TW201401619A - Method for manufacturing current collector for dye-sensitized solar cell comprising porous metal sheet, current collector for dye-sensitized solar cell comprising porous metal sheet and dye-sensitized solar cell - Google Patents

Abstract

Provided is a current collector capable of obtaining higher photoelectric conversion efficiency when being used for a dye-sensitized solar cell. A method for manufacturing current collector for dye-sensitized solar cell comprising a porous metal sheet comprises: a process of forming a sheet made from an alloy of a first metal component and a second metal component; a process of treating the sheet at a temperature lower than the minimum value of liquidus temperature in the phase diagram of the alloy by immersing the sheet in a molten metal bath of a third metal component which has positive heat of mixing for the first metal component and negative heat of mixing for the second metal component, while having a hardening point lower than the melting point of the alloy; and a process of taking the treated sheet from the molten metal bath. The current collector for dye-sensitized solar cell comprising porous metal sheet has a number of through-holes with nano-diameters isotropically communicating with each other with spherical molten metal lumps being mutually fused in three-dimensional directions.

Description

A method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet, a collector for a dye-sensitized solar cell comprising a porous metal sheet, and a dye-sensitized solar cell

The present invention relates to a method for producing a current collector for a dye-sensitized solar cell, a current collector for a dye-sensitized solar cell, and a dye-sensitized solar cell.

The dye-sensitized solar cell is called a wet solar cell or a Grätzel battery, and is characterized in that an electrochemical cell structure using an electrolyte is used without using a germanium semiconductor. For example, a titanium oxide powder or the like is baked on an anode electrode of a transparent conductive film such as a transparent conductive glass plate, and a porous semiconductor layer such as a titanium oxide layer is formed by adsorbing a dye, and a conductive glass plate (conductive substrate) is used. An iodine solution or the like as an electrolyte is disposed between the counter electrode (cathode electrode) configured as described above, and has a simple structure.

The power generation mechanism of the dye-sensitized solar cell is as follows.

The light incident on the surface of the transparent conductive film on the light-receiving surface is absorbed by the dye adsorbed on the porous semiconductor layer to cause electron excitation, and the excited electrons migrate to the semiconductor and are guided to the conductive glass. Then, the electrons returning to the counter electrode are guided to the dye that has lost electrons via the electrolyte solution such as iodine, and the dye is regenerated.

The dye-sensitized solar cell is cheaper than the tantalum solar cell material, and does not require large-scale equipment for fabrication, so it is a low-cost solar cell. In order to further reduce the cost, it has been studied to omit, for example, a high-priced transparent conductive film, and further, since the transparent conductive film has a large impedance, there is a problem that it is not suitable for an increase in size of a battery.

One of the methods for omitting the transparent conductive film is a wiring made of a conductive metal instead of a transparent conductive film disposed on the surface of the glass. However, in this case, a part of the incident light is blocked by the metal wiring portion with a drop in efficiency.

In order to improve this, for example, there is a disclosure of forming a dye-carrying semiconductor layer on a transparent substrate that does not have a transparent conductive film on the light-irradiating side, and a photoelectric conversion element in which a hole collecting electrode is disposed on the dye-supporting semiconductor layer ( Refer to Patent Document 1). The hole-collecting electrode is a structure in which a thin wire or a thin plate-shaped electrode material is vertically or horizontally combined into a mesh shape or a lattice shape, and the collector electrode is placed on a coating film of a porous semiconductor substrate, for example, calcined at 500 ° C. 30 minutes.

Further, for example, a gold mesh having a wire diameter of 1 μm to 10 mm is used as a collecting electrode having a hole, and a paste of a material of the porous semiconductor layer is coated on the gold mesh, and the paste is calcined to form a porous semiconductor layer to be porous. The technique of arranging a gold mesh toward a transparent substrate made of glass without a transparent conductive film is disclosed (see Patent Document 2).

However, in these techniques, since a gold mesh or a perforated plate formed by pre-processing is used as the collector electrode, the size of the material such as the metal thin wire is limited, and the thickness of the gold mesh or the like is limited. Therefore, the thickness of the gold mesh or the like is thick, and the diffusion resistance when the electrolyte is transferred to the porous semiconductor layer via the gold mesh is increased, whereby the photoelectric conversion efficiency is lowered.

For this, for example, as a collector electrode, by sputtering or vapor deposition, etc. In the method of depositing a metal such as tungsten, titanium or nickel, a method of forming a pattern by lithography or the like is disclosed (see Patent Document 3). The resulting collector electrode is a very thin metal film.

However, in this method, when the thickness of the formed metal film is extremely thin, for example, if the thickness of the metal film is less than 50 nm, the area resistance of the metal film is increased, and the power extraction efficiency cannot be improved. Further, when a thick film of 50 nm or more is provided, the film becomes dense, and the void ratio remarkably decreases, which hinders the flow of the electrolytic solution and causes insufficient performance. Further, this method is premised on the formation of a metal film on a certain substrate, so that the metal film itself cannot exist as a self-standing film, and the degree of freedom in designing the dye-sensitized solar cell is restricted.

On the other hand, the present inventors have disclosed a technique of using a metal porous body sheet composed of a sintered metal sintered body as a collector electrode of a dye-sensitized solar cell (Patent Document 4). The porous titanium sheet is a porous metal body in which a plurality of pores communicate with each other. The porosity of the porous metal body is 30 to 60% by volume, and the pore diameter is 1 to 40 μm.

The collector electrode having such a void structure contributes to the improvement of power generation efficiency. The thickness of the metal porous body sheet is preferably thinner from the viewpoint of easy flow of the electrolyte, but the lower limit of the thickness of the metal porous body sheet which can be produced is subject to the particle size of the industrially produced metal powder (industrially 20μm or more).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-283941

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-73505

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-158470

[Patent Document 4] WO2010/150461 Bulletin

The problem to be solved is to contribute to further improve the photoelectric conversion efficiency of the dye-sensitized solar cell, and to further improve the point of the collector electrode.

A method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention, comprising the step of forming a sheet composed of an alloy of a first metal component and a second metal component And immersing the sheet in a third metal component having a positive heat of mixing for the first metal component and having a negative heat of mixing with respect to the second metal component and having a freezing point lower than a melting point of the alloy The metal melting bath is treated at a temperature lower than a minimum of the liquidus temperature of the alloy in the state diagram; and the treated sheet is taken out of the molten metal bath.

Further, in the method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention, in the step of forming an alloy sheet, a single roll quenching method is preferably used.

Further, in the method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention, the sheet after the treatment is taken out from the molten metal bath, and further washed with an acid or an alkali. A step of.

Further, in the method for producing a current collector for a dye-sensitized solar cell comprising the porous metal sheet of the present invention, the first metal component is selected from the group consisting of Ti, W, Zr, Nb and Ta. More than one species.

Further, in the method for producing a current collector for a dye-sensitized solar cell comprising the porous metal sheet of the present invention, the second metal component is selected from one or two of Cu, Ni, Co, and Fe. the above.

In the method of producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention, the third metal component is selected from one or more of Mg, Ca and Bi.

Further, the current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention has a molten spherical metal block which is fused to each other in a three-dimensional direction and has a nanometer diameter which is connected in a plurality of isotropic directions. Through hole.

Further, the current collector for a dye-sensitized solar cell comprising a porous metal sheet of the present invention has a porosity of 20 to 90% and a sheet thickness of 50 nm to 100 μm.

In addition, the current collector for a dye-sensitized solar cell comprising a porous metal sheet of the present invention is composed of a metal selected from the group consisting of Ti, W, Zr, Nb, and Ta, or two or more kinds of metals.

Further, the dye-sensitized solar cell of the present invention includes: a transparent substrate; a conductive substrate serving as a cathode; and the transparent substrate and the conductive base layer are disposed adjacent to and in contact with the transparent substrate to be adsorbed a porous semiconductor layer of a dye; and a current collector that is disposed on the opposite side of the transparent substrate disposed on the porous semiconductor layer; and is formed by encapsulating an electrolyte, wherein the current collector is made of the porous metal A porous metal sheet produced by a method for producing a current collector for a dye-sensitized solar cell comprising a sheet.

Further, regarding the dye-sensitized solar cell of the present invention, its characteristics The present invention includes a transparent substrate, a conductive substrate that serves as a cathode, and a porous semiconductor layer that is adjacent to and in contact with the transparent substrate to adsorb a dye between the transparent substrate and the conductive substrate; and is disposed in contact with the porous material The opposite side of the transparent substrate of the semiconductor layer serves as a current collector for the anode, and the current collector is a current collector for a dye-sensitized solar cell comprising the porous metal plate.

According to the method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention, the current collector obtained is a mixture of molten spherical metal blocks in a three-dimensional direction, and has a plurality of the like. The through-holes of the nano-diameter diameter that are directionally connected, the charge mobility in the electrolyte passing through the current collector is high. Therefore, it is expected that a higher photoelectric conversion efficiency can be obtained for a dye-sensitized solar cell.

Further, the current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present invention has a plurality of isotropically connected nanometer grades because the molten spherical metal blocks are mutually fused in the three-dimensional direction. The through hole of the diameter has a high charge mobility in the electrolyte passing through the current collector. Therefore, it is expected that a higher photoelectric conversion efficiency can be obtained for a dye-sensitized solar cell.

10‧‧‧Pigment sensitized solar cells

12‧‧‧Transparent substrate

14‧‧‧Electrically conductive substrate

16‧‧‧Porous semiconductor layer

18‧‧‧ Collector for dye-sensitized solar cells

20‧‧‧ Electrolytes

22‧‧‧Package

24‧‧‧Porous sintered metal sheets

26‧‧‧Metal Department

28‧‧‧ Hole Department

Fig. 1 is a view showing a schematic configuration of a dye-sensitized solar cell according to the embodiment.

Fig. 2 is a view showing the porous titanium sheet of the embodiment viewed from the main surface (surface) A picture of the SEM photo.

Hereinafter, an embodiment of the present invention (hereinafter referred to as an example of the present embodiment) will be described.

The present inventors focused on the results of the structure of the current collector for a dye-sensitized solar cell, and it is considered to be useful whether a through-hole having a nano-diameter diameter not disclosed by the conventional current collector is useful.

First, a method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present embodiment (hereinafter, abbreviated as a method for producing a current collector according to the present embodiment) will be described. .

A metal material having minute pores of a nanometer order (nm size) is not only a current collector for a dye-sensitized solar cell, but is generally not easy to manufacture.

However, Japanese Laid-Open Patent Publication No. WO 2011/092909 discloses a method of producing a metal member comprising a second component and a third component each having a positive and negative heat of mixing for the first component, and having a first component and a third component. A metal material composed of a compound having a high melting point of a metal bath and an alloy or a non-equilibrium alloy is immersed in a liquidus which is reduced in the third component by the metal material and whose temperature is controlled within a range in which the composition changes to the second component. The metal bath having a lower minimum temperature causes the third component to be selectively eluted to obtain a metal member having a small gap. Then, since the metal member material thus obtained has a large specific area of more than an order of magnitude with respect to the bulk metal, it can be expected to exhibit, in terms of catalyst characteristics, electrode characteristics, gas storage characteristics, and side properties, which cannot be obtained by previous materials. The high energy obtained.

However, in the examples of this publication, no quantitative data is shown about the pores of the nanometer scale, and specific application examples are not shown.

The present inventors have considered the use of the above-described method for producing a metal member as a method for producing a current collector for a dye-sensitized solar cell, and whether a useful current collector can be obtained, and the present invention has been achieved.

A collector for a dye-sensitized solar cell, unlike other electrode materials, requires corrosion resistance to an electrolyte, electrical inertness to an electrolyte, mobility or diffusion between electrodes of an electrolyte or a carrier, and metal electrode-to-oxide semiconductor Heat resistance and oxidation resistance during sintering. Further, since it is necessary to have a bonding force with the porous semiconductor and a fluidity of the electrolytic solution, it is necessary to control the thickness, the porosity, the pore diameter, and the like.

The method for producing a current collector according to the embodiment has a step of forming a sheet composed of an alloy of a first metal component and a second metal component, and immersing the sheet in a positive manner for the first metal component. While mixing heat and having a negative heat of mixing for the second metal component, the metal melting bath having a third metal component having a freezing point lower than the melting point of the alloy is more than the minimum value of the liquidus temperature of the alloy in the state diagram. a step of low temperature treatment; a step of removing the treated sheet from a molten metal bath.

Here, the first metal component is preferably one or more selected from the group consisting of Ti, W, Zr, Nb, and Ta, and more preferably Ti. Further, the second metal component is preferably one or more selected from the group consisting of Cu, Ni, Co, and Fe, and more preferably Cu. Further, the third metal component is preferably one or more selected from the group consisting of Mg, Ca, and Bi, and more preferably Mg.

The raw material of each of the metal components is preferably a high-purity metal powder, and may be a sponge metal powder, a gas spray metal powder, or a metal block.

Forming an alloy composed of a first metal component and a second metal component The method of the sheet is not particularly limited, and a single-roller rapid cooling method (Melt-spinning method) is a good embodiment.

The single roll quenching method is known as a method of producing an amorphous alloy having no crystal structure, and the obtained amorphous alloy is excellent in strength and the like. The first metal component and the second metal component are melted by an arc melting method to form an alloy, for example, in a pure Ar atmosphere, and then melted, for example, by quenching the surface of the rotating drum to obtain an amorphous alloy ribbon.

The alloy sheet is obtained by immersing the sheet in a third metal component having a positive heat of mixing with respect to the first metal component and having a negative heat of mixing with respect to the second metal component and having a freezing point lower than a melting point of the alloy. The molten metal bath is treated at a temperature lower than the minimum of the liquidus temperature of the alloy in the state diagram. The treated sheet was taken out of the molten metal bath.

For example, according to the calculation using the Miedema model, a mixed heat of 16 kJ/mol and -3 kJ/mol is generated between Mg as the third metal component and Ti as the first metal component and between Mg and Cu as the second metal component. (Refer to Ou Wenzhi of the Japan Institute of Metals, Volume 46, 2818, 2005). Therefore, it is known that Mg and Ti are phase-separated by the positive and negative signs, and on the other hand, Mg and Cu have the property of forming a mixed body. That is, on the other hand, Cu remains on the sheet, and Cu is eluted from the sheet to the metal bath.

The Ti remaining in the sheet repeatedly combines with the surrounding Ti to form fine particles of a nanometer size. Then, the through-holes of the majority nanometer diameter are formed by the combination of the fine particle portions.

Here, when Cu is eluted from Ti-Cu, a nano-sized Ti molten droplet is generated at the place where Cu is eluted. Melt-formed nanometer-sized droplets pass through the production stage At this time, the droplets are coupled to each other to form a dendritic block of molten metal Ti in which the droplets are connected in a dendritic shape. When the molten state is maintained, the molten metal lump which grows into a dendritic shape is affected by the surface tension of the molten metal, and the surrounding fine droplets are combined to form a shape change as close to the spherical block, and are closer to a spherical shape via a shape such as a jelly. The molten spherical metal block of the present invention comprises all the shapes of the tree-like block, the spherical block, the shape of the ginkgoose, and the process of changing to a spherical shape in the above-mentioned production stage.

When the fine particles are excessively bonded to each other, the diameter of the fine particles and the diameter of the through holes become substantially on the order of micrometers. Here, the nanometer size is, for example, 1 μm or less, and the average pore diameter is preferably 10 to 990 nm.

The treatment temperature in the molten metal bath is lower than the temperature at the minimum of the liquidus in the state diagram of the alloy. When the treatment temperature is higher than the temperature of the minimum value of the liquidus, the alloy component is melted, and the effect of the present invention cannot be obtained. The processing temperature lower than the minimum value of the liquidus line varies depending on the type of the alloy component. For example, when Ti is used as the first metal component and Cu is used as the second metal component, the temperature is lower than the minimum value of the liquidus line of 1141 K, and preferably 973 K or more. Here, when the lower limit of the treatment temperature is Mg as the third metal component of the molten metal bath, the temperature of the molten state of Mg can be surely maintained.

The time for immersing the sheet in the molten metal bath is not particularly limited, and may be, for example, several seconds.

The diameter and void ratio of the through holes can be changed by changing the treatment temperature or the immersion time. For example, when the first metal component is titanium and the second metal component is copper, the treatment temperature is low, and the shorter the immersion time is, the smaller the immersion time is, the smaller the diameter of the Ti particles is, and the smaller the diameter and the porosity of the through holes are. Furthermore, the diameter of the through hole or The void ratio can also be controlled by changing the composition of the alloy. For example, when the first metal component is titanium and the second metal component is copper, the presence ratio of copper increases, and the void ratio and the average pore diameter become larger.

The current collector for a dye-sensitized solar cell comprising a porous metal sheet obtained by the method for producing a current collector of the present embodiment is a molten spherical metal block which is fused in three dimensions, and has a plurality of the like. A through-hole of a nanometer diameter that is directionalally connected.

The sheet is immersed in a molten metal bath, and the alloy liquid (adhesive mixture) of Mg-Cu is filled in a plurality of through holes having a diameter of a nanometer, in other words, a gap between the fine particles, and the gap is filled. The sheet was taken out from the molten metal bath, and by cooling to room temperature, a part of the alloy liquid of Mg-Cu was removed from the sheet, and the remainder remained in the sheet as an adherent.

Therefore, after the treated sheet is taken out from the molten metal bath and further washed with an acid or an alkali, the residual deposit of the alloy liquid of Mg-Cu can be removed, and it is more preferable.

Next, a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the present embodiment will be described (hereinafter, this sheet is abbreviated as a collector for a dye-sensitized solar cell according to the present embodiment). The situation of the body.).

The current collector for a dye-sensitized solar cell according to the present embodiment is a porous body having a through-hole having a nanometer-diameter diameter in which a molten spherical metal block is mutually fused in the three-dimensional direction and has a plurality of isotropic interfaces. The composition of the metal plate. In the current collector for the dye-sensitized solar cell, the diameter of the through-hole is preferably a nanometer diameter, but is not limited thereto. A certain number of through-holes may have a diameter of a nanometer, and other through-holes may be used. It can also be a micron diameter.

The void ratio and the average pore diameter (through-hole) are values obtained by mercury intrusion measurement.

A mercury intrusion type pore size distribution measuring apparatus (Pascal 140 and Pascal 440 manufactured by CARLOERBA INSTRUMENTS Co., Ltd., measuring range: specific surface area: 0.1 m ² /g or more, pore distribution: 0.0034 to 400 μm), with a pressure range of 0.3 to 400 kPa and 0.1 In the range of ~400 MPa, the area to be measured is calculated according to the cylindrical pore model.

The current collector for a dye-sensitized solar cell of the present embodiment can be obtained by the method for producing a current collector according to the above-described embodiment, but the production method is not limited to this method.

The collector for the dye-sensitized solar cell has a porosity of 20 to 90%, and a (plate) concentration of 50 nm to 100 μm. The void ratio is preferably 40 to 90%. The thickness is preferably 200 nm to 25 μm.

When the porosity is 20% or less, the fluidity or diffusibility of the electrolyte inside the sheet is deteriorated, and if it exceeds 90%, the adhesion of the porous semiconductor layer or the bonding strength may be impaired. In addition, more than 90% may impair the strength of the sheet or may not provide the proper conductivity as an electrode.

When the thickness is less than 50 nm, the strength of the sheet is impaired, and the area resistance is increased. On the other hand, when the thickness exceeds 100 μm, the flow resistance of the electrolytic solution inside the sheet becomes large, and the flowability and diffusibility of the electrolyte in the inside or between the sheets are deteriorated, so that the electrolyte is impaired on the porous semiconductor layer. Uniform penetration.

A dye-sensitized solar cell using a current collector for a dye-sensitized solar cell according to the present embodiment for a current collector is used in the electrolyte of the current collector. The mobility of the charge is large. Therefore, it is expected that a higher photoelectric conversion efficiency can be obtained for a dye-sensitized solar cell.

The through-hole having a nanometer diameter of the current collector is not clear to the mechanism for contributing to the improvement of the photoelectric conversion efficiency, and the following effects can be predicted.

The increase in photoelectric conversion efficiency is considered to be caused by an increase in conductivity of the electrolyte (electrolyte). The increase in conductivity of the electrolyte (electrolyte) is considered to be the so-called electron jump effect. That is, the ion-pair of the electron carrier and the ion pair with the cation, which are passed through the through-hole of the nanometer-diameter, are regularly arranged, and the oxidation-reduction reaction is repeated with the adjacent ion pair. Different from the migration phenomenon of ion pairs, even if the ions do not move, it can also produce only electron migration, and the charge can be transported at high speed. At this time, it is considered that the higher the ratio of the through-holes of the nano-diameter diameter to the entire through-holes, the more the jump effect can be increased.

Next, a dye-sensitized solar cell according to the embodiment will be described.

As shown in Fig. 1, the dye-sensitized solar cell 10 of the present embodiment includes a transparent substrate 12, a conductive substrate 14 serving as a cathode, and between the transparent substrate 12 and the conductive substrate 14. And contacting the porous semiconductor layer 16 disposed on the transparent substrate 12 to adsorb the dye; and contacting the opposite side of the transparent substrate 12 disposed on the porous semiconductor layer 16 to form the current collector 18 of the anode; and encapsulating the electrolyte 20 Made. The current collector 18 is a porous metal sheet produced by the method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the above-described embodiment, or the above-described embodiment. A current collector for a dye-sensitized solar cell comprising a porous metal sheet. In addition, reference numeral 22 in Fig. 1 denotes a package.

The constituent elements of the dye-sensitized solar cell 10 other than the current collector 18 for the dye-sensitized solar cell can be produced by an appropriate method using a suitable material which is usually used.

The transparent substrate 12 may be, for example, a glass plate or a plastic plate. However, when a plastic plate is used, the flexibility of the solar cell can be imparted to the dye. When a plastic plate is used, for example, PET, PEN, polyimide, hardened acrylic resin, hardened epoxy resin, hardened ketone resin, various engineering plastics, and cyclic polymer obtained by metathesis polymerization may be mentioned.

The conductive substrate 14 is made of the same substrate as the transparent substrate 12, and a part of the surface of the substrate facing the electrolyte 20 is laminated with, for example, ITO (tin-doped indium oxide film), FTO (fluorine-doped tin oxide film), and A conductive film such as a SnO ₂ film, a metal film such as Ti, W, Mo, Rh, Pt or Ta is further provided with a catalyst film such as a platinum film on the conductive film. Further, the transparent substrate may be omitted, and a catalyst film layer such as a platinum film may be provided on the metal foil. Metal foil, preferably Ti.

As the material of the porous semiconductor layer 16, as the material, ZnO, SnO ₂ or the like can be used, and TiO _{2 is} preferable. The shape of the fine particles such as TiO ₂ is not particularly limited, and is preferably from 1 nm to 100 nm.

The porous semiconductor layer 16 is formed by repeatedly forming a paste film of TiO ₂ and then firing it at a temperature of 300 to 550 ° C to form a desired thick film.

The pigment is adsorbed on the surface of the fine particles constituting the porous semiconductor layer 16. The dye has absorption in at least a part of a wavelength region of 400 nm to 1000 nm, and examples thereof include a metal complex such as a metal phthalocyanine dye or a metallic violet, a phthalocyanine dye, a purple pigment, a rhodamine pigment, and a coumarin. Pigment, squarylium pigment, An organic pigment such as a cyanine pigment or a polymethine dye. The method of the adsorption is not particularly limited, and for example, a so-called impregnation method in which the dye-sensitized solar cell current collector 18 forming the porous semiconductor layer 16 is immersed in the dye solution to chemically adsorb the dye on the surface of the fine particles can be used.

Further, in order to increase the light collection efficiency, scattering particles of 200 nm or more may be mixed with the material of the porous semiconductor layer 16. Further, a layer composed of the scattering particles may be provided independently on the counter electrode side.

The transparent substrate 12 may or may not be in contact with the porous semiconductor layer 16, and the shorter the interval therebetween, the better. In addition, in order to prevent the conductive metal layer 18 from being placed in contact with the conductive substrate (counter electrode) 14, for example, it has corrosion resistance to the electrolyte 20 and has sufficient pores that do not interfere with electrolyte ion diffusion. A method of spacer insulation such as cellophane. The distance between the current collector 18 for the dye-sensitized solar cell and the conductive substrate 14 is preferably 100 μm or less, more preferably 25 μm or less.

The electrolyte 20 is not particularly limited, and includes, for example, iodine, lithium ion, ionic liquid, or butyl pyridine. In the case of iodine, a redox body composed of a combination of iodide ion and iodine can be used. Further, a metal complex such as cobalt may be used as the redox couple. Further, a solvent which can dissolve the redox body is also included, and examples thereof include acetonitrile, γ-butyrolactone, propionitrile, ethylene carbonate, and an ionic liquid.

The method of injecting the electrolyte 20 is not particularly limited. For example, a part of the sealing material 22 may be unsealed to form an opening, and the electrolyte 20 may be injected from the opening to seal the opening.

Further, an opening portion may be provided in advance in a part of the conductive substrate 14 . After the electrolyte 20 is thus injected, the opening is sealed.

The encapsulating material 22 encapsulated in the electrolyte 20 is injected between the transparent substrate 12 and the conductive substrate 14, and a thermoplastic resin sheet having a thickness of 100 μm or less after curing, a photocurable resin, a thermosetting resin, or the like can be used.

In the dye-sensitized solar cell, the order of lamination in the thickness direction may be the same as described above, and the entire electrode may be formed into a cylindrical shape.

Regarding the dye-sensitized solar cell of the embodiment, a high photoelectric conversion efficiency can be obtained.

Further, in the dye-sensitized solar cell other than the dye-sensitized solar cell of the present embodiment, for example, the current collection of the dye-sensitized solar cell of the present embodiment is provided on a transparent substrate provided with a transparent conductive film. Or one or two or more collectors are disposed in a portion different from the transparent substrate of the porous semiconductor layer on the opposite side of the transparent substrate; and the entire dye-sensitized solar cell is preferably used in the present embodiment. A porous metal sheet produced by a method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet or a set of dye-sensitized solar cells comprising the porous metal sheet according to the present embodiment. Electric body, it goes without saying.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the invention is not limited to the examples.

(Example 1)

<Production of Porous Titanium Sheet (A)>

About 30 g of Cu ₇₀ Ti ₃₀ having a Cu:Ti atomic ratio of 7:3 was produced by an arc dissolving method in a pure argon atmosphere. This mother alloy was fabricated into a foil-shaped metal material having a width of 10 mm, a thickness of 25 μm, and a length of 50 mm in a pure argon atmosphere using a single roll type quenching method.

Next, about 10 g of pure magnesium was inserted into a graphite container having an inner diameter of 30 mm and a depth of 50 mm, and the high-frequency wave was melted in a pure argon atmosphere, and the liquid temperature was adjusted at 700 ° C (973 K) to adjust the output to prepare a magnesium metal molten bath. This temperature and has more reduced from ₇₀ Ti ₃₀ Cu alloy copper component to a lower minimum temperature of 868 ℃ (1141K) consisting liquidus temperature fluctuation range of the titanium component. The above-mentioned foil-like metal material was used, and the molybdenum-made steel wire was hung, immersed in the above-mentioned magnesium metal melting bath for about 1 second, and then pulled up to be cooled in argon gas. During this period, the copper element in the foil-like metal material is eluted into the molten metal bath of the magnesium metal, and the remaining titanium is bonded to each other to form a fine granular material, and the eluted copper is filled in the gap generated by the combination of the portions. A mixture of magnesium components.

The foil-shaped metal material cooled by the above molten magnesium metal bath is treated in a 0.1 m aqueous solution of nitric acid in a beaker container at room temperature for 30 minutes to form the above-mentioned adhered mixture of magnesium and copper components. After the elution was removed, the mixture was pulled up to the atmosphere and dried to obtain a porous titanium plate (A).

Fig. 2 is a SEM photograph showing the porous titanium sheet (A) as viewed from the main surface (surface) side.

From the image analysis of the cut surface of the porous titanium sheet (A), the void ratio was calculated to be about 47%, and the specific area defined by the ratio of the surface area to the volume was about 2.4 × 10 ⁷ m ² /m ³ .

The thickness of the obtained porous titanium plate sheet (A), the average particle diameter of titanium, the void ratio, and the average pore diameter are shown in Table 1. Further, as shown in the first table, the value of the void ratio measured by the mercury intrusion method was 50%.

<Production of Pigment Sensitized Solar Cell (C-1)>

A titanium dioxide paste (trade name: Nanoxide D, manufactured by SOLARONIX Co., Ltd.) was printed in a range of 5 mm × 5 mm of a porous titanium sheet (A) cut into 10 mm × 10 mm, dried, and then calcined in air at 450 ° C for 30 minutes. On the titanium dioxide after calcination, the operation of printing and calcining the titanium dioxide paste was further repeated three times to obtain a porous Ti plate substrate having a titanium dioxide layer.

The porous Ti plate substrate to which the titanium dioxide layer was formed was immersed in a mixed solvent solution of acetonitrile and third butanol of N719 pigment (manufactured by SOLARONIX Co., Ltd.) for 64 hours to adsorb a pigment on the surface of the titanium oxide. The adsorbed substrate was washed with a mixed solvent of acetonitrile and third butanol to obtain a porous Ti plate substrate having a pigment-adsorbed titanium oxide layer.

A titanium foil of 12 mm × 30 mm and a thickness of 25 μm was laminated on the side of the unformed surface of the titanium dioxide paste on the porous Ti plate substrate with the dye-adsorbed titanium dioxide layer, and the anode with the electrode removed was obtained.

On one side of a 12 mm × 30 mm, 30 μm thick titanium foil, platinum was sputtered at 400 nm to form a Ti substrate with a Pt catalyst layer. Further, a titanium foil having a thickness of 15 mm × 40 mm and a thickness of 20 μm was laminated on the side of the surface of the Ti substrate having the Pt catalyst layer and having no Pt, and a cathode having the extraction electrode was obtained.

A PEN film having a thickness of 125 μm, which was a resin plate sheet (manufactured by SOLARONIX Co., Ltd., trade name: MELTONIX 1170-60) having a thickness of 60 μm, was attached, and the surface of the resin plate was laminated on the surface of the titanium foil with the cathode on which the electrode was taken out. Further, a cellophane having a thickness of 50 μm and a porosity of 85% or more was laminated on the Pt catalyst layer on which the anode of the extraction electrode was attached. Further, the above-mentioned titanium dioxide paste with the anode of the extraction electrode is not formed on the film surface, and the phase on the cellophane For the formation. Further, a PEN film having a thickness of 125 μm in a resin sheet having a thickness of 60 μm was applied, and the surface of the resin sheet was laminated on the surface of the resin-adsorbed titanium oxide layer having the anode on which the electrode was taken out. Further, a POM film on the cathode electrode side was provided with an electrolyte insertion hole of 3 mm. These were pressed at a temperature of 130 ° C.

Further, the electrolytic solution insertion hole is injected under reduced pressure into an electrolyte containing iodine or LiI γ-butyrolactone solvent, and then the electrolyte is inserted into the hole and encapsulated with a UV-curable resin to obtain a dye-sensitized solar cell (C- 1)

The obtained dye-sensitized solar cell was subjected to a short-circuit current value at the time of irradiation of the anode side with simulated sunlight of an intensity of 35, 50, 70, and 100 mW/cm ² . The relative value of the short-circuit current value of each light amount (light intensity) and the value of Example 1 when the light amount is 35 mW/cm ² is normalized in the second table.

(Example 2)

A dye-sensitized solar cell (C-2) was obtained in the same manner as in Example 1 except that a PEN film was used. The characteristics of the dye-sensitized solar cell (C-2) are shown in Table 2.

(Comparative example)

A dye-sensitized solar cell (C-3) was obtained in the same manner as in Example 1 except that the porous titanium sheet (A) was used instead of the porous titanium sheet (B) (trade name: TIPOROUS). The characteristics of the Osaka titanium porous titanium sheet (B) are shown in Table 1, and the characteristics of the dye-sensitized solar cell (C-3) are shown in Table 2.

From the second table, it is understood that the short-circuit current value increases greatly with the increase of the amount of light (light hardness) in the first and second embodiments, and the short-circuit current value does not significantly increase in the comparative example even if the amount of irradiation light (light hardness) is increased. increase. This can be considered as, The amount of electrons generated by increasing the amount of light in addition to the electron jump phenomenon in Examples 1 and 2, even in the comparative example, even if the amount of light (light hardness) is increased, the size of the through-hole of the titanium plate is large in the order of micrometers. Therefore, there will be no significant electronic jump phenomenon.

Claims (11)

A method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet, comprising the step of forming a sheet composed of an alloy of a first metal component and a second metal component; a sheet, a metal melting bath immersed in a third metal component having a positive heat of mixing for the first metal component and having a negative heat of mixing for the second metal component and having a freezing point lower than a melting point of the alloy a step of treating at a lower temperature than a minimum of the liquidus temperature of the state diagram of the alloy; and removing the treated sheet from the molten metal bath. According to the method of producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the first aspect of the invention, in the step of forming an alloy sheet, a single roll quenching method is preferably used. A method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the first aspect of the invention, wherein the processed sheet is taken out from the molten metal bath, and further has an acid or The step of alkaline cleaning. The method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the first aspect of the invention, wherein the first metal component is selected from the group consisting of Ti, W, Zr, Nb, and Ta. Or two or more. The method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the first aspect of the invention, wherein the second metal component is selected from the group consisting of Cu, Ni, Co, and Fe or 2 or more types. The method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the first aspect of the invention, wherein the third metal component is one or two selected from the group consisting of Mg, Ca, and Bi. the above. A current collector for a dye-sensitized solar cell, which is fused by a molten spherical metal block in a three-dimensional direction, and has a plurality of through-holes of a nanometer diameter that are connected in an isotropic manner. According to the seventh aspect of the patent application, the current collector for a dye-sensitized solar cell comprising a porous metal sheet has a porosity of 20 to 90% and a sheet thickness of 50 nm to 100 μm. The current collector for a dye-sensitized solar cell comprising a porous metal sheet according to the seventh aspect of the patent application is composed of one or more metals selected from the group consisting of Ti, W, Zr, Nb, and Ta. . A dye-sensitized solar cell comprising: a transparent substrate; a conductive substrate serving as a cathode; and a porous semiconductor which is adjacent to and in contact with the transparent substrate and adsorbs a pigment between the transparent substrate and the conductive substrate And a current collector that is disposed on the opposite side of the transparent substrate disposed on the porous semiconductor layer to form an anode; and the electrolyte is encapsulated by the first to sixth patent applications. A porous metal sheet produced by a method for producing a current collector for a dye-sensitized solar cell comprising a porous metal sheet. A dye-sensitized solar cell comprising: a transparent substrate; a conductive substrate serving as a cathode; and a color difference between the transparent substrate and the conductive base layer disposed adjacent to and in contact with the transparent substrate a porous semiconductor layer; and a current collector that is disposed on the opposite side of the transparent substrate disposed on the porous semiconductor layer to form an anode; and the electrolyte is encapsulated, and the current collector is in the range of claims 7 to 9 A collector for a dye-sensitized solar cell comprising a porous metal sheet according to any one of the items.