JP5144986B2 - Dye-sensitized solar cell and dye-sensitized solar cell module - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell and a dye-sensitized solar cell module. More specifically, the present invention relates to a dye-sensitized solar cell in which a conductive layer for current collection is formed while minimizing a reduction in light receiving area, and a dye-sensitized solar cell module using the same.

Dye-sensitized solar cells are attracting widespread attention because they exhibit high photoelectric conversion efficiency among organic solar cells. In such a dye-sensitized solar cell, a semiconductor film having a spectral dye adsorbed on its surface and having an absorption spectrum in the visible light region is used as a photoelectric conversion material.
For example, Japanese Patent No. 2664194 (Patent Document 1) describes a dye-sensitized solar cell using, as a photoelectric conversion material, a metal oxide semiconductor film having a surface adsorbed with a spectral dye made of a transition metal complex. .

Japanese Patent Publication No. 8-15097 (Patent Document 2) describes a dye-sensitized solar cell having a spectral dye layer such as a transition metal complex on the surface of a titanium oxide semiconductor film doped with metal ions. .
Further, JP-A-7-249790 (Patent Document 3) discloses dye sensitization using a semiconductor film for a photoelectric conversion material obtained by heating and refluxing an ethanol solution of a spectral sensitizer on the surface of a semiconductor film. A solar cell is described.

For example, a dye-sensitized solar cell is one in which a photoelectric conversion layer composed of the above-described photoelectric conversion material and electrolyte layer material (electrolytic solution) is sandwiched between electrodes of two glass substrates having electrodes formed on the surface. is there. A dye-sensitized solar cell (see FIG. 2) using such an electrolytic solution is generally produced as follows.
First, a transparent conductor film 22 and a porous semiconductor film 23 such as titanium oxide are sequentially formed on the transparent support 21, and a dye is adsorbed on the obtained porous semiconductor film 23. Next, a catalyst layer 26 such as a platinum film is optionally formed (coated) on the counter electrode 25, and the transparent support 21 and the counter electrode 25 are overlapped so that the porous semiconductor film 23 and the catalyst layer 26 or the counter electrode 25 face each other. Match. Next, an electrolyte solution is injected between them to form an electrolyte solution layer 24, and the side surfaces of the transparent support 21 and the counter electrode 25 are sealed with a sealing material 27 such as an epoxy resin, whereby a dye-sensitized solar cell is obtained. obtain.

  However, the basic structure of the dye-sensitized solar cell as described above is a mode in which an electrolyte is injected between the electrodes of two glass substrates, and even if a small-area solar cell can be prototyped, a 1 m square It is difficult to apply to a large area solar cell. That is, when the area of one solar cell is increased, the generated current increases in proportion to the area, but the resistance in the in-plane direction of the transparent conductive layer used for the electrode portion increases, and as a result, the internal series electricity as a solar cell increases. Resistance increases. As a result, there arises a problem that the characteristics of the solar battery cell, that is, the fill factor (FF) in the current-voltage characteristics at the time of photoelectric conversion, and further, the short-circuit current is lowered and the photoelectric conversion efficiency is lowered.

In order to solve the above problems, the following techniques have been proposed.
In Japanese Patent Laid-Open No. 2000-285777 (Patent Document 4), for the purpose of reducing the substrate resistance when the area of the dye-sensitized solar cell is increased, metal leads (busper electrodes and grids) are formed on the transparent conductive substrate. A photoelectric conversion element in which an electrode or the like is formed and a photovoltaic cell using the photoelectric conversion element are described.
Japanese Patent Laid-Open No. 2004-39471 (Patent Document 5) increases the thickness of an oxide semiconductor film for the purpose of using light on a longer wavelength side and improving the open-circuit voltage, and A dye-sensitized solar cell in which a conductive layer is formed on at least a part of the oxide semiconductor film opposite to the transparent electrode is described.
Furthermore, Japanese Patent No. 3237621 (Patent Document 6) describes a photoelectric conversion device in which unit photoelectric conversion elements are connected in series by connecting to a back electrode through a through hole penetrating a substrate.

Japanese Patent No. 2664194 Japanese Patent Publication No. 8-15097 JP 7-249790 A JP 2000-285777 A JP 2004-39471 A Japanese Patent No. 3237621

In the photoelectric conversion element described in Patent Document 4, since a metal lead is formed on a transparent electrode, a porous semiconductor film may not be formed and a porous semiconductor film may be formed on a metal lead. Even in this case, the metal lead portion blocks the light, so that the light receiving area is reduced. Therefore, if the distance between the metal leads is increased in order to increase the light receiving area, the resistance of the transparent electrode is increased, and the cell characteristics are deteriorated.
As described above, in the dye-sensitized solar cell, it is difficult to reduce the resistance of the transparent electrode while securing a large light receiving area.

  The present invention relates to a dye-sensitized solar cell (hereinafter, also referred to as a “solar cell”) having a high open-circuit voltage and photoelectric conversion efficiency, in which a decrease in the light receiving area is suppressed and the resistance of the transparent electrode is reduced, and It is an object to provide a dye-sensitized solar cell module (hereinafter also referred to as “module”).

  As a result of intensive studies to solve the above problems, the present inventors have found that in a dye-sensitized solar cell in which a porous semiconductor film on which a dye is adsorbed is formed on at least part of the non-light-receiving surface side of the transparent electrode The porous semiconductor film is provided with a through-hole that reaches the transparent electrode from the non-light-receiving surface side, and the transparent electrode in the through-hole and the transparent electrode in the region where the porous semiconductor film is not formed are connected to the porous semiconductor film. The inventors have found that the above problems can be solved by electrically connecting the conductive layers provided on the light receiving surface side, and have completed the present invention.

Thus, according to the present invention, the transparent electrode formed on the translucent substrate serving as the light-receiving surface and the counter electrode are arranged to face each other through the electrolyte layer, and the porous semiconductor film on which the dye is adsorbed is formed on the non-transparent electrode. a solar cell which is formed on at least a portion of the light-receiving surface side, the porous semiconductor film is provided with a through hole surrounded by reach vital said porous semiconductor film on the transparent electrode from the non-light-receiving side, In addition, the transparent electrode in the through hole and the transparent electrode in a region where the porous semiconductor film is not formed are electrically connected by a conductive layer formed on the non-light-receiving surface side of the porous semiconductor film. A solar cell is provided.

  In addition, according to the present invention, there is provided a module characterized in that the transparent electrode and the counter electrode of each of at least two or more solar cells including the above solar cell are electrically connected in series.

  According to the present invention, the porous semiconductor film is provided with a through hole reaching the transparent electrode from the non-light-receiving surface side, and the transparent electrode in the through hole and the transparent electrode in the region where the porous semiconductor film is not formed are porous. Electrically connected by a conductive layer provided on the non-light-receiving surface side of the conductive semiconductor film, that is, a through-hole is formed in the porous semiconductor film, and the through-hole and the transparent electrode in and around the through-hole are electrically connected by the conductive layer. Since it connects, the resistance of a transparent electrode can be reduced and the solar cell which has the outstanding photoelectric conversion efficiency, and a module using the same can be provided.

  The solar cell described in Patent Document 5 uses long-wavelength light by taking out electrons from both sides of a thick porous semiconductor film, and improves the open-circuit voltage. The effect is quite different. Further, the photoelectric conversion device described in Patent Document 6 is a device in which a through hole is formed in a substrate itself to connect a lower electrode and an upper electrode, and the form is completely different from the solar cell of the present invention.

In the solar cell of the present invention, a transparent electrode formed on a light-transmitting substrate serving as a light-receiving surface and a counter electrode are disposed to face each other through an electrolyte layer, and a porous semiconductor film on which a dye is adsorbed is formed on the non-transparent electrode. A solar cell formed on at least a part of the light receiving surface side, wherein the porous semiconductor film has a through hole reaching the transparent electrode from the non-light receiving surface side, and the transparent electrode in the through hole and the The transparent electrode in a region where a porous semiconductor film is not formed is electrically connected by a conductive layer formed on the non-light-receiving surface side of the porous semiconductor film.
The module of the present invention is characterized in that the transparent electrode and the counter electrode of at least two or more solar cells including the above-described solar cell are electrically connected in series.

A preferred embodiment of the solar cell of the present invention will be described with reference to the drawings. In addition, this embodiment is an example and implementation with a various form is possible within the scope of the present invention.
FIG. 22 is a schematic cross-sectional view of the main part showing the layer structure of the solar cell of the present invention. In the figure, 220 is a translucent substrate, 221 is a transparent electrode, 222 is a porous semiconductor film that adsorbs a dye and is filled with an electrolytic solution, 223 is a through-hole and a transparent electrode in and around the through-hole. Electrically connected conductive layer, 224 is a catalyst layer (platinum film), 225 is a support substrate with a counter electrode (ITO conductive substrate), 226 is a heat fusion film, 227 is a hole for electrolyte injection, 228 is an electrolyte layer, 229 is an ultraviolet curable resin, and 230 is a collecting electrode portion. The “surrounding transparent electrode” in FIG. 223 means the outer periphery and the outer side of the porous semiconductor film in a region where the porous semiconductor film is not formed.

As shown in FIG. 1, in the present invention, the “through hole (No. 3)” included in the porous semiconductor film refers to the transparent electrode 1 from the non-light-receiving surface side surrounded by the porous semiconductor film 2. The hole which reaches | attains, ie, the hole formed in the porous semiconductor film 2 so that the transparent electrode 1 may be exposed is shown.
FIG. 1A shows a schematic plan view showing through-holes formed in the porous semiconductor film in the solar cell of the present invention, and FIG. 1B shows a schematic cross-sectional view (XY cross section).

The through hole is not limited as long as the transparent electrode in the through hole and the transparent electrode in the region where the porous semiconductor film is not formed can be electrically connected via the conductive layer. However, in order to maximize the effects of the present invention, it is preferable to have a plurality. The distance between the through holes is 0.5 to 40 mm, preferably 1 to 10 mm.
The through-holes are provided to reduce the resistance of the transparent electrodes. If the distance between the through-holes is long, the effect of the resistance of the transparent electrode becomes large. If the distance is short, many through-holes will be formed. The above range is preferred because the area is greatly reduced.

Moreover, it is preferable that at least one through hole is formed at a distance of 0.5 to 40 mm, preferably 1 to 10 mm from the outer periphery of the porous semiconductor film.
Similar to the above, if the distance between the through hole and the outer periphery of the porous semiconductor film is long, the effect of the resistance of the transparent electrode becomes large, and if the distance is short, many through holes are formed and the light receiving area is greatly reduced. Therefore, the above range is preferable.

Area of the through holes, 0.01~100mm ² / number, preferably 0.01 to 10 mm ^2. If the area of the through hole is small, the light receiving area is reduced, and if the area is large, it is difficult to obtain the effect of reducing the resistance of the transparent electrode. Therefore, the above range is preferable.
The total area of the through holes is 0.05 to 15%, preferably 0.5 to 10% of the total area of the porous semiconductor film including the through holes. If the total area of the through-holes is small, the necessary number of through-holes for sufficient electrical connection with the transparent conductive film cannot be formed, and if it is large, the light-receiving area is reduced. preferable.

The shape of the through hole is not particularly limited as long as the transparent electrode in the through hole and the transparent electrode in the region where the porous semiconductor film is not formed can be electrically connected via the conductive layer. Examples of the shape include a circle, an ellipse, and a polygon.
In addition, if the transparent electrode inside the through hole and the conductive layer can be electrically connected, the formed through hole has a constituent material such as a porous semiconductor film attached to a part of the transparent electrode inside, or the through hole A part of the transparent conductive film may be lost at the time of forming.

In the solar cell of the present invention, it is preferable that the transparent conductive film in at least one through hole of the plurality of through holes and the transparent conductive film around the porous semiconductor film are not electrically connected except for the conductive layer ( See Example 7).
Next, a porous semiconductor film provided with through holes will be described.

(Porous semiconductor film)
The material which comprises a porous semiconductor film will not be specifically limited if it is generally used for a photoelectric conversion material. Examples of such materials include titanium oxide, zinc oxide, tin oxide, iron oxide, niobium oxide, cerium oxide, tungsten oxide, barium titanate, strontium titanate, cadmium sulfide, lead sulfide, zinc sulfide, and indium phosphide. , Semiconductor compounds such as copper-indium sulfide (CuInS ₂ ), CuAlO ₂ , SrCu ₂ O ₂ , and combinations thereof. Among these, titanium oxide is particularly preferable from the viewpoint of stability and safety.

  This titanium oxide includes various narrowly defined titanium oxides such as anatase type titanium oxide, rutile type titanium oxide, amorphous titanium oxide, metatitanic acid, orthotitanic acid, titanium hydroxide, hydrous titanium oxide, etc. Or it can be used as a mixture. The two types of crystal systems, anatase type and rutile type, can be in any form depending on the production method and thermal history, but the anatase type is common. In the present invention, with respect to dye sensitization, those having a high anatase type content, for example, 80% or more are particularly preferred.

  As for the form of the semiconductor film, a porous semiconductor film obtained by sintering semiconductor fine particles, etc., a thin-film semiconductor film obtained by a sol-gel method, a sputtering method, a spray pyrolysis method, a fibrous semiconductor film, and an acicular crystal The semiconductor film etc. which will be mentioned are mentioned, It can select suitably according to the intended purpose of a solar cell. Among these, a semiconductor film having a large specific surface area such as a porous semiconductor film or a semiconductor film made of needle crystals is preferable from the viewpoint of the amount of dye adsorption. In addition, a porous semiconductor film formed from semiconductor fine particles is particularly preferable from the viewpoint that the utilization factor of incident light can be adjusted by the particle size of the semiconductor fine particles.

  The semiconductor fine particles can be produced by a known method such as a sol-gel method such as a hydrothermal synthesis method, a sulfuric acid method, or a chlorine method, and is not particularly limited as long as the target semiconductor fine particles can be produced. Among these, the hydrothermal synthesis method is particularly preferable from the viewpoint of crystallinity.

  The average particle size of the semiconductor fine particles is about 1 nm to 500 nm, and about 1 to 50 nm is preferable from the viewpoint of increasing the specific surface area of the porous semiconductor film. In addition, in order to efficiently use incident light in a solar cell, semiconductor fine particles having different average particle diameters may be mixed. For example, the semiconductor fine particles have large average particle diameters of about 200 to 400 nm. May be added.

  The thickness of the porous semiconductor film is not particularly limited, but is preferably about 0.5 to 45 μm from the viewpoints of permeability, conversion efficiency, and the like.

(Method for forming porous semiconductor film)
A porous semiconductor film is, for example, a semiconductor fine particle optionally added together with an organic compound such as a polymer to a dispersant, an organic solvent, water, etc. and dispersed to obtain a suspension, and the suspension is formed on a transparent substrate It can apply | coat on the made transparent conductive film, and can form by drying and baking the obtained coating film.

By adding an organic compound to the suspension, the organic compound is burned in the firing step, and a void can be secured in the porous semiconductor film. Further, the porosity of the porous semiconductor film can be changed by selecting the molecular weight or the addition amount of the organic compound.
Such an organic compound is not particularly limited as long as it can be dissolved in a suspension and burned and removed in a baking step, and examples thereof include polymers such as polyethylene glycol and ethyl cellulose.

  The type and amount of the organic compound may be appropriately set depending on the type of semiconductor fine particles used and the ratio to the total weight of the suspension. When the proportion of the semiconductor fine particles is too small, the desired strength as the porous semiconductor film of the solar cell may not be obtained. When the proportion of the semiconductor fine particles is too large, the desired strength as the porous semiconductor film may be obtained. Porosity may not be obtained. Therefore, the ratio of the semiconductor fine particles to the total weight of the suspension is, for example, about 10 to 40% by weight.

  Examples of the organic solvent include glyme solvents such as ethylene glycol monomethyl ether, alcohol solvents such as isopropyl alcohol, mixed solvents such as isopropyl alcohol / toluene, and water.

The method for applying the suspension is not particularly limited as long as it is a method capable of forming a porous semiconductor film having through-holes, and includes known methods such as a doctor blade method, a squeegee method, a spin coating method, and a screen printing method. .
The method for forming the through hole in the porous semiconductor film is not particularly limited as long as it can form a desired through hole. For example, (1) before the formation of the porous semiconductor film, the portion that becomes the through hole is formed in advance. (2) A method of removing a film after forming a film (for example, a polymer film or a tape) and applying a suspension, (2) A method of removing a portion to be a through hole after forming a porous semiconductor film, 3) A method of applying a suspension (for example, a screen printing method) using a mask having a pattern corresponding to the through hole.

  The porous semiconductor film is not only a single layer film formed using a single semiconductor fine particle having a specific average particle diameter, but also a single film formed using a suspension containing semiconductor fine particles of different types and average particle diameters. The layer film may be a multilayer film in which individual suspensions containing semiconductor fine particles having different types and average particle diameters are continuously applied. When a desired film thickness cannot be obtained by a single application, the same suspension may be continuously applied to increase the film thickness.

  Next, the obtained coating film is dried and fired. Conditions such as temperature, time, and atmosphere in each step may be appropriately set depending on the support of the porous semiconductor film, the type of semiconductor fine particles, and the like. Drying and baking can be performed, for example, in an air atmosphere or an inert gas atmosphere within a range of about 50 to 800 ° C. for about 10 seconds to 12 hours. This drying and baking can be performed once at a single temperature or twice or more at different temperatures.

In order to improve the photoelectric conversion efficiency of the solar cell, it is necessary to adsorb more dye described later on the porous semiconductor film. For this reason, the porous semiconductor film preferably has a certain specific surface area to some extent, and is preferably about 10 to 200 m ² / g.
The porosity of the porous semiconductor film is preferably about 40 to 80% from the viewpoints of dye adsorption and ion diffusion in the electrolyte layer described later, that is, charge transport.
The “porosity” means a value indicating the ratio of the volume occupied by the pores in% in the volume of the porous semiconductor film.

(Conductive layer)
In the present invention, the conductive layer is formed on the non-light-receiving surface side of the porous semiconductor film, and electrically connects the transparent electrode in the through hole and the transparent electrode in the region where the porous semiconductor film is not formed.
For this reason, if the inside of the through hole is not covered with a conductive layer, not only power generation is not possible inside it but also electrical connection with the transparent electrode is not possible, so all the through holes are covered with the conductive layer. Is preferred.

The material constituting the conductive layer includes titanium, tantalum, tungsten, nickel, indium, aluminum, rhodium, gold, silver, copper, zinc, iridium and other metals, silicon and other semi-metals and semiconductors, tin oxide, fluorine-doped oxidation Examples thereof include conductive oxides such as tin (FTO), indium oxide, tin-doped indium oxide (ITO), and zinc oxide.
Among materials constituting the conductive layer, a material having corrosion resistance with respect to an electrolyte layer described later is preferable because it is not necessary to provide a layer for protecting the conductive layer. Examples of such a material include FTO, platinum, nickel, titanium, tantalum, and the like. A metal material selected from titanium, tantalum, and nickel is preferable, and titanium is particularly preferable.

Further, when the material constituting the conductive layer is a material that does not have corrosion resistance to the electrolyte layer described later, such as silver, copper, aluminum, etc., the conductive layer is protected, that is, the surface of the conductive layer is In order to prevent direct contact with the electrolyte layer, it is preferable to provide a protective layer (electrical insulating layer) between the collecting electrode and the porous semiconductor layer. Specifically, a current collecting electrode is formed after forming an electrical insulating layer to be described later.
The conductive layer may be formed using two or more materials instead of a single material. For example, the side surface in a through-hole is coated with an insulating material such as silica, and a method of forming a conductive layer of titanium so as to cover and cover the inside of silver is exemplified.

The shape of the conductive layer is not particularly limited as long as the transparent electrode in the through hole and the transparent electrode in the region where the porous semiconductor film is not formed can be electrically connected via the conductive layer.
However, if the conductive layer is formed on the entire surface of the porous semiconductor layer, problems such as the transfer of electrons and the transportation of the electrolyte solution occur, so the shape of the conductive layer is linear or That combination is preferred.
When the porous semiconductor film has a plurality of through-holes, forming a linear conductive layer for each through-hole increases the ratio of covering the porous semiconductor film. It is preferable that at least two or more through holes are covered with the layer.

Examples of the shape of the conductive layer include a stripe shape as shown in FIGS. 3 to 5, a lattice shape as shown in FIGS. 6 and 7, a comb shape as shown in FIG. 8, or a combination thereof. It is done. Here, “linear” means a straight or curved shape.
In addition, “striped” means a linear conductive layer formed inside the periphery of the porous semiconductor film without intersecting each other, and “lattice” means at least one or more places. It means what is formed by crossing.

The conductive layer may also be formed on the outer periphery of the porous semiconductor film on the non-light-receiving surface side of the transparent electrode as shown in FIGS.
As shown in FIGS. 12 and 13, the conductive layer may be electrically connected to a collecting electrode portion provided in addition to the transparent electrode. Further, the conductive layer may be integrated with the current collecting electrode portion as shown in FIG.
In the case of a solar cell, the “collecting electrode part” means a connection terminal portion of the solar cell (single cell), and in the case of a module described later, it means a connection portion between the solar cells (single cells). To do. The collecting electrode part will be specifically described in the examples.

  The conductive layer is preferably electrically connected to a collecting electrode part provided other than the transparent electrode, and the conductive layer is directly connected to the collecting electrode part directly without passing through the transparent electrode, or The conductive layer is preferably integrated with the collecting electrode portion.

It is preferable that at least a part of the conductive layer is formed in a direction perpendicular to the major axis direction of the current collecting electrode portion. Since the conductive layer needs to efficiently transport electrons generated in the porous semiconductor film around the porous semiconductor film, at least a part of the conductive layer transports electrons at the shortest distance to the collector electrode. A shape that can be formed is preferable.
In the present invention, “vertical” includes not only strictly 90 ° but also substantially vertical (about 45 to 135 °).

  In addition, the width of the conductive layer is not particularly limited and can be set by considering the specific resistance of the material used for the conductive layer, the thickness of the conductive layer, and the cost. It is preferably ˜12 mm. Thereby, the ratio which covers a porous semiconductor film can be made as low as possible, and sufficient electron transport can be performed.

The width of the conductive layer may vary depending on its position. When electrons flow into the conductive layer from a plurality of through holes, the number of electrons transported increases toward the periphery of the porous semiconductor film. Therefore, the width of the conductive layer is porous as shown in FIGS. It is preferable that the width is wider toward the outer periphery of the semiconductor film, that is, as it gets closer to the periphery of the porous semiconductor film.
3 to 17 are schematic plan views showing examples of the shape of the conductive layer in the solar cell of the present invention, in which 31 is a transparent electrode, 32 is a porous semiconductor film, 34 is a conductive layer, and 35 is a collecting layer. It is an electric electrode part.

  The ratio of the conductive layer covering the porous semiconductor film is 0.01 to 99%, preferably 1 to 40%, more preferably 2 to 25%.

(Method for forming conductive layer)
The method for forming the conductive layer is not particularly limited, for example, a method of depositing a metal by a physical vapor deposition method such as a magnetron sputtering method and an electron beam vapor deposition method using a mask in which a predetermined pattern is formed, Examples thereof include a method of patterning by photolithography after depositing a metal by the method. In order to form a conductive layer having a desired shape, the above steps may be repeated twice or more. Moreover, the method of baking after patterning by the screen printing method etc. using the paste containing each metal component is mentioned.

  Other components in the solar cell of the present invention will be described.

(Translucent substrate, transparent support)
The material constituting the light-transmitting substrate is not particularly limited as long as it can substantially transmit light having a wavelength having effective sensitivity to at least a dye described later and can support a solar cell. For example, soda Glass such as lime float glass, quartz glass, tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PA), polyetherimide (PEI), phenoxy resin And transparent polymer sheets. Although glass is most commonly used, the transparent polymer sheet is advantageous in terms of cost in that it has flexibility.
Although the thickness of a translucent board | substrate is not specifically limited, Usually, it is about 0.5-8 mm.
A transparent electrode to be described later is formed on the translucent substrate.

(Transparent electrode, transparent conductive film)
The material constituting the transparent electrode may be any material that can substantially transmit light having a wavelength having effective sensitivity to at least a dye described later, and is necessarily transparent to light in all wavelength regions. There is no. Examples of such materials include indium tin complex oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (FTO), zinc oxide (ZnO), titanium oxide doped with tantalum or niobium, and the like. Is mentioned.
The transparent conductive layer can be formed on the translucent substrate by a known method such as sputtering or spraying. The film thickness of the transparent conductive layer is about 0.02 to 5 μm, and the lower the film resistance, the better, preferably 40Ω / sq or less.
A translucent conductive substrate obtained by laminating FTO as a transparent conductive layer on soda-lime float glass as a translucent substrate is particularly preferable. In the present invention, a commercially available product of such a translucent conductive substrate may be used. Good.

  Further, the transparent electrode does not need to be electrically connected to the entire surface of the porous semiconductor film, and may be insulated by scribing or the like, and is electrically connected to at least one or more through holes and a conductive layer. It only has to be. The area of the transparent electrode delimited by scribe is not limited, but may be appropriately set in consideration of the area of the through hole and the width and thickness of the conductive layer so that electrons from the through hole are sufficiently transported. .

(Dye)
Examples of the dye that functions as a photosensitizer by being adsorbed on the porous semiconductor film include various organic dyes and metal complex dyes having absorption in the visible light region and / or infrared light region. One or more of these dyes can be selectively used.

  Examples of organic dyes include azo dyes, quinone dyes, quinone imine dyes, quinacridone dyes, squarylium dyes, cyanine dyes, merocyanine dyes, triphenylmethane dyes, xanthene dyes, porphyrin dyes, and phthalocyanines. And dyes, perylene dyes, indigo dyes, naphthalocyanine dyes and the like.

  As metal complex dyes, Cu, Ni, Fe, Co, V, Sn, Si, Ti, Ge, Cr, Zn, Ru, Mg, Al, Pb, Mn, In, Mo, Y, Zr, Nb, Sb, Metals such as La, W, Pt, TA, Ir, Pd, Os, Ga, Tb, Eu, Rb, Bi, Se, As, Sc, Ag, Cd, Hf, Re, Au, Ac, Tc, Te, Rh Specific examples include ruthenium metal complex dyes such as ruthenium bipyridine metal complex dyes, ruthenium terpyridine metal complex dyes, and ruthenium quarter pyridine metal complex dyes. .

Moreover, in order to adsorb | suck a pigment | dye firmly to a porous semiconductor film, a carboxyl group (COOH group), an alkoxy group, a hydroxyl group, a hydroxyalkyl group, a sulfonic acid group, an ester group, a mercapto group, a phosphonyl group in a pigment molecule. Those having an interlock group such as are preferable, and among these, a carboxyl group is particularly preferable. In general, the interlock group provides an electrical bond that facilitates electron transfer between the excited state dye and the conduction band of the porous semiconductor film.
Examples of the dye having such an interlock group include the above organic dyes and metal complex dyes, and among these, ruthenium-based metal complex dyes represented by the following formulas (1) to (3) are particularly preferable.

(Dye adsorption method)
Examples of the method of adsorbing the dye on the porous semiconductor film include a method of immersing the porous semiconductor film formed on the transparent electrode in a solution in which the dye is dissolved (dye adsorption solution).
The solvent for dissolving the dye may be any solvent that dissolves the dye. Examples thereof include alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether and tetrahydrofuran, nitrogen compounds such as acetonitrile, chloroform, and the like. Halogenated aliphatic hydrocarbons, aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene, esters such as ethyl acetate, and water. In the present invention, two or more of these solvents can be mixed and used.

The dye concentration in the dye adsorbing solution can be adjusted as appropriate depending on the type of dye and solvent to be used, but a higher concentration is preferable in order to improve the adsorption function. For example, 5 × 10 ⁻ The concentration may be ⁵ mol / liter or more.
Further, an organic compound such as deoxycholic acid may be added as a coadsorbent to the dye adsorption solution in order to control the dye adsorption state, the surface of the porous semiconductor film, and the like.

  Conditions such as temperature, time, and atmosphere when the porous semiconductor film formed on the transparent electrode is immersed in the dye adsorption solution are the materials and states constituting the porous semiconductor film, the composition material of the dye adsorption solution, etc. May be set as appropriate. Immersion can be performed at about room temperature in an air atmosphere, for example. By soaking under heating, the dye can be efficiently adsorbed to the porous semiconductor film.

(Catalyst layer)
The material which comprises a catalyst layer will not be specifically limited if it is generally used for a photoelectric conversion material. Examples of such a material include platinum, carbon black, ketjen black, carbon nanotube, fullerene and the like.
For example, when using platinum, the catalyst layer can be formed by a known method such as sputtering, thermal decomposition of chloroplatinic acid, or electrodeposition. The film thickness should just be able to express a catalyst function, for example, is about 1 to 2000 nm. In the case of using carbon such as carbon black, ketjen black, carbon nanotube, or fullerene, a catalyst layer can be formed by applying carbon paste dispersed in a solvent by a screen printing method or the like.

(Counter electrode, counter electrode conductive layer)
When the resistance of the catalyst layer is high, it is preferable that a counter electrode is further laminated on the non-light-receiving surface side layer of the catalyst layer.
As the material constituting the counter electrode, indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (F-doped SnO ₂ , FTO), zinc oxide (ZnO), platinum, Gold, silver, copper, aluminum, nickel, titanium, etc. are mentioned.
The counter electrode can be formed on the catalyst layer by a known method such as sputtering or spraying. The film thickness is about 0.02 to 5 μm, the film resistance is preferably as low as possible, and is preferably 40Ω / sq or less.

(Support substrate, cover)
As the support substrate, glass, a polymer film, a metal plate (foil), or the like can be considered. In particular, in order to reduce the resistance value, the support substrate is preferably a conductive substrate. Further, when the conductivity of the support substrate is low, the electrode may be formed by the same method and material as the conductive layer.

(Electrolyte layer)
The electrolyte layer is made of a conductive material that can transport ions, and examples thereof include a liquid electrolyte layer and a solid electrolyte layer.

The liquid electrolyte layer is not particularly limited as long as it is a liquid substance containing a redox species, and can be generally used in a battery or a solar battery. Specifically, a composition comprising a redox species and a solvent capable of dissolving the same is mentioned.
Examples of the redox species include a combination of a metal iodide such as LiI, NaI, KI, and CaI ₂ and iodine, a combination of a metal bromide such as LiBr, NaBr, KBr, and CaBr ₂ and bromine, and a salt made of iodide ion. A combination of iodine, a combination of a salt made of bromide ions and a bromine can be mentioned. Among these, a combination of LiI and iodine, and a combination of a salt made of iodide ions and iodine are preferable. These redox species can be used in combination of two or more.
To the liquid electrolyte layer, ionic compounds such as guanidine thiocyanate, nitrogen-containing heterocyclic compounds such as 4-tert-butylpyridine, and other organic compounds are added to improve characteristics by adsorption to the electrode surface. Also good.

  Examples of the solvent capable of dissolving the redox species include carbonate compounds such as propylene carbonate, lactones such as γ-butyrolactone, nitrile compounds such as acetonitrile, alcohols such as ethanol, water, aprotic polar substances, and the like. Among these, carbonate compounds, lactones, and nitrile compounds are particularly preferable. Two or more of these solvents can be used in combination.

A molten salt can also be used as a solvent capable of dissolving the redox species, and a mixture with the above-described solvent can also be used.
The “molten salt” is a salt in a liquid state that does not contain a solvent and is composed only of ions.
Molten salts are described in, for example, Inorg. Chem., 1996, 35, p. 1168-1178 and Electrochemistry., 2002, 2, p. 130-136, and Japanese Patent Publication No. 9-507334 and It is not particularly limited as long as it can be generally used in a battery, a solar battery, or the like as described in patent documents such as 8-259543. In addition, the molten salt may be used regardless of whether it is involved in the production of redox species, or a mixture thereof.
As the molten salt, a salt having a melting point lower than room temperature (25 ° C.), or a liquid state at room temperature by dissolving with another molten salt or an electrolyte layer salt other than the molten salt even when having a melting point higher than room temperature. Salts are preferred.

  Molten salt cations include ammonium, imidazolium, oxazolium, thiazolium, pyrazolium, isoxazolium, thiadiazolium, oxadiazolium, triazolium, pyrrolidinium, pyridinium, pyrimidinium, pyridazinium, pyrazinium, triazinium, phosphonium, sulfonium, carbazolium Indolium and its derivatives are preferable, and among these, ammonium, imidazolium, pyridinium, and sulfonium are particularly preferable.

Examples of the anion of the molten salt include metal chlorides such as AlCl ₄ ⁻ and Al ₂ Cl ₇ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , N (CF ₃ SO ₂ ) ₂ ⁻ , and N (SO ₂ Fluorine-containing materials such as F) ₂ ⁻ and F (HF) _n ⁻ , non-fluorine-containing materials such as NO ₃ ⁻ , CH ₃ COO ⁻ , C ₆ H ₁₁ COO ⁻ , SCN ⁻ and N (CN) ₂ ^— , iodine And halides such as bromine.

  The molten salt can be synthesized by known methods described in the above-mentioned various documents and patent publications. Taking a quaternary ammonium salt as an example, a quaternization of an amine is performed using a tertiary amine as an alkylating agent as an alkylating agent as a first step, and an ion exchange from a halide anion to a target anion is performed as a second step. And a method of obtaining a target compound in one step by reacting a tertiary amine with an acid having a target anion.

When a solvent or a molten salt is used as a solvent capable of dissolving the redox species, a separator layer may be provided between them in order to prevent a short circuit between the conductive layer and the counter electrode.
The separator layer is not particularly limited as long as it is electrically insulating and stable with respect to the constituent material of the solar cell. Specifically, the separator layer is a porous layer formed from a metal oxide such as SiO ₂ or ZrO _2. Nonwoven fabrics formed from layers, polymer compounds, and the like.

  As the solid electrolyte layer constituting the electrolyte layer, a polymer electrolyte layer (gel electrolyte layer) obtained by solidifying a liquid electrolyte layer with a polymer compound, an electrolyte layer obtained by solidifying a liquid electrolyte layer containing a molten salt with fine particles, organic P Type semiconductors, inorganic P-type semiconductors such as CuI, and the like.

  The polymer compound in the polymer electrolyte layer obtained by solidifying the liquid electrolyte layer with the polymer compound is not particularly limited as long as it is a polymer compound that can hold the electrolytic solution composed of the mixed solvent and the electrolyte layer. Examples of such a polymer compound include a poly (meth) acrylate polymer or copolymer obtained by polymerizing or copolymerizing a monomer unit represented by the following general formula (4), and a compound A having an isocyanate group. And an epoxy resin and the like. Among these, a poly (meth) acrylate polymer or copolymer, a compound A having an isocyanate group and an active hydrogen group are included. A compound obtained by polyaddition of the compound B is preferably used.

（式中、Ｒは水素原子またはメチル基であり、Ｘはエステル基と炭素原子で結合している残基であり、ｎは２〜４の整数である。）

(In the formula, R is a hydrogen atom or a methyl group, X is a residue bonded to an ester group with a carbon atom, and n is an integer of 2 to 4.)

  The polymerization method of the polymer compound is not particularly limited, and may be appropriately set depending on the monomer material used, such as polymerization under normal temperature and normal pressure, thermal polymerization, and photopolymerization. However, when titanium oxide is used for the porous semiconductor film, there is a problem that titanium oxide causes a photocatalytic reaction due to light irradiation in the ultraviolet region, and the dye adsorbed on the porous semiconductor film is decomposed. Polymerization of the molecular compound is preferably polymerization under normal temperature and normal pressure or thermal polymerization.

What is necessary is just to select suitably the injection | pouring method of the electrolyte layer in a solid electrolyte layer with the compound to be used.
For example, when using a compound containing an isocyanate in which iodine does not affect polymerization and a compound containing an active hydrogen group, the mixture is mixed with a solvent to which an electrolyte layer is added before polymerization, and the resulting mixture is polymerized to form a gel electrolyte layer. Get.
In addition, when (meth) acrylates are polymerized by radical polymerization in which iodine acts as a polymerization inhibitor, the polymer is polymerized only with a polymer compound and a solvent, and the resulting polymer is contained in an electrolyte solution composed of an electrolyte layer and a solvent. The gel electrolyte layer is obtained by immersing in

  The fine particles in the electrolyte layer obtained by solidifying the liquid electrolyte layer containing a molten salt with fine particles are not particularly limited as long as the liquid electrolyte layer can be solidified. Examples of such compounds include metal oxides such as silicon oxide and carbon nanotubes.

When the content of the electrolyte layer in the porous semiconductor film is small, the photoelectric conversion efficiency of the obtained solar cell is lowered. Therefore, it is necessary to inject more liquid electrolyte layers or form solid electrolyte layers in the porous semiconductor film (inside the pores).
If the liquid electrolyte layer has a low viscosity, it is possible to inject the liquid electrolyte layer into the porous semiconductor film even at room temperature and normal pressure, but the high viscosity liquid electrolyte layer contains a large amount of a high viscosity solvent or molten salt. In this case, it becomes difficult to inject into the porous semiconductor film even under normal temperature and pressure. Therefore, the method of injecting the liquid electrolyte layer into the porous semiconductor film is preferably a vacuum injection method.

When a polymer electrolyte layer obtained by solidifying a liquid electrolyte layer with a polymer compound is used as the electrolyte layer, for example, a liquid prepolymer solution may be impregnated in a porous semiconductor film and then polymerized. The method of injecting the prepolymer solution into the porous semiconductor film is preferably a vacuum injection method.
Also, when using a solid electrolyte layer that is formed by ion bonding or the like and causes a solid-liquid phase change reversibly by heat, for example, vacuum injection of the solid electrolyte layer that has been changed to a liquid state by heating or the like. It may be injected into the porous semiconductor film by the method.

  The other components, heat-sealing film, electrolyte injection hole, and ultraviolet curable resin can be applied with materials and forming methods used in the technical field, and these will be specifically described in the section of the module described later.

(module)
In the module of the present invention, the transparent electrode and the counter electrode of at least two or more solar cells including the above-described solar cell (solar cell single cell) are electrically connected in series. That is, at least one of the at least two solar cell single cells constituting the module may be the solar cell of the present invention. Here, “solar cell single cell (dye-sensitized solar cell single cell)” refers to a solar cell comprising a pair of transparent electrodes and a counter electrode.

In the module of the present invention, in order to maximize the effects of the solar cell of the present invention, it is preferable that two or more solar cells are all the above-described solar cells, and the porous semiconductor films of the solar cells are the same. It is preferably formed on a transparent electrode on the substrate.
In the module of the present invention, the transparent electrode and the counter electrode of each of the solar cell whose porous semiconductor film side is the light receiving surface and the solar cell whose counter electrode side is the light receiving surface may be electrically connected in series. In such a case, as shown in FIG. 19, the solar cell having the light-receiving surface on the porous semiconductor film side is preferably the solar cell of the present invention.

  Examples of manufacturing the module of the present invention will be specifically described, but the present invention is not limited to these manufacturing examples.

(Production Example 1)
A module having the configuration shown in FIG. 18 was produced.
FIG. 18 is a schematic cross-sectional view of the main part showing the layer structure of the module of the present invention, in which 180 is a translucent substrate, 181 is a support substrate (cover), 182 is a transparent electrode, and 183 is an adsorbing dye. And 184 is a conductive layer that electrically connects the through-hole and the inside of the through-hole to the surrounding transparent electrode, 185 is an insulating layer on the scribe, and 186 is porous. An insulating layer, 187 is a catalyst layer, 188 is a counter electrode (conductive film), 189 is an inter-cell insulating layer, and 190 is an electrolyte layer.

49 mm × 66.3 mm × thickness 1 mm glass substrate (glass with SnO ₂ film, manufactured by Nippon Sheet Glass Co., Ltd.), on which a transparent electrode 182 made of SnO ₂ film is formed on a transparent substrate 180 made of glass Prepared. Using a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (basic wavelength: 1.06 μm) to irradiate a predetermined position on the transparent electrode 182 to cut the SnO ₂ film A groove (scribe line) was formed.

  Next, a commercially available titanium oxide paste is formed on the transparent electrode 182 by using a screen plate having a pattern of a porous semiconductor film having a through hole and a screen printing machine (manufactured by Neurong Seimitsu Co., Ltd., model number: LS-150). (Trade name: Ti-Nanoxide T / SP, manufactured by Solaronix) was applied, and leveling was performed at room temperature for 1 hour. Then, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in the air for 60 minutes in an air using a baking furnace (model number: KDF P-100 manufactured by Denken Co., Ltd.) set at 450 ° C. As a result, a porous semiconductor film α having a thickness of 8 μm was obtained.

  Next, using the screen plate and the screen printing machine, a commercially available titanium oxide paste (manufactured by Solaronix, trade name: Ti-Nanoxide D / SP) is applied on the porous semiconductor film α, and 1 at room temperature. Time leveling was performed. Thereafter, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in the air for 60 minutes using the above baking furnace set at 450 ° C. This coating and baking process was repeated three times to obtain a porous semiconductor film β having a film thickness of 18 μm.

Next, a titanium oxide paste prepared in advance was applied onto the porous semiconductor film β using the screen plate and the screen printing machine, and leveling was performed at room temperature for 1 hour. Thereafter, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in the air for 40 minutes using the above baking furnace set at 450 ° C. to form a porous semiconductor film having a thickness of 5 μm. γ was obtained, and a porous semiconductor film having through-holes composed of three layers of porous semiconductor films α, β, and γ was obtained. In this porous semiconductor film, α, β, and γ were laminated in the order from a layer having a low light scattering property to a layer having a high light scattering property from the transparent electrode 182 side.
The titanium oxide paste was prepared by dispersing anatase-type titanium oxide particles having an average primary particle size of 350 nm in terpineol and further mixing ethyl cellulose.

Next, a glass paste (manufactured by Noritake Co., Ltd.) is applied on the scribe line using a screen plate for forming the scribe upper insulating layer 185 between the porous semiconductor films and the screen printing machine described above. It dried for 15 minutes in the oven set to ℃, and also baked for 60 minutes in the air using the above-mentioned calcination furnace set to 500 ℃, and obtained insulating layer 185 on a scribe.
Next, titanium is deposited on the porous semiconductor film at a deposition rate of 0.5 Å / S using a mask on which a predetermined pattern is formed and a vapor deposition apparatus (model number: EVD500A, manufactured by Anelva Corporation). The 800 nm through hole and the conductive layer 184 that electrically connects the inside of the through hole and the surrounding transparent electrode were patterned.

Next, using a screen plate for forming the porous insulating layer 186 on the porous semiconductor film on which the conductive layer 184 has been formed and the above-described screen printer, a zirconium oxide paste prepared in advance is applied, and room temperature is applied. And leveling for 60 minutes. Subsequently, the obtained coating film was preliminarily dried at 80 ° C. for 20 minutes, and baked in the air for 60 minutes using the above-described baking furnace set at 450 ° C. to obtain a porous insulating layer 186 having a thickness of 5 μm.
The zirconium oxide paste was dispersed in zirconium oxide particles having an average particle diameter of 100 nm (manufactured by CI Kasei Co., Ltd.) terpineol, and further mixed with ethyl cellulose to prepare a paste.

Next, Pt was deposited on the porous insulating layer 186 using the above-described deposition apparatus at a deposition rate of 0.5 Å / S to obtain a catalyst layer 187 having a thickness of 50 nm.
Further, titanium having a film thickness of 300 nm is formed by using the above-described vapor deposition apparatus so as to reach the conductive layer 184 on the catalyst layer 187, the scribe upper insulating layer 185, and the scribe upper insulating layer 185 side at a vapor deposition rate of 0.5 Å / S. A counter electrode (conductive film) 188 was obtained.

Next, the laminate is immersed in a dye adsorbing solution prepared in advance at room temperature for 24 hours, and then the laminate is washed with ethanol and dried at about 60 ° C. for about 5 minutes to obtain a porous semiconductor film. The dye was adsorbed on the surface.
The dye solution for adsorption is a mixture of acetonitrile and t-butanol in a volume ratio of 1: 1 so that the dye of the formula (3) (manufactured by Solaronix, trade name: Ruthenium 620) has a concentration of 3 × 10 ⁻⁴ mol / liter. It was prepared by dissolving in a mixed solvent.

  Next, using a dispenser (manufactured by EFD, trade name: ULTRASAVER), an ultraviolet curable resin (manufactured by ThreeBond, model number: 31X-101) is applied to the position of the number 189 on the conductive layer 184 of FIG. A 49 mm × 56 mm × 1 mm thick glass substrate (Corning 7059) as a prepared support substrate (cover) 181 was bonded. The glass substrate was previously provided with an electrolyte injection hole (not shown). Next, by using an ultraviolet lamp (trade name: NOVACURE, manufactured by EFD), the coated portion is quickly irradiated with ultraviolet rays to cure the ultraviolet curable resin, thereby obtaining an inter-cell insulating layer 189 and a translucent substrate. 180 and the support substrate 181 were fixed.

Next, an electrolyte prepared in advance from the electrolyte injection hole of the support substrate 181 is injected to obtain the porous semiconductor film 183 that adsorbs the electrolyte layer 190 and the dye and is filled with the electrolyte. The module was completed by sealing the electrolyte injection hole using an ultraviolet curable resin in the same manner as described above.
The electrolyte is acetonitrile as a solvent, LiI (manufactured by Aldrich) as a redox species at a concentration of 0.1 mol / liter, and I ₂ (manufactured by Kishida Chemical) at a concentration of 0.01 mol / liter. Furthermore, t-butylpyridine (manufactured by Aldrich) is added as an additive to a concentration of 0.5 mol / liter, and dimethylpropylimidazole iodide (manufactured by Shikoku Kasei Kogyo Co., Ltd.) is added to a concentration of 0.6 mol / liter and dissolved. I got it.

(Production Example 2)
A module having the configuration shown in FIG. 19 was produced.
FIG. 19 is a schematic cross-sectional view of the main part showing the layer structure of the module of the present invention, in which 191 is a translucent substrate, 192 is a support substrate (insulating support), 193 is a transparent electrode, and 194 is The counter electrode (conductive film) 195 is a porous semiconductor film I that adsorbs a dye and the gap is filled with an electrolytic solution I, 196 is a catalyst layer II, 197 is a through-hole and the inside of the through-hole and the surrounding transparent electrode are electrically connected 198 is a scribe (grid) electrode, 199 is a porous semiconductor film II that adsorbs a dye and is filled with an electrolytic solution II, 200 is a catalyst layer I, 201 is an inter-cell insulating layer , 202 is an electrolyte layer I formed by the electrolyte solution I, and 203 is an electrolyte layer II formed by the electrolyte solution II.

A 49 mm × 71 mm × 1 mm thick glass substrate (Nippon Sheet Glass Co., Ltd. glass with SnO ₂ film) in which a transparent electrode 193 made of SnO ₂ film was formed on a transparent substrate 191 made of glass was prepared. . By using a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (basic wavelength: 1.06 μm), irradiating a predetermined position on the transparent electrode with laser light to cut the SnO ₂ film, A scribe line was formed.

  Next, a commercially available titanium oxide paste is formed on the transparent electrode 193 using a screen plate having a pattern of a porous semiconductor film having a through-hole and a screen printing machine (manufactured by Neurong Seimitsu Kogyo Co., Ltd., model number: LS-150). (Product name: D / SP, manufactured by Solaronix) was applied, and leveling was performed at room temperature for 1 hour. Then, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in the air for 60 minutes in an air using a baking furnace (model number: KDF P-100 manufactured by Denken Co., Ltd.) set at 450 ° C. did. This coating and baking process was repeated three times to obtain a porous semiconductor film having a thickness of 20 μm.

Next, Pt was deposited on the transparent electrode 193 using a deposition apparatus in the same manner as in Production Example 1 at a deposition rate of 0.5 作 製 / S to obtain a catalyst layer I196 having a thickness of 5 nm.
Next, in the same manner as in Production Example 1, titanium was formed on the porous semiconductor film using a vapor deposition apparatus at a vapor deposition rate of 0.5 Å / S. A conductive layer 197 for electrically connecting the electrodes was patterned.
The laminate obtained in this manner is used as the substrate upper.

Next, a glass substrate (manufactured by Nippon Sheet Glass Co., Ltd.) having a counter electrode (conductive film) 194 made of SnO ₂ film formed on a support substrate (insulating support) 192 made of glass. , SnO ₂ film-attached glass) was prepared. A scribe line was formed at a predetermined position on the counter electrode (conductive film) 194 using a laser scribing device in the same manner as the substrate upper. The glass substrate was previously provided with an electrolyte injection hole (not shown).
Next, titanium was deposited on the counter electrode (conductive film) 194 at a deposition rate of 0.5 Å / S using a vapor deposition apparatus in the same manner as in Production Example 1 to obtain a scribe (grid) electrode 198 having a thickness of 600 nm. It was.

Next, using a screen printing machine having a pattern on a part of the scribe (grid) electrode 198 and a screen printing machine, a titanium oxide paste (product name: Solaronix, trade name D / SP) is applied in the same manner as the substrate A. And leveling at room temperature for 1 hour. Then, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in air using a baking furnace set at 450 ° C. for 60 minutes. This coating and baking process was repeated three times to obtain a porous semiconductor film having a thickness of 20 μm and no through holes.
Next, a Pt film was formed on the scribe (grid) electrode 198 and the counter electrode (conductive film) 194 using a vapor deposition apparatus in the same manner as in Production Example 1 at a vapor deposition rate of 0.5 Å / S. Layer I200 was obtained.
The laminate obtained in this way is referred to as a substrate B.

Next, in the same manner as in Production Example 1, the above-mentioned substrate A and substrate B are immersed in a dye adsorption solution prepared in advance, and these are washed and dried to adsorb the dye to the porous semiconductor film. It was.
Next, using a dispenser in the same manner as in Production Example 1, an ultraviolet curable resin was applied to the position of the drawing number 201 in FIG. Next, as shown in FIG. 19, the substrate upper and the substrate B were bonded together. Next, using an ultraviolet lamp, the applied portion was quickly irradiated with ultraviolet rays to cure the ultraviolet curable resin, thereby obtaining the inter-cell insulating layer 201 and fixing the substrate upper and the substrate end B at the same time.

Next, in the same manner as in Production Example 1, the electrolyte solution I prepared in advance was injected into the porous semiconductor film I195 side from the electrolyte solution injection hole of the support substrate 192 to adsorb the electrolyte layer I202 and the dye. A porous semiconductor film I195 filled with the electrolyte I in the gap is obtained, and the electrolyte II prepared in advance is injected into the porous semiconductor film II 199 side to adsorb the electrolyte layer II 203 and the dye, and A porous semiconductor film II199 in which the gap was filled with the electrolytic solution II was obtained. Then
The module was completed by sealing the electrolyte injection hole with an ultraviolet curable resin.

  The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

Example 1
A solar cell (single cell) was produced based on FIGS.
20 and 21 are schematic plan views for explaining the manufacturing process of the solar cell of the present invention, and FIG. 22 is a schematic cross-sectional view of the main part showing the layer configuration (VW cross section in FIG. 21). It is. In the figure, 31 is a transparent electrode substrate, 32 is a porous semiconductor film, 33 is a through hole, 34 is a conductive layer, 35 is a collecting electrode part, 220 is a translucent substrate, 221 is a transparent electrode, and 222 is a dye. 226 is a conductive layer that electrically connects the through hole and the inside of the through hole with the surrounding transparent electrode, 224 is a catalyst layer (platinum film), 225 Is a support substrate with a counter electrode (ITO conductive substrate), 226 is a heat-sealing film, 227 is a hole for electrolyte injection, and 228 is an electrolyte layer.

Transparent electrode made of SnO ₂ film on a transparent substrate made of glass is deposited, 22.5 mm × 32.5 mm × 1mm thick transparent electrode substrate 31 (Nippon Sheet Glass Co. Ltd., glass with SnO ₂ film ) Was prepared.
Next, using a screen plate having a porous semiconductor film pattern provided with a through hole 33 of φ0.5 mm and a screen printing machine (manufactured by Neurong Seimitsu Co., Ltd., model number: LS-150), the transparent electrode 31 (translucent electrode 31) A commercially available titanium oxide paste (manufactured by Solaronix, trade name: D / SP) was applied on the transparent electrode 221 of the light-sensitive substrate 220 + transparent electrode 221), and leveling was performed at room temperature for 1 hour. Then, the obtained coating film was dried in an oven set at 80 ° C. for 20 minutes, and further baked in the air for 60 minutes in an air using a baking furnace (model number: KDF P-100 manufactured by Denken Co., Ltd.) set at 450 ° C. did. This coating and baking process was repeated four times to obtain a porous semiconductor film 32 (222) having a film thickness of 25 μm.
Each dimension in FIG. 20 was 22.5 mm, b 32.5 mm, c 18.5 mm, d 2 mm, e 4 mm, f 10 mm, g 3.5 mm, and h 5 mm.

Next, titanium is deposited on the porous semiconductor film 32 (222) at a deposition rate of 0.5 Å / S using a mask on which a predetermined pattern is formed and a vapor deposition apparatus (model number: EVD500A manufactured by Anelva Corporation). Thus, the 800-nm-thick conductive layer 34 (223) is obtained that electrically connects the through-hole and the inside of the through-hole to the surrounding transparent electrode, that is, covers the through-hole 33 and covers a part of the collector electrode portion 35. .
In FIG. 21, c is 18.5 mm, g is 3.5 mm, h is 5 mm, i is 0.5 mm, j is 1 mm, and k is 5 mm.

Next, the laminate is immersed in a dye adsorbing solution prepared in advance at room temperature for 24 hours, and then the laminate is washed with ethanol and dried at about 60 ° C. for about 5 minutes to obtain a porous semiconductor film. The dye was adsorbed on the surface.
The dye solution for adsorption is a mixture of acetonitrile and t-butanol at a volume ratio of 1: 1 so that the dye of the formula (2) (manufactured by Solaronix, trade name: Ruthenium 620 1H3TBA) has a concentration of 4 × 10 ⁻⁴ mol / liter. It was prepared by dissolving in a mixed solvent.

  Next, the obtained laminate and a support substrate with a counter electrode (ITO conductive substrate) 225 provided with a catalyst layer (platinum film) 224 were cut out so as to surround the porous semiconductor film 223 (DuPont). It was bonded using Surlyn 1702) 226 manufactured by the company. A support substrate 225 with a counter electrode was previously provided with an electrolyte solution injection hole 227. Subsequently, these were crimped | bonded by heating for 10 minutes in the oven set to about 100 degreeC.

Next, an electrolyte prepared in advance is injected from the electrolyte injection hole 227 to obtain the porous semiconductor film 222 that adsorbs the electrolyte layer 228 and the dye and is filled with the electrolyte, and is cured by ultraviolet rays. A solar cell (single cell) was completed by sealing the electrolyte injection hole 227 with a resin (manufactured by ThreeBond Co., Ltd., model number: 31X-101) 229.
The electrolyte is acetonitrile as a solvent, LiI (manufactured by Aldrich) as a redox species at a concentration of 0.1 mol / liter, and I ₂ (manufactured by Kishida Chemical) at a concentration of 0.01 mol / liter. Furthermore, t-butylpyridine (manufactured by Aldrich) is added as an additive to a concentration of 0.5 mol / liter, and dimethylpropylimidazole iodide (manufactured by Shikoku Kasei Kogyo Co., Ltd.) is added to a concentration of 0.6 mol / liter and dissolved. I got it.

Ag paste (manufactured by Fujikura Kasei Co., Ltd., trade name: Dotite) was applied to the obtained solar cell as the collecting electrode part 35 (230). Next, a black mask having an opening area of 3.4 cm ² is installed on the light receiving surface of the solar cell, and the solar cell is irradiated with light of 1 kW / m ² (AM1.5 solar simulator). The photoelectric conversion efficiency was measured. The results are shown in Table 1.

(Examples 2 to 6)
A solar cell (single cell) was produced in the same manner as in Example 1 except that the conductive layer 34 was formed in a pattern as shown in FIGS. 23 to 27, and the photoelectric conversion efficiency was measured. The results are shown in Table 1.
23 to 27 are schematic plan views for explaining the shape of a conductive layer used for manufacturing a solar cell, in which 31 is a transparent electrode substrate, 32 is a porous semiconductor film, 34 is a conductive layer, 35, Reference numeral 36 denotes a collecting electrode portion.
In each figure, c, g, h, i, and k are the same as in Example 1, j is 1 mm, l is 4 mm, m is 20.5 mm, n is 0.5 mm, and o 9.5 mm, p was 1, r was 4.5 mm, and s was 21.5 mm.

(Example 7)
Similarly to Production Example 1, a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (basic wavelength: 1.06 μm) is used to emit laser light at a predetermined position on the transparent electrode in the transparent electrode substrate 31. A solar cell (single cell) was produced in the same manner as in Example 1 except that a scribe line having a width of 0.1 mm was formed as shown in FIG. 28 by irradiating and cutting the SnO ₂ film. The photoelectric conversion efficiency was measured. The results are shown in Table 1.
FIG. 28 is a schematic plan view for explaining the shape of a scribe line formed on a transparent electrode used for production of a solar cell, in which 31 is a transparent electrode substrate and 37 is a scribe line. In the figure, a and b are the same as those in Example 1, and t is 8.1 mm, u is 6.1 mm, and v is 10.1 mm.

(Comparative Example 1)
Except not forming the through-hole 33 and the conductive layer 34, the solar cell (single cell) was produced like Example 1 and the photoelectric conversion efficiency was measured. The results are shown in Table 1.

(Example 8)
Based on Production Example 1, a three-series module as shown in FIG. 30 was produced using the same electrolytic solution as in Example 1. The light receiving area of the porous semiconductor film that adsorbs the dye in this module and is filled with the electrolyte in the gap is 13 mm × 29 mm (including the area of the through hole).

FIGS. 29A and 29B are (a) a schematic plan view of a through-hole and a porous semiconductor film, and (b) a schematic plan view of a porous semiconductor film and a conductive layer, which were used for manufacturing the module of the present invention. In the figure, 31 is a transparent electrode substrate, 32 is a porous semiconductor film, 33 is a through-hole, and 34 is a conductive layer.
The dimensions of the through holes are all φ0.5 mm. In FIG. 29, the dimensions are 13 mm for A, 29 mm for B, 5 mm for C, 3.5 mm for D, and 2.6 mm for E (distance between porous semiconductor films). , F was 9.7 mm, and G was 1.5 mm.

FIG. 30 is a schematic cross-sectional view of the main part showing the layer structure of the module of the present invention. In the figure, 180 is a translucent substrate, 181 is a support substrate (cover), 182 is a transparent electrode, 183 is a porous semiconductor film that adsorbs a dye and is filled with an electrolyte, and 184 is a through hole and a through hole. Conductive layer that electrically connects the inside and surrounding transparent electrodes, 185 is an insulating layer on the scribe, 186 is a porous insulating layer, 187 is a catalyst layer, 188 is a counter electrode, 189 is an inter-cell insulating layer, 190 is an electrolyte Is a layer.
The dimensions in FIG. 30 are as follows: H is 10 mm, I is 13 mm, J is 0.5 mm, K is 0.6 mm, L is 1.5 mm, M is 1 mm, N is 11 mm, O is 13.25 mm, and P is 15. It was 6 mm.

A black mask with an opening area of 12.8 cm ² was installed on the light receiving surface of the obtained module, and this module was irradiated with light of 1 kW / m ² intensity (AM1.5 solar simulator). The photoelectric conversion efficiency was measured. The results are shown in Table 2.

(Comparative Example 2)
A solar cell was produced in the same manner as in Example 8 except that the through hole 33 and the conductive layer 34 were not formed, and the photoelectric conversion efficiency was measured. The results are shown in Table 2.

Example 9
As shown in FIG. 33, an electrolytic solution similar to that of Example 1 was used as the electrolytic solution I based on Preparation Example 2, and an electrolytic solution in which the iodine concentration of the electrolytic solution I was changed to 0.01M was used as the electrolytic solution II. A serial module was produced. The substrate A was prepared based on Production Example 2, and the substrate B was formed with 800 nm thick titanium as a grid electrode in the same shape and the same position by the same method as the conductive layer 316. The light receiving area of the porous semiconductor film that adsorbs the dye in this module and is filled with the electrolyte in the gap is 13 mm × 29 mm (including the area of the through hole).

FIG. 31 is a schematic plan view of a through hole, a porous semiconductor film, a catalyst layer, and a scribe line used for manufacturing the module of the present invention. In the figure, 311 is a transparent electrode substrate, 312 is a scribe line, 313 is a porous semiconductor film, 314 is a through hole, and 315 is a catalyst layer.
FIG. 32 is a schematic plan view of a porous semiconductor film, a catalyst layer, a scribe line, and a conductive layer used for manufacturing the module of the present invention, in which 316 is a conductive layer.

FIG. 33 is a schematic cross-sectional view of the main part showing the layer structure of the module of the present invention. In the figure, 191 is a translucent substrate, 192 is a support substrate (insulating support), 193 is a transparent electrode, 194 is a counter electrode (conductive film), 195 is adsorbing a dye, and the gap is filled with an electrolytic solution I. The porous semiconductor film I, 196 is a catalyst layer II, 197 is a through hole and a conductive layer electrically connecting the inside of the through hole and the surrounding transparent electrode, 198 is a scribe (grid) electrode, 199 adsorbs a dye and Porous semiconductor film II, 200 filled with electrolyte solution II in the gap is catalyst layer I, 201 is an inter-cell insulating layer, 202 is electrolyte layer I formed by electrolyte solution I, and 203 is formed by electrolyte solution II. Electrolyte layer II.
The dimensions of the through holes are all φ0.5 mm, and the dimensions in FIGS. 31 to 33 are A, B, C and D as in Example 8, Q is 2 mm, R is 10 mm, S is 10 mm, and T is 9 mm. It was.

A black mask with an opening area of 16.8 cm ² was placed on the light receiving surface of the obtained module, and this module was irradiated with light having an intensity of 1 kW / m ² (AM1.5 solar simulator). The photoelectric conversion efficiency was measured. The results are shown in Table 3.

(Comparative Example 3)
A module was produced in the same manner as in Example 9 except that the through hole 314 and the conductive layer 316 were not formed, and the photoelectric conversion efficiency was measured. The results are shown in Table 3.

It is the (a) schematic plan view which shows the through-hole formed in the porous semiconductor film in the solar cell of this invention, and (b) schematic sectional drawing (XY cross section of (a)). It is a schematic sectional drawing of the principal part which shows the layer structure of the conventional dye-sensitized solar cell. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention.

It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention. It is a schematic plan view which shows an example of the shape of the conductive layer in the solar cell of this invention.

It is a schematic sectional drawing of the principal part which shows the laminated constitution of the module of this invention (manufacture example 1). It is a schematic sectional drawing of the principal part which shows the laminated constitution of the module of this invention (manufacture example 2).

It is a schematic plan view for demonstrating the manufacturing process of the solar cell of this invention (Example 1). It is a schematic plan view for demonstrating the manufacturing process of the solar cell of this invention (Example 1). (Example 1) which is a schematic sectional drawing (VW cross section of FIG. 21) of the principal part which shows the layer structure of the solar cell of this invention. It is a schematic plan view for demonstrating the shape of the conductive layer used for preparation of the solar cell of this invention (Example 2). It is a schematic plan view for demonstrating the shape of the conductive layer used for preparation of the solar cell of this invention (Example 3). It is a schematic plan view for demonstrating the shape of the conductive layer used for preparation of the solar cell of this invention (Example 4). It is a schematic plan view for demonstrating the shape of the conductive layer used for preparation of the solar cell of this invention (Example 5). It is a schematic plan view for demonstrating the shape of the conductive layer used for preparation of the solar cell of this invention (Example 6). (Example 7) which is a schematic plan view for demonstrating the shape of the scribe line formed on a transparent electrode used for preparation of the solar cell of this invention.

(A) A schematic plan view of a through-hole and a porous semiconductor film, and (b) a schematic plan view of a porous semiconductor film and a conductive layer, which were used for manufacturing a module of the present invention (Example 8). (Example 8) which is a schematic sectional drawing of the principal part which shows the layer structure of the module of this invention. (Example 9) which is a schematic plan view of the through-hole used for preparation of the module of this invention, a porous semiconductor film, a catalyst layer, and a scribe line. FIG. 9 is a schematic plan view of a porous semiconductor film, a catalyst layer, a scribe line, and a conductive layer used for producing the module of the present invention (Example 9). (Example 9) which is a schematic sectional drawing of the principal part which shows the layer structure of the module of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent electrode 2 Porous semiconductor film 3 Through-hole 21 Transparent support 22 Transparent conductor film 23 Porous semiconductor film 24 Electrolyte layer 25 Counter electrode 26 Catalyst layer (platinum film)
27 Sealing material (epoxy resin)
31 Transparent electrode 32 Porous semiconductor film 33 Through-hole 34 Conductive layers 35 and 36 Current collecting electrode part 37 Scribe line

180 Translucent substrate 181 Support substrate (cover)
182 Transparent electrode 183 Porous semiconductor film 184 that adsorbs the dye and is filled with an electrolyte solution Through hole and conductive layer 185 electrically connecting the inside of the through hole and the surrounding transparent electrode 186 Insulating layer 186 on scribe porous Conductive layer 187 Catalyst layer 188 Counter electrode (conductive film)
189 Inter-cell insulating layer 190 Electrolyte layer

191 Translucent substrate 192 Support substrate (insulating support)
193 Transparent electrode 194 Counter electrode (conductive film)
195 Porous semiconductor film I that adsorbs a dye and is filled with electrolyte I in the gap
196 Catalyst layer II
197 Conductive layer 198 for electrically connecting through hole and inside transparent electrode with surrounding transparent electrode 199 Scribe (grid) electrode 199 Porous semiconductor film II adsorbing dye and filling gap II with electrolyte II
200 Catalyst layer I
201 Inter-cell insulating layer 202 Electrolyte layer I formed by electrolytic solution I
203 Electrolyte Layer II Formed with Electrolyte II

220 Translucent substrate 221 Transparent electrode 222 Porous semiconductor film 223 that adsorbs the dye and the gap is filled with an electrolytic solution Conductive layer 224 that electrically connects the inside of the through-hole and the surrounding transparent electrode to the surrounding transparent electrode (Platinum film)
225 Support substrate with counter electrode (ITO conductive substrate)
226 Heat fusion film 227 Electrolyte injection hole 228 Electrolyte layer 229 UV curable resin 230 Current collecting electrode part

Claims (20)

A transparent electrode formed on a light-transmitting substrate serving as a light receiving surface and a counter electrode are arranged to face each other through an electrolyte layer, and a porous semiconductor film adsorbing a dye is at least a part on the non-light receiving surface side of the transparent electrode a dye-sensitized solar cells formed, the porous semiconductor film is provided with the transparent electrode from the non-light-receiving surface side reach vital said porous semiconductor film enclosed by the through-hole, and the through hole And the transparent electrode in a region where the porous semiconductor film is not formed is electrically connected by a conductive layer formed on the non-light-receiving surface side of the porous semiconductor film. Dye-sensitized solar cell characterized.   The dye-sensitized solar cell according to claim 1, wherein the conductive layer has a stripe shape, a lattice shape, a comb shape, or a combination thereof.   The dye-sensitized solar cell according to claim 1 or 2, wherein the conductive layer is also formed on the outer periphery of the porous semiconductor film on the non-light-receiving surface side of the transparent electrode.   The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the conductive layer is electrically connected to a collecting electrode portion provided other than the transparent electrode.   The dye-sensitized solar cell according to claim 4, wherein the conductive layer is directly connected to the collecting electrode part directly without the transparent electrode.   The dye-sensitized solar cell according to claim 4, wherein the conductive layer is integrated with the collecting electrode portion.   The dye-sensitized solar cell according to any one of claims 4 to 6, wherein at least a part of the conductive layer is formed in a direction perpendicular to a major axis direction of the collecting electrode portion.   The dye-sensitized solar cell according to any one of claims 1 to 7, wherein a width of the conductive layer is wider toward an outer periphery of the porous semiconductor film.   The dye-sensitized solar cell according to any one of claims 1 to 8, wherein a width of the conductive layer is 0.05 to 12 mm in a region in contact with the porous semiconductor film.   The dye-sensitized solar cell according to any one of claims 1 to 9, wherein the conductive layer is formed of a metal material selected from titanium, tantalum, and nickel.   The dye-sensitized solar cell according to any one of claims 1 to 10, wherein a plurality of the through holes are provided, and a distance between the through holes is 0.5 to 40 mm.   The dye-sensitized solar cell according to any one of claims 1 to 11, wherein at least one through hole is formed at a distance of 0.5 to 40 mm from an outer periphery of the porous semiconductor film. The area of the said through-hole is 0.01-100 mm < ² > / piece, The dye-sensitized solar cell as described in any one of Claims 1-12.   The dye-sensitized solar cell according to any one of claims 1 to 13, wherein a total area of the through holes is 0.05 to 15 of a total area of the porous semiconductor film including the through holes.   The transparent conductive film in at least one through hole of the plurality of through holes and the transparent conductive film around the porous semiconductor film are not electrically connected except for the conductive layer. The dye-sensitized solar cell as described in one. The transparent electrode and the counter electrode of at least two or more dye-sensitized solar cells including the dye-sensitized solar cell according to any one of claims 1 to 15 are electrically connected in series. Dye-sensitized solar cell module characterized. The dye-sensitized solar cell module according to claim 16, wherein all of the two or more dye-sensitized solar cells are the dye-sensitized solar cells according to any one of claims 1 to 15. The dye-sensitized solar cell module according to claim 16 or 17, wherein the porous semiconductor film of the dye-sensitized solar cell is formed on a transparent electrode on the same substrate. The transparent electrode and counter electrode of each of the dye-sensitized solar cell having a light-receiving surface on the porous semiconductor film side and the dye-sensitized solar cell having a light-receiving surface on the counter electrode side are electrically connected in series. Dye-sensitized solar cell module. The dye-sensitized solar cell according to any one of claims 1 to 15, wherein the dye-sensitized solar cell having a light receiving surface on the porous semiconductor film side is the dye-sensitized solar cell according to any one of claims 1 to 15.

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