JP2012146505A - Sheet formation material, and method for producing porous semiconductor electrode using the sheet formation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet formation material capable of easily and efficiently producing a porous semiconductor electrode which can enhance the photoelectric efficiency of a photoelectric conversion element, and a method for producing the porous semiconductor electrode.SOLUTION: The present invention relates to a sheet formation material for transfer and a method for producing a porous semiconductor electrode. In the sheet formation material for transfer, a kneaded material layer containing an oxide semiconductor particle and a binder is formed on a film comprising a resin. In the method for producing the porous semiconductor electrode, the porous semiconductor electrode is obtained by laminating the kneaded material layer of the sheet formation material on a transparent conductive layer of a laminate comprising a transparent heat resistance substrate and the transparent conductive layer and then firing the kneaded material layer.

Description

  The present invention relates to a transfer sheet formation containing an oxide semiconductor and a method for producing a porous semiconductor electrode using the sheet formation.

  As a photoelectric conversion element, a dye-sensitized solar cell has been developed. In dye-sensitized solar cells, light passing through a transparent substrate and a transparent conductive layer excites a sensitizing dye carried on an oxide semiconductor, and the excited electrons move to the transparent electrode via the oxide semiconductor. On the other hand, the electrolyte transmits electrons obtained from the counter electrode to the sensitizing dye via the charge transport layer, and the sensitizing dye returns to its original state. Therefore, in order to increase the photoelectric conversion efficiency, it is important to absorb the incident light as much as possible to the oxide semiconductor.

  As a method of efficiently using incident light by an oxide semiconductor, for example, Non-Patent Document 1 discloses a multilayer structure of oxide semiconductor particles so that the average particle diameter of the oxide semiconductor particles gradually increases from the light incident side. A method is described in which the photoelectric efficiency is increased by forming (see Non-Patent Document 1). Non-Patent Document 2 describes a method of using scattered light and reflected light in a solar cell of incident light (see Non-Patent Document 2).

  On the other hand, the dye-sensitized semiconductor electrode of the dye-sensitized solar cell forms a porous semiconductor electrode by firing a layer coated with a paste in which oxide semiconductor particles are dispersed in a binder on a transparent electrode, It can be obtained by immersing the electrode in a dye solution. Firing is necessary not only to remove the solvent and binder, but also to fuse the oxide semiconductor particles (necking) together to form a porous structure. As a result, while increasing the dye adsorption area, Can be formed.

  Therefore, in order to produce a dye-sensitized semiconductor electrode having a multilayer structure of oxide semiconductor particle layers, it is necessary to repeat the steps of coating and drying and then baking, or to repeat the steps of coating, drying and baking. . In the former case, the firing need not be repeated, but the solvent used for the binder must be a low boiling point solvent such as water. However, since the low boiling point solvent is difficult to control, the former is not practical. On the other hand, in the latter case, since a high boiling point solvent can be used as the solvent used in the binder, control is easy, but it is necessary to repeat firing. When coating, drying and firing are repeated as in the latter case, resistance is formed at the interface between the layers formed in each repeated process, and by repeating firing, necking is excessively promoted, and oxide semiconductor particles There is a problem that an increase in the particle size of the dye causes a decrease in the dye adsorption area, and a decrease in pores and a decrease in ion diffusion space in the electrolytic solution, which hinders improvement in photoelectric efficiency.

  As a method for solving the above problem, a sintered body having a layer containing oxide semiconductor particles having a small particle size and a layer having large particle size or a small particle size and a large particle size oxide semiconductor particle on a heat-resistant substrate is used as a transfer material. As a method, a method of transferring onto a substrate film or a transparent conductive layer serving as an electrode is known (see Patent Document 1). However, with this method, the degree of freedom of the combination of particles is small, and thus, in the formation of a sintered layer having oxide semiconductor particles having a plurality of particle sizes, a method for preparing a paste containing oxide semiconductor particles is also used. And know-how such as coating method was required. Moreover, since the said transfer material is formed on hard heat-resistant base materials, such as glass, ceramics, and a metal, the method of winding a transfer material around a roller and producing efficiently was not employable.

JP 2006-313668 A

Coordination Chemistry Reviews, Elsevier, 2004, 248,1381-1389 Solar Energy Materials & Solar Cells, Elsevier, 1999, 58, 321-326

  This invention makes it a subject to provide the sheet | seat formation material and manufacturing method which can manufacture the porous semiconductor electrode which can raise the photoelectric efficiency of a photoelectric conversion element easily and efficiently.

The present invention comprises, for example, the following [1] to [10].
[1] A sheet-formed product, wherein a kneaded material layer containing oxide semiconductor particles and a binder is formed on a resin film.
[2] (Step 1-1) On the transparent conductive layer on the transparent heat-resistant substrate, the sheet-formed product according to claim 1 is laminated so that the kneaded material layer is in contact with the transparent conductive layer, and then the sheet is formed. Peeling the film of the product from the kneaded material layer,
(Step 2) A method for producing a porous semiconductor electrode, comprising a step of firing the kneaded material layer.
[3] After step 1-1, before step 2 (step 1-2) On the kneaded material layer of the laminate obtained in step 1-1, the sheet formed product according to claim 1 is The method according to [2], including a step of laminating the kneaded material layer so as to be in contact with the kneaded material layer of the laminate and then peeling the film of the sheet-formed material from one time to a plurality of times. A method for producing a porous semiconductor electrode.
[4] In the step 1-1 and the step 1-2, the average particle diameter of the oxide semiconductor particles in the kneaded material layer of the sheet formed product is different for each sheet formed product used in each step [3] ] The manufacturing method of the porous semiconductor electrode of description.

[5] A sheet having a kneaded material layer containing oxide semiconductor particles having the smallest average particle size in a group of sheet formed materials in which the average particle size of the oxide semiconductor particles in the kneaded material layer differs for each sheet formed material. The method for producing a photoelectric conversion element according to [3] or [4], wherein the formed product is used in Step 1-1 and another sheet-formed product is used in Step 1-2.
[6] Step 1-1 and Step 1-2 are performed so that the average particle diameter of the oxide semiconductor particles in the kneaded material layer laminated on the transparent conductive layer increases stepwise from the transparent conductive layer side. The method for producing a porous semiconductor electrode according to any one of [3] to [5], wherein:
[7] In the step 1-1 and the step 1-2, the average particle diameter of the oxide semiconductor particles in the kneaded product layer of the sheet formation is the same in the sheet formation used in any step, The method for producing a porous semiconductor electrode according to [3].
[8] A porous semiconductor electrode manufactured by the manufacturing method according to any one of [2] to [7].
[9] A photoelectric conversion element using the porous semiconductor electrode manufactured by the manufacturing method according to any one of [2] to [7].
[10] The sheet formed product according to [1], which is for producing a porous semiconductor electrode of a photoelectric conversion element.

  When the sheet-formed product of the present invention is used for producing a porous semiconductor electrode of a photoelectric conversion element, the oxide semiconductor of the porous semiconductor electrode is increased in the photoelectric conversion element so that the amount of incident light absorbed by the oxide semiconductor particles is increased. The arrangement of the particles can be arbitrarily adjusted, and the photoelectric efficiency of the photoelectric conversion element can be easily improved. In addition, by forming a sheet formation using a soft film as a substrate, the porous semiconductor layer of the porous semiconductor electrode can be efficiently produced using a roller or the like, and the sheet formation is made into a roll. It is also easy to carry.

FIG. 1 shows a method for manufacturing a porous semiconductor. It is a graph which shows the current-voltage characteristic of a photoelectric conversion element.

Hereinafter, the present invention will be specifically described.
In the present specification, the sheet-formed product is a material to be sintered when a semiconductor is manufactured, in which a layer is formed on a film, and oxide semiconductor particles are mixed with a binder resin or the like to form a paint And a sheet formed by depositing the coating material on a film to a thickness of several μm to several hundred μm and then drying. The particle is not limited to a spherical shape but also includes a rod shape, a needle shape and the like as long as the average particle diameter measured by SEM observation is 1 to 1000 nm.

1. Sheet-formed product The sheet-formed product of the present invention is for transfer, and is characterized in that a kneaded material layer containing oxide semiconductor particles and a binder is formed on a resin film.

  As the resin used for the film used in the sheet-formed product of the present invention, polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, polyvinyl alcohol, vinylon, polyvinylidene chloride, acrylic, triacetylcellulose, polycarbonate, polyethersulfone, Examples thereof include polyphenyl sulfide, polyimide, polyurethane, polyethylene naphthalate, polyetherimide, polyether ether ketone, and cycloolefin, and preferably polyethylene terephthalate.

Since the film needs to be peeled off from the kneaded material layer, a release agent such as silicone is usually applied to the surface in contact with the kneaded material layer.
The thickness of the film is preferably 10 to 200 μm, and more preferably 25 to 100 μm, from the viewpoint of workability at the time of winding the sheet.

  Examples of the oxide semiconductor particles of the kneaded material layer containing the oxide semiconductor particles of the sheet-formed product of the present invention and a binder include titanium oxide, zinc oxide, tungsten oxide, tin oxide, niobium oxide, and indium oxide, preferably Titanium oxide, zinc oxide, and tin oxide are mentioned, More preferably, titanium oxide is mentioned. These oxide semiconductor particles may be used alone or in combination of two or more. As the average particle diameter of the oxide semiconductor particles, the average particle diameter by SEM observation is preferably 1 to 1000 nm, and more preferably 10 to 500 nm. The average particle diameter of the oxide semiconductor particles in the kneaded material layer may be one type or two or more types.

The shape of the oxide semiconductor particles is not particularly limited, and may be a spherical shape, a rod shape, a needle shape, a scale shape, or the like.
The binder contained in the kneaded material layer carries oxide semiconductor particles and is dispersed in the kneaded material layer. Examples of the binder include (meth) acrylic resin, butyral resin, polyether, ethyl cellulose, polyester, polyacetal, polystyrene, polyolefin, polyurethane, etc., preferably (meth) acrylic resin, butyral resin, polyether, ethyl cellulose, Polyester is mentioned, More preferably, (meth) acrylic resin and butyral resin are mentioned. The reason why it is preferable is that the dispersibility and firing properties of the oxide fine particles are good.

  The kneaded material layer contains fine particles such as acrylic fine particles, olefin fine particles, butyral fine particles, and ethyl cellulose fine particles in order to adjust the porous pores after firing the kneaded material layer, as long as the object of the present invention is not impaired. The dispersion stabilizer in the kneaded material layer of oxide semiconductor particles may contain acetylacetone, an acid or an amine, and may contain a plasticizer to give adhesion to the kneaded material layer. Xylene, cyclohexane, n-hexane, n-heptane, n-octane, methylene chloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, ethyl bromide, propyl bromide, isopropyl bromide, diethyl ether, diisopropyl ether , Tetrahydrofuran, 1,2-dimethoxyethane, dimethylformamide, dimethylacetamide, acetonitrile n-butylnitrile, nitromethane, nitroethane, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, acetylacetone, methyl acetate, ethyl acetate, isopropyl acetate, N-butyl acetate, amyl acetate, n-butyl butyrate, methanol, ethanol, isopropanol, n-butanol, 2-butanol, t-butanol, cyclohexanol, 2-ethylhexanol, ethylene glycol, propylene glycol, 1,3-butane Diol, diethylene glycol, methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ether, propylene group Monoethyl ether, may contain a dispersing solvent such as 3-methoxy-3-methyl-1-butanol.

  In the kneaded material layer, the mass ratio of the oxide semiconductor particles and the binder is preferably 80:20 to 40:60, more preferably 70:30 to 50:50 in terms of solid content. The above compounding ratio is because the dispersibility and transferability of the oxide semiconductor particles are good. In the kneaded product layer, the mass of the dispersion solvent is preferably 1 to 7 times the mass of the total solid content.

The thickness of the kneaded material layer applied to the film and dried is preferably 5 to 50 μm, more preferably 15 to 40 μm from the viewpoints of the film thickness after firing, transferability and sheet strength.
In the method for producing a sheet-formed product, first, the above components are kneaded by a method capable of uniformly dispersing oxide semiconductor particles such as a rotation / revolution mixer, a bead mill, and a three roll mill. Next, the kneaded product is applied on the film to a thickness of 10 to 100 μm by, for example, a gravure coater, a Meyer bar coater, a doctor blade, a die coater, etc., and then dried at 80 to 150 ° C. for about 1 to 10 minutes. To do.

2. Manufacturing method of porous semiconductor electrode The manufacturing method of the porous semiconductor electrode of this invention is demonstrated using FIG.
The method for producing the porous semiconductor electrode of the present invention comprises:
(Step 1-1) The sheet-formed product of the present invention is laminated on the transparent conductive layer on the transparent heat-resistant substrate so that the kneaded material layer is in contact with the transparent conductive layer, and then the film of the sheet-formed product is kneaded. Peeling from the layer;
(Step 2) including the step of firing the kneaded product layer, preferably further after Step 1-1 and before Step 2 (Step 1-2) kneading the laminate obtained in Step 1-1 A step of laminating the sheet-formed product of the present invention on the material layer so that the kneaded material layer is in contact with the kneaded material layer of the laminate, and then peeling the film of the sheet-formed product from once to a plurality of times May be included.

(Step 1-1)
As shown in (I) of FIG. 1, the sheet-formed product A-1 of the present invention is placed on the transparent conductive layer 2 on the transparent heat-resistant substrate 1 so that the kneaded product layer 3-1 is in contact with the transparent conductive layer 2. Laminate. Next, the film 4 of the sheet-formed product A-1 is peeled from the kneaded material layer 3-1, and as shown in FIG. 1 (II), the transparent heat-resistant substrate 1, the transparent conductive layer 2, and the kneaded material layer are sequentially formed from the bottom. A laminate in which 3-1 is laminated is manufactured.

  The transparent heat-resistant substrate 1 is not particularly limited as long as it is a plate having transparency and heat resistance, but includes ceramics such as glass. This is because it has good transparency and can withstand firing.

  The transparent conductive layer 2 is not particularly limited as long as it is a conductive material layer having transparency, but fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), tin oxide, antimony oxide, antimony-doped tin oxide (ATO). ), A layer obtained by combining one or more of niobium-doped titanium oxide and the like.

From the viewpoint of adhesion after bonding, the temperature of the laminate of the transparent heat-resistant substrate 1 and the transparent conductive layer when the kneaded material layer 3-1 is laminated on the transparent conductive layer 2 is 20 to 120 ° C. preferable.
The thickness of the kneaded material layer 3-1 is 5 to 50 μm, preferably 15 to 40 μm.

(Step 1-2)
As shown in FIG. 1 (III), the sheet-formed product A-2 of the present invention is formed of a laminate of the transparent heat-resistant substrate 1, the transparent conductive layer 2 and the kneaded material layer 3-1 produced in step 1-1. It laminates | stacks so that the kneaded material layer 3-2 may contact | connect on the kneaded material layer 3-1. Next, the film 4 of the sheet-formed product A-2 is peeled from the kneaded material layer 3-2, and as shown in FIG. 1 (IV), the transparent heat-resistant substrate 1, the transparent conductive layer 2, and the kneaded material layer are sequentially arranged from the bottom. A laminate in which the 3-1 and the kneaded material layer 3-2 are laminated is manufactured.

Step 1-2 may be repeated. That is, you may laminate | stack the further kneaded material layer 3-n (n is an integer greater than or equal to 3) on the kneaded material layer 3-2 using sheet | seat formation material An.
As thickness of each kneaded material layer 3-2-3-n, it is 5-50 micrometers, Preferably it is 15-40 micrometers.

The sheet formed product A-1 used in the step 1-1 and the sheet formed products A-2 to An used in the step 1-2 have different average particle diameters of the oxide semiconductor particles in the kneaded material layer for each sheet. Preferably it is. For example, the kneaded material layer 3-1 contains small particles (average particle size of 10 to 30 nm by SEM observation) of oxide semiconductor particles, and the kneaded material layer 3-2 has large particles (average particle size of 100 to 500 nm by SEM observation). In addition, the kneaded material layer 3-1 contains small oxide semiconductor particles, and the kneaded material layer 3-2 contains medium particles (average particle diameter of 30 nm by SEM observation). And less than 100 nm) and large oxide semiconductor particles are contained, the kneaded material layer 3-1 has small oxide semiconductor particles, 3-2 has medium oxide semiconductor particles, 3-3 has Examples include large oxide semiconductor particles. Among these, the average of the oxide semiconductor particles contained in the kneaded material layer 3-1 of the sheet formation A-1 used in step 1-1 among the group of sheet formations having different average particle diameters of the oxide semiconductor particles. The particle diameter is preferably smaller than the average particle diameter of the oxide semiconductor particles contained in the kneaded material layers 3-2 to 3-n of the other sheet-formed products A-2 to An. In addition, the sheet formation is selected from a group of sheet formations having different average particle diameters of the oxide semiconductor particles so that the average particle diameter of the oxide semiconductor particles gradually increases from the transparent conductive layer side, and kneaded. It is also preferable to stack physical layers.
The reason is as follows.

  A photoelectric conversion element is required to efficiently use light that has passed through a transparent substrate and a transparent conductive layer in a kneaded material layer containing oxide semiconductor particles adsorbed with a sensitizing dye. For this purpose, it is desirable to scatter the light that has passed without being absorbed by the oxide semiconductor particles upon incidence and use it again for absorption. Therefore, the average particle diameter of the oxide semiconductor particles in the kneaded material layer is selected from that viewpoint, and it is preferable to use oxide semiconductor particles having a plurality of average particle diameters. For example, the average particle diameter of the oxide semiconductor particles contained in the kneaded material layer 3-1 closest to the transparent conductive layer side formed in step 1-1 is the smallest, and the kneaded material formed in step 1-2 In the layers 3-2 to 3 -n, if oxide semiconductor particles having an average particle size larger than the average particle size of the oxide semiconductor particles in the kneaded material layer 3-1 are used, they are absorbed by the kneaded material layer 3-1. The light which was not present is scattered by the kneaded material layers 3-2 to 3 -n, returned to the kneaded material layer 3-1, and absorbed by the oxide semiconductor particles in the kneaded material layer 3-1. Can be used well. The same applies to the case where the average particle diameter of the oxide semiconductor particles increases stepwise from the transparent conductive layer side.

  The adjustment of the particle arrangement in the layer containing the oxide semiconductor particles as described above has been conventionally left to the coating technique, but in the present invention, in steps 1-1 and 1-2, oxidation is performed for each sheet formed product. This can be easily carried out by laminating the kneaded product layer using a sheet-formed product selected from a group of sheet-formed products having different average particle diameters.

  Furthermore, the sheet formed product A-1 used in step 1-1 and the sheet formed products A-2 to An used in step 1-2 are the average particle diameters of the oxide semiconductor particles in the kneaded product layer for each sheet. May be the same.

  By stacking the kneaded material layers containing oxide semiconductor particles having the same average particle diameter, the amount of dye adsorbed in the cell can be increased, and the amount of light absorbed in the cell can be increased.

(Process 2)
Single layer or laminated kneaded material layer 3-1 formed in Step 1-1 and optional Step 1-2, or 3-1 and 3-2, or 3-1 and 3-2 to 3-n (n Is an integer of 3 or more.

The firing condition is required to be a temperature at which the binder disappears, and is, for example, about 400 ° C to 1000 ° C.
By baking, a binder, an additive, etc. lose | disappear, and a porous semiconductor electrode is manufactured.
3-40 micrometers is preferable and, as for the thickness of each layer of the kneaded material layer 3-1 to 3-n after baking, 5-30 micrometers is more preferable.

3. Photoelectric Conversion Element The porous semiconductor electrode manufactured by the manufacturing method of the present invention can be used for a photoelectric conversion element. A method for producing a photoelectric conversion element comprises: immersing a porous semiconductor electrode produced by the production method of the present invention in a photosensitizing dye; and then adsorbing the porous semiconductor electrode adsorbed with the dye and a photoelectric conversion element substrate having a counter electrode. Join using an adhesive or the like. Then, the space between the porous semiconductor electrode and the counter electrode is filled with the electrolyte solution. As the photosensitizing dye, in addition to complex dyes such as Ru complex, phthalocyanine, and porphyrin, organic dyes such as carbazole, coumarin, xanthene, and indoline can be used. As the photoelectric conversion element substrate having the counter electrode, a known conductive material can be used without limitation, in addition to platinum, gold, silver, palladium, aluminum, carbon, an organic conductive material such as PEDOT, and the porous semiconductor electrode of the present application. The material used for the transparent conductive layer can also be used. The electrolyte solution may be a liquid containing a known electrolyte such as iodine, iodide salt, imidazolium salt, pyridine, or a solid organic / inorganic hole transport material.

  The photoelectric conversion element generates power when light enters from the electrode side of the porous semiconductor electrode of the present invention.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
In the present specification, the following values were measured by the following measuring methods unless otherwise specified.

<Average particle size>
By particle size distribution measurement by SEM observation.
[Polymer production example 1 (for binder)]
A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 60 parts by weight of toluene, 98 parts by weight of 2-ethylhexyl methacrylate, and 2 parts by weight of 2-hydroxyethyl methacrylate, and nitrogen gas was introduced into the flask. The mixture was stirred for 30 minutes and purged with nitrogen, and then the contents of the flask were heated to 90 ° C. Then, while maintaining the contents in the flask at 90 ° C., 0.3 part by weight of dimethyl 2,2-azobis (2-methylpropinate) was added to initiate polymerization. Every 2 hours from the start of polymerization, 0.3 part by weight of 2,2-azobis (2-methylpropinate) was added three times in total. 12 hours after the start of polymerization, 10 parts by weight of toluene was added and cooled to room temperature to obtain a polymer (A) having a polymer solid content of 55%. The obtained polymer (A) had a weight average molecular weight (in terms of polystyrene measured by GPC method, hereinafter the same) of 150,000.

[Polymer production example 2 (for binder)]
A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser is charged with 60 parts by weight of toluene, 98 parts by weight of 2-ethylhexyl methacrylate, and 2 parts by weight of acrylic acid, while introducing nitrogen gas into the flask. After stirring for 30 minutes and purging with nitrogen, the contents of the flask were heated to 90 ° C. Then, while maintaining the contents in the flask at 90 ° C., 0.3 part by weight of dimethyl 2,2-azobis (2-methylpropinate) was added to initiate polymerization. Every 2 hours from the start of polymerization, 0.3 part by weight of 2,2-azobis (2-methylpropinate) was added three times in total. 12 hours after the start of polymerization, 10 parts by weight of toluene was added and cooled to room temperature to obtain a polymer (B) having a polymer solid content of 55%. The weight average molecular weight of the obtained polymer (B) was 150,000.

[Example 1]
4g of titanium oxide particles (trade name P-25, average particle size 21nm (by SEM observation particle size distribution measurement), manufactured by Degussa) in a butanol 16g using a bead mill (product name pulverisette7, manufactured by FRITSCH, the same shall apply hereinafter) To obtain a titanium oxide particle dispersion. 4.85 g of the polymer (A) was added to the obtained dispersion, and the mixture was stirred using a rotation / revolution mixer (product name: Awatori Nertaro ARE-310, manufactured by Shinky Co., Ltd., hereinafter the same) to obtain a kneaded product. (Mixed mass ratio of titanium oxide particles and polymer (A) = 60: 40 (solid content ratio)).

  60 μm of the kneaded product was peeled onto the surface of a polyethylene terephthalate film (thickness: 40 μm) (trade name: MERAPE, manufactured by Toray Film Processing Co., Ltd., the same applies hereinafter) that was peeled off with silicone by a doctor blade (clearance 60 μm) After coating to a thickness, the sheet was dried at 90 ° C. for 10 minutes with a hot air circulation dryer to obtain a sheet formed product (a). The thickness of the kneaded material layer was 25 μm.

  The kneaded material layer of the sheet-formed product (a) is formed on a transparent conductive layer of glass having a fluorine-doped tin oxide thin film (hereinafter also referred to as FTO glass) (trade name A110U80, manufactured by Asahi Glass Co., Ltd., the same shall apply hereinafter) at 100 ° C. The porous titanium oxide electrode (a) was obtained by sintering in an oven at 450 ° C. for 15 minutes. The thickness of the kneaded material layer after firing was 16.1 μm.

[Example 2]
A sheet formed product (b) was obtained by the same operation except that the polymer (B) was used instead of the polymer (A). A porous titanium oxide electrode (b) was obtained by the same transfer method and firing method as in Example 1 using the sheet formed product (b).

[Example 3]
4 g of titanium oxide particles (P-25) were dispersed in 16 g of butanol using a bead mill. 28 g of a polyvinyl butyral (trade name ESREC BH-3, manufactured by Sekisui Chemical Co., Ltd., the same applies hereinafter) solution dissolved in toluene and ethanol 50:50 (weight ratio) in the dispersion so as to have a solid content of 10%, As a plasticizer, 1.2 g of dibutyloctyl phthalate was added and mixed and stirred using a rotation / revolution mixer to obtain a kneaded product (mixing mass ratio of titanium oxide particles, polyvinyl butyral, and plasticizer = 50: 35: 15 ( Solids ratio)).

The kneaded material was applied to a thickness of 90 μm on the surface of the polyethylene terephthalate film (therapeutic MFA) with a doctor blade (clearance 150 μm), and then dried at 90 ° C. for 10 minutes with a hot air circulation dryer. A formation (c) was obtained. The thickness of the kneaded material layer was 25 μm.
Using this sheet formed product (C), a porous titanium oxide electrode (c) was obtained by the same transfer method and firing method as in Example 1.

[Example 4]
4 g of titanium oxide particles (P-25) were dispersed in 16 g of butanol using a bead mill. 28 g of an ethyl cellulose solution (trade name Etcel Gr. 10, manufactured by Nisshinsei Co., Ltd., the same applies hereinafter) dissolved in ethyl acetate so as to have a solid content of 10% in the dispersion, and dibutyloctylphthalate as a plasticizer. 2 g was added and mixed and stirred using a rotation / revolution mixer to obtain a kneaded product (mixed mass ratio of titanium oxide particles, ethyl cellulose and plasticizer = 50: 35: 15 (solid content ratio)).

The above kneaded material is applied to the surface of the peeled surface of the therapeutic MFA with a doctor blade (clearance 150 μm) to a thickness of 90 μm, and then dried at 90 ° C. for 10 minutes with a hot air circulating drier to form a sheet formed product (d) Got. The thickness of the kneaded material layer was 25 μm.
Using this sheet-formed product (d), a porous titanium oxide electrode (d) was obtained by the same transfer method and firing method as in Example 1.

[Example 5]
The kneaded material layer of the sheet-formed product (c) produced in Example 3 was transferred onto the transparent conductive layer of FTO glass (A110U80) in the same manner as in Example 1, and further, the kneaded material layer at 100 ° C. on the kneaded material layer. The kneaded product layer of the sheet-formed product (c) was further transferred to obtain a laminate. The laminate was fired in the same manner as in Example 1 to obtain a porous titanium oxide electrode (cc) in which two layers were laminated.

[Example 6]
A sheet-formed product (e) was produced under the same conditions as in Example 3 except that titanium oxide having a large particle size (trade name ST41, average particle size 160 nm (converted from the BET method), manufactured by Ishihara Sangyo Co., Ltd.) was used. . After transferring the kneaded product layer of the sheet formed product (c) onto the transparent conductive layer of FTO glass (A110U80), the kneaded product layer of the sheet formed product (e) was transferred onto the kneaded product layer at 100 ° C. and laminated. . The laminate was fired in the same manner as in Example 1 to obtain a porous titanium oxide electrode (ce) in which two layers were laminated.

[Production Example 1]
The calcined porous titanium oxide electrode obtained in Example 1 was immersed in an Ru complex (commonly known as N719) dye (PECD07, manufactured by Pexel Technologies) acetonitrile solution for 18 hours, then rinsed with acetonitrile, dried and dyed. A sensitizing electrode was prepared. The semiconductor surface of the dye-sensitized electrode was bonded to a platinum electrode via a 30 μm thermal adhesive film (trade name HM-52, manufactured by Tamapoly). Thereafter, a solution of iodine, lithium iodide, 1,2-dimethyl-3-propylimidazolium iodide and 4-tert-butylpyridine dissolved in acetonitrile was injected between the electrodes, and the dye-sensitized photoelectron was then added. A conversion element was produced.

[Production Example 2]
A dye-sensitized photoelectric conversion element was produced in the same manner as in Production Example 1 using the fired porous titanium oxide electrode (b) obtained in Example 2.

[Production Example 3]
A dye-sensitized photoelectric conversion element was produced in the same manner as in Production Example 1 using the fired porous titanium oxide electrode (c) obtained in Example 3.

[Production Example 4]
A dye-sensitized photoelectric conversion element was produced in the same manner as in Production Example 1 using the fired porous titanium oxide electrode (d) obtained in Example 4.

[Production Example 5]
A dye-sensitized photoelectric conversion element was produced in the same manner as in Production Example 1 using the fired porous titanium oxide electrode (cc) obtained in Example 5.

[Production Example 6]
A dye-sensitized photoelectric conversion element was produced in the same manner as in Production Example 1 using the fired porous titanium oxide electrode (ce) obtained in Example 6.

[Performance evaluation of photoelectric conversion elements]
1SUN, simulated sunlight (incident light intensity 100mW / cm ² (AM1.5) is used as the light source, incident from the dye-sensitized electrode side of the photoelectric conversion element, and voltage is applied by a voltage / current generator (R6243, manufactured by ADVANTEST) The current-voltage characteristics were measured.

  The sheet-formed product and porous semiconductor manufacturing method of the present invention can be used for manufacturing a photoelectric conversion element.

1: Transparent heat-resistant substrate 2: Transparent conductive layer 3-1, 3-2: Kneaded material layer 4: Film A-1, A-2: Sheet formed product

Claims (10)

A sheet-formed product, wherein a kneaded material layer containing oxide semiconductor particles and a binder is formed on a resin film. (Step 1-1) On the transparent conductive layer on the transparent heat-resistant substrate, the sheet-formed product according to claim 1 is laminated so that the kneaded material layer is in contact with the transparent conductive layer, and then the film of the sheet-formed product Peeling from the kneaded material layer,
(Step 2) A method for producing a porous semiconductor electrode, comprising a step of firing the kneaded material layer. After step 1-1, before step 2 (Step 1-2) On the kneaded product layer of the laminate obtained in Step 1-1, the sheet-formed product according to claim 1 is added to the kneaded product layer. 3. The porous semiconductor according to claim 2, further comprising a step of laminating the laminate so as to be in contact with the kneaded material layer of the laminate and then peeling the film of the sheet-formed product from one time to a plurality of times. Electrode manufacturing method.   The average particle diameter of the oxide semiconductor particles in the kneaded material layer of the sheet formation in Step 1-1 and Step 1-2 is different for each sheet formation used in each step. Manufacturing method of porous semiconductor electrode.   A sheet-formed product having a kneaded material layer containing oxide semiconductor particles having the smallest average particle size among the group of sheet-formed products in which the average particle size of the oxide semiconductor particles in the kneaded material layer is different for each sheet-formed material. The method for producing a porous semiconductor electrode according to claim 3 or 4, wherein the other sheet-formed product is used in the step 1-1 and used in the step 1-1.   Step 1-1 and Step 1-2 are performed such that the average particle diameter of the oxide semiconductor particles in the kneaded material layer laminated on the transparent conductive layer is increased stepwise from the transparent conductive layer side. The manufacturing method of the porous semiconductor electrode as described in any one of Claims 3-5.   The average particle diameter of the oxide semiconductor particles in the kneaded product layer of the sheet formed product in Step 1-1 and Step 1-2 is the same in any sheet formed product used in any step. 4. A method for producing a porous semiconductor electrode according to 3.   The porous semiconductor electrode manufactured with the manufacturing method as described in any one of Claims 2-7.   The photoelectric conversion element using the porous semiconductor electrode manufactured with the manufacturing method as described in any one of Claims 2-7.   The sheet-formed product according to claim 1, which is for producing a porous semiconductor electrode of a photoelectric conversion element.

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