WO2005122322A1

WO2005122322A1 - Dye sensitization solar cell and manufacturing method thereof

Info

Publication number: WO2005122322A1
Application number: PCT/JP2005/009677
Authority: WO
Inventors: Hideo Abe; Yasuhito Tanaka; Ariyoshi Ogasawara
Original assignee: Sfc Co., Ltd.
Priority date: 2004-06-08
Filing date: 2005-05-26
Publication date: 2005-12-22
Also published as: JPWO2005122322A1; WO2005122321A1; KR20070050906A

Abstract

A dye sensitization solar cell having excellent reproducibility and stable performance is provided by maintaining a fixed interval between two boards and controlling the quantity and the flowability of an electrolyte held between the boards, and a method for manufacturing such dye sensitization solar cell is also provided. At least one transparent board surface of the two boards is provided with a transparent conductive film and a dye sensitization semiconductor electrode. The dye sensitization solar cell is provided by placing the two boards one on another and encapsulating the electrolyte between the two boards. Between the two boards, a mesh-like member composed of two or more wire rods is arranged to operate as an electrode.

Description

Specification

Dye-sensitized solar cell and method of manufacturing the same

Technical field

The present invention relates to a dye-sensitized solar cell that directly converts light energy into electric energy, and a method for manufacturing the same.

Background art

[0002] The dye-sensitized solar cell announced by Gretzell et al. In 1991 operates according to a mechanism different from that of a solar cell using pn junction of silicon semiconductors, and has the advantages of high conversion efficiency and low power and low manufacturing costs. This solar cell is also called a dye-sensitized solar cell because an electrolyte is sealed therein.

In this solar cell, as shown in FIG. 4, a transparent conductive film 7 formed on one surface of a transparent substrate 1 and a semiconductor electrode carrying a sensitizing dye (dye-sensitized semiconductor electrode 4) The formed conductive substrate 5 is overlapped with the electrolyte contained therein, and the periphery thereof is sealed with a resin. When a porous titanium oxide film provided on the surface of a conductive substrate is coated with a sensitizing dye capable of efficiently absorbing sunlight, such as a ruthenium complex, as a dye-sensitized semiconductor electrode, The excited electrons are injected into titanium oxide and electricity can flow. In this type of solar cell, an electrolytic solution is required to transfer electrons, and an iodine electrolytic solution is generally used.

Patent Document 1: Japanese Patent Publication No. 8-15097.

Patent Document 2: Japanese Patent Application Laid-Open No. 2000-173680.

Disclosure of the invention

Problems to be solved by the invention

[0004] In the conventional dye-sensitized solar cell shown in Fig. 4, only a thick resin is applied to the periphery (near a cross section) and cured in order to seal the electrolyte. The distance between the cells varies from one solar cell to another, or even within a single solar cell, so that the amount of electrolyte is not constant, and if the solar cell is tilted, the electrolyte will flow out. Reproducibility 'There was a stability problem. [0005] Further, the porous titanium oxide film used as the dye-sensitized semiconductor electrode has irregularities on the surface depending on the coating method, the particle size and the thickness, but the convex portions face each other. If it comes into contact with the conductive film on the substrate, the dye-sensitized semiconductor electrode and the conductive film will be energized without passing through the electrolytic solution, so electrons will not be transferred sufficiently and the efficiency of the solar cell And the performance is unstable.

Accordingly, the present invention has been made in view of such a problem, and it is an object of the present invention to keep the distance between two substrates constant and to control the amount and fluidity of an electrolyte held between the substrates. Accordingly, it is an object of the present invention to provide a dye-sensitized solar cell having excellent reproducibility and stable performance and a method for producing the same.

Means for solving the problem

[0007] As a result of earnest studies, the inventors have solved the above-mentioned problem by sandwiching a wire woven in a mesh shape between both substrates of a dye-sensitized solar cell, thereby holding an electrolyte. I came up with

[0008] That is, according to the present invention, two substrates having a transparent conductive film and a dye-sensitized semiconductor electrode formed on at least one transparent substrate surface are overlapped, and an electrolytic solution is sealed between the two substrates. In the dye-sensitized solar cell, a member formed by meshing two or more wires in a mesh shape and serving as an electrode is disposed between the two substrates. A dye-sensitized solar cell is provided.

[0009] The dye-sensitized solar cell of the present invention is characterized in that the wire has conductivity. Alternatively, the wire may be insulative, and a conductive coating may be formed on one or both surfaces of the wire.

[0010] In the dye-sensitized solar cell of the present invention, the thickness of the wire is larger than the height of irregularities on the surface of the substrate on which the transparent conductive film and the dye-sensitized semiconductor electrode are formed. And

[0011] The dye-sensitized solar cell of the present invention is characterized in that, of the two substrates, a transparent conductive film and a dye-sensitized semiconductor electrode are formed, and the substrate is insulative. The invention's effect

[0012] As described above, according to the present invention, an electrolyte holding electrode material is disposed between two substrates. As a result, the amount of the retained electrolyte is stabilized, the fluidity thereof is suppressed, and the current is not passed between the dye-sensitized semiconductor electrode and the conductive film without passing through the electrolyte. And a dye-sensitized solar cell with good reproducibility and stable performance. Brief Description of Drawings

FIG. 1 is a schematic sectional view showing a configuration example of a dye-sensitized solar cell of the present invention.

FIG. 2 is a process flow chart showing an example of a manufacturing process of the dye-sensitized solar cell of the present invention.

FIG. 3 is a view showing a configuration example of an electrolyte holding electrode material in a dye-sensitized solar cell of the present invention.

FIG. 4 is a schematic sectional view showing a configuration example of a conventional dye-sensitized solar cell.

Explanation of symbols

[0014] 1 substrate

2 Electrolyte retention 'electrode material

3 Electrolyte

4 Dye-sensitized semiconductor electrode

5 Transparent glass substrate

6 Transparent conductive film

7 Conductive film

8 Sealing material

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a dye-sensitized solar cell as an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a dye-sensitized solar cell according to an embodiment of the present invention.

In FIG. 1, the dye-sensitized solar cell of the present embodiment has a substrate 1 and a transparent glass substrate 5 on which a dye-sensitized semiconductor electrode 4 and a transparent conductive film 6 are formed. Between the two substrates, a mesh-like electrolyte holding electrode material 2 is arranged, and the electrolyte 3 is contained. In addition, both substrates are sealed by applying a sealing material to the side surfaces.

The substrate 1 is made of an insulating glass substrate, a ceramic substrate, or a conductive material such as metal or carbon. It can be composed of a substrate on which a material is formed, a metal plate, or the like. Transparent glass substrate

5 may be replaced by a transparent plastic substrate or the like. The dye-sensitized semiconductor electrode 4 can also be composed of titanium oxide, titanium oxide tantalum, niobium oxide, zirconium oxide, or the like, but is not limited thereto. The transparent conductive film 6 can also be composed of ITO (tin-containing indium oxide), tin oxide, zinc oxide, and the like, but is not limited thereto, and has a film thickness that does not lower the transmittance. Platinum, metal, or carbon films are also applicable. The sealing material may be a material whose hardness changes depending on the temperature or the like, as long as it can seal between the substrates.

The electrolyte holding electrode material 2 is in the form of a mesh in which a plurality of wires are woven in a mesh shape, and the method of weaving the wires includes plain weave, twill weave, plain tatami weave, twill tatami weave, and the like. . It is possible to use not only braided single wire but also braided twisted wire composed of two or more twisted wires. The shape of the wire of the electrolyte holding electrode material 2 may be a prism, a column, or the like, but is not limited thereto. The thickness of the electrolyte holding electrode material 2 may be larger than the unevenness of the surface of the conductive substrate or the unevenness of the dye-sensitized semiconductor electrode 4 and is generally about several / zm to lmm, more preferably several tens of mm. / zm to several hundred / zm. Electrolyte retention 電極 The mesh spacing and wire diameter of the electrode material 2 can be arbitrarily selected so that the effect of the electrolyte immersing between the meshes and the wire and suppressing the flow of the electrolyte occurs. Good.

[0019] The material of the wire for the electrolyte holding electrode material 2 is made of a metallic conductive material such as stainless steel or A1 or Ni, but may be a weak force, a ceramic such as glass or alumina, or a polymer material such as nylon or polyimide. A metal such as Pt, carbon, A1 or Ni may be coated on the surface of one side of the insulating material by a vapor deposition method, but it is not limited to these. Anything that does not dissolve or drip (repellent) the electrolyte solution is acceptable.

Next, a method for manufacturing a dye-sensitized solar cell according to an embodiment of the present invention will be described with reference to FIG.

First, a transparent glass substrate or a plastic substrate is prepared as the transparent glass substrate 5. On this substrate, ITO (tin-containing indium oxide), tin oxide, zinc oxide, or the like is formed. Platinum, Ti or other metal or carbon film with a film thickness that does not decrease The conductive film 6 is formed.

Next, on the surface of the transparent conductive film 6, fine particles of a metal oxide such as titanium oxide, titanium oxide tantalum, niobium oxide, silica gel, and a small amount of an organic polymer Is applied by a printing method or the like, air-dried, and then heat-treated at a temperature of 500 ° C. to volatilize the organic polymer. At this time, fine pores are formed on the surface coated with the metal oxide fine particles. Here, the height of the surface irregularities is measured by a surface shape evaluation device such as α step. The porous metal oxide film formed on the surface of the transparent conductive film 6 in this manner is immersed in a solution of a sensitizing dye, and the sensitizing dye is adsorbed on the surface thereof to form a dye-sensitized semiconductor electrode 4. To form

On the dye-sensitized semiconductor electrode 4 thus formed on the transparent conductive substrate 5, the electrolyte holding electrode material 2 woven in a mesh is arranged. FIG. 3 is a top view schematically showing an arrangement of the electrode material 2 for holding the electrolytic solution. At this time, the electrolyte-holding electrode material 2 is prepared to have a thickness larger than the height of the irregularities on the surface of the dye-sensitized semiconductor electrode 4 measured as described above.

Thereafter, the substrates 1 are overlapped so as to sandwich the electrolyte holding electrode material 2 from above, an iodine electrolyte is injected between the substrates, and a sealing material is applied to the periphery between the substrates. The electrolytic solution 3 is not limited to the iodine electrolytic solution, but may be an organic electrolytic solution containing oxidized and reduced species.

Example

[0025] Example 1

The dye-sensitized solar cell according to the above-described embodiment was manufactured by the following procedure. Two glass substrates having a size of 2 × 3 cm and a thickness of 2.8 mm were prepared, and an ITO film was formed on one of them as a transparent conductive film 6 by a sputtering method to a thickness of 200 nm. The height of the irregularities on this surface was approximately 1 μm or less. After masking and coating with a tape or the like on the substrate 5 on which the transparent conductive film 6 was formed, titanium dioxide for photocatalyst having a particle diameter of about 20 nm was mixed well with water, polyethylene glycol, and nitric acid to form a paste, which was then printed.

Next, heat treatment was performed at 500 ° C. for 30 minutes in the atmosphere, and the resultant was cooled to obtain a titania film having an average thickness of about 10 m. The height of the irregularities on this surface was approximately 30 m or less. From this, the electrolysis used The liquid holding electrode material 2 has a thickness of 30 / zm or more. Further, the titanium film formed above was immersed in an acetonitrile solution of a ruthenium complex. As a result, a ruthenium complex as a sensitizing dye was adsorbed and coated on the titanium oxide fine particles constituting the film, and a dye-sensitized semiconductor electrode 4 was formed.

[0027] As the electrolyte holding electrode material 2, a wire was formed by binding three 16-μm-diameter stainless steel wires, and then a mesh was formed at a pitch of approximately 100 / zm. . The thickness is about 50 m. After holding the electrolyte solution and the electrode material 2 between the substrate 5 on which the dye-sensitized semiconductor electrode 4 was formed and the other substrate 1, the iodine electrolyte solution 3 was poured between the substrates.

[0028] As the iodine electrolyte 3, a solution obtained by dissolving 0.5M lithium iodide and 0.05M iodine in a mixed solution of 3-methoxypropio-tolyl and acetonitrile was used. Further, using a dispenser, a sealant was applied to the periphery between the substrates and sealed, thereby producing a dye-sensitized solar cell.

[0029] Decoration 12

In this example, the same procedure as in Example 1 was used except that the electrolyte solution was used in Example 1 and the electrode material was coated with about 10 Pt of Pt by ion beam assisted vapor deposition on one surface of the electrode material. A dye-sensitized solar cell was manufactured. Ten cells were produced in this example.

[0030] Decoration 13

In this example, the same procedure as in Example 1 was carried out except that the electrolyte solution holding used in Example 1 and the electrode material coated with about 10 Å of Pt by ion beam assisted vapor deposition on both surfaces were used. A dye-sensitized solar cell was manufactured. Ten cells were produced in this example.

Example 4

In the present embodiment, a nylon wire having a diameter of 16 / zm was used as the electrolyte holding electrode material 2, and a mesh having a thickness of about 100m and a pitch of about 100m was used. A dye-sensitized solar cell was fabricated in the same manner as in Example 1, except that one surface of the electrolyte-holding electrode material 2 was coated with Pt of about 10 nm by an ion beam assisted vapor deposition method. In this example, 10 cells were manufactured.

[0032] Comparative example

As a comparative example with respect to the above-described embodiment, the actual operation was the same except that the electrolyte holding electrode material 2 was not used. In the same manner as in Example 1, 10 dye-sensitized solar cells were produced.

[0033] Comparison results

The dye-sensitized solar cells prepared in Examples 1 to 4 were irradiated with a xenon lamp to measure the electromotive force.The cell of the comparative example was 100 mW, the short-circuit current per 1 cm ² was 5 to 15 mA, and the open-circuit voltage was In contrast to 0.57 to 0.65 V, the cell of Example 1 had a short-circuit current of about 15 mA per lcm ² , the open-circuit voltage was about 0.6 V, and the cell of Example 2 had a short-circuit current of about 20 mA per lcm ² , open circuit voltage of about 0. 65V, the short-circuit current of about 25 mA of cell per lcm ² of example 3, the open circuit voltage is about 0. 65V, short circuit current per lcm ² with the cells of example 4 10 cells The open circuit voltage was about 0.60 V, about 8 mA.

[0034] As described above, it was confirmed that the dye-sensitized solar cell of the present invention had excellent reproducibility and had stable performance.

As described above, the dye-sensitized solar cell of the present invention and the method of manufacturing the same have been described with reference to specific embodiments, but the present invention is not limited to these. A person skilled in the art can make various changes and improvements to the configuration and functions of the present invention that are effective in the above embodiments or other embodiments without departing from the gist of the present invention.

Claims

The scope of the claims

[1] A dye-sensitized type in which a transparent conductive film and a dye-sensitized semiconductor electrode are formed on at least one transparent substrate and two substrates are superimposed on each other, and an electrolyte is sealed between the two substrates. In solar cells,

A dye-sensitized solar cell, comprising a member formed by weaving two or more wires in a mesh shape and serving as an electrode between the two substrates.

2. The dye-sensitized solar cell according to claim 1, wherein the wire has conductivity.

3. The dye-sensitized solar cell according to claim 1, wherein the wire is insulative, and a conductive film is formed on one or both surfaces of the wire.

[4] The wire according to any one of claims 1 to 3, wherein the thickness of the wire is larger than the height of irregularities on the surface of the substrate on which the transparent conductive film and the dye-sensitized semiconductor electrode are formed. Dye-sensitized solar cells.

5. The dye sensitizer according to claim 1, wherein, of the two substrates, a substrate on which the transparent conductive film and the dye-sensitized semiconductor electrode are not formed is insulative. Type solar cell.