and evaluated as long-term stability.
[0064]
The results are shown in Table 1.
The OH group was identified by measuring the weight after drying silica particles at 100 ° C. for 1 hour, and then measuring the weight loss due to water when the silica particles were heated at 600 ° C. for 2 hours. (Pieces / nm^-2) And calculated.
[0065]
[referenceExample 2]
Creation of photoelectric cell (2)
Preparation of electrolyte solution (2) containing silica-based particles
  Silica sol (manufactured by Catalyst Kasei Kogyo Co., Ltd .: SN-550, SiO as silica-based particles)₂Silica particles (surface OH group content 3 nm) obtained by freeze-drying a concentration of 20.5 wt% and an average particle size of 5 nm^-2) Was mixed so that the content of silica particles in the electrolyte tank was 30% by weight to prepare an electrolytic solution (2) containing silica particles.
[0066]
  Next, except that the electrolyte (2) was usedReference examplePhotoelectric cell (2) was prepared in the same manner as in Example 1, and Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage and long-term stability were evaluated.
  The results are shown in Table 1.
[0067]
[referenceExample 3]
Creation of photoelectric cell (3)
  referenceIn Example 2, the silica sol was freeze-dried and then subjected to heat treatment at 450 ° C. for 1 hour (surface OH group content: 0.5 nm).^-2An electrolyte solution (3) containing silica particles was prepared in the same manner except that was used.
[0068]
  Next, except that the electrolyte (3) was usedreferenceA photoelectric cell (3) was prepared in the same manner as in Example 1, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage and long-term stability were evaluated.
  The results are shown in Table 1.
[0069]
[referenceExample 4]
Creation of photovoltaic cell (4)
  referenceIn Example 1, silica-alumina sol (manufactured by Catalyst Chemical Industry Co., Ltd .: USB-120, SiO as silica-based particles)₂Silica-based particles (concentration of 20% by weight, average particle size of 20 nm) freeze-dried (surface OH group content: 4 nm)^-2An electrolyte solution (4) containing silica-based particles was prepared in the same manner except that was used.
[0070]
  Next, except that the electrolyte (4) was usedreferenceA photoelectric cell (4) was prepared in the same manner as in Example 1, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage was observed and the long-term stability was evaluated.
  The results are shown in Table 1.
[0071]
[referenceExample 5]
Creation of photoelectric cell (5)
  In the electrolyte layer, 67% by weight of an electrolyte (a mixture of 95% by weight of CuI and 5% by weight of 1-propyl-2,3-dimethylimidazolium oxide),referenceThe silica particles obtained in the same manner as in Example 1 were mixed so that the content of silica particles was 30% by weight and water was 3% by weight, and acetonitrile was added as a diluent to the extent that it could be transferred to the electrolyte layer. A solid electrolyte (5) precursor containing was prepared.
[0072]
  Then, after the solid electrolyte (5) precursor was transferred between the electrodes, acetonitrile was evaporated under reduced pressure while heating to 80 ° C., and the solid electrolyte (5) was sealed.referenceA photoelectric cell (5) was prepared in the same manner as in Example 1, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage and long-term stability were evaluated.
  The results are shown in Table 1.
[0073]
[referenceExample 6]
Creation of photoelectric cell (6)
  In the electrolyte tank, 69% by weight of electrolyte (mixture of 95% by weight of CuI and 5% by weight of 1-propyl-2,3-dimethylimidazolium oxide), 30% by weight of silica particles, and 1% of water A solid electrolyte (6) precursor containing silica-based particles was prepared by mixing so as to be in weight percent and adding acetonitrile as a diluent to such an extent that it can be transferred to the electrolyte layer.
[0074]
  Then, after transferring the solid electrolyte (6) precursor between the electrodes, the acetonitrile was evaporated under reduced pressure while heating at 80 ° C., and the solid electrolyte (6) was sealed.referenceA photoelectric cell (6) was prepared in the same manner as in Example 5, and Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage was observed and the long-term stability was evaluated.
  The results are shown in Table 1.
[0075]
[referenceExample 7]
Creation of photoelectric cell (7)
  In the electrolyte layer,referenceThe electrolyte used in Example 1 was 60% by weight, 1-propyl-2,3-dimethylimidazolium oxide was 7% by weight,referenceAn electrolyte solution (7) containing silica-based particles was prepared by mixing so that the silica particles used in Example 1 were 30% by weight and water was 3% by weight.
[0076]
  Then, except using the obtained electrolyte (7)referenceA photoelectric cell (7) was prepared in the same manner as in Example 5, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage and long-term stability were evaluated.
  The results are shown in Table 1.
[0077]
[Example 8]
Preparation of hydrolyzate of organosilicon compound
Silica sol (Catalyst Kasei Kogyo Co., Ltd .: SN-50, SiO₂Silica organosol (SiO 2) obtained by solvent substitution of isopropyl alcohol with a concentration of 20.6% by weight and an average particle size of 12 nm.₂10 g of γ-glycidoxypropyltrimethoxysilane (GPTMS) was added to 100 g of a concentration of 20% by weight, and the mixture was stirred at room temperature for 30 minutes. Subsequently, 5 g of water was added for hydrolysis, and the mixture was stirred for 3 hours. Subsequently, the total concentration of the hydrolyzate of organosilicon compound and silica particles was adjusted to 20% by weight to prepare a mixture of the organosilicon compound hydrolyzate and silica particles.
[0078]
Creation of photoelectric cell (8)
  In the electrolyte layer,reference30% by weight of the electrolyte used in Example 1, 5% by weight of 1-propyl-2,3-dimethylimidazolium oxide,referenceSilica particles were prepared by mixing 30 wt% of silica particles used in Example 1 and a hydrolyzate of the organic silicon compound having a concentration of 20 wt% obtained above to a solid content of 30 wt% and water of 5 wt%. A jelly-like solid electrolyte (8) containing particles was prepared.
[0079]
  Next, the obtained solid electrolyte was sealed between (8) electrodes.referenceA photoelectric cell (8) was prepared in the same manner as in Example 1, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage was observed and the long-term stability was evaluated.
  The results are shown in Table 1.
[0080]
[Example 9]
Creation of photoelectric cell (9)
  In Example 8, in the electrolyte layer,reference30% by weight of the electrolyte used in Example 1, 5% by weight of 1-propyl-2,3-dimethylimidazolium oxide,referenceThe silica particles used in Example 1 were mixed with the hydrolyzate of the organic silicon compound having a concentration of 20% by weight obtained in the above so that the solid content was 10% by weight and water was 5% by weight. A jelly-like solid electrolyte (9) containing particles was prepared.
[0081]
  Next, except that the obtained solid electrolyte (9) was sealed between electrodesreferenceA photoelectric cell (9) was prepared in the same manner as in Example 1, Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage was observed and the long-term stability was evaluated.
  The results are shown in Table 1.
[0082]
[Comparative Example 1]
Electrolyte (R-1) Preparation of
Tetrapropylammonium iodide is dissolved in a solvent in which acetonitrile and ethylene carbonate are mixed at a volume ratio of 1: 4 as a solvent so that 0.46 mol / liter of iodine and 0.06 mol / liter of iodine are dissolved. (R-1) was prepared.
[0083]
Creation of photoelectric cell (R-1)
  referenceIn Example 1, except that the electrolytic solution (R-1) was used as the electrolytic solution, a photoelectric cell (R-1) was prepared in the same manner, and Voc, Joc, FF, and η were measured, and whether or not there was liquid leakage Observation and long-term stability were evaluated.
  The results are shown in Table 1.
[0084]
[Comparative Example 2]
Photoelectric cell (R-2) Create
An electrolytic solution (R-2) was prepared in the same manner as in Comparative Example 1, except that water was added to the electrolytic solution (R-1) so that the water content was 3% by weight. A photoelectric cell (R-2) was prepared in the same manner as Comparative Example 1 except that this electrolytic solution (R-2) was used, and Voc, Joc, FF, and η were measured, and the presence or absence of liquid leakage was observed. And long-term stability was evaluated.
[0085]
The results are shown in Table 1.
[0086]
[Comparative Example 3]
Photoelectric cell (R-3) Create
In Comparative Example 1, the photoelectric cell (R-3) was similarly prepared except that the electrolyte solution (R-1) was mixed in the electrolyte layer so that the content was 20% by weight and the content of silica particles was 80% by weight. It was prepared, Voc, Joc, FF, and η were measured, and observation of the presence or absence of liquid leakage and long-term stability were evaluated.
[0087]
The results are shown in Table 1.
[0088]
[Table 1]

[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a photovoltaic cell according to the present invention.
[Explanation of symbols]
1 ... Transparent electrode layer
2 ... Semiconductor film
3 ... Electrode layer
4 ... Electrolyte layer
5 ... Board
6 ... Board

Claims (6)

A substrate having an electrode layer (1) on the surface and a semiconductor film (2) having a photosensitizer adsorbed on the surface of the electrode layer (1);
A substrate having an electrode layer (3) on the surface,
The electrode layer (1) and the electrode layer (3) are arranged so as to face each other,
In the photoelectric cell in which the electrolyte layer is provided between the semiconductor film (2) and the electrode layer (3),
The electrolyte layer is composed of an electrolyte and silica-based particles, the content of silica-based particles in the electrolyte layer is in the range of 1 to 60% by weight, and further includes a hydrolyzate of an organosilicon compound having ion conductivity,
At least one substrate and an electrode layer have transparency, The photoelectric cell characterized by the above-mentioned. The photoelectric cell according to claim 1, wherein the silica-based particles have a surface OH group and the amount of OH groups is in the range of 0.01 to 5 nm ^-2 .   The photoelectric cell according to claim 1 or 2, wherein an average particle diameter of the silica-based particles is in a range of 0.5 to 100 nm. The photoelectricity according to any one of claims 1 to 3, wherein the organosilicon compound having ion conductivity is at least one selected from organosilicon compounds represented by the following formula (1). cell.
R _n SiX _4-n (1)
[However, R: an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different. X: C1-C4 alkoxy group, silanol group, halogen, hydrogen, n: 0-3]   The photoelectric cell according to claim 4, wherein R is a substituted hydrocarbon group and a ring-opening functional group containing oxygen.   6. The photoelectric cell according to claim 1, wherein the electrolyte layer further contains water, and the content of water in the electrolyte layer is in the range of 0.01 to 10% by weight.

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