JP2013182771A - Dye-sensitized photoelectric conversion element, method for manufacturing the same, and solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye-sensitized photoelectric conversion element having high photoelectric conversion efficiency and high durability.SOLUTION: The dye-sensitized photoelectric conversion element has a semiconductor layer, a charge transport layer, and a counter electrode in order on a conductive substrate. The semiconductor layer contains semiconductor particles on which a sensitizing dye and a silicon compound are carried.

Description

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

  In recent years, the use of sunlight, which is infinite and does not generate harmful substances, has been energetically studied. What is currently put into practical use as solar energy, which is a clean energy source, includes residential single crystal silicon, polycrystalline silicon, amorphous silicon, and inorganic solar cells such as cadmium telluride and indium copper selenide. .

  However, the disadvantages of these inorganic solar cells include, for example, that silicon is required to have a very high purity, and naturally, the purification process is complicated, the number of processes is large, and the manufacturing cost is high.

  On the other hand, many solar cells using organic materials have been proposed. As an organic solar cell, a Schottky photoelectric conversion element that joins a p-type organic semiconductor and a metal having a low work function, a p-type organic semiconductor and an n-type inorganic semiconductor, or a p-type organic semiconductor and an electron-accepting organic compound are joined. There are heterojunction photoelectric conversion elements and the like, and organic semiconductors used are synthetic dyes and pigments such as chlorophyll and perylene, conductive polymer materials such as polyacetylene, or composite materials thereof.

  These are thinned by a vacuum deposition method, a casting method, a dipping method, or the like to form a battery material. Although organic materials have advantages such as low cost and easy area enlargement, there are many problems that the conversion efficiency is as low as 1% or less and the durability is poor.

  Under such circumstances, a solar cell exhibiting good characteristics has been reported by Dr. Gretzell of Switzerland (see, for example, Non-Patent Document 1).

  The battery proposed in Non-Patent Document 1 is a dye-sensitized solar cell, which is a wet solar cell using a titanium oxide porous thin film spectrally sensitized with a ruthenium complex as a working electrode. The advantage of this method is that it is not necessary to purify an inexpensive metal compound semiconductor such as titanium oxide to a high purity, and the available light extends over a wide visible light region. It can convert a lot of sunlight into electricity effectively.

  However, since a high temperature exceeding 400 ° C. is used to form the titanium dioxide porous thin film, and a flexible support using a polymer or the like cannot be used, there is a problem that the application is limited. In addition, the use of high temperature has been a problem because it uses a large amount of energy and has a large impact on the environment.

  Therefore, a semiconductor thin film layer is produced by irradiating ultraviolet light having a wavelength of 400 nm or less in the presence of semiconductor fine particles such as titanium dioxide and a semiconductor fine particle precursor, and a photoelectric conversion element using a flexible support has been reported ( For example, see Patent Document 1).

  There has also been reported an example in which a semiconductor thin film layer is formed by irradiating ultraviolet rays in the presence of a semiconductor precursor and an organic polymer of a foaming agent (see, for example, Patent Document 2). This is because the organic polymer of the foaming agent is decomposed by irradiation with ultraviolet rays, and when the gas escapes from the inside of the semiconductor thin film, fine pores are produced to promote the porous formation of the thin film.

JP 2001-357896 A JP 2002-231326 A

Nature, 353, 737 (1991), B.R. O'Regan and M.M. Gratzel

  However, in the case of a semiconductor thin film layer prepared by the method described in Patent Document 1, a pigment having high hydrophilicity and high hydrophobicity cannot be sufficiently adsorbed on the surface of titanium dioxide particles, or there is selection of a pigment imparted with hydrophilicity. When necessary, there was a problem that sufficient efficiency was not exhibited.

  Further, in the method described in Patent Document 2, although the thin film is made porous to increase the adsorption of the dye to improve the efficiency, the adsorption of the dye is not sufficient, and the efficiency decreases with time, resulting in durability. Was not enough.

  Therefore, an object of the present invention is to provide a dye-sensitized photoelectric conversion element having high photoelectric conversion efficiency and high durability.

  Another object of the present invention is to provide a method for producing the dye-sensitized photoelectric conversion element.

  Still another object of the present invention is to provide a solar cell using the dye-sensitized photoelectric conversion element.

  The present inventor has accumulated extensive research. As a result, the present inventors have found that the above problems can be solved by a dye-sensitized photoelectric conversion element having a semiconductor layer containing semiconductor particles carrying a silicon compound and a dye, and have completed the present invention.

  The above object of the present invention is achieved by the following configurations.

  1. A dye-sensitized photoelectric conversion element having a semiconductor layer, a charge transport layer, and a counter electrode in this order on a conductive substrate, wherein the semiconductor layer comprises semiconductor particles carrying a sensitizing dye and a silicon compound. A dye-sensitized photoelectric conversion element.

  2. The silicon compound is a compound formed by irradiating at least one selected from the group consisting of polysilazane and silsesquioxane with vacuum ultraviolet rays. The dye-sensitized photoelectric conversion element as described in 1.

  3. A method for producing a dye-sensitized photoelectric conversion device, comprising a semiconductor layer, a charge transport layer, and a counter electrode in this order on a conductive substrate, and at least selected from the group consisting of semiconductor particles and semiconductor particle precursors A step of preparing a mixed solution containing one type and a silicon compound, a step of applying the mixed solution and drying to form a coating film, and a step of irradiating the coating film with vacuum ultraviolet light having a wavelength of 200 nm or less; And a step of sensitizing the coating film after irradiation with the vacuum ultraviolet ray. A method for producing a dye-sensitized photoelectric conversion element.

  4). The silicon compound is at least one selected from the group consisting of polysilazane and silsesquioxane. The manufacturing method as described in.

  5. Above 1. Or 2. 2. The dye-sensitized photoelectric conversion element described in 3) above, or 3. Or 4. The solar cell which has a dye-sensitized photoelectric conversion element obtained by the manufacturing method of description.

  According to the present invention, a dye-sensitized photoelectric conversion element having high photoelectric conversion efficiency and high durability is provided.

It is a cross-sectional schematic diagram which shows an example of the dye-sensitized photoelectric conversion element of this invention.

  The present invention is a dye-sensitized photoelectric conversion element having a semiconductor layer, a charge transport layer, and a counter electrode in this order on a conductive substrate, and the semiconductor layer carries a sensitizing dye and a silicon compound. It is a dye-sensitized photoelectric conversion element having a semiconducting particle.

  The detailed reason why the dye-sensitized photoelectric conversion element of the present invention has high photoelectric conversion efficiency and high durability is unknown, but the silicon compound supported on the surface of the semiconductor particles has good hydrophobicity and hydrophilicity for dye adsorption. It is possible to achieve high dye adsorption by this, and further, the photocatalytic property of the semiconductor particles is weakened by the loading of the silicon compound, and the decomposition of the dye is suppressed, It is considered that a dye-sensitized photoelectric conversion element having high photoelectric conversion efficiency and high durability has been realized. This mechanism is based on speculation, and the present invention is not limited to the above mechanism.

  Hereafter, the component and embodiment of this invention are demonstrated in detail.

<< Dye-sensitized photoelectric conversion element >>
The structure of the dye-sensitized photoelectric conversion element of the present invention (hereinafter also simply referred to as a photoelectric conversion element) will be described with reference to FIG.

  FIG. 1 is a schematic cross-sectional view showing an example of the dye-sensitized photoelectric conversion element of the present invention.

  As shown in FIG. 1, the dye-sensitized photoelectric conversion device according to one embodiment of the present invention includes an ultraviolet absorbing layer 1, a conductive substrate 2 (installed on the light incident surface side), a transparent conductive film 3, and a semiconductor. It is composed of a layer 4, a charge transport layer 5, a catalyst layer 6, a conductive layer 7 and a conductive substrate 8.

  The dye-sensitized photoelectric conversion element of the present invention has a charge transport layer 5 between a pair of electrodes, one electrode being a conductive substrate 2, a transparent conductive film 3 (also referred to as a transparent conductive layer 3), and a semiconductor. The semiconductor electrode 10 is composed of the layer 4, and the other electrode is the counter electrode 9 composed of the catalyst layer 6, the conductive layer 7, and the conductive substrate 8.

  Hereafter, each structure of the dye-sensitized photoelectric conversion element of this invention is demonstrated in detail.

[Semiconductor electrode]
As shown in FIG. 1, a semiconductor electrode 10 according to the present invention includes a conductive substrate 2 (hereinafter also referred to as a light incident surface side substrate 2), a transparent conductive film 3 (hereinafter also referred to as a transparent conductive layer 3), And a semiconductor layer 4.

<Conductive substrate>
The conductive substrate 2 constituting the semiconductor electrode 10 is provided on the light incident 11 side (also referred to as the light incident surface side). From the viewpoint of improving the photoelectric conversion efficiency of the dye-sensitized photoelectric conversion element of the present invention, The light average transmittance is preferably 80% or more. The light average transmittance can be measured using, for example, a HAZE meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH2000).

  Examples of the plastic base material having the light average transmittance as described above and applicable to the present invention include methacrylic acid ester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, Polystyrene (PS), aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, polyetherimide, cycloolefin, cellulose ester film, glass cloth and cellulose nanofiber impregnated resin, acrylic Examples thereof include a film obtained by mixing an inorganic monomer such as silsesquioxane or inorganic particles with the monomer and curing the film. From the viewpoints of cost, availability, heat resistance and weather resistance, polycarbonate (PC) with UV absorber, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) with suppressed hydrolyzability, etc. Is preferably used. These materials may be used alone or in combination of two or more.

  As for the thickness of this base material, about 5-200 micrometers is preferable, More preferably, it is 15-150 micrometers.

<Transparent conductive film (transparent conductive layer)>
The transparent conductive film 3 constituting the semiconductor electrode 10 is provided on the other surface different from the surface on which the later-described ultraviolet absorbing layer is provided on the conductive substrate 2.

As a material for forming the transparent conductive film 3, a transparent conductive metal oxide is preferably used. For example, SnO ₂ , CdO, ZnO, CTO (CdSnO ₃ , Cd ₂ SnO ₄ , CdSnO ₄ ), In ₂ O ₃ , CdIn ₂ O _{4 and the} like. In addition, you may use this transparent conductive metal oxide individually or in combination of 2 or more types.

  Preferably, a composite (dope) material in which one or more selected from Sn, Sb, F and Al is added to the above metal oxide can be used.

Among them preferred are, Sn _In 2 _O 3 doped with (tin) (ITO), an _SnO 2, F (fluorine) conductive metal oxides SnO ₂ or the like doped with doped with Sb (antimony), heat From the viewpoint of improving the properties, SnO ₂ doped with F is more preferably used.

<Transparent conductive support (conductive substrate)>
A transparent conductive support (conductive substrate) is formed from the conductive substrate 2 and the transparent conductive film 3.

The film thickness of the transparent conductive support (consisting of the conductive substrate 2 and the transparent conductive layer 3) is preferably in the range of 0.3 mm to 5 mm. The surface resistance of the conductive support is preferably 50 [Omega / cm ² or less, more preferably 10 [Omega / cm ² or less.

  In addition, since the preferable range of the light average transmittance of the transparent conductive support is the same as the preferable range of the light average transmittance of the substrate 2, it is omitted here.

<Semiconductor layer>
The semiconductor layer 4 according to the present invention includes semiconductor particles in which a silicon compound and a sensitizing dye are supported (adsorbed) on the surface.

  Examples of the semiconductor particles include simple substances such as silicon and germanium, compounds having elements of Group 3 to Group 5 and Group 13 to Group 15 of the periodic table (also referred to as element periodic table), and metal chalcogenides. (For example, oxides, sulfides, selenides, etc.), metal nitrides, and the like.

  Preferred metal chalcogenides include, for example, titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, or tantalum oxide, cadmium, zinc, lead, silver Antimony or bismuth sulfide, cadmium or lead selenide, cadmium telluride and the like. Examples of other semiconductor particles include phosphides such as zinc, gallium, indium, and cadmium, compound semiconductor particles such as gallium-arsenic or copper-indium selenide, copper-indium sulfide, and titanium nitride.

As more specific examples of the semiconductor particles, for example, TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , CdS, ZnS, PbS, Bi ₂ S ₃ , CdSe, CdTe, _{GaP, InP, GaAs, CuInS 2} , CuInSe 2, Ti 3 N 4 and the like. Preferred is TiO ₂ , ZnO, SnO ₂ , Fe ₂ O ₃ , WO ₃ , Nb ₂ O ₅ , CdS, PbS, more preferred is TiO ₂ , WO ₃ , or Nb ₂ O ₅ , especially among them TiO ₂ (titanium oxide) is preferably used.

The semiconductor particles may be used alone or in combination of two or more. For example, several types of metal oxides or metal sulfides described above can be used in combination. Further, for the titanium oxide may be used by mixing 1 to 30% by weight of titanium nitride _(Ti 3 _{N 4).} In addition to titanium nitride, other metal oxides or metal sulfides that can be combined with titanium oxide include, for example, SnO ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , CdS, ZnS, and PbS. Bi ₂ S ₃ , CuInS _{2 and the} like.

  Further, the semiconductor particles according to the present invention may be surface-treated using an organic base. Examples of the organic base include diarylamine, triarylamine, pyridine, 4-t-butylpyridine, polyvinylpyridine, quinoline, piperidine, amidine, and the like, among which pyridine, 4-t-butylpyridine, and polyvinylpyridine. Is preferred.

  The semiconductor particles according to the present invention may be single crystal or polycrystalline. Single crystals are preferable from the viewpoint of conversion efficiency, polycrystals are preferable from the viewpoint of manufacturing cost, securing raw materials, energy payback time, and the like, and porous films made of semiconductor particles are more preferable.

  The particle size of the semiconductor particles can be conveniently selected in general on the order of nm to μm. In order to improve the adsorptivity of the dye, it is preferable to make the particles highly porous, and it is preferable to combine particles having various particle sizes.

  Semiconductor particle fabrication methods include "Science of Sol-Gel Method" written by Sakuo Sakuhana, Agne Jofusha (1998), and "Thin-Film Coating Technology by Sol-Gel Method" written by the Technical Information Association (1995). Sol-gel method described by Tadao Sugimoto, “Synthesis of monodisperse particles by the new synthesis method gel-sol method and size and shape control, Materia, Vol. 35, No. 9, 1012-1018 (1996). The gel-sol method described in “Year)” is preferable. In addition, a method of producing an oxide by hydrolyzing a chloride developed by Degussa in an oxyhydrogen salt is also preferable.

  When the semiconductor particles are titanium oxide, the sol-gel method, the gel-sol method, and the high-temperature hydrolysis method in the oxyhydrogen salt of chloride are preferable. The sulfuric acid method and the chlorine method described in “Gihodo Publishing (1997)” can also be used. Further, as a sol-gel method, the method described in Journal of American Ceramic Society of Barbe et al., Vol. 80, No. 12, pages 3157-3171 (1997), and the chemistry of materials of Burnside et al. , Vol. 10, No. 9, pages 2419-2425 are also preferred.

Titanium oxide has mainly two types of crystal forms, anatase type and rutile type. In the present invention, the anatase type is preferable. In the case of a mixture of the two, it is preferable that the content of the anatase type is higher, and more preferably 80% or more. The anatase content can be determined by X-ray diffraction, and can be determined from the ratio of the diffraction peak intensities derived from anatase and rutile.

<Silicon compound>
The silicon compound supported on the semiconductor particles of the present invention is not particularly limited, but for example, alkoxysilanes such as silicon oxide, silicon nitride, silicon oxynitride, tetraethoxysilane, polysilane, polysilazane, silsesquioxane, polysiloxane And the like. These silicon compounds can be used alone or in combination of two or more.

  These silicon compounds are obtained by baking a coating film containing semiconductor particles and a silicon compound at a temperature in the range of 200 to 1000 ° C., preferably 300 to 800 ° C., or having a wavelength of more than 200 nm and not more than 400 nm, or a wavelength of 200 nm or less. It is carried on the semiconductor particles by performing a process of irradiating active energy rays such as vacuum ultraviolet rays. When a compound such as alkoxysilane, polysilane, polysilazane, silsesquioxane, polysiloxane or the like is used as the silicon compound, by performing such treatment, at least a part of the silicon compound includes silicon oxide, silicon nitride, Converted to silicon oxynitride or the like. Therefore, the silicon compound supported on the semiconductor particles of the present invention may be a compound formed by the above treatment. In particular, from the viewpoint of adsorptivity with a dye, a compound formed by subjecting at least one selected from the group consisting of polysilazane and silsesquioxane to vacuum ultraviolet irradiation treatment is preferable.

  Hereinafter, polysilazane and silsesquioxane which are preferable silicon compounds will be described.

[Polysilazane]
Polysilazane is a polymer having a silicon-nitrogen bond, and has a bond such as Si—N, Si—H, or N—H.

  As the polysilazane used in the present invention, those represented by the following general formula A are preferable.

In the general formula A, R ¹ , R ² , and R ³ are each independently a hydrogen atom, alkyl group, alkenyl group, cycloalkyl group, aryl group, alkylsilyl group, alkylamino group, or alkoxy group. is there.

More specific examples of polysilazane include, for example, perhydropolysilazane in which all of R ¹ , R ² , and R ^{3 in} the general formula A are hydrogen atoms, a part of hydrogen atoms bonded to Si are alkyl groups, and the like The organopolysilazane substituted with is preferably exemplified, and the substituent can be appropriately selected from the viewpoint of the supportability to the semiconductor particles, the compatibility with the structure of the dye, the adsorptivity, and the like. The perhydropolysilazane and the organopolysilazane can be mixed and used.

  Other polysilazanes include, for example, silicon alkoxide-added polysilazanes obtained by reacting silicon alkoxide (see JP-A-5-238827) and glycidol-added polysilazanes obtained by reacting glycidol (see JP-A-6-122852). ), An alcohol-added polysilazane obtained by reacting an alcohol (see JP-A-6-240208), a metal carboxylate-added polysilazane obtained by reacting a metal carboxylate (see JP-A-6-299118), An acetylacetonate complex-added polysilazane obtained by reacting a metal-containing acetylacetonate complex (see JP-A-6-306329), a metal fine particle-added polysilazane obtained by adding metal fine particles (JP-A-7-196986) reference Etc. The.

[Silsesquioxane]
Silsesquioxane (Silsesquioxane) is also called T-resin, while ordinary silica is represented by the general formula [SiO ₂ ], whereas silsesquioxane (also called polysilsesquioxane) is a general formula. It is a compound represented by [RSiO _1.5 ]. Usually, by hydrolysis-polycondensation of (RSi (OR ') 3) compound in which one alkoxy group of tetraalkoxysilane (Si (OR') 4) represented by tetraethoxysilane is replaced with an alkyl group or aryl group. The polysiloxane to be synthesized, and the molecular arrangement is typically amorphous, ladder-like, or cage-like (fully condensed cage-like). In the present invention, the shape can be appropriately selected from the supportability to the semiconductor particles, the structure of the dye and the adsorption, and a cage silsesquioxane is preferred.

As the cage silsesquioxane used in the present invention, specifically, a type represented by a chemical formula of [RSiO _1.5 ] ₈ (the following general formula (1)), a chemical formula of [RSiO _1.5 ] ₁₀ A type represented by the following formula (2), a type represented by the chemical formula [RSiO _1.5 ] ₁₂ (the following general formula (3)), and a formula [RSiO _1.5 ] ₁₄ The types (the following general formula (6) and the following general formula (7)) represented by the chemical formulas of the types (the following general formula (4) and the following general formula (5)) and [RSiO _1.5 ] ₁₆ are known. ing.

  Among these, those having a cubic structure represented by the general formula (1) (also referred to as T8-silsesquioxane) are preferable.

  More specifically, “Journal of the Society of Polymer Sciences, Vol. 47, December (1998), page 899” and catalogs issued by Chisso Corporation / Azmax Co., Ltd. “Special Silicon Reagent 7th Edition (November 3, 1998)” Page 351 of “Issue Date”) provides a detailed explanation.

  In the compounds represented by the general formulas (1) to (7) used in the present invention, the substituent represented by R may be a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituent. Alternatively, an unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and the like can be given. Among these, substituents can be appropriately selected from the supportability to semiconductor particles, the structure of the dye, the adsorptivity, and the like. Preferably, a hydrogen atom, methyl group, ethyl group, cyclopentyl group, cyclohexyl group, isopropyl group, 2-ethylhexyl group, 2-chloroethyl group, methacryloxypropyl group, allyl group, 3-hydroxypropyl group, 3-aminopropyl group 3-mercaptopropyl group, 3-glycidoxypropyl group, 3-methacryloyloxypropyl group, vinyl group, or phenyl group.

The cage silsesquioxane is synthesized by hydrolysis and polycondensation of the corresponding compound (RSi (OR ′) ₃ ). More specific examples of the cage silsesquioxane used in the present invention are shown below.

<Sensitizing dye>
As the sensitizing dye supported (adsorbed) on the semiconductor particles (hereinafter, also simply referred to as a dye), known ones can be used, but from the viewpoint of increasing the efficiency by increasing the adsorption rate with the silicon compound and the semiconductor particles. It preferably has a carboxy group.

  Specific examples of the dye used in the present invention include compounds represented by the following chemical formulas (1) to (38), but the present invention is not limited thereto.

  The present invention is not limited to the above, and any dye can be used in the present invention as long as it can spectrally sensitize the semiconductor particles according to the present invention. In order to widen the wavelength range of photoelectric conversion as much as possible and increase the conversion efficiency, two or more kinds of dyes may be mixed and used. Moreover, the kind of pigment | dye to mix and its ratio can be suitably selected so that it may match with the wavelength range and intensity distribution of the target light source.

<Charge transport layer>
The charge transport layer according to the present invention has a function of rapidly reducing an oxidant of a dye carried by semiconductor particles contained in the semiconductor layer and transporting holes injected at the interface with the dye to the counter electrode. Is a layer.

  The charge transport layer according to the present invention is mainly composed of a redox electrolyte dispersion or a p-type compound semiconductor (charge transport agent) as a hole transport material.

The redox ^electrolyte, I - ^{/ I 3- system,} Br - / ^{Br 3-} system, quinone / hydroquinone system. Such a redox electrolyte can be obtained by a conventionally known method. For example, an I ⁻ / I ³ -based electrolyte can be obtained by mixing an ammonium salt of iodine and iodine.

  These dispersions are called liquid electrolytes when they are solutions, solid polymer electrolytes when dispersed in a polymer that is solid at room temperature, and gel electrolytes when dispersed in a gel-like substance.

  When a liquid electrolyte is used as the charge transport layer, an electrochemically inert solvent is used as the solvent, for example, acetonitrile, propylene carbonate, ethylene carbonate, 3-methoxypropionitrile, or the like. Examples of solid polymer electrolytes include electrolytes described in JP-A No. 2001-160427, and examples of gel electrolytes include electrolytes described in “Surface Science” Vol. 21, No. 5, pages 288 to 293, respectively. .

  The charge transfer agent preferably has a large band gap so as not to prevent dye absorption. The band gap of the charge transfer agent used in the present invention is preferably 2 eV or more, and more preferably 2.5 eV or more.

  Further, the ionization potential of the charge transfer agent needs to be smaller than the dye adsorption electrode ionization potential in order to reduce the dye hole. The preferred range of the ionization potential of the charge transport agent used in the charge transport layer varies depending on the dye used, but generally it is preferably in the range of 4.5 eV to 5.5 eV, more preferably in the range of 4.7 eV to 5.3 eV. .

  As the charge transport agent, an aromatic amine derivative having an excellent hole transport capability is preferable. For this reason, photoelectric conversion efficiency can be improved more by comprising a charge transport layer mainly with an aromatic amine derivative.

  As the aromatic amine derivative, it is particularly preferable to use a triphenyldiamine derivative. Triphenyldiamine derivatives are particularly excellent in the ability to transport holes among aromatic amine derivatives.

  Moreover, such an aromatic amine derivative may use any of a monomer, an oligomer, a prepolymer, and a polymer, and may mix and use these.

<Electrode facing the semiconductor electrode (counter electrode)>
The counter electrode 9 facing the semiconductor electrode 10 (consisting of the substrate 2, the transparent conductive film 3, and the semiconductor layer 4) in FIG. 1 only needs to have conductivity, and can be made of any conductive material. From the viewpoint of allowing the reduction of I ³ -ion and the reduction reaction of other redox ions at a sufficient speed, the configuration shown in the counter electrode 9 shown in FIG. 1 (catalyst layer 6, conductive layer 7, conductive base material 8) It is preferable to have the catalyst layer 6 whose surface is covered with a substance having catalytic ability as shown in FIG.

  Examples of the material for forming the catalyst layer include platinum, the surface of the conductive material subjected to platinum plating or platinum deposition, rhodium metal, ruthenium metal, ruthenium oxide, carbon, and the like.

  In addition, about the electroconductive base material 8 and the conductive layer 7, the material which concerns on the board | substrate 2 and the transparent conductive film 3 which comprise said semiconductor electrode 10 can be used similarly. Therefore, detailed description is omitted here.

  However, the conductive layer 7 constituting the counter electrode 9 does not necessarily need to be transparent like the transparent conductive film 3 constituting the semiconductor electrode 10, and may be transparent or opaque, and is formed of a conductive material. Just do it.

  Here, examples of the opaque material include metals (platinum, gold, silver, copper, aluminum, rhodium, indium, chromium), carbon, and the like.

  Moreover, if it is a transparent material, the transparent conductive metal oxide as described in the transparent conductive film 3 which comprises said semiconductor electrode 10 can be used.

<Conductive support>
Similar to the transparent conductive support described above, a conductive support is composed of the conductive base material 8 and the conductive layer 7. The preferred range of the thickness and surface resistance of the conductive support is as described above. Since it is the same as that of a transparent electroconductive support body, description is abbreviate | omitted here.

<Ultraviolet absorbing layer>
The dye-sensitized photoelectric conversion element of the present invention may have an ultraviolet absorbing layer. The ultraviolet absorbing layer absorbs ultraviolet rays, preferably has an absorption edge between 370 nm and 410 nm, and preferably contains an inorganic ultraviolet absorber.

  Examples of the inorganic ultraviolet absorber include, for example, titanium oxide, cerium oxide, tin oxide, molybdenum oxide, zinc oxide, barium nitride, silica, alumina, antimony oxide, magnesium oxide, zirconium oxide, barium oxide, calcium oxide, and oxide. Examples thereof include metal oxides such as strontium, and inorganic compounds such as zinc sulfide, silicon nitride, aluminum nitride, boron nitride, and barium sulfate. These can be used alone or in combination of two or more. By using these materials as inorganic ultraviolet absorbers, the ultraviolet absorbing layer can be adjusted to have an absorption edge between 370 nm and 410 nm.

  Among these inorganic ultraviolet absorbers, metal oxides are preferable, have low toxicity, are very stable to light, and the light average transmittance in the visible light region of the ultraviolet absorbing layer is adjusted to 90% or more. From this viewpoint, titanium oxide or zinc oxide is particularly preferably used.

≪Method for producing dye-sensitized photoelectric conversion element≫
The method for producing the dye-sensitized photoelectric conversion device of the present invention is not particularly limited. For example, a mixed solution containing at least one selected from the group consisting of semiconductor particles and semiconductor particle precursors and a silicon compound is prepared. And a step of applying the mixed liquid and drying to form a coating film, a step of treating the coating film, and a step of sensitizing the coated film after the treatment. It is done.

  As a processing method performed in the process of processing the coating film, for example, a baking process at 200 to 1000 ° C., a process of irradiating ultraviolet light with a wavelength exceeding 200 nm and 400 nm or less, and a process of irradiating vacuum ultraviolet light with a wavelength of 200 nm or less. Etc. Among these treatment methods, vacuum ultraviolet irradiation treatment is preferable. Thereby, the silicon compound can be efficiently supported on the surface of the semiconductor particles, the adsorptivity of the dye is improved, and the efficiency and durability are improved. In addition, at least a part of the silicon compound is converted into silicon oxide, silicon nitride, silicon oxynitride, or the like, so that the adhesion between the semiconductor particles and the silicon compound, that is, the supportability is improved, and the durability is improved. Furthermore, irradiation with vacuum ultraviolet light having a wavelength of 200 nm or less can convert the semiconductor particle precursor into semiconductor particles, promote the crystallization of the semiconductor particles, that is, improve the conductivity. Even when a simple support is used, a highly efficient dye-sensitized photoelectric conversion element can be obtained.

  That is, a more preferable method for producing the dye-sensitized photoelectric conversion device of the present invention is a step of preparing a mixed solution containing at least one selected from the group consisting of semiconductor particles and semiconductor particle precursors, and a silicon compound. , Applying the mixed solution and drying to form a coating film; irradiating the coating film with vacuum ultraviolet light having a wavelength of 200 nm or less; and sensitizing the coating film after irradiating the vacuum ultraviolet light And a manufacturing method.

  Hereinafter, a more preferable production method of the present invention will be described in the order of steps.

<Step of preparing a mixed solution>
In this step, a mixed solution containing at least one selected from the group consisting of semiconductor particles and semiconductor particle precursors and a silicon compound is prepared.

  Since specific examples of the semiconductor particles are the same as described above, the description thereof is omitted here.

  The semiconductor particle precursor is not particularly limited as long as it is a precursor that is converted into semiconductor particles by heating or light irradiation. When the semiconductor particle is a metal oxide, examples of the semiconductor particle precursor include a metal alkoxide, a metal halide, a metal compound having a hydrolyzable group, and the like. Here, the hydrolyzable group may be anything as long as it can be substituted with a proton or a hydroxyl group, and preferably an acyloxy group, an alkoxycarbonyloxy group, a carbamoyloxy group, an acetylacetonyl group, and the like. Moreover, what hydrolyzed the precursor of said metal compound partially or entirely, the thing which superposed | polymerized the hydrolyzate, or those mixtures are also effective as a precursor. In particular, a mixture obtained by partially hydrolyzing a metal alkoxide or metal halide under an acid or alkaline condition and further partially polymerizing is effective in view of reactivity at a low temperature. Preferred acids in that case include hydrochloric acid and nitric acid, with hydrochloric acid being most preferred.

  More specific examples of the semiconductor particle precursor include, for example, tetraethoxytitanium, tetra-iso-propoxytitanium (titanium isopropoxide), tetra-n-butoxytitanium, tetrakis (2-ethylhexoxy) titanium, tetrasteare. Titanium alkoxides such as roxytitanium, di-iso-propoxy bis (acetylacetonato) titanium, di-n-butoxy bis (triethanolaminato) titanium, oxotitanium bis (monoammonium oxalate), tri-n-butoxy Titanium acylates such as titanium monostearate, iso-propoxy titanium dimethacrylate-iso-stearate, iso-propoxy titanium tris (4-aminobenzoate), iso-propoxy titanium tris (dioctyl phosphate) Titanium chelates such as dihydroxy bis (lactate) titanium, dihydroxy bis (ammonium lactate) titanium, (ethylene glycolate) titanium bis (dioctyl phosphate), poly (di-iso-propyl titanate), poly (di-n- Organic titanates such as titanium polymers such as butyl titanate and poly (octylene glycol titanate); titanium halides such as titanium tetrabromide and titanium tetrachloride; and acetylacetonatotin.

  The semiconductor particles and the semiconductor particle precursor may be used in combination. Use in combination is preferable because the conductivity can be improved, the support of silicon compounds such as polysilazane and silsesquioxane, and the adsorptivity with the dye can be improved. Moreover, you may use together 2 or more types of compounds for a semiconductor particle and a semiconductor particle precursor, respectively.

  Polysilazane and silsesquioxane may be used in combination. Use in combination is preferable because the supportability to the semiconductor particles becomes complex and the adsorptivity with the dye is improved. Polysilazane and silsesquioxane may be used in combination of two or more compounds.

  As the solvent, those in which semiconductor particles can be dispersed, those in which semiconductor particle precursors, polysilazane, and silsesquioxane can be dissolved can be appropriately selected and used. Organic solvents include water, alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone, acetone and acetylacetone, hydrocarbons such as pentane, hexane, cyclohexane, toluene, xylene, solvesso and turben, and halogen hydrocarbons such as methylene chloride and trichloroethane. , Ethers such as dibutyl ether, dioxane and tetrahydrofuran, and esters such as n-butyl acetate. These solvents are selected according to the purpose, such as the semiconductor particles to be dispersed, the semiconductor particle precursors to be dissolved, the types of polysilazane and silsesquioxane, the evaporation rate of the solvent that affects the conditions of coating and drying, etc. A plurality of solvents may be mixed.

  Moreover, in order to accelerate | stimulate the support | carrier of the silicon compound to the semiconductor particle in the process of irradiating the vacuum ultraviolet light below wavelength 200nm below mentioned, an amine and a metal catalyst can be added to the said liquid mixture. Specific examples include Aquamica (registered trademark) NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL150A, NP110, NP140, and SP140 manufactured by AZ Electronic Materials.

  If necessary, for example, a surfactant, an acid, a chelating agent, or the like can be added to the mixed solution.

<Process for forming coating film>
In this step, the liquid mixture obtained in the above step is applied onto a conductive support and dried. Thereby, the coating film which consists of solid content in a liquid mixture is obtained.

  Application method is not particularly limited, for example, natural coater, knife belt coater, floating knife, roll coat, air knife coat, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade And various coating methods using apparatuses such as a curtain flow coater, a doctor blade, a wire bar, a die coater, a comma coater, a spin coater, a baker applicator, a gravure coater, and a screen printing machine.

  The semiconductor layer according to the present invention may be a single layer or a plurality of layers (multilayer structure) containing semiconductor particles having different particle sizes and / or types. In the case of a multilayer structure, examples of the coating method include a multilayer coating method such as an extrusion method or a slide hopper method. Multi-layer coating is also effective when the film thickness is insufficient with a single coating. Moreover, when applying multilayer coating, a multilayer may be apply | coated simultaneously and you may apply it several times to dozens of times. In the case of overcoating, a screen printing method can also be preferably used.

  The drying conditions after coating are not particularly limited, and can be appropriately selected mainly considering the boiling point of the solvent. Moreover, drying can be performed in a short time so that heat damage to the conductive substrate is reduced. The drying temperature is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, and still more preferably 100 ° C. or lower. The drying time is preferably 1 to 120 minutes, more preferably 1 to 30 minutes, and further preferably 1 to 10 minutes.

<Step of irradiating vacuum ultraviolet light with a wavelength of 200 nm or less>
In this step, the coating film obtained as described above is subjected to a treatment of irradiating vacuum ultraviolet rays having a wavelength of 200 nm or less.

  As the vacuum ultraviolet light source, a rare gas excimer lamp is preferably used.

Excimer light is laser light using a rare gas excimer or a hetero excimer as an operating medium. Atoms of noble gases such as Xe, Kr, Ar, and Ne are called inert gases because they are not chemically bonded to form molecules. However, rare gas atoms (excited atoms) that have gained energy by discharge or the like can be combined with other atoms to form molecules. When the rare gas is xenon,
e + Xe → e + Xe ^*
Xe ^* + Xe + Xe → Xe ₂ ^* + Xe
Thus, when the excited excimer molecule Xe ₂ ^* transitions to the ground state, excimer light of 172 nm is emitted. A feature of the excimer lamp is that the radiation is concentrated on one wavelength, and since only the necessary light is not emitted, the efficiency is high.

  Further, since no extra light is emitted, the temperature of the object can be kept low. Furthermore, since no time is required for starting and restarting, instantaneous lighting and blinking are possible.

  As the form of discharge, either dielectric barrier discharge or electrodeless field discharge can be used. The electrode may have a flat surface in contact with the lamp, but if the shape is matched to the curved surface of the lamp, the lamp can be firmly fixed and the discharge is more stable when the electrode is in close contact with the lamp. Also, if the curved surface is made into a mirror surface with aluminum, it also becomes a light reflector.

  The Xe excimer lamp is excellent in luminous efficiency because it emits ultraviolet light having a short wavelength of 172 nm at a single wavelength. Since this light has a large oxygen absorption coefficient, radical oxygen atomic species and ozone can be generated at a high concentration with a small amount of oxygen. In addition, it is known that the energy of light having a short wavelength of 172 nm for dissociating organic bonds has high ability. Conversion, crystallization, loading, etc. can be realized by the high energy of the active oxygen, ozone and ultraviolet radiation. Therefore, compared with low-pressure mercury lamps with wavelengths of 185 nm and 254 nm and plasma cleaning, it is possible to shorten the process time associated with high throughput, reduce the equipment area, and irradiate organic materials and plastic substrates that are easily damaged by heat. .

  Since the excimer lamp has high light generation efficiency, it can be lit with low power. In addition, light having a long wavelength that causes a temperature rise due to light is not emitted, and energy is irradiated at a single wavelength in the ultraviolet region, so that the rise in the surface temperature of the object to be fired is suppressed. For this reason, it is suitable for flexible film materials such as PET that are easily affected by heat.

In the irradiation with vacuum ultraviolet light, the irradiation intensity and the irradiation time should be set so that the base material carrying the irradiated coating film is not damaged. Taking the case of using a plastic film as a base material, for example, a 2 kW (80 W / cm × 25 cm) lamp is used, and the strength of the base material surface is preferably 20 to 300 mW / cm ² , more preferably 50 to The distance between the base material and the lamp is set so as to be 200 mW / cm ² , and preferably irradiation can be performed for 0.1 second to 10 minutes.

The atmosphere of the vacuum ultraviolet irradiation is not particularly limited, and can be appropriately selected from air, N ₂ , ammonia and the like.

<Step of sensitizing treatment>
In this step, the coating film irradiated with vacuum ultraviolet rays is sensitized. Specifically, a dye solution is prepared by dissolving the dye in an appropriate solvent, and the conductive support (conductive substrate 2 and transparent conductive film 3) having a coating film irradiated with vacuum ultraviolet rays is immersed in the dye solution. To do.

  At this time, it is preferable to remove bubbles in the semiconductor layer by subjecting the conductive support having a coating film irradiated with vacuum ultraviolet rays to reduced pressure treatment or heat treatment in advance. Such treatment allows the dye to penetrate deeply into the semiconductor layer. In the case where the semiconductor layer is porous, such bubble removal processing becomes more effective.

  The time for immersing the conductive support provided with the coating film in the solution containing the dye is sufficient for the dye to enter the coating film to sufficiently advance the adsorption, etc., sufficiently sensitize the semiconductor particles, and From the viewpoint of suppressing degradation of the dye generated by decomposition of the dye in the medium and preventing the adsorption of the dye, immersion time of 3 hours to 48 hours is preferable under the condition of 25 ° C. 24 hours. The effect obtained by the immersion is particularly remarkable when the semiconductor film is a porous structure film. However, the immersion time is a value at 25 ° C., and is not limited to the above when the temperature condition is changed.

  In soaking, the solution containing the pigment may be used by heating to a temperature at which it does not boil as long as the pigment is not decomposed. The preferred temperature range is 5 ° C to 100 ° C, more preferably 25 ° C to 80 ° C. It is. When the solvent is boiled in the above temperature range, adjustment is separately required.

  The solvent used for dissolving the dye is not particularly limited as long as it can dissolve the dye and does not dissolve the semiconductor particles or react with the semiconductor particles. In order to prevent moisture and gas dissolved in the solvent from entering the semiconductor film and hindering sensitizing treatment such as dye adsorption, the solvent is preferably degassed and purified by distillation in advance.

  Examples of the solvent preferably used include nitrile solvents such as acetonitrile, alcohol solvents such as methanol, ethanol, n-propanol and t-butyl alcohol, ketone solvents such as acetone and methyl ethyl ketone, diethyl ether, diisopropyl ether and tetrahydrofuran. And ether solvents such as 1,4-dioxane, and halogenated hydrocarbon solvents such as methylene chloride and 1,1,2-trichloroethane. These solvents can be used alone or in combination of two or more. More preferably, acetonitrile, acetonitrile / methanol mixed solvent, methanol, ethanol, t-butyl alcohol, acetone, methyl ethyl ketone, tetrahydrofuran, or methylene chloride.

In general, as the thickness of the semiconductor layer increases, the amount of supported dye per unit projected area increases, and thus the light capture rate increases. However, the diffusion distance of the generated electrons increases, and the loss due to charge recombination also increases. Therefore, the preferable thickness of the semiconductor layer is 0.5 to 100 μm. When using the dye-sensitized photoelectric conversion element of this invention for a solar cell, 1-30 micrometers is preferable and, as for the thickness of a semiconductor layer, 2-25 micrometers is more preferable. The application amount of the semiconductor particles per 1 m ² of the conductive base material is preferably 1.0 to 100 g, and more preferably 4 to 50 g. In terms of the content of the semiconductor layer, it is 40% to 98%, preferably 50% to 95%.

  The semiconductor layer may have any structure, but is preferably a porous structure film (also referred to as a layer having voids or a porous layer).

  As for the porosity of a semiconductor layer, 10 volume% or less is preferable, More preferably, it is 8 volume% or less, More preferably, it is 0.01-5 volume%. Note that the porosity of the semiconductor layer means a porosity that is penetrating in the thickness direction of the dielectric, and is measured using a commercially available apparatus such as a mercury porosimeter (Shimadzu Polarizer 9220 type).

  Then, the dye-sensitized photoelectric conversion element of this invention is obtained by laminating | stacking a counter electrode.

≪Solar battery≫
The present invention provides a solar cell having the dye-sensitized photoelectric conversion element of the present invention. As an example of the solar cell of the present invention, for example, the transparent conductive layer 3 that is a constituent layer of the semiconductor electrode 10 of the dye-sensitized photoelectric conversion element of the present invention shown in FIG. A form in which a circuit is formed by attaching a terminal to the layer 7 to extract a photocurrent can be mentioned.

  The solar cell of the present invention preferably has a structure such that optimal design and circuit design are performed for sunlight, and optimal photoelectric conversion is performed when sunlight is used as a light source. That is, it is preferable that the semiconductor particles subjected to dye sensitization have a structure in which sunlight is irradiated.

  When the solar cell of the present invention is irradiated with sunlight or an electromagnetic wave equivalent to sunlight, the dye supported on the semiconductor particles is excited by absorbing the irradiated light or electromagnetic wave.

The electrons generated by the excitation move to the semiconductor particles, and then move to the counter electrode 9 via the circuit connected to the transparent conductive layer 3 and the solar cell to reduce the redox electrolyte of the charge transport layer. The catalyst layer 6 is made of a platinum layer, a conductive material subjected to platinum plating or platinum deposition, a material such as rhodium, ruthenium, ruthenium oxide, or carbon. For example, I ^{3 -ion} in the charge transport layer 5 is used. A material having a catalytic ability to perform the reduction of the above and other redox ions at a sufficient rate is preferably used.

  On the other hand, the dye that has moved electrons to the semiconductor particles is an oxidant, but is reduced to the original state by supplying electrons from the counter electrode 9 via the redox electrolyte of the charge transport layer 5. At the same time, the redox electrolyte of the charge transport layer 5 is oxidized and returns to a state where it can be reduced again by the electrons supplied from the counter electrode 9.

  Thus, electrons flow, and the solar cell of the present invention can be configured using the dye-sensitized photoelectric conversion element of the present invention.

  When constituting the solar cell of the present invention, the semiconductor electrode 10, the charge transport layer 5 and the counter electrode 9 shown in FIG. 1 are housed in a case and sealed, or the whole is sealed with resin. Is preferred.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

Example 1
<< Preparation of dye-sensitized photoelectric conversion element 1 >>
<Formation of Semiconductor Electrode 10 (Conductive Base Material 2, Transparent Conductive Film 3, Semiconductor Layer 4)>
A 20 mass% dibutyl ether solution of perhydropolysilazane (PHPS) (manufactured by AZ Electronic Materials Co., Ltd., AQUAMICA (registered) to titanium oxide paste (anatase type, average particle size of primary particles 18 nm, hereinafter also referred to simply as paste A). (Trademark) NN320 (hereinafter also referred to simply as PHPS solution) in a ratio of paste A: PHPS solution = 3: 2 (mass ratio) to prepare a mixed solution, and polyethylene naphthalate having a fluorine-doped tin oxide (FTO) thin film The mixed solution was applied to a (PEN) substrate (corresponding to the conductive substrate 2 and the transparent conductive film 3 in FIG. 1) by a screen printing method (application area: 5 mm × 5 mm).

  Coating and drying (at 120 ° C. for 3 minutes) were repeated three times, and excimer irradiation was performed under the following conditions to obtain a semiconductor layer having a thickness of 15 μm.

  Over the semiconductor layer, a titanium oxide paste (anatase type, primary average particle size 400 nm) was applied in the same manner, and a titanium oxide thin film having a thickness of 5 μm was overcoated.

As a dye, cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylato) -ruthenium (II) bistetrabutylammonium dye (N719 dye: manufactured by Pexel Technologies, Inc., the above chemical formula ( The compound represented by 37) was dissolved in a mixed solvent of acetonitrile: t-butyl alcohol = 1: 1 to prepare a solution of 5 × 10 ⁻⁴ mol / l.

  A PEN substrate having an FTO thin film coated and sintered with titanium oxide is immersed in this solution at room temperature (25 ° C.) for 20 hours, a dye adsorption process is performed to form the semiconductor layer 4, and the semiconductor electrode 10 is produced. did.

<Excimer irradiation device>
A sample is fixed on the operating stage of an excimer irradiation device (MODEL: MECL-M-1-200, wavelength 172 nm, lamp-filled gas Xe) manufactured by M.D. Went.

<Excimer irradiation treatment>
The obtained coated sample was treated for 1 minute in an atmosphere of a temperature of 85 ° C. and a humidity of 55% RH to obtain a dried sample. This dried sample was further kept in an atmosphere of a temperature of 25 ° C. and a humidity of 10% RH (dew point temperature −8 ° C.) for 10 minutes to perform a dehumidification treatment, and an excimer irradiation treatment was performed under the following conditions. The dew point temperature during excimer irradiation was -8 ° C.

<Processing conditions>
Excimer light intensity 130mW / cm ² (172nm)
1mm distance between sample and light source
Stage heating temperature 70 ℃
Oxygen concentration in irradiation device 1%
Excimer irradiation time 3 seconds <Formation of charge transport layer 5 and counter electrode 9 (conductive substrate 8, conductive layer 7, catalyst layer 6)>
As a catalyst layer 6, platinum was vapor-deposited, and as a conductive layer 7, chromium was vapor-deposited and a glass plate with an inlet (corresponding to the conductive substrate 8) was used as a counter electrode 9 (conductive substrate 8, conductive layer 7, catalyst layer 6. ), The semiconductor electrode 10 and the thermosetting resin film were bonded and bonded together, and then the following electrolyte was injected from the inlet and sealed.

<Preparation of electrolyte>
1,2-dimethyl-3-propylimidazolium iodide 0.6 mol / l, lithium iodide 0.1 mol / l, iodine 0.05 mol / l, and 4- (t-butyl) pyridine 0.5 A 3-methoxypropionitrile solution containing mol / l was prepared as an electrolytic solution.

<Formation of UV absorbing layer>
Zinc oxide nanoparticles were monodispersed in an ethyl acetate solution of an acrylic resin and an epoxy group-containing silane coupling agent (mass ratio 19: 1) using ultrasonic waves. The obtained dispersion was applied to the surface opposite to the semiconductor layer of the PEN substrate (2 in FIG. 1) constituting the semiconductor electrode 10 using a bar coater. Then, the solvent is dried and the film is cured by heat treatment at 80 ° C. for 1 hour, and the ultraviolet absorption layer 1 having a thickness of 1 μm is formed on the surface opposite to the semiconductor layer of the PEN substrate (2 in FIG. 1). Thus, a dye-sensitized photoelectric conversion element (sample number: dye-sensitized photoelectric conversion element 1) was produced.

(Example 2)
<< Preparation of dye-sensitized photoelectric conversion element 2 >>
Instead of the mixture of paste A and PHPS solution, paste A and silsesquioxane represented by the above chemical formula S-25 are used in a ratio of paste A: silsesquioxane = 3: 0.4 (mass ratio). A dye-sensitized photoelectric conversion element 2 was produced in the same manner as in Example 1 except that the mixed solution mixed in (1) was used.

(Example 3)
<< Preparation of dye-sensitized photoelectric conversion element 3 >>
Instead of the mixture of paste A and PHPS solution, a mixture of paste A, PHPS solution, and titanium isopropoxide and 1N hydrochloric acid in a ratio of 1: 5 (mass ratio) (hereinafter, Example 1 except that a mixture of paste A: PHPS solution: precursor mixture X = 3: 2: 1 (mass ratio) was used. Similarly, a dye-sensitized photoelectric conversion element 3 was produced.

Example 4
<< Preparation of dye-sensitized photoelectric conversion element 4 >>
Instead of the mixed solution of the paste A and the PHPS solution, the paste A, the silsesquioxane represented by the chemical formula S-25, and the precursor mixed solution X are replaced with the paste A: silsesquioxane: precursor mixed solution. A dye-sensitized photoelectric conversion element 4 was produced in the same manner as in Example 1 except that a mixed liquid mixed at a ratio of X = 3: 0.4: 1 (mass ratio) was used.

(Example 5)
<< Preparation of dye-sensitized photoelectric conversion element 5 >>
Instead of the mixed solution of the paste A and the PHPS solution, the paste A, the PHPS solution, the silsesquioxane represented by the above chemical formula S-25, and the precursor mixed solution X are used as a paste A: a PHPS solution: a silsesquioxy. Dye-sensitized photoelectric conversion element in the same manner as in Example 1 except that a mixed liquid in a ratio of sun: precursor mixed solution X = 3: 1: 0.2: 1 (mass ratio) was used. 5 was produced.

(Example 6)
<< Preparation of dye-sensitized photoelectric conversion element 6 >>
Instead of the mixture of paste A and PHPS solution, paste A, PHPS solution, silsesquioxane represented by the above chemical formula S-25, precursor mixture X, and acetylacetonatotin and n-butyl acetate Is mixed with a precursor mixture Y (hereinafter also simply referred to as a precursor mixture Y), paste A: PHPS solution: silsesquioxane: precursor mixture X: precursor mixture Y = 3: 1: 0.2: 0.5: 0.5 (mass ratio) Except for using a mixed solution in the same manner as in Example 1, the dye-sensitized photoelectric conversion element 6 Was made.

(Example 7)
<< Preparation of dye-sensitized photoelectric conversion element 7 >>
Instead of the mixed solution of the paste A and the PHPS solution, the paste A, the PHPS solution, the precursor mixed solution X, and the precursor mixed solution Y are changed to paste A: PHPS solution: precursor mixed solution X: precursor mixed solution Y. = Dye-sensitized photoelectric conversion element 7 was produced in the same manner as in Example 1 except that a mixed liquid mixed at a ratio of 3: 1: 0.5: 0.5 (mass ratio) was used.

(Example 8)
<< Preparation of dye-sensitized photoelectric conversion element 8 >>
Instead of the mixed solution of the paste A and the PHPS solution, a mixed solution in which the PHPS solution and the precursor mixed solution X were mixed at a ratio of PHPS solution: precursor mixed solution X = 1: 4 (mass ratio) was used. Except for the above, dye-sensitized photoelectric conversion element 8 was produced in the same manner.

Example 9
<< Preparation of dye-sensitized photoelectric conversion element 9 >>
Instead of the mixed solution of the paste A and the PHPS solution, the silsesquioxane represented by the chemical formula S-25 and the precursor mixed solution X are converted into silsesquioxane: precursor mixed solution X = 0.4: 4 ( A dye-sensitized photoelectric conversion element 9 was produced in the same manner as in Example 1 except that a mixed liquid mixed at a ratio of (mass ratio) was used.

(Example 10)
<< Preparation of dye-sensitized photoelectric conversion element 10 >>
A dye-sensitized photoelectric conversion element 10 was produced in the same manner as in Example 3 except that the precursor mixture liquid Y was used instead of the precursor mixture liquid X.

(Example 11)
<< Preparation of dye-sensitized photoelectric conversion element 11 >>
A dye-sensitized photoelectric conversion element 11 was produced in the same manner as in Example 3 except that a tungsten oxide paste (primary average particle size 35 nm, hereinafter also referred to simply as paste C) was used instead of paste A. did.

(Example 12)
<< Preparation of dye-sensitized photoelectric conversion element 12 >>
Instead of the mixed solution of paste A, PHPS solution, and precursor mixed solution X, paste A, paste C, PHPS solution, and precursor mixed solution X are used as paste A: paste C: PHPS solution: precursor mixed solution X. = Dye-sensitized photoelectric conversion element 12 was produced in the same manner as in Example 3 except that a mixture mixed at a ratio of 1.5: 1.5: 2: 1 (mass ratio) was used.

(Example 13)
<< Preparation of dye-sensitized photoelectric conversion element 13 >>
In the same manner as in Example 3, except that AQUAMICA (registered trademark) MHPS-20DB (organopolysilazane, manufactured by AZ Electronic Materials Co., Ltd., 20% by mass dibutyl ether solution) was used instead of the PHPS solution. A sensitive photoelectric conversion element 13 was produced.

(Example 14)
<< Preparation of dye-sensitized photoelectric conversion element 14 >>
In the same manner as in Example 4, except that the silsesquioxane represented by the above chemical formula S-41 was used instead of the silsesquioxane represented by the above chemical formula S-25, a dye-sensitized photoelectric device was used. A conversion element 14 was produced.

(Example 15)
<< Preparation of dye-sensitized photoelectric conversion element 15 >>
A dye-sensitized photoelectric conversion element was obtained in the same manner as in Example 3 except that tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-04, 20% by mass dibutyl ether solution) was used instead of the PHPS solution. 15 was produced.

(Example 16)
<< Preparation of dye-sensitized photoelectric conversion element 16 >>
A dye-sensitized photoelectric conversion element 16 was produced in the same manner as in Example 1 except that the baking treatment was performed at 200 ° C. for 10 minutes without performing the excimer irradiation treatment.

(Example 17)
<< Preparation of dye-sensitized photoelectric conversion element 17 >>
Except for the excimer irradiation treatment, a dye-sensitized dye was used in the same manner as in Example 1 except that ultraviolet irradiation treatment was performed in air using a high-pressure mercury lamp with an integrated light amount of 1.0 J / cm ^2. A photoelectric conversion element 17 was produced.

(Example 18)
<< Preparation of dye-sensitized photoelectric conversion element 18 >>
Instead of the mixture of paste A and PHPS solution, paste A and silsesquioxane represented by the above chemical formula S-25, paste A: silsesquioxane, paste A: silsesquioxane = 3: 0 A dye-sensitized photoelectric conversion element 18 was produced in the same manner as in Example 17 except that a mixed liquid mixed at a ratio of 0.4 (mass ratio) was used.

(Comparative Example 1)
<< Preparation of dye-sensitized photoelectric conversion element 19 >>
Except for using only paste A instead of the mixture of paste A and PHPS solution and performing a baking treatment at 500 ° C. for 15 minutes without performing the excimer irradiation treatment, A dye-sensitized photoelectric conversion element 18 was produced.

(Comparative Example 2)
<< Preparation of dye-sensitized photoelectric conversion element 20 >>
A dye-sensitized photoelectric conversion element 20 was produced in the same manner as in Example 1 except that only the paste A was used instead of the mixed solution of the paste A and the PHPS solution.

(Comparative Example 3)
<< Preparation of dye-sensitized photoelectric conversion element 21 >>
The same as Comparative Example 2 except that instead of paste A, a mixed liquid in which paste A and precursor mixed liquid X were mixed at a ratio of paste: precursor mixed liquid X = 3: 1 (mass ratio) was used. Thus, a dye-sensitized photoelectric conversion element 21 was produced.

(Comparative Example 4)
<< Preparation of dye-sensitized photoelectric conversion element 22 >>
Instead of the mixture of the paste A and the precursor mixture X, the paste A, the precursor mixture X, and polyethylene glycol (PEG) having a molecular weight of 20000 are used as the paste: precursor mixture X: PEG = 3: 1: A dye-sensitized photoelectric conversion element 22 was produced in the same manner as in Comparative Example 3 except that a mixed liquid mixed at a ratio of 0.1 (mass ratio) was used.

<< Production of solar cells 1 to 22 >>
Solar cells 1 to 22 were produced by attaching terminals to the transparent conductive film 3 and the conductive layer 7 of the dye-sensitized photoelectric conversion elements 1 to 22 and taking out photocurrent.

  About the obtained solar cells 1-22, the power generation characteristic was evaluated as follows.

(Power generation characteristics)
Using a solar simulator (manufactured by Eiko Seiki Co., Ltd.), 100 mW / cm ² of pseudo-sunlight was irradiated from a xenon lamp passed through an AM filter (AM-1.5), and an IV tester was applied to each photoelectric conversion element. The current-voltage characteristics were measured at room temperature (25 ° C.), and the photoelectric conversion efficiencies of the dye-sensitized photoelectric conversion elements 1 to 22 included in the solar cells 1 to 22 were obtained.

(Evaluation of weather resistance)
The conversion efficiency as the initial power generation characteristics was measured, and the degree of deterioration with time in performance was measured using a metal halide lamp type weather resistance tester (manufactured by Daipura Wintes Co., Ltd.). Sample surface radiation intensity: 2.16 MJ / m ² Thereafter, a weather resistance test was conducted under the conditions of a black panel temperature of 63 ° C., a relative humidity of 50% RH, and an irradiation time of 500 hours, and then the conversion efficiency remaining after the acceleration test was stored for 3000 hours at a temperature of 85 ° C. and a humidity of 85% RH. The rate (conversion efficiency after acceleration test / initial conversion efficiency × 100 (%)) was determined, and weather resistance against light, heat, and humidity was evaluated according to the following criteria.

5: The conversion efficiency remaining rate after the acceleration test is 90% or more 4: The conversion efficiency remaining rate after the acceleration test is 70% or more and less than 90% 3: The conversion efficiency remaining rate after the acceleration test is 40% or more and less than 70% 2: The conversion efficiency remaining rate after the acceleration test is 20% or more and less than 40% 1: The conversion efficiency remaining rate after the acceleration test is less than 20% Table 1 shows.

  As is clear from the results in Table 1, the solar cell using the dye-sensitized organic photoelectric conversion element of the present invention has high energy conversion efficiency as compared with the dye-sensitized organic photoelectric conversion element of the comparative example. Excellent in weather resistance.

1 UV absorbing layer,
2 conductive substrate (light incident surface side),
3 transparent conductive film (transparent conductive layer),
4 Semiconductor layer,
5 charge transport layer,
6 catalyst layer,
7 conductive layer,
8 conductive substrate,
9 Counter electrode,
10 Semiconductor electrode,
11 Light incident.

Claims (5)

A dye-sensitized photoelectric conversion element having a semiconductor layer, a charge transport layer, and a counter electrode in order on a conductive substrate,
The semiconductor layer is a dye-sensitized photoelectric conversion element having semiconductor particles carrying a sensitizing dye and a silicon compound.   The dye-sensitized photoelectric conversion element according to claim 1, wherein the silicon compound is a compound formed by irradiating at least one selected from the group consisting of polysilazane and silsesquioxane with vacuum ultraviolet rays. A method for producing a dye-sensitized photoelectric conversion element having a semiconductor layer, a charge transport layer, and a counter electrode sequentially on a conductive substrate,
Preparing a mixed solution containing at least one selected from the group consisting of semiconductor particles and semiconductor particle precursors, and a silicon compound;
Applying the mixture and drying to form a coating film; and
Irradiating the coating film with vacuum ultraviolet light having a wavelength of 200 nm or less;
Sensitizing the coating film after being irradiated with the vacuum ultraviolet ray;
The manufacturing method of the dye-sensitized photoelectric conversion element containing this.   The method for producing a dye-sensitized photoelectric conversion element according to claim 3, wherein the silicon compound is at least one selected from the group consisting of polysilazane and silsesquioxane.   A solar cell having the dye-sensitized photoelectric conversion element according to claim 1 or 2 or the dye-sensitized photoelectric conversion element obtained by the production method according to claim 3 or 4.