JP2012204169A - Dye sensitized photoelectric conversion element and method for manufacturing the same, and method for forming metal oxide semiconductor layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for forming an oxide semiconductor electrode by a simple method in a low temperature region where a polymer film base material can be used.SOLUTION: A dye sensitized photoelectric conversion element includes a conductive layer, a porous semiconductor layer, an electrolyte layer and a counter electrode. The porous semiconductor layer can be obtained by applying or printing a porous semiconductor formation composition, which contains a metal oxide semiconductor fine particle, a dispersant and a solvent, on a conductive layer and then firing the composition. The dispersant comprises an acetylene hydrocarbon skeleton and has one or more functional groups adsorbing to the metal oxide semiconductor fine particle.

Description

  The present technology relates to a dye-sensitized photoelectric conversion element including a metal oxide semiconductor layer and a method for manufacturing the same. Specifically, the present invention relates to a dye-sensitized photoelectric conversion element, a method for producing the same, and a method for forming a metal oxide semiconductor layer.

In recent years, solar cells that directly convert sunlight into electrical energy have been attracting attention and research and development from the viewpoint of effective use of resources and prevention of environmental pollution. Conventionally, silicon solar cells such as crystalline silicon solar cells and amorphous silicon solar cells have been mainly used as solar cells.

  Since a huge amount of energy is required to manufacture a silicon-based solar cell, the silicon-based solar cell is contrary to the original purpose of a solar cell that is an energy-saving battery using sunlight. Further, as a result of using a great deal of energy, silicon-based solar cells must be expensive.

  Therefore, in order to solve the problems of the silicon-based solar cell described above, a photoelectric conversion electrode and a dye-sensitized solar cell using a porous semiconductor layer sensitized with a dye, and a material and a production for producing the electrode. Techniques have been proposed (see Non-Patent Document 1 and Patent Document 1).

  A conventionally proposed dye-sensitized photoelectric conversion cell (dye-sensitized photoelectric conversion element) mainly comprises a titanium oxide porous layer (working electrode) spectrally sensitized with a sensitizing dye such as a ruthenium complex, and iodine. An electrolyte and a counter electrode. The first advantage of this battery is that an inexpensive photoelectric conversion element can be provided because an inexpensive oxide semiconductor such as titanium oxide is used. The second advantage is that a relatively high conversion efficiency can be obtained because the ruthenium complex used has a wide absorption in the visible light region.

  When forming a titanium oxide porous layer, it is common to prepare a dispersion paste of titanium oxide particles, apply it on a substrate, and apply a temperature of 500 ° C. or higher to the applied paste. . By applying a temperature of 500 ° C. or higher to the applied paste, necking occurs between the titanium oxide particles, and the titanium oxide particle layer becomes porous. Therefore, the electron transferability in the titanium oxide particle layer is improved.

  As described above, the production of a dye-sensitized photoelectric conversion cell usually requires a high-temperature sintering process. For this reason, the material of the base material is limited to a material having high heat resistance such as glass, and the material cost of the base material and the energy cost to be consumed at the time of manufacture are increased, and the manufacturing cost of the dye-sensitized photoelectric conversion cell Becomes higher.

  Therefore, in order to use a resin base material, a sintering method in which a temperature at which the resin does not dissolve is given and the titanium oxide porous layer is fired at a low temperature has been attempted (see Non-Patent Document 2). However, the dye-sensitized photoelectric conversion cell has only a low conversion efficiency. Moreover, in the low temperature firing, the porous titanium oxide layer became brittle, and the durability of the dye-sensitized photoelectric conversion cell was low. Furthermore, the sintering method for firing at a low temperature requires a relatively long sintering time and is not suitable as a mass production process.

As a method for producing an inorganic oxide porous layer in the case of using a resin base material, methods for improving power generation characteristics by pressurizing the inorganic oxide particle layer have been proposed (see Non-Patent Document 3 and Patent Document 2). ). However, since the pressure used for the pressure treatment is as high as several hundred kgf / cm ² , a high-pressure hydraulic device is required. Furthermore, the pressurization process is unsuitable for continuous production due to wear and breakage of rolls that transmit pressure, slow processing speed, etc., when applied to continuous production equipment such as roll-to-roll. .

B. O'Regan, M. Graetzel, Nature, 353, p. 737-740 (1991) ECN contributions 16th European Photovoltaic Solar Energy Conference and Exhibition, May 1-5, 2000 abstract; P.M.Sommeling et.al, “Flexible dye-sensitizednanocristalline TiO2 solar cells” Nanoletters, 1, (2001), p.p.97-100, H. Lindstron, et.al.

US Pat. No. 4,927,721 International Publication No. 00/072373

  There is a demand for a technique for producing a porous semiconductor layer by a simple method in a low temperature region where a polymer resin substrate such as a polymer film can be used.

  Accordingly, an object of the present technology is to provide a dye-sensitized photoelectric conversion element that can be manufactured in a low temperature region where a polymer resin substrate can be used without complicating the manufacturing process, a manufacturing method thereof, and a metal oxide. It is an object to provide a method for forming a semiconductor layer.

In order to solve the above-described problem, the first technique is:
A conductive layer, a porous semiconductor layer, an electrolyte layer, and a counter electrode;
The porous semiconductor layer is obtained by applying or printing a porous semiconductor-forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer and firing the composition.
The dispersant is a dye-sensitized photoelectric conversion element having an acetylene hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.

The second technology is
Applying or printing a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on the conductive layer;
Firing the applied composition for forming a porous semiconductor, and forming a porous semiconductor layer on the conductive layer;
A step of supporting a sensitizing dye on the porous semiconductor layer;
Providing a counter electrode facing the porous semiconductor layer carrying the sensitizing dye; and
And a step of providing an electrolyte layer between the porous semiconductor layer and the counter electrode,
The dispersant is a method for producing a dye-sensitized photoelectric conversion element having an acetylene-based hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.

The third technology is
A step of applying or printing a composition for forming a porous semiconductor containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer, followed by firing.
The dispersant is a method for forming a metal oxide semiconductor layer having an acetylene-based hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.

  The dispersant preferably has at least an acetylene alcohol structure or an acetylene diol structure as an acetylene hydrocarbon skeleton. The functional group adsorbed on the metal oxide semiconductor fine particles is at least selected from the group consisting of an amino group, a carboxyl group, a hydroxy group, a thiol group, a phosphono group, a cyano group, a nitro group, a sulfonyl group, and a sulfinyl group. It is preferred to have one or more.

  The average primary particle diameter of the metal oxide semiconductor fine particles is preferably 5 nm or more and 500 nm or less. This is because when the average primary particle diameter of the metal oxide semiconductor fine particles is 5 nm or more and 500 nm or less, the deterioration of crystallinity can be suppressed, and the decrease in the total amount of the dye adsorbed on the porous semiconductor layer can be suppressed.

  The metal oxide semiconductor fine particles preferably contain a metal oxide containing at least one of titanium, zinc, tin and niobium. More preferably, the metal oxide semiconductor fine particles include titanium oxide having an anatase type or brucite type crystal structure. An appropriate energy band is formed between the dye to be adsorbed and the metal oxide, and then the electrons generated in the dye by light irradiation are smoothly transferred to the metal oxide, contributing to the subsequent power generation by redox of iodine. Because it can.

  It is preferable that the dye-sensitized photoelectric conversion element further includes a resin base material having flexibility, and the conductive layer is formed on the resin base material. This is because the dye-sensitized photoelectric conversion element can be a flexible dye-sensitized photoelectric conversion element.

  Firing of the applied composition for forming a porous semiconductor is preferably performed in a temperature range of 40 ° C. or higher and 175 ° C. or lower. This is because even when a resin film is used for the base material, it is difficult to cause deformation of the base material.

  In the present technology, the porous semiconductor layer is obtained by applying or printing a porous semiconductor-forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer and baking it. Since the dispersant is composed of an acetylene hydrocarbon skeleton and has one or more functional groups that are adsorbed on the metal oxide semiconductor fine particles, when the functional groups are adsorbed on the surface of the metal oxide fine particles, the molecules of the dispersant are It takes a linear molecular form. Therefore, the acetylene-based hydrocarbon skeleton exhibits a steric repulsion effect, and good dispersibility is obtained.

  By heating the dispersion (the composition for forming a porous semiconductor), the dispersant and the solvent are removed, and the inclusion of impurities that deteriorate the power generation characteristics in the porous semiconductor layer is reduced. In the present technology, it is preferable to use a dispersant and water or an organic solvent having a characteristic of volatilizing in a temperature range in which deformation of a polymer resin substrate such as a polymer film is unlikely to occur in the dispersion. When a dispersant and water or an organic solvent that volatilizes in a temperature range where deformation of a polymer resin substrate such as a polymer film is unlikely to occur and the dispersion is used, the dispersion is used at a relatively low temperature. Substances other than the metal oxide semiconductor fine particles are effectively removed. Moreover, since the area | region which the dispersing agent existed becomes a space | gap, adsorption | suction of a pigment | dye and electrolyte penetration are accelerated | stimulated.

  According to the present technology, in a low temperature region where a polymer resin substrate such as a polymer film can be used, a dye-sensitized photoelectric conversion element, a method for producing the same, and a method for forming a metal oxide semiconductor layer can be obtained by a simple method. Can be provided.

FIG. 1 is a schematic cross-sectional view illustrating an example of the configuration of the dye-sensitized photoelectric conversion element according to the first embodiment of the present technology. 2A and 2B are process diagrams for explaining an example of the method for manufacturing the dye-sensitized photoelectric conversion element according to the first embodiment of the present technology. 3A to 3D are process diagrams for explaining an example of a method for manufacturing the dye-sensitized photoelectric conversion element according to the first embodiment of the present technology. FIG. 4A is a perspective view showing an example in which a dye-sensitized photoelectric conversion element is configured to be rollable. FIG. 4B is a diagram showing an example in which the dye-sensitized photoelectric conversion element shown in FIG. 4A is combined with clothes.

Embodiments of the present technology will be described in the following order with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals.
1. First embodiment (an example of a dye-sensitized photoelectric conversion element including a metal oxide semiconductor layer)
2. Second embodiment (example of dye-sensitized photoelectric conversion element configured to be foldable)

<1. First Embodiment>
[Configuration of dye-sensitized solar cell]
FIG. 1 is a schematic cross-sectional view illustrating an example of the configuration of the dye-sensitized photoelectric conversion element according to the first embodiment of the present technology. As shown in FIG. 1, the dye-sensitized photoelectric conversion element 1 includes a conductive substrate 3, a conductive substrate 13, a porous semiconductor layer 5 on which a dye is supported, an electrolyte layer 7, and a counter electrode. 15a. The dye-sensitized photoelectric conversion element 1 constitutes a so-called dye-sensitized solar cell.

  The conductive substrate 3 and the conductive substrate 13 are disposed to face each other. The conductive substrate 3 has one main surface facing the conductive substrate 13, and the porous semiconductor layer 5 is formed on this one main surface. The conductive substrate 13 has one main surface facing the conductive substrate 3, and a counter electrode 15a is formed on the one main surface. An electrolyte layer 7 is interposed between the opposed porous semiconductor layer 5 and the counter electrode 15a. At least one of the conductive base material 3 and the conductive base material 13 is transparent. For example, the conductive base material 3 has the other main surface opposite to the one main surface on which the porous semiconductor layer 5 is formed. The other main surface is a light receiving surface that receives the irradiation L of light such as sunlight.

  In order to prevent leakage and volatilization of the electrolyte layer, a sealing material is provided at the peripheral edge portion of the opposing surface of the conductive base material 3 and the conductive base material 13. The distance between the porous semiconductor layer 5 and the counter electrode 15a is preferably 1 to 100 μm, more preferably 1 to 40 μm. The electrolyte layer 7 is enclosed in a space surrounded by the conductive base material 3 on which the porous semiconductor layer 5 is formed, the conductive base material 13 on which the counter electrode 15a is formed, and a sealing material. Although not shown in FIG. 1, at least one of the conductive base materials 3 and 13 is provided with an injection port that is used for injection of electrolyte and is finally closed. As a material of the sealing material, for example, a thermoplastic resin, a photocurable resin, a glass frit, and the like can be used, but the material is not limited thereto.

  The conductive substrates 3 and 13 have, for example, the same square or rectangular planar shape. The conductive base materials 3 and 13 are arranged so as to be shifted from each other in the in-plane direction, and a part of the periphery of the conductive layers 3a and 13a shown in FIG. 1 is exposed to the outside of the sealing material. A current collecting layer or the like may be formed on 3a and 13a. This current collecting layer can be used when connecting to an external lead or connecting the dye-sensitized photoelectric conversion elements 1 to each other. A dye-sensitized photoelectric conversion device is configured by connecting small-area dye-sensitized photoelectric conversion elements 1 as necessary. For example, the electromotive voltage of the dye-sensitized photoelectric conversion device can be increased by combining the dye-sensitized photoelectric conversion elements 1 in series.

  Hereinafter, the conductive substrates 3 and 13, the porous semiconductor layer 5, the sensitizing dye, the counter electrode 15 a, and the electrolyte layer 7 that constitute the dye-sensitized photoelectric conversion element 1 will be sequentially described.

(Conductive substrate)
The conductive substrate 3 includes a substrate 3b and a conductive layer 3a formed on one main surface of the substrate 3b, and the porous semiconductor layer 5 is formed on the conductive layer 3a. The conductive base material 13 includes a base material 13b and a conductive layer 13a formed on one main surface of the base material 13b, and a counter electrode 15a is formed on the conductive layer 13a.

  As the base materials 3b and 13b, those having transparency are preferable, and various base materials can be used. The substrate having transparency is preferably one that absorbs less light from the visible to the near-infrared region of sunlight. For example, a glass substrate or a resin substrate can be used, but is not limited thereto. It is not something. As a material for the glass substrate, for example, quartz, blue plate, BK7, lead glass, or the like can be used, but is not limited thereto. Examples of the resin base material include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyester, polyethylene (PE), polycarbonate (PC), polyvinyl butyrate, polypropylene (PP), and tetraacetyl cellulose. Syndioctane polystyrene, polyphenylene sulfide, polyarylate, polysulfone, polyester sulfone, polyetherimide, cyclic polyolefin, brominated phenoxy, vinyl chloride, and the like can be used, but are not limited thereto. As the base materials 3b and 13b, for example, a film, a sheet, a substrate, or the like can be used, but is not limited thereto.

The conductive layers 3a and 13a are preferably transparent, and preferably have little light absorption from the visible to the near infrared region of sunlight. As a material for the conductive layers 3a and 13a, for example, it is preferable to use a metal oxide or carbon having good conductivity. Examples of the metal oxide include indium-tin composite oxide (ITO), fluorine-doped SnO ₂ (FTO), antimony-doped SnO ₂ (ATO), tin oxide (SnO ₂ ), zinc oxide (ZnO), and indium-zinc. One or more selected from the group consisting of composite oxide (IZO), aluminum-zinc composite oxide (AZO), and gallium-zinc composite oxide (GZO) can be used. A layer may be further provided between the conductive layer 3a and the porous semiconductor layer 5 for the purpose of promoting binding, improving electron transfer, or preventing reverse electron processes.

(Porous semiconductor layer)
The porous semiconductor layer 5 is preferably a porous layer containing metal oxide semiconductor fine particles. The metal oxide semiconductor fine particles preferably contain a metal oxide containing at least one of titanium, zinc, tin and niobium. By including such a metal oxide, an appropriate energy band is formed between the dye to be adsorbed and the metal oxide, and then electrons generated in the dye by light irradiation are smoothly transmitted to the metal oxide, This is because it can contribute to the subsequent power generation by oxidation and reduction of iodine. Specifically, the material of the metal oxide semiconductor fine particles includes titanium oxide, tin oxide, tungsten oxide, zinc oxide, indium oxide, niobium oxide, iron oxide, nickel oxide, cobalt oxide, strontium oxide, tantalum oxide, and antimony oxide. One or more selected from the group consisting of lanthanoid oxide, yttrium oxide, vanadium oxide, and the like can be used, but are not limited thereto. In order for the surface of the porous semiconductor layer to be sensitized by the sensitizing dye, the conduction band of the porous semiconductor layer 5 is preferably present at a position where electrons are easily received from the photoexcitation level of the sensitizing dye. From this viewpoint, among the materials of the metal oxide semiconductor fine particles described above, one or more selected from the group consisting of titanium oxide, zinc oxide, tin oxide, and niobium oxide is particularly preferable. Furthermore, titanium oxide is most preferable from the viewpoints of price and environmental hygiene. The metal oxide semiconductor fine particles particularly preferably contain titanium oxide having an anatase type or brucite type crystal structure. By including such titanium oxide, an appropriate energy band is formed between the dye to be adsorbed and the metal oxide, and then electrons generated in the dye by light irradiation are smoothly transmitted to the metal oxide, and thereafter This is because it can contribute to power generation by oxidation-reduction of iodine.

  The average primary particle diameter of the metal oxide semiconductor fine particles is preferably 5 nm or more and 500 nm or less, more preferably 20 nm or more and 100 nm or less, and particularly preferably 40 nm or more and 60 nm or less. Metal oxide semiconductor fine particles having different particle size distributions may be mixed.

  By making the average primary particle diameter within the range of 20 nm or more and 100 nm or less, the denseness of the porous semiconductor layer 5 is not deteriorated, and the adsorption of the dye and the penetration of the electrolytic solution due to the excessively dense are prevented. This is because inhibition can be prevented. When the average primary particle size is less than 5 nm, the crystallinity is extremely deteriorated, and the anatase structure cannot be maintained and an amorphous structure tends to be obtained. On the other hand, when the average primary particle diameter exceeds 500 nm, the specific surface area is remarkably lowered, and the total amount of the dye contributing to power generation to be adsorbed on the porous semiconductor layer 5 tends to decrease. Here, the average primary particle diameter was determined by a method of measuring by a light scattering method using a dilute solution in which a desired dispersant was added and dispersed to primary particles using a solvent system in which primary particles can be dispersed. Is.

(Sensitizing dye)
The sensitizing dye for photoelectric conversion is not particularly limited as long as it exhibits a sensitizing action, but usually a substance capable of absorbing light in the vicinity of the visible light region, for example, a bipyridine complex, a terpyridine complex, a merocyanine dye, a porphyrin , And phthalocyanine are used.

  As a sensitizing dye used alone, for example, cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex which is one kind of bipyridine complex (Commonly known as N719) is excellent in performance as a sensitizing dye and is generally used. In addition, cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) (common name: N3), which is a kind of bipyridine complex, is a kind of terpyridine complex. Tris (isothiocyanato) (2,2 ′: 6 ′, 2 ″ -terpyridyl-4,4 ′, 4 ″ -tricarboxylic acid) ruthenium (II) tritetrabutylammonium complex (commonly known as black dye) is generally used.

  In particular, when N3 or a black die is used, a co-adsorbent is often used. The co-adsorbent is a molecule added to prevent the dye molecules from associating on the porous semiconductor layer 3, and typical co-adsorbents include, for example, chenodeoxycholic acid, taurodeoxycholate, and Examples thereof include 1-decylphosphonic acid. The structural characteristics of these molecules are that they have a carboxyl group, a phosphono group, etc. as functional groups that are easily adsorbed to titanium oxide constituting the porous semiconductor layer 5, and are interposed between dye molecules. In order to prevent the interference, it may be formed by σ coupling.

  Examples of other sensitizing dyes include azo dyes, quinacridone dyes, diketopyrrolopyrrole dyes, squarylium dyes, cyanine dyes, merocyanine dyes, triphenylmethane dyes, xanthene dyes, porphine dyes. Chlorophyll dyes, ruthenium complex dyes, indigo dyes, perylene dyes, oxazine dyes, anthraquinone dyes, phthalocyanine dyes, naphthalocyanine dyes, and their derivatives, but they absorb light and are porous semiconductors. Any sensitizing dye capable of injecting excited electrons into the conduction band of the layer 5 is not limited thereto. When these sensitizing dyes have one or more linking groups in their structure, they can be connected to the surface of the porous semiconductor layer, and the excited electrons of the photoexcited sensitizing dye can be connected to the conduction band of the porous semiconductor layer 5. This is desirable because it can be communicated quickly.

  The thickness of the porous semiconductor layer 5 formed on the conductive layer 3a is desirably 0.5 μm or more and 200 μm or less. By setting the thickness of the porous semiconductor layer 5 within the above range, cracks and peeling are less likely to occur when the porous semiconductor layer 5 is formed, and the formation of the porous semiconductor layer 5 can be stabilized. In addition, the distance between the surface layer of the porous semiconductor layer 5 and the conductive surface can be in an appropriate range, and the generated charges are effectively transmitted to the conductive surface, so that good conversion efficiency can be obtained.

(Counter electrode)
The counter electrode 15a is formed on the conductive layer 13a, and the counter electrode 15 is configured by the counter electrode 15a and the conductive layer 13a. The counter electrode 15 functions as a positive electrode of a dye-sensitized solar cell (dye-sensitized photoelectric conversion element). Examples of the conductive material used for the counter electrode 15a include, but are not limited to, metals, metal oxides, and carbon. Examples of metals that can be used include platinum, gold, silver, copper, aluminum, rhodium, and indium, but are not limited thereto. Examples of the metal oxide include ITO (indium-tin oxide), tin oxide (including a material doped with fluorine), zinc oxide, and the like, but are not limited thereto. The thickness of the counter electrode 15a is not particularly limited, but is preferably 5 nm or more and 100 μm or less.

(Electrolyte layer)
The electrolyte layer 7 is preferably composed of an electrolyte, a medium, and an additive. The electrolyte is a mixture of I ₂ and iodide (for example, LiI, NaI, KI, CsI, MgI ₂ , CaI ₂ , CuI, tetraalkylammonium iodide, pyridinium iodide, imidazolium iodide, etc.), Br ₂ and bromide. A mixture of (for example, LiBr) is preferable. Among them, an electrolyte in which LiI, pyridinium iodide, imidazolium iodide, or the like is mixed as a combination of I ₂ and iodide is preferable, but the combination is not limited thereto.

As for the concentration of the electrolyte with respect to the medium, I ₂ is preferably 0.01 M or more and 0.5 M or less, and the iodide mixture is preferably 0.1 M or more and 15 M or less. Further, various additives such as 4-tert-butylpyridine and benzimidazoliums can be added for the purpose of improving the open-circuit voltage of the dye-sensitized solar cell.

  The medium used for the electrolyte layer 7 is preferably a compound that can exhibit good ionic conductivity. Examples of the solution medium include ether compounds such as dioxane and diethyl ether, chain ethers such as ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, and polypropylene glycol dialkyl ether, methanol, ethanol, and ethylene glycol. Alcohols such as monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, acetonitrile, glutarodi Nitrile, methoxyacetonitrile, Pionitoriru, nitrile compounds such as benzonitrile, ethylene carbonate, carbonate compounds such as propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazolidinone, dimethyl sulfoxide, or the like can be used aprotic polar substances such as sulfolane.

  Further, for the purpose of using a solid (including gel) medium, a polymer may be included. In this case, by adding a polymer such as polyacrylonitrile or polyvinylidene fluoride to the solution-like medium, a polyfunctional monomer having an ethylenically unsaturated group is polymerized in the solution-like medium, thereby solidifying the medium. To.

  As the electrolyte layer 7, an electrolyte that does not require a CuI or CuSCN medium, and 2,2 ′, 7,7′-tetrakis (N, N-di-p-methoxyphenylamine) 9,9′-spirobi A hole transport material such as fluorene can be used.

[Method for producing dye-sensitized solar cell]
Next, an example of a method for manufacturing the dye-sensitized solar cell according to the first embodiment of the present technology will be described.

(Formation of transparent conductive substrate on the porous semiconductor layer side)
First, as shown in FIG. 2A, a plate-like or film-like substrate 3b is formed. As a molding method, for example, a melt extrusion method, an injection molding method, or the like can be used, but the method is not limited thereto. Next, as shown in FIG. 2B, a conductive layer 3a is formed on the substrate 3b by a thin film manufacturing technique such as sputtering. Thereby, the electroconductive base material 3 is obtained.

(Formation of porous semiconductor layer)
Next, as shown in FIG. 2C, the porous semiconductor layer 5 is formed on the conductive layer 3 a of the conductive substrate 3.

  The present technology is characterized in that the porous semiconductor layer 5 is formed using a dispersion (a composition for forming a porous semiconductor) containing metal oxide semiconductor fine particles, a dispersant and a solvent. As will be described later, the dispersant has an acetylene-based hydrocarbon skeleton, and specifically has at least an acetylene alcohol structure or an acetylenic diol structure as the acetylene-based hydrocarbon skeleton. Moreover, the dispersant is at least an amino group, a carboxyl group, a hydroxy group (hydroxyl group), a thiol group, a phosphono group, a cyano group, a nitro group, a sulfonyl group, and a sulfinyl group as a functional group adsorbed on the metal oxide semiconductor particles. Having at least one selected from the group consisting of As the solvent, water or an organic solvent can be used.

  Hereinafter, the detail of the formation process of the porous semiconductor layer 5 is demonstrated.

  First, metal oxide semiconductor fine particles and a dispersing agent are dispersed in a solvent to prepare a dispersion (paste) that is a composition for forming a porous semiconductor layer. If necessary, a binder (binder) may be further dispersed in the solvent. In preparing the paste, monodispersed colloidal particles obtained from hydrothermal synthesis may be used as necessary.

  Examples of the metal oxide semiconductor fine particles include titanium oxide, tin oxide, tungsten oxide, zinc oxide, indium oxide, niobium oxide, iron oxide, nickel oxide, cobalt oxide, strontium oxide, tantalum oxide, antimony oxide, and lanthanoid oxide. One or more selected from the group consisting of yttrium oxide, vanadium oxide, and the like can be suitably used.

  As the dispersant, a dispersant having an acetylene hydrocarbon skeleton can be used. As the dispersant having an acetylene hydrocarbon skeleton, one having a structure represented by the following formula (Formula 1) is preferable.

R ₁ —C (CH ₃ ) (OR ₂ ) —C≡C—C (CH ₃ ) (OR ₃ ) —R ₄ (Chemical Formula 1)
(In the formula, R ₁ is selected from H, CH ₃ , C ₂ H ₅ , isoC ₃ H ₇ and C ₄ H _9. R ₂ is H, CH ₃ , C ₂ H ₅ , isoC ₃ H ₇ , Selected from C ₄ H _9, R ₃ represents — (CH ₂ —CH ₂ ) _m —OH, R ₄ represents — (CH ₂ —CH ₂ ) _n —OH, wherein m and n are These values are within the range of 1 ≦ m ≦ 10 and 1 ≦ n ≦ 10, respectively.

  The dispersant having the structure represented by the formula (Chemical Formula 1) tends to be solidified when m exceeds 10. Moreover, when n exceeds 10, there exists a tendency to solidify. Therefore, m and n are preferably values within the range of 1 ≦ m ≦ 10 and 1 ≦ n ≦ 10, respectively.

  That is, the dispersant preferably has at least an acetylene alcohol structure or an acetylene diol structure as an acetylene hydrocarbon skeleton. Having an acetylene alcohol structure is, for example, preferably a structure having one carbon-carbon triple bond and having a hydroxy group on one of the carbons adjacent to the carbon-carbon triple bond. The structure having an acetylenic diol structure is preferably, for example, a structure having one carbon-carbon triple bond and having a hydroxy group at two carbons adjacent to the carbon-carbon triple bond.

  The dispersant preferably has at least one functional group that adsorbs to the metal oxide semiconductor particles. As the functional group adsorbed on the metal oxide semiconductor particles, at least one or more selected from the group consisting of amino group, carboxyl group, hydroxy group, thiol group, phosphono group, cyano group, nitro group, sulfonyl group and sulfinyl group is selected. It is preferable. Examples of the carboxyl group-containing substance include 3,5-dimethyl-3-carboxyl-1-hexyne. Examples of the thiol group-containing substance include 3,5-dimethyl-3-thionyl-1-hexyne.

  Since the dispersant has an acetylene hydrocarbon skeleton and has at least one functional group that adsorbs to the metal oxide semiconductor particles, when the functional group is adsorbed on the surface of the metal oxide fine particles, Agent molecules take a linear molecular form. Therefore, the acetylene-based hydrocarbon skeleton exhibits an ideal steric repulsion effect, and good dispersibility can be obtained.

  Further, when such a dispersion is used, it is possible to ensure the dispersion and dispersion stability of the metal oxide semiconductor particles in the solvent, and in addition to heating the dispersion, And the solvent can be removed. Therefore, it is possible to reduce the content of impurities that degrade the power generation characteristics in the porous semiconductor layer 5. In addition, by adding such a dispersant, the region where the dispersant was present becomes a void in the baking step described later, so that the adsorption of the dye and the promotion of the penetration of the electrolytic solution are achieved. In the present technology, a dense porous semiconductor layer can be obtained as compared with a porous semiconductor layer obtained by baking at a high temperature using a dispersion containing a polymer material such as ethyl cellulose.

  The denseness of the porous semiconductor layer depends on the ratio of the solid content in the dispersion. From this, it is also possible to control the denseness of the porous semiconductor layer by adjusting the ratio of the solid content in the dispersion. From the viewpoint of obtaining good photoelectric conversion efficiency, the ratio of the solid content in the dispersion is preferably in the range of 8% to 12%. The denseness of the porous semiconductor layer can be confirmed by, for example, cross-sectional observation with a SEM (Scanning Electron Microscope).

  Examples of the solvent include lower alcohols having 4 or less carbon atoms such as methanol, ethanol, isopropanol, n-butanol, sec-butanol, t-butanol, ethylene glycol, propylene glycol (1,3-propanediol), 1, Aliphatic glycols such as 3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, ketones such as methyl ethyl ketone, dimethylethylamine Such amines can be used alone or in admixture of two or more, but are not particularly limited thereto. As the dispersion method, for example, a known method can be used. Specifically, for example, stirring treatment, ultrasonic dispersion treatment, bead dispersion treatment, kneading treatment, homogenizer treatment, etc. can be used. It is not limited to.

  Next, after applying or printing the prepared dispersion liquid on the conductive layer 3a, the solvent is volatilized by drying. Thereby, the porous semiconductor layer 5 is formed on the conductive layer 3a. The drying conditions are not particularly limited, and may be natural drying or artificial drying that adjusts the drying temperature, drying time, and the like. In the case of artificially drying, it is preferable to set the drying temperature and drying time in a range that does not change the quality of the base material 3b in consideration of the heat resistance of the base material 3b. As a coating or printing method, it is preferable to use a simple and suitable method for mass production. Examples of coating methods include spray coating, micro gravure coating, wire bar coating, direct gravure coating, die coating, dipping, reverse roll coating, curtain coating, comma coating, knife coating, and spin coating. A coating method or the like can be used, but is not particularly limited thereto. In addition, as a printing method, for example, a relief printing method, an offset printing method, a gravure printing method, an intaglio printing method, a rubber plate printing method, a screen printing method and the like can be used, but it is not particularly limited thereto. .

(Baking)
Next, the porous semiconductor layer 5 produced as described above is fired to improve the electronic connection between the metal oxide semiconductor fine particles in the porous semiconductor layer 5.

  The firing temperature is preferably in a range where the substrate does not change in quality. Specifically, the firing temperature is preferably about 40 to 175 ° C, more preferably about 40 to 150 ° C. As the dispersant having an acetylene hydrocarbon skeleton, a dispersant having a structure represented by the above formula (Chemical Formula 1) is preferably used because the dispersant can be volatilized in the above temperature range. When manufacturing a metal oxide semiconductor layer using a resin base material, for example, when PET is used as a base material, it is heated up to about 100 ° C., and when PEN is used as a base material, it is heated up to about 150 ° C. Preferably there is. If it is in the said temperature range, since a deformation | transformation of a base material etc. will not be caused and it will not interfere with manufacture, it is preferable.

  The firing time is preferably about 30 seconds to 2 hours, but is not particularly limited to this time range.

(Dye support)
Next, a sensitizing dye is dissolved in a solvent to prepare a solution. In order to dissolve the sensitizing dye, heating, addition of a dissolution aid, and filtration of insoluble matter may be performed as necessary. The solvent is preferably a solvent capable of dissolving a sensitizing dye and capable of mediating dye adsorption on the porous semiconductor layer 5, for example, an alcohol solvent such as ethanol, isopropyl alcohol, benzyl alcohol, acetonitrile, etc. , Nitrile solvents such as propionitrile, halogen solvents such as chloroform, dichloromethane and chlorobenzene, ether solvents such as diethyl ether and tetrahydrofuran, ester solvents such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone Solvents, carbonate solvents such as diethyl carbonate and propylene carbonate, carbohydrate solvents such as hexane, octane, toluene and xylene, dimethylformamide, dimethylacetamide, dimethylsulfoxide 1,3-dimethyl imidazolinone, N-methylpyrrolidone, water and the like can be used alone or in combination, but is not limited thereto.

  Next, for example, the porous semiconductor layer 5 is immersed in a solution containing a sensitizing dye, whereby the sensitizing dye is supported on the metal oxide fine particles. By immersing the porous semiconductor layer 5 together with the conductive substrate 3 in a solution containing a sensitizing dye, the affinity of the connecting substituent of the sensitizing dye is used to sensitize the porous surface of the porous semiconductor. The dye can be contacted and bound. Of course, the method for supporting the sensitizing dye is not limited to this method.

(Formation of transparent conductive substrate on the counter electrode side)
Next, a transparent conductive substrate on the counter electrode side is formed in the same manner as the transparent conductive substrate on the porous semiconductor layer side.

  As shown in FIG. 3A, a plate-like or film-like substrate 13b is formed. As a molding method, the same molding method as that for the substrate 3b can be used. Next, as shown in FIG. 3B, the conductive layer 13a is formed on the base material 13b by a thin film manufacturing technique such as sputtering. Thereby, the electroconductive base material 13 is obtained.

(Formation of counter electrode)
Next, as illustrated in FIG. 3C, the counter electrode 15 a is formed on the conductive layer 13 a of the conductive substrate 13 by a thin film manufacturing technique such as a sputtering method.

(Electrolyte filling)
Next, an ultraviolet curable adhesive as a sealant is formed on the peripheral edge of the conductive layer 13a of the conductive substrate 13 by screen printing, and then the conductive substrate 3 is passed through the ultraviolet curable adhesive. Paste together. At this time, the porous semiconductor layer 5 and the counter electrode 15a are arranged to face each other at a predetermined interval, for example, 1 to 100 μm, preferably 1 to 50 μm. Thereby, a space filled with the electrolyte layer 7 is formed by the conductive base material 3, the conductive base material 13, and the sealing agent. Next, an electrolyte is injected into the space from, for example, an injection port previously formed in the conductive base material 3, and the electrolyte is filled into the space to form the electrolyte layer 7. Thereafter, the inlet is closed. Thereby, the target dye-sensitized solar cell shown to FIG. 3D is manufactured.

  In a conventional method for forming a metal oxide semiconductor layer, a dispersant, a thickener, or the like is added to metal oxide semiconductor fine particles, and ink having a viscosity behavior suitable for screen printing is adjusted and used. Then, when a polymer film is used as a base material, the firing temperature is limited due to the heat resistance of the film. For example, at a relatively low temperature of about 150 ° C. or less, the added dispersant or The thickener remains in the metal oxide semiconductor layer without burning or volatilizing. When the added dispersant or thickener remains in the metal oxide semiconductor layer, the sintering reaction between the metal oxide semiconductor fine particles is suppressed. Moreover, adsorption | suction of the sensitizing dye to the titanium oxide surface is inhibited. Therefore, the movement of electrons generated in the process in which the sensitizing dye absorbs and excites sunlight is hindered, the resistance value of the metal oxide semiconductor layer is increased, and power generation efficiency is reduced.

  In the present technology, a dispersant having a characteristic of volatilizing in a temperature range where deformation of a polymer resin substrate such as a polymer film hardly occurs and water or an organic solvent is used for the dispersion. Therefore, substances other than the metal oxide semiconductor particles in the dispersion can be effectively removed and the metal oxide semiconductor particles can be fixed to each other at a relatively low temperature. Further, as described above, in the firing step, the region where the dispersant was present becomes a void, so that the adsorption of the dye and the penetration of the electrolytic solution are promoted. Therefore, the movement of electrons generated in the process in which the sensitizing dye absorbs and excites sunlight is not hindered, and the resistance value of the metal oxide semiconductor layer can be prevented from increasing.

[Operation of dye-sensitized solar cell]
Next, the operation of the dye-sensitized photoelectric conversion element 1 according to the first embodiment of the present technology will be described.

  The dye-sensitized photoelectric conversion element 1 operates as a battery having the counter electrode 15 as a positive electrode and the conductive layer 3a as a negative electrode when the light receiving surface L of the conductive substrate 3 is irradiated with light L. The principle is as follows.

  When the sensitizing dye absorbs the photons transmitted through the substrate 3b and the conductive layer 3a, the electrons in the sensitizing dye are excited from the ground state (HOMO) to the excited state (LUMO). Excited electrons are drawn out to the conduction band of the porous semiconductor layer 5 through the electrical coupling between the sensitizing dye and the porous semiconductor layer 5 and pass through the porous semiconductor layer 5 to the conductive layer 3a. To reach.

On the other hand, the sensitizing dye that has lost electrons receives electrons from the reducing agent in the electrolyte layer 4, such as I ^−, by the following reaction, and oxidants such as I ₃ ⁻ (I ₂ and I ⁻ and the like in the electrolyte layer 7. To form a conjugate).
2I ⁻ → I ₂ + 2e ^{−
_{I 2 + I - → I 3}} -

The generated oxidizing agent, for example, I ₃ ⁻ reaches the counter electrode 15a by diffusion, receives electrons from the counter electrode 15a by, for example, the following reaction (reverse reaction of the above reaction), and is reduced to the original reducing agent, for example, I ^−. The
I ₃ ⁻ → I ₂ + I ⁻
I ₂ + 2e ^- → 2I ^-

The electrons sent from the conductive layer 3a to the external circuit return to the counter electrode 15a after performing electrical work in the external circuit. In this way, light energy is converted into electrical energy without leaving any change in the sensitizing dye or the electrolyte layer 7. In the above description, FTO is used as the material of the conductive layer 3a, N719 is used as the photosensitizing dye, titanium oxide TiO ₂ is used as the material of the porous semiconductor layer 5, and I ⁻ / I ₃ ⁻ is used as the redox pair. The use of redox species was assumed.

[Configuration example of dye-sensitized photoelectric conversion element]
FIG. 4A is a perspective view showing an example in which a dye-sensitized photoelectric conversion element is configured to be rollable.

  According to the present technology, a film-like resin base material can be used as the base material. Therefore, the dye-sensitized photoelectric conversion element can be configured as a flexible dye-sensitized photoelectric conversion element having flexibility. For example, when not used, the dye-sensitized photoelectric conversion element 21 illustrated in FIG. 4A is rounded down to improve the portability of the dye-sensitized photoelectric conversion element 21. Further, by expanding the dye-sensitized photoelectric conversion element 21, a large light receiving surface can be obtained during use, and a large electromotive force can be obtained.

  FIG. 4B is a diagram showing an example in which the dye-sensitized photoelectric conversion element shown in FIG. 4A is combined with clothes.

  As shown in FIG. 4B, for example, the dye-sensitized photoelectric conversion element 21 can be disposed on the shoulder or sleeve of the jacket 31. Electric power can be obtained from the dye-sensitized photoelectric conversion element 21 by irradiating sunlight outdoors and by irradiating light from a fluorescent lamp or the like indoors. The dye-sensitized photoelectric conversion element 21 can be used as a power source for a portable audio player, for example.

  According to the present technology, since a film-like resin base material can be used as the base material, as shown in FIG. 4B, the dye-sensitized photoelectric conversion element 21 is incorporated in the outer jacket 31, and the dye-sensitized type is used. The photoelectric conversion element 21 can be used as a portable power source. In addition to the dye-sensitized photoelectric conversion element 21, a flexible substrate on which an electric circuit or an electronic circuit is formed, a battery, a communication device, or the like may be incorporated in the outer jacket 31.

<2. Second Embodiment>
The dye-sensitized photoelectric conversion element may be configured to be foldable. For example, a single plate-like or film-like substrate is divided into a plurality of compartments, the electrolyte is sealed, and a dye-sensitized solar cell is configured to include a plurality of dye-sensitized solar cells. May be. The plurality of dye-sensitized solar cells are electrically connected in series or in parallel.

  At this time, it is convenient to provide a thin portion between adjacent dye-sensitized solar cells so that the dye-sensitized photoelectric conversion element is easily bent at the thin portion. The thin portion is a portion corresponding to a fold line in the dye-sensitized photoelectric conversion element. By doing in this way, a dye-sensitized photoelectric conversion element can be made easy to fold. When not in use, the dye-sensitized photoelectric conversion element is folded into a small size, and when in use, for example, the dye-sensitized photoelectric conversion element is expanded in the vertical direction and the horizontal direction in this order.

  By making the dye-sensitized photoelectric conversion element foldable, the portability of the dye-sensitized photoelectric conversion element can be improved, and a large light-receiving surface can be obtained during use, thereby obtaining a large electromotive force. . Therefore, the dye-sensitized photoelectric conversion element according to the second embodiment can be used as a power source particularly suitable for outdoor use.

  Thus, according to the present technology, a film-like resin base material can be used as the base material, and the dye-sensitized photoelectric conversion element has flexibility even when combined with a flexible substrate. However, it can be installed on a three-dimensional structure such as a roof, wall surface, or window of a building. Further, by allowing the dye-sensitized photoelectric conversion element to be rounded or folded, the dye-sensitized photoelectric conversion element can be used as a portable generator during outdoor or disaster.

In addition, this technique can also take the following structures.
(1)
A conductive layer, a porous semiconductor layer, an electrolyte layer, and a counter electrode;
The porous semiconductor layer is obtained by applying or printing a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on the conductive layer and baking the composition.
The dispersant is a dye-sensitized photoelectric conversion element having an acetylene hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.
(2)
The dye-sensitized photoelectric conversion element according to (1), wherein the dispersant has at least an acetylene alcohol structure or an acetylene diol structure as the acetylene hydrocarbon skeleton.
(3)
The dispersant was selected from the group consisting of at least an amino group, a carboxyl group, a hydroxy group, a thiol group, a phosphono group, a cyano group, a nitro group, a sulfonyl group, and a sulfinyl group as a functional group that adsorbs to the metal oxide. The dye-sensitized photoelectric conversion element according to (1) or (2), which has at least one kind.
(4)
The average primary particle diameter of the metal oxide semiconductor fine particles is the dye-sensitized photoelectric conversion device according to any one of (1) to (3), which is 5 nm to 500 nm.
(5)
The said metal oxide semiconductor fine particle is a dye-sensitized photoelectric conversion element in any one of (1)-(4) containing the metal oxide containing at least 1 sort (s) of titanium, zinc, tin, and niobium.
(6)
The said metal oxide semiconductor fine particle is a dye-sensitized photoelectric conversion element in any one of (1)-(5) containing the titanium oxide which has a crystal structure of an anatase type or a brookite type.
(7)
A resin base material having flexibility;
The dye-sensitized photoelectric conversion element according to any one of (1) to (6), wherein the conductive layer is formed on the resin base material.
(8)
A garment comprising one or more dye-sensitized photoelectric conversion elements according to any one of (1) to (7).
(9)
It is obtained by applying or printing a porous semiconductor-forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer, and baking the composition.
The dispersing agent is a photoelectrode for a dye-sensitized photoelectric conversion element having an acetylene hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.
(10)
Applying or printing a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on the conductive layer;
Firing the applied composition for forming a porous semiconductor, and forming a porous semiconductor layer on the conductive layer;
A step of supporting a sensitizing dye on the porous semiconductor layer;
Providing a counter electrode facing the porous semiconductor layer carrying the sensitizing dye; and
A step of providing an electrolyte layer between the porous semiconductor layer and the counter electrode,
The said dispersing agent consists of acetylene type hydrocarbon frame | skeletons, The manufacturing method of the dye-sensitized photoelectric conversion element which has one or more functional groups adsorb | sucking to the said metal oxide semiconductor fine particle.
(11)
Firing of the coated or printed composition for forming a porous semiconductor is carried out in a temperature range of 40 ° C. or higher and 175 ° C. or lower.
(12)
A step of applying or printing a composition for forming a porous semiconductor containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer, followed by firing.
The said dispersing agent consists of acetylene type hydrocarbon frame | skeleton, The formation method of the metal oxide semiconductor layer which has one or more functional groups which adsorb | suck to the said metal oxide semiconductor fine particle.

  Hereinafter, the present technology will be specifically described by way of examples. However, the present technology is not limited only to these examples.

<Sample 1-1>
Hereinafter, the manufacturing process of the metal oxide semiconductor layer of Sample 1-1 will be described. Sample 1-1 is an example in which a dispersant having an acetylene alcohol structure was used for the dispersion.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser.
Titanium oxide microparticles: Showa Titanium Co., Ltd. Titanium oxide 5g
Solvent: 45g ethanol
Dispersant: 3,5-dimethyl-1-hexyn-3-ol 0.5 g

  Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer is formed by baking in an oven at a temperature environment of 150 ° C. for 1 hour. As a result, a target metal oxide semiconductor layer was obtained.

<Sample 2-1>
Hereinafter, the manufacturing process of the dye-sensitized photoelectric conversion element of Sample 2-1 will be described. Sample 2-1 is an example in which a dispersant having an acetylenic diol structure was used as the dispersion.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser.
Titanium oxide microparticles: Showa Titanium Co., Ltd. Titanium oxide 5g
Solvent: 45g ethanol
Dispersant: 3,6-dimethyl-4-octyl-3,6-diol 0.5 g

  Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 150 ° C. for 1 hour. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a good conversion efficiency of 5% was obtained.

<Sample 2-2>
Hereinafter, the manufacturing process of the dye-sensitized photoelectric conversion element of Sample 2-2 will be described. Sample 2-2 is an example in which a dispersant containing an acetylene alcohol structure and containing an amino group as a functional group adsorbed on the metal oxide fine particles is used in the dispersion.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser.
Titanium oxide microparticles: Showa Titanium Co., Ltd. Titanium oxide 5g
Solvent: 45g ethanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.5 g

Next, the prepared titanium oxide dispersion solution is spray-coated on the transparent conductive layer to form a coating film, and then fired in an ultrahigh vacuum of 3.0 × 10 ⁻⁷ torr in a temperature environment of 150 ° C. for 1 hour. As a result, a porous semiconductor layer was formed.

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a good conversion efficiency of 5.7% was obtained.

<Sample 3-1>
The dye-sensitized photoelectric conversion elements of Sample 3-1 to Sample 3-6 were prepared, and the correlation between the particle size distribution of the metal oxide semiconductor fine particles and the photoelectric conversion efficiency was evaluated using a light scattering method.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser. The amount of dispersant added to titanium oxide was 5% in terms of titanium oxide weight ratio. Further, the solid content of the titanium oxide dispersion was 8%.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 90 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

    Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 150 ° C. for 30 minutes. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 3.5% was obtained.

<Sample 3-2>
A dye-sensitized photoelectric conversion element of Sample 3-2 was produced in the same manner as in Sample 3-1, except that the materials constituting the titanium oxide dispersion solution were as follows.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 4.5% was obtained.

<Sample 3-3>
A dye-sensitized photoelectric conversion element of Sample 3-3 was produced in the same manner as in Sample 3-1, except that the materials constituting the titanium oxide dispersion solution were as follows.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 50 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 3-4>
A dye-sensitized photoelectric conversion element of Sample 3-4 was produced in the same manner as in Sample 3-1, except that the materials constituting the titanium oxide dispersion solution were as follows.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 30 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 3.5% was obtained.

<Sample 3-5>
A dye-sensitized photoelectric conversion element of Sample 3-5 was produced in the same manner as in Sample 3-1, except that the materials constituting the titanium oxide dispersion solution were as follows.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 20 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 2.5% was obtained.

<Sample 3-6>
A dye-sensitized photoelectric conversion element of Sample 3-6 was produced in the same manner as in Sample 3-1, except that the material constituting the titanium oxide dispersion solution was as follows.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 15 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 1.5% was obtained.

  Table 1 below shows the particle size distribution of the metal oxide semiconductor fine particles and the measurement result of the photoelectric conversion efficiency with respect to Sample 3-1 to Sample 3-6.

  Table 1 shows the following. It turned out that the effect which makes the photoelectric conversion efficiency of a dye-sensitized photoelectric conversion element favorable is acquired by making the average particle diameter of metal oxide semiconductor fine particle into the range of 20 nm-100 nm. In particular, it has been found that the effect is high when the average particle size of the metal oxide semiconductor fine particles is in the range of 40 nm to 60 nm.

<Sample 4-1>
The dye-sensitized photoelectric conversion elements of Sample 4-1 to Sample 4-5 were prepared, and the correlation between the solid content ratio of the titanium oxide dispersion and the photoelectric conversion efficiency was evaluated.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser. The amount of dispersant added to titanium oxide was 5% in terms of titanium oxide weight ratio. Further, the solid content of the titanium oxide dispersion was 4%.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 2g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 48 g of 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.1 g

    Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 150 ° C. for 30 minutes. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 3.0% was obtained.

<Sample 4-2>
The material constituting the titanium oxide dispersion solution is as follows, and the sample 4-2 was prepared in the same manner as in the case of the sample 4-1, except that the solid content of the titanium oxide dispersion solution was 8%. A dye-sensitized photoelectric conversion element was produced.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 4.5% was obtained.

<Sample 4-3>
The material constituting the titanium oxide dispersion solution is as follows. Except that the solid content of the titanium oxide dispersion solution is 10%, the same as in the case of sample 4-1, the sample 4-3 A dye-sensitized photoelectric conversion element was produced.
Titanium oxide microparticles: Showa Titanium Co., Ltd. Titanium oxide 5g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 45 g of 2-propanol
Dispersant: 0.25 g of 3,5-dimethyl-3-amino-1-hexyne

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 4-4>
The material constituting the titanium oxide dispersion solution is as follows, and the sample 4-4 was prepared in the same manner as in the case of the sample 4-1, except that the solid content of the titanium oxide dispersion solution was 12%. A dye-sensitized photoelectric conversion element was produced.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 6g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 44 g of 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.3 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion device having a conversion efficiency of 6.0% was obtained.

<Sample 4-5>
The material constituting the titanium oxide dispersion solution is shown below, and the sample 4-5 was prepared in the same manner as in the case of the sample 4-1, except that the solid content of the titanium oxide dispersion solution was 15%. An attempt was made to prepare a dye-sensitized photoelectric conversion element.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 7.5g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 42.5 g of 2-propanol
Dispersant: 0.375 g of 3,5-dimethyl-3-amino-1-hexyne

  When the solid content of the titanium oxide dispersion was 15%, good dispersibility was not obtained, and a porous semiconductor layer could not be formed on the transparent conductive layer.

  Table 2 below shows the ratio of the solid content of the titanium oxide dispersion solution and the measurement result of the photoelectric conversion efficiency for Sample 4-1 to Sample 4-5.

  Table 2 shows the following. The best photoelectric conversion efficiency can be obtained when the solid content of the titanium oxide dispersion is 12%. If the solid content of the titanium oxide dispersion is 15%, it is difficult to form a porous semiconductor layer. I understood it.

<Sample 5-1>
Samples 5-1 to 5-5 were prepared dye-sensitized photoelectric conversion elements, and the correlation between the firing temperature and the photoelectric conversion efficiency was evaluated.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser. The amount of dispersant added to titanium oxide was 5% in terms of titanium oxide weight ratio. Further, the solid content of the titanium oxide dispersion was 8%.
Titanium oxide fine particles: Showa Titanium Co., Ltd. Titanium oxide 4g
Titanium oxide fine particle average particle diameter: 60 nm
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

    Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 100 ° C. for 30 minutes. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 1.0% was obtained.

<Sample 5-2>
A dye-sensitized photoelectric conversion element of Sample 5-2 was produced in the same manner as in Sample 5-1, except that the firing temperature was 125 ° C.

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 2.0% was obtained.

<Sample 5-3>
A dye-sensitized photoelectric conversion element of Sample 5-3 was produced in the same manner as in Sample 5-1, except that the firing temperature was 150 ° C.

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 4.5% was obtained.

<Sample 5-4>
A dye-sensitized photoelectric conversion element of Sample 5-4 was produced in the same manner as in Sample 5-1, except that the firing temperature was 175 ° C.

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.0% was obtained.

<Sample 5-5>
A dye-sensitized photoelectric conversion element of Sample 5-5 was produced in the same manner as in Sample 5-1, except that the firing temperature was 200 ° C.

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

  Table 3 below shows the baking temperature and the measurement result of the photoelectric conversion efficiency with respect to Sample 5-1 to Sample 5-5.

  From Table 3, it was found that the photoelectric conversion efficiency tends to improve as the firing temperature increases. As the firing temperature increases, the photoelectric conversion efficiency tends to improve. However, when PEN is used for the base material, for example, from the viewpoint of preventing the base material from being deformed, it is heated up to about 150 ° C. for 30 minutes. Preferably there is.

<Sample 6-1>
In forming the porous semiconductor layer, for the purpose of improving the density of the porous semiconductor layer, metal oxide semiconductor fine particles having different particle size distributions may be mixed during the preparation of the titanium oxide dispersion. Therefore, dye-sensitized photoelectric conversion elements of Sample 6-1 to Sample 6-4 were prepared, and the correlation between the mixing ratio of metal oxide semiconductor fine particles having different particle size distributions and photoelectric conversion efficiency was evaluated.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser. In the titanium oxide dispersion solution, titanium oxide fine particles having an average particle diameter of 50 nm were basically mixed, and titanium oxide fine particles having an average particle diameter of 20 nm were mixed.
Titanium oxide fine particles (average particle size: 50 nm): 4 g of titanium oxide manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle size: 20 nm): Titanium oxide 0 g, manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

    Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 150 ° C. for 30 minutes. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 6-2>
The material constituting the titanium oxide dispersion solution is shown below, and sample 6-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 20 nm in the titanium oxide dispersion solution is 5% by weight of titanium oxide. In the same manner as described above, a dye-sensitized photoelectric conversion element of Sample 6-2 was produced.
Titanium oxide fine particles (average particle size: 50 nm): 3.8 g titanium oxide manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle diameter: 20 nm): Titanium oxide 0.2 g manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 6-3>
The material constituting the titanium oxide dispersion solution is as follows, and sample 6-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 20 nm in the titanium oxide dispersion solution is 10% by weight of titanium oxide. In the same manner as described above, a dye-sensitized photoelectric conversion element of Sample 6-3 was produced.
Titanium oxide fine particles (average particle size: 50 nm): Titanium oxide 3.6 g manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle diameter: 20 nm): 0.4 g of titanium oxide manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion device having a conversion efficiency of 6.0% was obtained.

<Sample 6-4>
The material constituting the titanium oxide dispersion solution is as follows, and sample 6-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 20 nm in the titanium oxide dispersion solution is 20% by weight of titanium oxide. In the same manner as described above, a dye-sensitized photoelectric conversion element of Sample 6-4 was produced.
Titanium oxide fine particles (average particle diameter: 50 nm): Titanium oxide 3.2 g, manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle size: 20 nm): 0.8 g of titanium oxide manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 4.0% was obtained.

  Table 4 below shows the mixing ratio of the metal oxide semiconductor fine particles having different particle size distributions and the measurement results of the photoelectric conversion efficiency with respect to Sample 6-1 to Sample 6-4.

  Table 4 shows the following. It was found that the photoelectric conversion efficiency was the best when the proportion of fine titanium oxide particles having an average particle diameter of 20 nm was about 10%. Further, it was found that when the titanium oxide fine particles having an average particle diameter of 20 nm are mixed exceeding 10%, the characteristics of the titanium oxide fine particles having an average particle diameter of 20 nm become dominant, and the photoelectric conversion efficiency is lowered.

<Sample 7-1>
When forming the porous semiconductor layer, metal oxide semiconductor fine particles having a large particle size may be mixed as scattering particles when preparing the titanium oxide dispersion. Therefore, dye-sensitized photoelectric conversion elements of Sample 7-1 to Sample 7-4 were prepared, and the correlation between the mixing ratio of metal oxide semiconductor fine particles having different particle size distributions and photoelectric conversion efficiency was evaluated.

  First, a soda lime glass substrate was prepared as a substrate having no absorption in the visible region, and a transparent conductive layer was formed on the soda lime glass substrate as a conductive layer having no absorption in the visible region to which a current-voltage was applied. As a transparent conductive layer, an ITO film having a thickness of 100 nm was formed by sputtering to obtain a transparent conductive substrate. The transparent conductive layer can be patterned with an inorganic acid typified by hydrogen chloride or the like, if necessary, using a mask formed by a photolithography method. In this embodiment, the transparent conductive layer is patterned. Did not do.

  Next, a porous semiconductor layer holding a sensitizing dye was formed on the transparent conductive substrate as follows.

First, a titanium oxide dispersion solution was prepared by dispersing the following materials for 16 hours using a bead disperser. In the titanium oxide dispersion solution, titanium oxide fine particles having an average particle diameter of 50 nm were basically used, and titanium oxide fine particles having an average particle diameter of 200 nm were mixed as scattering particles.
Titanium oxide fine particles (average particle size: 50 nm): Titanium oxide 4.0 g manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle diameter: 200 nm): Titanium oxide 0 g, manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

  Next, after spray-coating the prepared titanium oxide dispersion solution on the transparent conductive layer to form a coating film, the porous semiconductor layer was formed by baking in an oven at a temperature environment of 150 ° C. for 30 minutes. .

Next, the porous semiconductor layer was immersed in a dye solution having the following composition to adsorb the sensitizing dye. Thereafter, excess sensitizing dye was washed with ethanol and dried to form a porous semiconductor layer holding the photosensitizing dye.
Sensitizing dye: cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) ditetrabutylammonium complex (common name N719) 25 mg
Solvent: ethanol 50ml

  Next, the transparent conductive base material on which the porous semiconductor layer was formed and the transparent conductive base material on which the counter electrode was formed were placed opposite to each other and sealed with a resin film spacer and an acrylic ultraviolet curable resin. As the resin film spacer, a film having a thickness of 25 μm (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: High Milan (registered trademark)) was used.

Next, an electrolyte solution having the following composition was injected from the injection port using a liquid feed pump to form an electrolyte layer. Thus, the intended dye-sensitized photoelectric conversion element was obtained.
Methoxypropionitrile 1.5g
Sodium iodide 0.02g
1-propyl-2,3-dimethylimidazolium iodide 0.8g
Iodine 0.1g
4-tert-butylpyridine (TBP) 0.05 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 7-2>
The material constituting the titanium oxide dispersion solution is as follows. Sample 7-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 200 nm in the titanium oxide dispersion solution is 5% by weight of titanium oxide. In the same manner as described above, a dye-sensitized photoelectric conversion element of Sample 7-2 was produced.
Titanium oxide fine particles (average particle size: 50 nm): 3.8 g titanium oxide manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle size: 200 nm): Titanium oxide 0.2 g manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion element having a conversion efficiency of 5.5% was obtained.

<Sample 7-3>
The material constituting the titanium oxide dispersion solution is as follows. Sample 7-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 200 nm in the titanium oxide dispersion solution is 10% by weight of titanium oxide. In the same manner as in Example 1, a dye-sensitized photoelectric conversion element of Sample 7-3 was produced.
Titanium oxide fine particles (average particle size: 50 nm): Titanium oxide 3.5 g, manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle size: 200 nm): 0.5 g of titanium oxide manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion device having a conversion efficiency of 6.0% was obtained.

<Sample 7-4>
The material constituting the titanium oxide dispersion solution is as follows. Sample 7-1 except that the ratio of titanium oxide fine particles having an average particle diameter of 200 nm in the titanium oxide dispersion solution is 20% by weight of titanium oxide. In the same manner as described above, a dye-sensitized photoelectric conversion element of Sample 7-4 was produced.
Titanium oxide fine particles (average particle diameter: 50 nm): Titanium oxide 3.2 g, manufactured by Showa Titanium Co., Ltd.
Titanium oxide fine particles (average particle size: 200 nm): 0.8 g of titanium oxide manufactured by Showa Titanium Co., Ltd.
Solvent: 46g 2-propanol
Dispersant: 3,5-dimethyl-3-amino-1-hexyne 0.2 g

Next, for the dye-sensitized photoelectric conversion element obtained as described above, the short-circuit current, the open-circuit voltage, the fill factor in the current-voltage curve during irradiation with pseudo sunlight (AM1.5, 100 mw / cm ² ), And the photoelectric conversion efficiency was measured. As a result, a dye-sensitized photoelectric conversion device having a conversion efficiency of 6.0% was obtained.

  Table 5 below shows the mixing ratio of the metal oxide semiconductor fine particles having different particle size distributions and the measurement results of the photoelectric conversion efficiency with respect to Sample 7-1 to Sample 7-4.

  Table 5 shows the following. It was found that the photoelectric conversion efficiency was the best when the ratio of the titanium oxide fine particles having an average particle diameter of 200 nm was about 10%, and that the scattering effect was saturated above that.

  As described above, according to the present technology, the porous semiconductor layer provided in the dye-sensitized photoelectric conversion element comprises a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent. It is obtained by coating or printing on a transparent conductive layer and baking. The dispersant is composed of an acetylene hydrocarbon skeleton and has one or more functional groups that are adsorbed on the metal oxide.

  Since the dispersant has the characteristic of volatilizing at a relatively low temperature that does not easily cause deformation of the substrate, substances other than the metal oxide semiconductor particles in the dispersion are effectively removed and the substrate is selected. The resin material can be suitably used as a base material. According to the present technology, a metal oxide semiconductor layer can be formed by a simple method in a low temperature region where a resin material can be used, and a dye-sensitized photoelectric conversion element excellent in power generation efficiency is manufactured. Can do.

  The present technology is not limited to the above-described embodiments of the present technology, and various modifications and applications are possible without departing from the gist of the present technology.

  For example, the configurations, methods, steps, shapes, materials, numerical values, and the like given in the above-described embodiments and examples are merely examples, and different configurations, methods, steps, shapes, materials, numerical values, and the like are necessary as necessary. May be used.

  The configurations, methods, processes, shapes, materials, numerical values, and the like of the above-described embodiments can be combined with each other without departing from the gist of the present technology.

  Further, a module may be formed by combining a plurality of dye-sensitized solar cells (cells) according to the above-described embodiment. The plurality of dye-sensitized solar cells are electrically connected in series and / or in parallel. For example, when combined in series, a high electromotive voltage can be obtained.

DESCRIPTION OF SYMBOLS 1, 21 Dye-sensitized photoelectric conversion element 3, 13 Conductive base material 3a, 13a Conductive layer 3b, 13b Base material 5 Porous semiconductor layer 7 Electrolyte layer 15 Counter electrode 15a Counter electrode 31 Outer coating

Claims (10)

A conductive layer, a porous semiconductor layer, an electrolyte layer, and a counter electrode;
The porous semiconductor layer is obtained by applying or printing a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on the conductive layer and baking the composition.
The dispersant is a dye-sensitized photoelectric conversion element having an acetylene hydrocarbon skeleton and having one or more functional groups adsorbed on the metal oxide semiconductor fine particles.   The dye-sensitized photoelectric conversion element according to claim 1, wherein the dispersant has at least an acetylene alcohol structure or an acetylene diol structure as the acetylene hydrocarbon skeleton.   The dispersant was selected from the group consisting of at least an amino group, a carboxyl group, a hydroxy group, a thiol group, a phosphono group, a cyano group, a nitro group, a sulfonyl group, and a sulfinyl group as a functional group that adsorbs to the metal oxide. The dye-sensitized photoelectric conversion element according to claim 1, comprising at least one kind.   2. The dye-sensitized photoelectric conversion element according to claim 1, wherein the metal oxide semiconductor fine particles have an average primary particle diameter of 5 nm to 500 nm.   The dye-sensitized photoelectric conversion element according to claim 1, wherein the metal oxide semiconductor fine particles include a metal oxide containing at least one of titanium, zinc, tin, and niobium.   The dye-sensitized photoelectric conversion element according to claim 1, wherein the metal oxide semiconductor fine particles include titanium oxide having an anatase type or a brucite type crystal structure. A resin base material having flexibility;
The dye-sensitized photoelectric conversion element according to claim 1, wherein the conductive layer is formed on the resin base material. Applying or printing a porous semiconductor forming composition containing metal oxide semiconductor fine particles, a dispersant and a solvent on the conductive layer;
Firing the applied composition for forming a porous semiconductor, and forming a porous semiconductor layer on the conductive layer;
A step of supporting a sensitizing dye on the porous semiconductor layer;
Providing a counter electrode facing the porous semiconductor layer carrying the sensitizing dye; and
A step of providing an electrolyte layer between the porous semiconductor layer and the counter electrode,
The said dispersing agent consists of acetylene type hydrocarbon frame | skeletons, The manufacturing method of the dye-sensitized photoelectric conversion element which has one or more functional groups adsorb | sucking to the said metal oxide semiconductor fine particle.   The method for producing a dye-sensitized photoelectric conversion element according to claim 8, wherein the firing of the coated or printed composition for forming a porous semiconductor is performed in a temperature range of 40 ° C. or more and 175 ° C. or less. A step of applying or printing a composition for forming a porous semiconductor containing metal oxide semiconductor fine particles, a dispersant and a solvent on a conductive layer, followed by firing.
The said dispersing agent consists of acetylene type hydrocarbon frame | skeleton, The formation method of the metal oxide semiconductor layer which has one or more functional groups which adsorb | suck to the said metal oxide semiconductor fine particle.

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