JP6775175B1 - Dye-sensitized solar cell that can obtain high power generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell in which a high amount of power generation is maintained even when the position of the sun changes or indoors where light is weak. SOLUTION: This is a dye-sensitized solar cell 1 in which at least a pair of photoelectrodes and counterpoles are arranged to face each other via an electrolyte layer, and the photoelectrodes are porous oxidation containing a dye-sensitizer on a titanium material. A titanium sintered body layer is formed, and an electrochemical reduction catalyst layer is formed on a transparent conductive glass or a transparent conductive film whose counter electrode is a transparent conductive glass, and the light incident on the dye-sensitized solar cell side is converged. As described above, the condensing lens 3 and the reflecting plate 4 that reflects the light that has passed through the condensing lens are installed, and the normal line N of the light receiving surface of the dye-sensitized solar cell is in the direction of the optical axis L of the condensing lens. Dye-sensitized solar cells are arranged so as to intersect, and the reflector is the light that has passed through the condenser lens on the side where the normal lines of the light receiving surface of the dye-sensitized solar cell intersect with respect to the optical axis direction. It is arranged so as to reflect at least a part and irradiate the dye-sensitized solar cell. [Selection diagram] Fig. 1

Description

The present invention relates to a dye-sensitized solar cell, and more particularly to a dye-sensitized solar cell including a condensing lens and a reflector.

There are many types of solar cells such as single crystal, polycrystalline or amorphous silicon type solar cells, compound semiconductor solar cells such as CIGS, CdTe, and GaAs, organic thin film solar cells, perovskite type solar cells, and dye-sensitized solar cells. There is a thing.
Among these solar cells, silicon type solar cells are currently the mainstream. However, this silicon-type solar cell requires a high-purity silicon material, consumes a lot of energy in the manufacturing process, and has a problem of high manufacturing cost, and it is also difficult to reduce the weight of the solar cell. ..

Under these circumstances, dye-sensitized solar cells are attracting attention as next-generation solar cells because they can be manufactured at low cost and have high photoelectric conversion efficiency.
In a dye-sensitized solar cell, after injecting an electrolyte such as iodine or iodide ion having reversible electrochemical redox characteristics between the photoelectrode and the counter electrode, the photoelectrode and the counter electrode are sealed and connected. It can be constructed by a simple method of doing.

As the dye-sensitized solar cell, for example, there is one manufactured by the following method.
First, a paste agent containing titanium oxide fine particle powder is applied onto a transparent conductive glass which is a glass substrate on which a transparent conductive film such as fluorine-doped tin oxide (FTO) is formed. Next, the photoelectrode substrate in which the porous titanium oxide sintered body layer is formed on the transparent conductive film is produced by heat treatment.
Next, by immersing the above photoelectrode substrate in an organic solvent containing a dye sensitizer such as a ruthenium complex dye or an indoline dye, the photosensitizer is adsorbed on the surface of the porous titanium oxide. Make an electrode.
Next, a platinum layer having a high electrochemical reducing action is formed on a glass substrate or film on which a transparent conductive film is formed by a method such as sputtering or CVD (Chemical Vapor Deposition). Creates a counter electrode.
An electrolyte layer composed of an organic solvent such as acetonitrile containing iodine, iodide ions, etc., which has reversible electrochemical redox properties, is injected between the photoelectrode produced in this manner and the counter electrode, and sealed. A dye-sensitized solar cell is manufactured by a simple method of stopping.

Further, the dye-sensitized solar cell is generated as follows.
When the dye sensitizer adsorbed on the porous titanium oxide sintered body layer of the photoelectrode is irradiated with light, electrons are excited by the light absorption of the dye sensitizer. These excited electrons reach a transparent conductive film such as FTO through the porous titanium oxide layer on which the dye sensitizer is adsorbed. The dye sensitizer that emits electrons due to photoexcitation causes an oxidation reaction that robs the electrolyte of electrons.
Further, the electrons that reach the transparent conductive film of the photoelectrode substrate move to the counter electrode via the external circuit. The electrons that have moved to the opposite electrode undergo a reduction reaction that supplies electrons to the electrolyte that has been deprived of electrons. By repeating such a series of flows, the dye-sensitized solar cell generates electricity.

However, since the electric resistance of the conventional transparent conductive film is high and the electric resistance is further increased in the heat treatment when producing the titanium oxide sintered body, the photoelectric conversion efficiency of the obtained dye-sensitized solar cell is increased. There was a problem that it became low.

Therefore, the present inventor has developed a dye-sensitized solar cell module capable of expressing high power by using metallic titanium or titanium alloy or surface-treated metallic titanium or titanium alloy as an optical electrode (Patent Document 1). ..
Here, since the orbit of the sun changes during the day or every season, if the orientation of the solar cell is fixed, the power generation efficiency will change during the day or every season.
At present, it is difficult to change the orientation of the solar cell according to the movement of the sun from the viewpoint of cost. Therefore, in the silicon type solar cell, as a means for increasing the expression efficiency, a tracking type condensing lens is used. Such a condensing device is used.

Japanese Patent No. 6104446

However, the sun accordingly the position of the sun changes in mainstream is silicon solar cell and a conventional dye-sensitized solar cell using the transparent conductive glass and a transparent conductive film on the photoelectrode of the current solar cell Since the amount of light emitted to the battery changes, it is difficult to maintain a high amount of power generation even when a condensing device is used.
Further, the silicon type solar cell has a drawback that it hardly generates electricity because not only the current but also the voltage drops indoors where the incident light intensity is weak. On the other hand, the dye-sensitized solar cell has the advantage that it can be used indoors because the current decreases even if the incident light is weak, but the voltage hardly changes, but the magnitude of the current is still the incident light intensity. The amount of power generated is not so large because it depends on.

An object of the present invention is to provide a dye-sensitized solar cell that maintains a high amount of power generation even when the position of the sun changes or indoors where the light is weak, in order to solve the above problems. To do.

The present inventor has studied to solve the above-mentioned problems of the prior art, and found that a dye-sensitized solar cell having a specific structure can achieve the above-mentioned object.

The gist of the present invention is
[1] In a dye-sensitized solar cell in which at least a pair of photoelectrodes and counter electrodes are arranged to face each other via an electrolyte layer.
(1) The photoelectrode is a titanium oxide material on which a porous titanium oxide sintered body layer containing a dye sensitizer is formed.
(2) The counter electrode is a transparent conductive glass or a transparent conductive film on which an electrochemical reduction catalyst layer is formed.
(3) A condenser lens is arranged so as to converge the light incident on the dye-sensitized solar cell side, and a reflector for reflecting the light passing through the condenser lens is installed.
The dye-sensitized solar cell is arranged so that the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction of the condenser lens.
The reflecting plate reflects at least a part of the light passing through the condensing lens on the side where the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction, and the dye. Arranged to illuminate the sensitized solar cell ,
A dye-sensitized solar cell, wherein the substrate to which the dye-sensitized solar cell is fixed, the condenser lens, and the reflector are arranged so as to have a substantially triangular tubular shape .
[2] The dye increase according to the above [1], wherein the angle formed by the normal of the light receiving surface of the dye-sensitized solar cell and the optical axis of the condenser lens is more than 0 ° and less than 180 °. Sensitive solar cell ,
[ 3 ] The above-mentioned [1] or [2] , wherein the titanium material is one or more materials selected from the group consisting of metallic titanium, titanium alloys, surface-treated metallic titanium and surface-treated titanium alloys . Dye-sensitized solar cells, described in
[ 4 ] A block layer is provided on the side where the photoelectrode is arranged opposite to the counter electrode of the titanium material, and a porous titanium oxide sintered body layer containing a dye sensitizer is further formed on the block layer. The block layer is selected from the group consisting of a titanium oxide layer, an aluminum oxide layer, a silicon oxide layer, a zirconium oxide layer, a strontium titanate layer, a magnesium oxide layer, and a niobium oxide layer. The dye-sensitized solar cell according to any one of [1] to [ 3 ] above, which is composed of at least two layers.
[ 5 ] The dye-sensitized solar cell according to any one of [1] to [ 4 ] above, wherein the electrochemical reduction catalyst layer is a platinum catalyst layer.
[ 6 ] Any of the above [1] to [ 5 ], wherein the counter electrode is a transparent conductive glass or a transparent conductive film on which a collector is provided and then an electrochemical reduction catalyst layer is formed. Dye-sensitized solar cells, described in
[ 7 ] The dye-sensitized solar cell according to any one of [1] to [ 6 ] above, wherein an antireflection film is further provided on the light irradiation surface of the transparent conductive glass or the transparent conductive film at the opposite electrode.
[ 8 ] The photoconductor and the counter electrode were arranged in a T shape via an electrolyte layer, and a porous titanium oxide sintered body layer containing a dye sensitizer was formed on the cross section of the titanium material. Two or more optical electrodes are arranged via an insulator, and the optical electrodes are integrated with each other via an insulating material. Regarding the transparent conductive glass or transparent conductive film of the counter electrode. includes a transparent conductive film and the electrochemical reduction catalyst layer in which the transparent conductive glass or a transparent conductive film has are both insulated by etching, and each of the photoelectrode and the counter electrode, electrically in series or in parallel The dye-sensitized solar cell according to any one of [1] to [ 7 ], which is connected to the above.
[ 9 ] The titanium material of the photoelectrode forms titanium nitride on metallic titanium or a titanium alloy, and then anodized at a spark discharge voltage or higher using an electrolytic solution having an etching action on metallic titanium. The dye-sensitized solar cell according to any one of [1] to [ 8 ] above, which is a metallic titanium or titanium alloy material having an anatase-type titanium oxide film formed on its surface.
[ 10 ] The titanium material of the photoelectrode forms titanium nitride on metallic titanium or a titanium alloy, and then uses an electrolytic solution having no etching action on metallic titanium in an anodized and oxidizing atmosphere. The dye-sensitized solar cell according to any one of [1] to [ 8 ] above, which is a metallic titanium or titanium alloy material having an anatase-type titanium oxide film formed on its surface by heat treatment.

The dye-sensitized solar cell module of the present invention can maintain a high amount of power generation even when the position of the sun changes or indoors where the light is weak.

It is the schematic which shows the embodiment of the dye-sensitized solar cell of this invention. It is the schematic which shows the embodiment of the dye-sensitized solar cell of this invention. It is the schematic which shows the embodiment of the dye-sensitized solar cell of this invention. It is a schematic diagram of the dye-sensitized solar cell 1 produced in Example 1. It is the schematic of the dye-sensitized solar cell used in the comparative example 2.

The present invention will be described in detail below.

The dye-sensitized solar cell of the present invention
In a dye-sensitized solar cell in which at least a pair of photoelectrodes and counter electrodes are arranged to face each other via an electrolyte layer.
(1) The photoelectrode is a titanium oxide material on which a porous titanium oxide sintered body layer containing a dye sensitizer is formed.
(2) The counter electrode is a transparent conductive glass or a transparent conductive film on which an electrochemical reduction catalyst layer is formed.
(3) A condenser lens is arranged so as to converge the light incident on the dye-sensitized solar cell side, and a reflector for reflecting the light passing through the condenser lens is installed.
The dye-sensitized solar cell is arranged so that the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction of the condenser lens.
The reflecting plate reflects at least a part of the light passing through the condensing lens on the side where the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction, and the dye. It is characterized in that it is arranged so as to irradiate a sensitized solar cell.

In the dye-sensitized solar cell of the present invention, unlike the conventional solar cell, the direction of the normal line of the light receiving surface of the dye-sensitized solar cell is arranged so as to be parallel to the optical axis direction of the condenser lens. Instead, the dye-sensitized solar cell is arranged so that the normal line of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction of the condensing lens, and the dye-sensitized solar cell is arranged. In view of this, at least a part of the light passing through the condensing lens is reflected on the side where the normal line of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction, and the dye sensitization is performed. Since the reflector is arranged so as to irradiate the type solar cell, the dye-sensitized type is used even when the light used is sunlight whose position changes over time or even indoors where the light is weaker. It is possible to prevent the reduction of the light emitted to the solar cell body and maintain a high amount of power generation.

FIGS. 1 to 3 show schematic views of embodiments of the dye-sensitized solar cells 1, 1A, and 1B of the present invention, respectively.
The dye-sensitized solar cells 1, 1A, and 1B include a solar cell body 2, a condenser lens 3, and a reflector 4.
The solar cell body 2 is fixed to the substrate 5.
In the dye-sensitized solar cells 1, 1A and 1B of the present invention, as shown in FIGS. 1 to 3, the substrate 5 to which the solar cell body 2 is fixed, the condenser lens 3 and the reflector 4 are substantially triangular. It is arranged in a tubular shape, and solar power is generated using the light that enters the inside of this cylinder.

The solar cell main body 2 is arranged so that the normal line N orthogonal to the light receiving surface of the solar cell main body 2 intersects the optical axis L direction, which is the central axis of the condenser lens 3.

The angle θ of the intersecting portion is an angle formed by the normal line N and the optical axis L in the direction in which the light is incident, and is adjusted so as to be more than 0 ° and less than 180 °.
For example, as shown in FIG. 1, when the temperature is adjusted to a range of more than 0 ° and less than 90 °, the light that has passed through the condenser lens 3 is directly irradiated to the light receiving surface of the solar cell body 2. Therefore, the light that is not directly irradiated is also reflected by the reflector 4 and is irradiated on the light receiving surface.
Further, when the angle θ is adjusted to 90 ° as shown in FIG. 2 or the angle θ is adjusted to exceed 90 ° and less than 180 ° as shown in FIG. 3, the light is focused. Most of the light that has passed through the lens 3 is not directly irradiated to the light receiving surface of the solar cell main body 2, but is reflected by the reflector 4 and is irradiated to the light receiving surface.

The reflector 4 is arranged on the side where the normal line N of the light receiving surface of the solar cell main body 2 intersects with the optical axis L direction when viewed from the solar cell main body 2.
At least a part of the light that has passed through the condensing lens 3 hits and is reflected on the reflector 4 arranged as described above, and the reflected light irradiates the light receiving surface of the solar cell main body 2.

In the dye-sensitized solar cells 1, 1A and 1B shown in FIGS. 1 to 3, the amount of power generation can be maintained high even when the position of the sun changes or indoors where the light is weak.
For example, in the dye-sensitized solar cell 1 shown in FIG. 1, even when the position of the sun changes and the light irradiation angle changes, the light passing through the condenser lens 3 is directly irradiated to the solar cell body 2. Or, because it is reflected by the reflector 4, the amount of power generation is maintained high.
Further, even indoors where the light is weak, the light that has passed through the condenser lens 3 efficiently hits the reflector of the solar cell main body 2, so that the amount of power generation is maintained high.
The dye-sensitized solar cell 1A shown in FIG. 2 is an example of an indoor embodiment in which light such as sunlight is mainly irradiated from the horizontal direction. The light that has passed through the condenser lens 3 from the horizontal direction is reflected by the reflector 4 and is applied to the light receiving surface of the solar cell body 2 installed in the horizontal direction with respect to the installation surface 6. Therefore, since the light emitted from the horizontal direction can be efficiently used, the amount of power generation can be maintained high even indoors.
The dye-sensitized solar cell 1B shown in FIG. 3 is an example of an indoor embodiment in which light such as sunlight is mainly irradiated from an obliquely downward right direction. The light that has passed through the condenser lens 3 from diagonally lower right is reflected by the reflector 4 and is applied to the light receiving surface of the solar cell body 2 installed in the horizontal direction with respect to the installation surface 6. Therefore, since the emitted light can be used efficiently, the amount of power generation can be maintained high even indoors.

Normally, in a solar cell using a condenser lens, the amount of power generation can be increased by arranging the solar cell so as to be perpendicular to the direction of light irradiation, but the focus of the condenser lens is the solar cell. In an environment where the light is weak, such as indoors, if the condenser lens is enlarged to collect a lot of light, it is also necessary to adjust the distance to the solar cell for a long time, and as a result, the solar cell device However, there was a big restriction especially when using it indoors because of the large size.
On the other hand, in the case of the dye-sensitized solar cell of the present invention having the above-mentioned configuration, as shown in FIGS. Moreover, by arranging the solar cell main body 2, the condensing lens 2 and the reflector 4 in a substantially triangular tubular shape, it is possible to use the solar cell without increasing the size.

In the present invention, the number of the solar cell main bodies 2 may be a cell type in which one is used, or a module type in which two or more are used.

Hereinafter, each part of the dye-sensitized solar cell of the present invention will be described.

(Photoelectrode)
The photoelectrode constituting the main body of the dye-sensitized solar cell is a material selected from the group consisting of metallic titanium, titanium alloy, surface-treated metallic titanium and surface-treated titanium alloy (hereinafter, also referred to as "titanium material"). A porous titanium oxide layer containing a dye sensitizer is formed on the photoelectrode substrate).

(Photoelectrode substrate)
The photoelectrode substrate may be made of only metallic titanium. The type of titanium alloy material is not particularly limited. Examples of the titanium alloy include Ti-6Al-4V, Ti-5Al-2.5Sn, Ti-8Al-1Mo-1V, Ti-0.15Pd and the like.
The metallic titanium or the titanium alloy may be surface-treated. The surface treatment refers to a treatment for forming a crystalline titanium oxide, more preferably anatase-type titanium oxide film, on the surface of the photoelectrode substrate.
Examples of the surface treatment include the following two types of surface treatment methods A and B.

Surface treatment method A:
(1) A step of forming titanium nitride on the surface of a metallic titanium or titanium alloy material, and (2) A metallic titanium or titanium alloy material having titanium nitride formed on the surface obtained in step (1) is metallic titanium. A step of forming a film of anatase-type titanium oxide by anodic oxidation at a spark discharge voltage or higher using an electrolytic solution having an etching action.

Surface treatment method B:
The step of forming titanium nitride on the surface of (1) metallic titanium or titanium alloy material, and (2) the metallic titanium or titanium alloy material on which titanium nitride is formed on the surface obtained in step (1) are metal. The step of performing anodization using an electrolytic solution that does not have an etching action on titanium, and the anodized metallic titanium or titanium alloy material obtained in step (3) and (2) are heated in an oxidizing atmosphere. A process of performing treatment to form an anatase-type titanium oxide film.

Steps of surface treatment methods A and B (1)
In the step (1), in the step of forming the titanium nitride on the surface of the titanium material (metal titanium or titanium alloy), a layer of titanium nitride is usually formed at 0.1 μm to 100 μm on the surface of the titanium material. it can.
The titanium nitride layer is preferably 0.5 μm to 50 μm, more preferably 1 μm to 10 μm.
Regarding the means for forming the titanium nitride on the surface of the titanium material, for example, a method of physically or chemically adhering the titanium nitride to the surface of the titanium material, heat treatment of the titanium material with ammonia gas or nitrogen gas, etc. A method of reacting with nitrogen gas can be mentioned, but a method using nitrogen gas is preferable in consideration of convenience, economy, safety and the like.

Further, in the step of reacting nitrogen gas with titanium to form a titanium nitride, since the titanium material has an extremely high oxygen affinity, it is preferable to use an oxygen trapping agent in combination.
The oxygen trapping agent is preferably a carbon material, metal powder, hydrogen gas or the like, but a carbon material is preferable in consideration of convenience, economy, safety and the like.

Examples of the carbon material include graphitic carbon and amorphous carbon, but the carbon material is not particularly limited. Further, the shape of the carbon material may be any shape such as a flat plate shape or a powder shape, but a flat plate shape carbon material is preferable because it can be handled easily and thermal strain during heat treatment of the titanium material can be prevented. When the flat plate-shaped carbon material is used, a method of sandwiching the titanium material between the carbon materials is preferable.

As a method of heat-treating the titanium material in a nitrogen gas atmosphere, first, a rotary vacuum pump, then a mechanical booster pump, and then an oil diffusion pump are used to reduce the pressure in the furnace. Next, nitrogen gas is introduced into the depressurized furnace to restore the pressure. By repeating this depressurization and decompression twice or more, it is preferable to reduce the oxygen gas concentration in the furnace to be heat-treated to the utmost limit.
The reaction pressure of the heat treatment in a nitrogen gas atmosphere is preferably about 0.01 MPa to 10 MPa, more preferably about 0.1 MPa to 10 MPa, and even more preferably about 0.1 MPa to 0.2 MPa.
The heat treatment temperature in a nitrogen gas atmosphere is preferably about 500 ° C. or higher, more preferably 750 to 1050 ° C., and even more preferably 750 ° C. to 950 ° C.
The heat treatment time in a nitrogen gas atmosphere is preferably about 1 minute to 12 hours, more preferably about 10 minutes to 8 hours, and even more preferably 1 hour to 6 hours.

Step of surface treatment method A (2)
In the step (2) of the surface treatment method A, the titanium material in which titanium nitride is formed on the surface is anodized at a spark discharge generation voltage or higher by using an electrolytic solution having an etching action on metallic titanium. An etching type titanium oxide film is formed on the surface of the titanium material.

The electrolytic solution preferably contains an inorganic acid or an organic acid having an etching action on metallic titanium. Examples of the inorganic acid include sulfuric acid, hydrofluoric acid, hydrochloric acid and the like. Examples of the organic acid include oxalic acid, formic acid, citric acid and the like. Two or more of these inorganic acids and organic acids may be used in any combination.
Further, as the electrolytic solution, it is preferable that sulfuric acid contains phosphoric acid and hydrogen peroxide.

The voltage equal to or higher than the spark discharge generation voltage is usually 100 V or higher, preferably 150 V or higher.
Anodization by spark discharge can be performed by current control instead of voltage control.
As the anodic oxidation condition by current control, the current density may be 0.1 A / dm ² or more, but 1 A / dm ^{2 to} 10 A / dm ² is preferable from the viewpoint of economy, convenience, and performance.
The anodizing time is preferably 1 minute or longer, more preferably 1 to 60 minutes, and even more preferably 10 to 30 minutes.
By the treatment in the above method, an anodized film having a film thickness of about 1 to 100 μm can be obtained.

Step of surface treatment method B (2)
In the step (2) of the surface treatment method B, the titanium material having the titanium nitride formed on the surface is anodized by using an electrolytic solution having no etching action on metallic titanium to obtain the titanium material. An amorphous oxide film can be formed on the surface.

The electrolytic solution having no etching action on metallic titanium is preferably an electrolytic solution containing at least one compound selected from the group consisting of inorganic acids, organic acids and salts thereof.
As the inorganic acid, phosphoric acid, carbonic acid and the like are preferable. As the organic acid, acetic acid, lactic acid and the like are preferable. Examples of the salt include sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydrogen carbonate, sodium acetate, sodium lactate, sodium sulfate, sodium nitrate and the like, and among them, the viewpoint of easily forming the amorphous oxide film. Therefore, phosphoric acid and phosphate are preferable.

The anodic oxidation may be carried out under voltage-controlled or current-controlled conditions.
In voltage-controlled anodizing, the voltage is preferably adjusted to about 10 to 300 V, more preferably about 50 to 200 V.
In current-controlled anodic oxidation, the current density may be adjusted to 0.1 A / dm ² or more, but from the viewpoint of economy, convenience, and performance, 0.5 A / dm ^{2 to 2} A / dm ² Is preferable.

The treatment temperature for anodizing is preferably about 10 to 80 ° C, more preferably about 10 to 50 ° C, and even more preferably about 20 to 30 ° C.
The anodizing treatment time is preferably about 1 minute to 30 minutes, more preferably about 5 minutes to 20 minutes.

Step of surface treatment method B (3)
In the step (3) of the surface treatment method B, the titanium material in which an amorphous titanium oxide film is formed on the surface by anatase is heat-treated in an oxidizing atmosphere to form an anatase-type titanium oxide film. To form.

Examples of the oxidizing atmosphere in which the heat treatment is performed include the atmosphere, a gas obtained by mixing oxygen gas and nitrogen gas, and oxygen gas, but the atmosphere is preferable from the viewpoint of convenience, economy, safety, and the like.
The heat treatment temperature in an oxidizing atmosphere may be about 300 to 800 ° C., but is preferably 300 to 700 ° C., more preferably 400 to 700 ° C.
The reaction pressure of the heat treatment in an oxidizing atmosphere is preferably about 0.01 MPa to 10 MPa, more preferably about 0.1 MPa to 10 MPa, and even more preferably about 0.1 MPa to 0.2 MPa.
The heat treatment time in an oxidizing atmosphere is preferably about 10 minutes to 12 hours, more preferably about 10 minutes to 8 hours, and even more preferably about 1 hour to 6 hours.
By the treatment in the above method, an anodized film having a film thickness of about 1 to 10 μm can be obtained.

(Porous titanium oxide sintered body layer)
A paste agent containing titanium oxide particles is applied onto a photoelectrode substrate prepared by the surface treatment method A or B, and then heat-treated in an oxidizing atmosphere to form a porous titanium oxide sintered body layer. To form.

The average particle size of the titanium oxide particles may be about 1 to 3000 nm, preferably about 1 to 1000 nm, and more preferably about 10 to 500 nm.
Further, it is not necessary to use one kind of titanium oxide particles, and by using a mixture of small particle size particles and large particle size particles, light is scattered in the porous titanium oxide layer. The photoelectric conversion characteristics of the dye-sensitized solar cell are improved.

Examples of the method of applying the paste agent on the photoelectrode substrate include a squeegee method, a screen printing method, an inkjet method, a roll coating method, a doctor blade method, a spray coating method and the like, but are not particularly limited.

Further, by carrying out UV ozone treatment before applying the paste agent, the wettability of the photoelectrode substrate is improved and a high-quality porous titanium oxide layer is formed. As the method of UV ozone treatment, a known method may be used.

Examples of the oxidizing atmosphere include the atmosphere, a gas obtained by mixing oxygen gas and nitrogen gas, and oxygen gas, as in the step (3) of the surface treatment method B, but the convenience, economy, safety, etc. From the point of view, the atmosphere is preferable.

The heat treatment temperature is preferably about 300 to 600 ° C, more preferably about 400 to 500 ° C.

The shape of the obtained porous titanium oxide sintered body layer is preferably rectangular. By making the shape of the porous titanium oxide sintered body layer rectangular instead of square, the electrons generated by the photoexcitation of the dye sensitizer are less likely to disappear in the porous titanium oxide sintered body layer. The photoelectric conversion characteristics of the obtained dye-sensitized solar cell are improved.

(Block layer)
In the dye-sensitized solar cell of the present invention, it is possible to improve the photoelectric conversion characteristics by providing a block layer on the optical electrode.

When the dye sensitizer adsorbed on the porous titanium oxide layer is irradiated with light, electrons are excited by the light absorption of the dye sensitizer. When these excited electrons are transferred to the titanium material which is the photoelectrode substrate through the porous titanium oxide sintered body layer on which the dye sensitizer is adsorbed, the porous titanium oxide layer and the photoelectrode substrate are transferred to the electrolyte layer. Due to the leakage of electrons and the emission of excited electrons and electrons, the dye sensitizer in an oxidized state and the electrons may recombine, and the photoelectric conversion characteristics tend to deteriorate.
Therefore, by providing a dense block layer on the photoelectrode, it is possible to efficiently prevent the leakage of electrons and the recombination of electrons, so that the photoelectric conversion characteristics of the obtained dye-sensitized solar cell are improved.

As the block layer, an n-type semiconductor is preferable.
The block layer is at least two selected from the group consisting of a titanium oxide layer, an aluminum oxide layer, a silicon oxide layer, a zirconium oxide layer, a strontium titanate layer, a magnesium oxide layer, and a niobium oxide layer. It is preferably composed of layers.

As a method for producing the block layer, a solution containing a titanium compound, an aluminum compound, a silicon compound, a zirconium compound, a strontium titanate compound, a magnesium compound, a niobium compound, etc., which are precursors of the block layer, is used to construct a porous titanium oxide layer. The photoelectrode substrate is coated by the dip method, sol-gel method, spin coating method, squeegee method, screen printing method, spray method, etc., and heat-treated at about 450 ° C., sputtering, vacuum deposition, electron beam, etc. Can be formed by

A block layer can be formed on the porous titanium oxide sintered body layer by the same method as described above.

When the block layer is constructed on the photoelectrode substrate, it is preferably constructed with two or three layers selected from the group consisting of a titanium oxide layer, an aluminum oxide layer, and a niobium oxide layer.
In particular, it is more preferable to provide aluminum oxide as a block layer on the titanium material. Aluminum oxide unime is a substance having a large band gap (gap between the conduction band and the variance band) among the materials of the block layer, and has a high energy value of the conduction band. The electrons associated with the photoexcitation of the dye sensitizer move to the conduction band. Since the energy value of the conduction band of aluminum oxide is at a high position, it is difficult to transfer back electrons to the electrolyte side beyond the wall of this high conduction band, and the photoelectric conversion of the obtained dye-type solar cell is difficult. The characteristics are improved.

Above all, a block layer is provided on the side where the photoelectrode is arranged opposite to the counter electrode of the titanium material, and a porous titanium oxide sintered body layer containing a dye sensitizer is further formed on the block layer. The block layer was selected from the group consisting of a titanium oxide layer, an aluminum oxide layer, a silicon oxide layer, a zirconium oxide layer, a strontium titanate layer, a magnesium oxide layer, and a niobium oxide layer. It is preferably composed of at least two layers.

(Dye sensitizer)
By immersing the photoelectrode substrate on which the porous titanium oxide sintered body layer is formed or the photoelectrode substrate on which the block layer is also constructed as described above in a solution containing a dye sensitizer, a dye sensitizer is used. Is adsorbed on the porous titanium oxide sintered body layer.

It is preferable to carry out UV ozone treatment before immersing in the dye sensitizer solution because the dye sensitizer is easily adsorbed on the porous titanium sintered body layer.

The dye sensitizer may be any dye sensitizer having light absorption in the near infrared region and the visible light region. For example, a metal complex other than ruthenium such as ruthenium metal complex and copper phthalocyanine, eosin, and rhodamine. , Organic complexes such as melocilinin and indolin, but are not particularly limited.
These dye sensitizers can be used alone or in combination of two or more, but a dye sensitizer having light absorption in the near infrared light region and a dye sensitizer having absorption in the visible light region. It is preferable to combine the agents.

(Electrolyte layer)
The electrolyte layer constituting the dye-sensitized solar cell body is capable of injecting electrons into the dye sensitizer that has lost electrons by injecting electrons into the porous titanium oxide sintered body layer at the photoelectrode. All you need is. Further, the electrolyte layer may be one capable of injecting electrons from the counter electrode into the electrolyte layer that has lost electrons by causing electron injection into the dye sensitizer at the counter electrode.

Examples of the electrolyte layer include non-aqueous electrolytes containing oxidatively reduced species. As the oxidation-reduced species, a combination of iodide salts such as lithium iodide, sodium iodide and potassium iodide and iodine, a combination of bromide salts such as lithium bromide, sodium bromide and potassium bromide and bromine are preferable.
Further, it is preferable to add DMPII (1,2-dimethyl-3-propylimidazolium iodide), TBP (tert-butyl pyridine) or the like to the electrolyte layer.
Examples of the solvent contained in the electrolyte layer include acetonitrile, 3-methoxypropylnitrile, ethylene carbonate, proprene carbonate, γ-butyl lactone and the like.
The thickness of the electrolyte layer is the distance between the photoelectrode and the counter electrode, and the thickness is preferably 25 to 100 μm, more preferably 25 to 50 μm.

(Opposite pole)
The counter electrode constituting the dye-sensitized solar cell body is preferably one in which an electrochemical reduction catalyst layer is formed on transparent conductive glass or a transparent conductive film.
The electrochemical reduction catalyst layer can be carried out by coating a transparent conductive glass or a transparent conductive film with an electrochemical catalyst substance by vacuum vapor deposition, electron beam deposition, sputtering or the like.

Examples of the electrochemical catalyst include platinum, carbon, rhodium, indium, PEDOT / PSS and the like. Of these, platinum is preferable because electrons are easily injected into the electrolyte layer that has lost electrons due to the low hydrogen overvoltage.

In the present invention, since a titanium material having no light transmission is used as the light electrode, it is necessary to carry out light irradiation from the counter electrode. Therefore, the thickness of the electrochemical reduction catalyst layer is preferably several nm or less, and 0. More preferably, it is 5 to 1 nm or less.

(Collection electrode)
In the main body of a dye-sensitized solar cell, a dye-sensitized solar cell, in particular, is formed by wiring a conductive material having a current collecting effect on the surface of a transparent conductive glass or a transparent conductive film as a counter electrode in a striped or lattice pattern. Even in a large-area dye-sensitized solar cell, reduction of photoelectric conversion characteristics is suppressed.

The aperture ratio of the counter electrode after the collector electrode is installed is preferably about 50 to 99%, more preferably 70 to 99%, and even more preferably about 80 to 95% of the total area of the counter electrode.

In the present invention, the collecting electrode material may be any material having conductivity, but when a combination of an iodide salt and iodine is used for the electrolyte layer, the collecting electrode can be used because the electrolyte exhibits high corrosiveness. As the material, a material having excellent corrosion resistance is used.
Collecting electrode materials with high corrosion resistance include titanium, niobium, tantalum, zirconium, chromium, molybdenum and metals such as titanium alloys containing them as main components, niobium alloys, tantalum alloys, zirconium alloys, chromium alloys, molybdenum alloys, and platinum. In addition to the material, a carbon material such as carbon, graphite, or carbon nanotube is preferable.

As a method of producing a collector electrode on the counter electrode, a chemical method such as electrolytic plating or electroless plating is applied to a material patterned by masking with polyimide tape and etching, or a counter electrode material patterned by photolithography. Examples include physical methods such as vacuum vapor deposition, electron beam deposition, and sputtering. It is also possible to prepare a concave surface in advance on a polymer material or a glass material, prepare a material in which a collecting electrode member is embedded in the concave surface, coat the surface with a transparent conductive film, and then coat the surface with an electrochemical catalyst substance. Good.
The thickness of the collecting electrode is preferably about 0.01 to 100 μm, more preferably about 0.1 to 10 μm, and even more preferably about 1 to 10 μm.

(Anti-reflective coating)
The dye-sensitized solar cell body, do not face the photoelectrode, it is preferable that an antireflection film on a non-conductive surface of the transparent conductive glass or transparent conductive film of the counter electrode.

The antireflection film can be produced by subjecting MgF ₂ or SiO ₂ to a physical method such as vacuum vapor deposition, electron beam deposition, or sputtering, or a chemical method such as spin coating or dip coating. Further, although one type of antireflection film may be used, it is preferable to use two or more types in combination.

By providing the antireflection film, the amount of light reaching the photoelectrode of the dye-sensitized solar cell body is increased, so that the amount of current of the obtained dye-sensitized solar cell is increased and the amount of power generation is improved.

(Spacer and sealant)
When the photoelectrode of the main body of the dye-sensitized solar cell comes into contact with the counter electrode, the photoelectrode and the counter electrode are short-circuited, so that the function of the dye-sensitized solar cell is not exhibited. It is preferable to prevent contact between the photoelectrode and the counter electrode by installing a spacer in the space.

As the spacer, a known spacer usually used in the battery field can be used. Specifically, an ionomer resin film, a polyimide resin film, a UV curable resin, a glass material, a polyimide tape, or the like can be used.

On the other hand, in the optical electrode in which the anatase-type titanium oxide film is formed on the surface by surface-treating metallic titanium or titanium alloy, the photoelectrode and the counter electrode come into contact with each other because the anatase-type titanium oxide film has semiconductor characteristics. However, since there is no problem, it is not necessary to install a spacer between the photoelectrode produced by surface-treating metallic titanium or titanium alloy and the counter electrode.

When the spacer is not used, the distance between the photoelectrode and the counter electrode, that is, the thickness of the electrolyte can be reduced, so that the dye sensitizer adsorbed on the porous titanium oxide layer on the photoelectrode is efficiently irradiated with light. Therefore, a high amount of current can be obtained, and the photoelectric conversion characteristics of the obtained dye-sensitized solar cell are improved.

Further, as the sealing agent used for sealing the leakage of the electrolyte from the electrolyte layer, a UV curable resin, an ionomer resin film, an epoxy resin, a silicon elastomer, a frit glass material or the like can be used.

As a sealing method, it is preferable to first carry out the main seal by applying or installing the sealing agent on the photoelectrode facing the counter electrode, installing the counter electrode, and then curing the sealing agent. ..
Next, an electrolyte injection hole provided in the counter electrode or the photoelectrode is provided in advance. After injecting the electrolyte layer from the electrolyte injection holes, it is preferable to carry out end sealing by closing the electrolyte injection holes with the sealant and curing the electrolyte layer.
Examples of the injection of the electrolyte include immersing the dye-sensitized solar cell in a container filled with the electrolyte and applying pressure to return it to atmospheric pressure, or directly injecting the electrolyte using a dispenser or the like. ..

(Dye-sensitized solar cell module)
When the dye-sensitized solar cell body is a module including two or more solar cell bodies, for example, the photoelectrode and the counter electrode are arranged in a T shape via an electrolyte layer, and the titanium material is used. A porous titanium oxide sintered body layer containing a dye sensitizer is formed on the cross section. Two or more photoelectrodes are arranged via an insulator, and two or more photoelectrodes are arranged between the photoelectrodes via an insulating material. It has an integrated structure, and with respect to the opposite electrode transparent conductive glass or transparent conductive film, the transparent conductive film of the transparent conductive glass or transparent conductive film and the electrochemical reduction catalyst layer (hereinafter, electrochemical) also referred to as a catalyst layer) and are both insulated by etching, and each of the photoelectrode and the counter electrode, are electrically in series or dye-sensitized solar cell module having a configurations that are connected in parallel Is preferable.

In the dye-sensitized solar cell module, the photoelectrode is formed by forming a porous titanium oxide layer on a cut surface of a titanium material having a thickness of about 0.1 to 5 mm, and then dyeing the porous titanium oxide layer. It is preferable that the titanium material and the insulator are integrated with each other while adsorbing the sensitizer.

In the dye-sensitized solar cell module of the present invention, the counter electrode is a transparent conductive glass or a transparent conductive film coated with an electrochemical catalyst layer, and the two or more photoelectrodes and an insulating material are integrated. It is preferable that the film is installed in a T shape on the upper part of the film.

In order to integrate the optical electrode and the insulating material, a group of epoxy resin, acrylic resin, polyethylene resin, polypropylene resin, PEEK (Polyether ethyl ketone) resin, silicon resin, etc., which are durable against the electrolyte layer. It is preferable to use at least one selected material selected from the above. Further, it is also possible to insert a photoelectrode into a member obtained by pre-cutting or injection processing these resin materials.

The insulating layer is patterned by performing etching or the like together with the transparent conductive film of the counter electrode and the electrochemical catalyst layer according to the pattern of the integrated optical electrode and the insulator arranged opposite to the counter electrode. Can be mentioned.

In the patterning process, a polyimide tape or the like is attached to a portion facing the photoelectrode to mask it. Next, in order to etch, it is preferable to perform a patterning treatment of an insulating treatment such as removing the transparent conductive film and the electrochemical catalyst layer on the non-masking surface with a chemical agent. Further, a method of potting by a photolithography method capable of performing fine patterning by forming an exposed portion and a non-exposed portion by applying a resist having photosensitivity to the counter electrode and exposing it to light is also preferable.

Further, also in the dye-sensitized solar cell module, in order to increase the amount of power generation, it is preferable to apply antireflection film processing or the like to the counter electrode.
The dye-sensitized solar cell module is manufactured by electrically connecting the photoelectrode and the counter electrode thus manufactured in series or in parallel.

(Condenser lens)
The condenser lens may be any one that can be used for a solar cell, and is not particularly limited. As the material of the condenser lens, a linear Fresnel lens made of transparent plastic such as glass, PMMA (polymethylmethacrylate), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate) is preferable.

Organic components such as dye sensitizers used in dye-sensitized solar cells may be deteriorated by the ultraviolet rays contained in sunlight, but by using this condensing lens, the ultraviolet rays are dye-sensitized. Since it is possible to prevent the solar cell from entering the dye-sensitized solar cell, the durability of the dye-sensitized solar cell can be improved.
Further, the condenser lens is not limited to the convex lens, and may be a concave lens.

(Combined use of condenser lens and mirror)
The amount of power generated by using the condenser lens is improved to some extent even in the conventional silicon type solar cell. However, the power generation of the silicon type solar cell is highly dependent on the incident light, and if the incident angle is slightly different, the amount of power generation is significantly reduced.

The dye-sensitized solar cell or the dye-sensitized solar cell module of the present invention has no dependence on incident light, and there is no difference in the amount of power generation regardless of the light from any angle. After diligently examining the characteristic of having no dependence on incident light, the light incident from the condenser lens is diffusely reflected using a mirror. It was found that the dye-sensitized solar cell or the dye-sensitized solar cell module of the present invention can obtain a high amount of power generation even when the diffusely reflected light is used.

Further, the product of the present invention in which a mirror is used in combination has a compact structure as compared with a product in which a condenser lens is simply used.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1
(1) Preparation of anodized titanium material The side surface of a metal titanium plate (titanium material, photoelectrode substrate) is smoothed with a milling machine (VHR-SD, manufactured by Shizuoka Iron Works) and degreased using trichloroethylene. After the treatment, a nitride furnace (NVF-600-PC, manufactured by Nakanihon Furnace Industry Co., Ltd.) was used to form titanium nitride on the surface of the degreased metal titanium plate.
First, a metal titanium plate was sandwiched between flat carbon materials installed in a nitriding furnace. Next, the nitriding furnace was depressurized to 1 Pa or less in order to remove oxygen, and then nitrogen gas having a high purity of 99.99% or more was introduced into the nitriding furnace to restore the pressure to 0.1 MPa (atmospheric pressure). The nitriding furnace was then heated to 950 ° C. over 2 hours. Next, in this 950 ° C. nitriding furnace, heat treatment was performed for 1 hour to form titanium nitride on the surface of the metal titanium plate.

Metal titanium plate with titanium nitride formed on the surface, 1.5M sulfuric acid (manufactured by Wako Pure Chemical Industries), 0.05M phosphoric acid (manufactured by Wako Pure Chemical Industries), 0.3M hydrogen peroxide (manufactured by Wako Pure Chemical Industries) An anatase-type titanium oxide film was formed on the surface of metallic titanium by performing anodization treatment at a current density of 10 A / dm ^{2 for} 30 minutes at Yakuhin Kogyo Co., Ltd.).

(2) Preparation of Photoelectrode A dye-sensitized solar cell was prepared using the surface-treated 10 mm × 50 mm × 2 mm metal titanium plate as a photoelectrode. First, the surface-treated metallic titanium plate was washed with ethanol as a solvent and dried.
Then, the pretreated material was dip-coated with a 50 mM aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution using a desktop dip coater (manufactured by SDI, DT-0303-S1) at a pulling speed of 1 mm / sec. After drying, it was baked at 450 ° C. for 15 minutes. Next, dip coat with a 5 mM niobium ethoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution at a pulling rate of 1 mm / sec, dry, and then bake at 450 ° C. for 15 minutes, and then 60 mM titanium tetraisopropoxide ( Wako Pure Chemical Industries, Ltd.) Dip-coated with an ethanol solution at a pulling speed of 1 mm / sec, dried, and then baked at 450 ° C. for 15 minutes. Further, by immersing in a 40 mM titanium tetrachloride (TiCl ₄ ) (manufactured by Wako Pure Chemical Industries, Ltd.) aqueous solution at 70 ° C. for 30 minutes, drying, and then firing at 450 ° C. for 15 minutes, the lower layer is aluminum oxide and the intermediate layer. Niobium oxide was formed on the titanium material, and a lower block layer of titanium oxide was formed on the titanium material.

In the above-treated surface-treated material, a titanium oxide material (Nikki Catalyst Kasei, PST-18NR) and ethanol are added to the milled (smoothed) surface (width 2 mm x length 50 mm) in a weight ratio of 2: The paste mixed so as to be 1 was applied by a squeegee method so that the coating area was 0.8 cm ² (2 mm × 40 mm), and baked at 450 ° C. for 15 minutes. This was coated 10 times (semiconductor layer) so as to have a film thickness of 20 to 25 μm, and then fired at 450 ° C. for 1 hour.
The upper layer of the semiconductor layer is dip-coated with a 60 mM titanium tetraisopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution at a pulling rate of 1 mm / sec, fired at 450 ° C. for 15 minutes, and then further 40 mM Tycol ₄ (manufactured by Wako Pure Chemical Industries, Ltd.). Wako Pure Chemical Industries, Ltd.) Immersed in an aqueous solution at 70 ° C. for 30 minutes and fired at 450 ° C. for 15 minutes to form an upper block layer.
The obtained photoelectrode material was subjected to oxygen flow (0.05 MPa, 2 minutes) in UV ozone cleaner UV253S (manufactured by Filgen Co., Ltd.), then ultraviolet irradiation for 15 minutes, and further nitrogen flow (0.2 MPa). , 7 minutes), and tert-butanol (t-BuOH) (Japanese) of the dye sensitizer ruthenium dye C106 (manufactured by Solaronix) 0.3 mM and the indolin dye D131 (manufactured by Mitsubishi Paper) 0.3 mM. A dye solution was prepared by diluting with a mixed solution containing (manufactured by Kojunyaku Kogyo) and acetonitrile (CH ₃ CN) (manufactured by Wako Pure Chemical Industries). The mixed solution has a mixing ratio of t-BuOH: CH ₃ CN = 1: 1.
After immersing the photoelectrode material in the present dye solution at 40 ° C. for 14 hours, a titanium foil cut to 1.5 mm × 50 mm was spot-welded to the photoelectrode substrate as negative electrode wiring to obtain a photoelectrode material.

(3) Preparation of counter electrode plate As a counter electrode, an FTO-deposited glass plate (manufactured by AGC) is washed with a solvent in acetone and ethanol, dried, and then antireflection coated (manufactured by Taisho Optical Co., Ltd.), followed by electron beam deposition of platinum. Was vapor-deposited at 1 nm.
After masking the counter electrode plate with polyimide tape on the part facing the optical electrode and rubbing it well, the FTO film and platinum on the non-masking surface are zinc powder (manufactured by Wako Pure Chemical Industries, Ltd.) and hydrochloric acid (Wako Pure Chemical Industries, Ltd.). Was peeled off and insulated. Then, the counter electrode plate was washed with water and ethanol, masked with a polyimide tape, and then a platinum current collector electrode (manufactured by Bee Sputter) was obtained by sputtering.
Next, a hole was made in the glass plate using an electric handpiece (manufactured by Argofile Japan, SPC-40), and an electrolyte injection hole was provided. The terminal part was coated with special solder Cerasolza # 186 (manufactured by Kuroda Techno).

(4) Fabrication of Dye-Sensitized Solar Cell Module Using a PEEK mold (made by Alice) for the module outer frame, the photoelectrode is inserted into the mold, and an acrylic UV curable resin is inserted between the outer periphery of the mold and the photoelectrode. TB3035B (manufactured by ThreeBond, a sealant) was applied and a counter electrode plate was installed. Then, the sealant was cured with an integrated intensity of 40 kJ / m ² using a conveyor-type UV irradiation device (VB-15201BY-A manufactured by Ushio, Inc.), and the main seal of the photoelectrode and the counter electrode was performed.
0.04M iodine (manufactured by Aldrich), 0.08M lithium iodide (manufactured by Aldrich), 0.72M DMPII (manufactured by Solaronix), 1.0M TBP (manufactured by Aldrich) dissolved in acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) The electrolyte was prepared. The prepared electrolyte was put into the cell through the electrolyte injection hole.
Next, an acrylic UV curable resin TB3035B was used to close the electrolyte injection hole, and a cover glass was adhered thereto to perform end sealing.
Then, the photoelectrode of each cell and the counter electrode were connected in series, two dye-sensitized solar cell modules in eight series were manufactured, and then they were connected in parallel.

(5) Manufacturing and Evaluation Results of Solar Cell As shown in FIG. 4, the 8-series 2-parallel dye-sensitized solar cell module obtained as the solar cell body 2 was fixed to the surface of the substrate 5, and the substrate 5 and the collection were collected. A module-type dye-sensitized solar cell 1 was produced by arranging a Fresnel lens (LF200-B manufactured by Nippon Special Optical Resin) which is an optical lens 3 and a mirror which is a reflecting plate 5 in a substantially triangular tubular shape.
Specifically, the solar cell body 2 is arranged so that the normal of the light receiving surface of the solar cell body 2 intersects the optical axis direction of the condensing lens 3, and is viewed from the solar cell body 2. The reflecting plate 5 is arranged on the side where the normal of the light receiving surface of the solar cell main body 2 intersects the optical axis direction.
The angle formed by the normal N of the light receiving surface of the solar cell body 1 and the optical axis L of the condenser lens 3 was adjusted to about 57 °.
The dye-sensitized solar cell 1 was installed on a horizontal installation surface 6 as shown in FIG. Specifically, the angle θ1 from the installation surface 6 to the substrate 5 was adjusted to 70 °, and the angle θ2 from the installation surface 6 to the reflector 4 was adjusted to 35 °.

(Comparative Example 1)
Only the substrate 5 on which the solar cell main body 2 was fixed was placed on the installation surface 6 without using the condenser lens 3 and the reflector 4.

(Comparative Example 2)
As shown in FIG. 5, the substrate 5 to which the solar cell main body 2 is fixed is placed on the installation surface 6 as in Comparative Example 1, and the condensing lens 3 is arranged parallel to the solar cell main body 2 (solar cell main body). The angle between the normal line of the light receiving surface of 2 and the optical axis L of the condensing lens 3: 0 °). Moreover, the reflector 4 was not used.

(Test Example 1: Measurement of photoelectric conversion efficiency)
Using the dye-sensitized solar cells 1 produced in Example 1 and the solar power generation devices of Comparative Examples 1 and 2, light was irradiated from a direction perpendicular to the installation surface 6 to measure the photoelectric conversion efficiency.
The amount of light was measured using a solar cell standard cell (manufactured by SN / 667 BS-520BK spectrometer).
The results obtained are shown in Table 1.

From the results shown in Table 1, it can be seen that the conversion efficiency of the dye-sensitized solar cell 1 of Example 1 is slightly higher than that of Comparative Example 1 and slightly lower than that of Comparative Example 2, but sufficiently high.
Further, in Comparative Examples 1 and 2, light is irradiated from directly above the light receiving surface of the solar cell main body 2, and the light irradiation has the highest conversion efficiency, whereas in Example 1, the light is irradiated. As shown in FIG. 1, although the light receiving surface of the solar cell main body 2 is not irradiated with light from directly above, the conversion efficiency is high as described above.
Therefore, when the irradiation direction of light changes, such as when the position of the sun changes, the effect on the conversion efficiency of the dye-sensitized solar cell 1 of Example 1 is smaller than that of Comparative Examples 1 and 2, and the amount of power generation is large. It can be seen that it is kept high.

Test Example 2 (Comparison of photoelectric conversion efficiency between dye-sensitized solar cell and silicon type solar cell)
(1) Preparation of anodized titanium material After degreasing a metal titanium plate (titanium material, photoelectrode substrate) with trichloroethylene, a nitriding furnace (NVF-600-PC, manufactured by Nakanihon Furnace Industry Co., Ltd.) ) Was used to form titanium nitride on the surface of the degreased metallic titanium plate.
First, a metal titanium plate was sandwiched between flat carbon materials installed in a nitriding furnace. Next, the nitriding furnace was depressurized to 1 Pa or less in order to remove oxygen, and then nitrogen gas having a high purity of 99.99% or more was introduced into the nitriding furnace to restore the pressure to 0.1 MPa (atmospheric pressure). The nitriding furnace was then heated to 950 ° C. over 2 hours. Next, in this 950 ° C. nitriding furnace, heat treatment was performed for 1 hour to form titanium nitride on the surface of the metal titanium plate.
Metallic titanium plate with titanium nitride formed on the surface, 1.5M sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.), 0.05M phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd.), 0.3M hydrogen peroxide (manufactured by Wako Pure Chemical Industries, Ltd.) Anodization treatment was carried out at a current density of 10 A / dm ^{2 for} 30 minutes at Yakuhin Kogyo). A film of anatase-type titanium oxide was formed on the surface of metallic titanium.

(2) Preparation of Photoelectrode A dye-sensitized solar cell was prepared using the above-mentioned surface-treated 12 mm × 50 mm metal titanium plate as a photoelectrode. First, the surface-treated metallic titanium plate was washed with ethanol as a solvent and dried.
Then, the pretreated material was dip-coated with a 50 mM aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution using a desktop dip coater (manufactured by SDI, DT-0303-S1) at a pulling speed of 1 mm / sec. After drying, it was baked at 450 ° C. for 15 minutes. Next, dip coat with a 5 mM niobium ethoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution at a pulling rate of 1 mm / sec, dry, and then bake at 450 ° C. for 15 minutes, and then 60 mM titanium tetraisopropoxide ( Wako Pure Chemical Industries, Ltd.) Dip-coated with an ethanol solution at a pulling speed of 1 mm / sec, dried, and then baked at 450 ° C. for 15 minutes. Further, by immersing in a 40 mM titanium tetrachloride TiCl ₄ (manufactured by Wako Pure Chemical Industries, Ltd.) aqueous solution at 70 ° C. for 30 minutes, drying, and then firing at 450 ° C. for 15 minutes, the lower layer is oxidized with aluminum oxide and the intermediate layer is oxidized. A lower block layer of titanium oxide was formed on the titanium material in the upper layer of niobium.
A paste in which a titanium oxide material (Nikki Catalyst Kasei Co., Ltd., PST-18NR) and ethanol are mixed so as to have a weight ratio of 2: 1 is applied to the above-treated surface treatment material, and the coating area is 1.2 cm ² (3 mm ×). It was applied by the squeegee method so as to be 40 mm) and baked at 450 ° C. for 15 minutes. This was coated 10 times (semiconductor layer) so as to have a film thickness of 20 to 25 μm, and then fired at 450 ° C. for 1 hour.
The upper layer of the semiconductor layer is dip-coated with a 60 mM titanium tetraisopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) ethanol solution at a pulling rate of 1 mm / sec, calcined at 450 ° C. for 15 minutes, and then further 40 mM Tycol ₄ (sum). An upper block layer was formed by immersing in an aqueous solution (manufactured by Kojunyaku Kogyo) at 70 ° C. for 30 minutes and firing at 450 ° C. for 15 minutes.
The obtained photoelectrode material was subjected to oxygen flow (0.05 MPa, 2 minutes) in UV ozone cleaner UV253S (manufactured by Filgen), then ultraviolet irradiation for 15 minutes, and further nitrogen flow (0.2 MPa, 7). (Minute), 0.3 mM of the dye sensitizer ruthenium dye C106 (manufactured by Solaronix) and 0.3 mM of the indolin dye D131 (manufactured by Mitsubishi Paper), tert-butanol (t-BuOH) (Wako Jun) A dye solution was prepared by diluting with a mixed solution containing (manufactured by Yakuhin Kogyo) and acetonitrile (CH ₃ CN) (manufactured by Wako Pure Chemical Industries). The mixed solution has a mixing ratio of t-BuOH: CH ₃ CN = 1: 1.
The photoelectrode material was immersed in the dye solution at 40 ° C. for 14 hours to obtain a photoelectrode material. A current collector was provided by polishing the surface-treated metallic titanium with an electric handpiece (manufactured by Argofile Japan, SPC-40).

(3) Preparation of counter electrode As the counter electrode, an FTO (Fluorine doped Tin Oxide) vapor-deposited glass plate (manufactured by AGC) was washed with a solvent in acetone and ethanol, dried, and then subjected to an antireflection coating (manufactured by Taisho Optical). Later, platinum was deposited at 1 nm by electron beam deposition.
The terminal part was coated with special solder Cerasolza # 186 (manufactured by Kuroda Techno).

(4) Fabrication of Dye-Sensitized Solar Cell Cell A conveyor-type UV irradiation device by superimposing a photoelectrode and a counter electrode, applying acrylic UV curable resin TB3035B (manufactured by ThreeBond, a sealing material) between the outer periphery and the photoelectrode. The sealant was cured with an integrated strength of 40 kJ / m ² using (VB-15201BY-A manufactured by Ushio Denki Co., Ltd.), and the photoelectrode and the counter electrode were adhered to each other.
0.04M iodine (manufactured by Aldrich), 0.08M lithium iodide (manufactured by Aldrich), 0.72M DMPII (manufactured by Solaronix), 1.0M TBP (manufactured by Aldrich) dissolved in acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) The electrolyte was prepared. The prepared electrolyte was put into the cell through the electrolyte injection hole.
Next, the electrolyte injection hole is closed with the acrylic UV curable resin TB3035B, and the sealant is cured with an integrated strength of 40 kJ / m ² using a conveyor-type UV irradiation device (VB-15201BY-A manufactured by Ushio, Inc.). To produce a dye-sensitized solar cell.

(5) Evaluation result After attaching a light-shielding mask (manufactured by a spectroscope) with an opening of 2 mm x 40 mm to the obtained dye-sensitized solar cell and setting it in a condensing device using a Fresnel lens (L250 manufactured by organic optics). Table 2 shows the results of measuring the photoelectric conversion characteristics. In addition, the measurement was performed even when the condensing device was not used. In the same way, the performance of a commercially available silicon type solar cell module (single crystal 3V, 125mA, 55mm × 55mm, purchased from: Wing Solar work mini solar panel store) was also evaluated.
The amount of light was measured using a standard solar cell (SN / 667 BS-520BK spectrometer).
The results are shown in Table 2.

From the results in Table 2, the amount of power generation increases when the silicon type solar cell also collects light, but the amount of power generation is not proportional to the amount of light, whereas the dye-sensitized solar cell used in the present invention has. It was found that the amount of power generation increases in proportion to the amount of light.
Therefore, in the present invention, it can be seen that, as compared with the silicon type solar cell, even if the light irradiation direction changes such as the position of the sun, the influence on the conversion efficiency is small and the power generation amount is maintained high.

1, 1A, 1B Dye-sensitized solar cell 2 Solar cell body 3 Condensing lens 4 Reflective plate 5 Substrate 6 Installation surface N Normal line of light receiving surface of solar cell body 2 L Optical axis of condensing lens 3 θ Solar cell body Angle formed by the normal line N of the light receiving surface of 2 and the optical axis L of the condensing lens 3 θ1 Angle between the installation surface 6 and the substrate 5 θ2 Angle between the installation surface 6 and the reflecting plate 4

Claims (10)

In a dye-sensitized solar cell in which at least a pair of photoelectrodes and counter electrodes are arranged to face each other via an electrolyte layer.
(1) The photoelectrode is a titanium oxide material on which a porous titanium oxide sintered body layer containing a dye sensitizer is formed.
(2) The counter electrode is a transparent conductive glass or a transparent conductive film on which an electrochemical reduction catalyst layer is formed.
(3) A condenser lens is arranged so as to converge the light incident on the dye-sensitized solar cell side, and a reflector for reflecting the light passing through the condenser lens is installed.
The dye-sensitized solar cell is arranged so that the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction of the condenser lens.
The reflecting plate reflects at least a part of the light passing through the condensing lens on the side where the normal of the light receiving surface of the dye-sensitized solar cell intersects the optical axis direction, and the dye. are arranged so as to irradiate the sensitizing solar cell,
A dye-sensitized solar cell, wherein the substrate to which the dye-sensitized solar cell is fixed, the condenser lens, and the reflector are arranged so as to have a substantially triangular tubular shape . The dye-sensitized solar cell according to claim 1, wherein the angle between the normal of the light receiving surface of the dye-sensitized solar cell and the optical axis of the condenser lens is more than 0 ° and less than 180 °. .. The dye sensitization according to claim 1 or 2 , wherein the titanium material is one or more materials selected from the group consisting of metallic titanium, titanium alloys, surface-treated metallic titanium and surface-treated titanium alloys. Type solar cell. A block layer is provided on the side where the photoelectrode is arranged opposite to the counter electrode of the titanium material, and a porous titanium oxide sintered body layer containing a dye sensitizer is further formed on the block layer. The block layer is selected from the group consisting of a titanium oxide layer, an aluminum oxide layer, a silicon oxide layer, a zirconium oxide layer, a strontium titanate layer, a magnesium oxide layer, and a niobium oxide layer. The dye-sensitized solar cell according to any one of claims 1 to 3 , which is composed of one layer. The dye-sensitized solar cell according to any one of claims 1 to 4 , wherein the electrochemical reduction catalyst layer is a platinum catalyst layer. The dye sensitization according to any one of claims 1 to 5 , wherein the counter electrode is a transparent conductive glass or a transparent conductive film on which a collecting electrode is provided and then an electrochemical reduction catalyst layer is formed. Type solar cell. The dye-sensitized solar cell according to any one of claims 1 to 6 , further comprising an antireflection film on the light irradiation surface of the counter electrode transparent conductive glass or the transparent conductive film. A photoelectrode in which a photoconductor and a counter electrode are arranged in a T shape via an electrolyte layer, and a porous titanium oxide sintered body layer containing a dye sensitizer is formed on a cross section of a titanium material. Two or more of them are arranged via an insulator, and the optical electrodes are integrated with each other via an insulating material. Regarding the transparent conductive glass or the transparent conductive film of the counter electrode, the said. Both the transparent conductive film of the transparent conductive glass or the transparent conductive film and the electrochemical reduction catalyst layer are insulated by etching, and the respective optical electrodes and the counter electrode are electrically connected in series or in parallel. The dye-sensitized solar cell according to any one of claims 1 to 7 . After forming titanium nitride on metallic titanium or titanium alloy, the titanium material of the photoelectrode is anatase-type oxidation by anodization at a spark discharge voltage or higher using an electrolytic solution having an etching action on metallic titanium. The dye-sensitized solar cell according to any one of claims 1 to 8 , which is a metallic titanium or titanium alloy material having a titanium film formed on its surface. After the titanium material of the photoelectrode forms titanium nitride on metallic titanium or titanium alloy, it is subjected to anodization and heat treatment in an oxidizing atmosphere using an electrolytic solution having no etching action on metallic titanium. The dye-sensitized solar cell according to any one of claims 1 to 8 , which is a metallic titanium or titanium alloy material having an anatase-type titanium oxide film formed on its surface.

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