JP2000195569A - Photochemical battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photochemical battery with a pigment layer capable of absorbing a larger amount of light and capable of absorbing light over a wider range of wavelengths. SOLUTION: This photochemical battery has a structure made up by layering a semiconductor electrode, pigment layers 3, 4, a charge carrying layer 5, and a counter electrode 6, in order, and at least one of the electrodes is transparent, The photochemical battery is characterized in that the pigment layers 3, 4 are stacked pigment layers made up by stacking at least two pigment layers made of pigments different from each other, In this manufacturing method of the photochemical battery, a solution including a first pigment 3 electrified with a fixed polarity is brought into contact with and adsorbed to a surface of a semiconductor layer and then a solution including a second pigment 4 electrified with the opposite polarity to the first pigment 3 is brought into contact with and adsorbed to the first pigment, thus forming the stacked pigment layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye-sensitized photochemical cell and a method for producing the same.

[0002]

2. Description of the Related Art In general, a photochemical battery using an electrode constituted by supporting a dye on the surface of a semiconductor layer is described in, for example, JP-A-1-220380 or JP-A-5-504023. I have.

[0003] In such a photochemical battery, a transparent semiconductor electrode having a fine structure obtained by sintering fine metal oxide particles is generally used. Photochemical cells are usually prepared by immersing these transparent semiconductor films in a liquid containing a dye, causing the dye to substantially adsorb a single molecule on the surface of the transparent semiconductor film to form a dye layer, and forming a liquid or solid charge transport layer. It is manufactured by sandwiching a dye layer with a counter electrode through a.

[0004] The resulting photochemical cell operates through the following steps. That is, light incident from the transparent electrode side reaches the dye carried on the surface of the transparent semiconductor film through the transparent electrode and the transparent semiconductor film, and excites this dye. The excited dye quickly transfers electrons to the transparent semiconductor film. The electrons that have reached the transparent semiconductor film reach the transparent electrode. On the other hand, the positively charged dye accepts electrons from the charge transport layer and neutralizes it. As described above, the above-described photochemical cell operates as a dye-sensitized photochemical cell having the transparent electrode and the counter electrode as the negative electrode and the positive electrode, respectively.

In this photochemical cell, it is necessary to increase the surface area of the semiconductor layer as much as possible in order to sufficiently increase the amount of light absorbed by the dye layer in which the dye is monomolecularly adsorbed. Therefore, semiconductor particles of nm size are sintered, and the surface is made uneven to increase the surface area. However, in the dye layer in which a single type of dye is adsorbed as a single molecule as described above, it is difficult to increase the absolute amount of the dye, and there is room for improvement in order to achieve a sufficient amount of light absorption. Was.
In addition, a dye layer using such a single type of dye can absorb only light in a limited range of wavelengths with respect to sunlight having a wide spectral range, and can absorb light in a wider wavelength range. There was room for improvement to allow for absorption.

[0006] In order to ensure the bonding between the dye layer having the uneven surface and the charge transport layer, a liquid such as iodine is generally used for the charge transport layer. The liquid used is
If it is harmful to the environment, photochemical cells using liquids should be strictly shielded to prevent liquid leakage. However, it is difficult to maintain the shield for many years, and there is a concern that the leakage of the liquid into the environment may be affected. In order to solve such problems, an all-solid-state photochemical battery using an ion-conductive solid electrolyte or an electron-conductive organic solid substance without using a low-molecular solvent instead of the liquid charge transport layer has been proposed. However, there is no risk of liquid leakage in these solid-state photochemical cells, but the energy conversion efficiency decreases due to the increase in electrical resistance, and the conversion efficiency due to incomplete bonding between the uneven semiconductor electrode and the solid conductive material. Is a problem.

[0007]

As described above, the conventional dye-sensitized type photochemical cell is improved in terms of the amount of light absorption by the dye layer and the width of the wavelength range in which light can be absorbed. There was room for Further, in conventional photochemical cells, those having a liquid charge transport layer have a problem of liquid leakage, and those having a solid charge transport layer have a decrease in energy conversion efficiency due to an increase in electrical resistance and a decrease in the charge transport layer and the dye layer. There is room for improvement in terms of lowering the conversion efficiency due to poor bonding.

[0008]

Means for Solving the Problems [Summary of the Invention] <Summary> The photochemical battery of the present invention comprises (1) a semiconductor electrode comprising a conductor layer and a semiconductor layer laminated thereon, (2) a dye layer, (3) A photovoltaic cell having a structure in which a charge transport layer and (4) a counter electrode are sequentially stacked, wherein at least one electrode is transparent, and the dye layer is at least two.
It is a laminated dye layer in which dye layers made of different dyes are laminated.

[0009] The method for producing a photochemical cell of the present invention comprises:
It has a structure in which (1) a semiconductor electrode composed of a conductor layer and a semiconductor layer laminated thereon, (2) a dye layer, (3) a charge transport layer, and (4) a counter electrode are sequentially laminated. A method for manufacturing a photovoltaic cell in which one electrode is transparent, wherein a solution containing a first dye charged to a predetermined polarity is brought into contact with the surface of the semiconductor layer of the semiconductor layer electrode to adsorb the first dye. A step of contacting a solution containing a second dye charged to a polarity opposite to that of the first dye with the first dye, and allowing the first dye to adsorb the second dye, It is characterized by the following.

<Effects> According to the present invention, a photochemical cell capable of absorbing light in a wider wavelength range with a larger amount of light absorption by a dye layer than a conventional dye-sensitized photochemical cell. Provided is a photochemical cell which does not have a problem of liquid leakage or has a decrease in energy conversion efficiency due to an increase in electric resistance due to the use of a solid charge transport layer and a decrease in conversion efficiency due to poor junction between a charge transport layer and a dye layer. You.

[Specific Description of the Invention] <Structure of photochemical cell> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a model diagram illustrating a cross-sectional shape of an example of a photochemical battery according to the present invention. The semiconductor electrode includes an electrode 1 and a semiconductor 2 as shown in FIG. For example, as shown in FIG.
The first dye layer 3 and the second dye layer 4 are adsorbed,
The charge transport layer 5 and the counter electrode 6 are formed thereon.
The photochemical cell of the present invention has at least one of the two electrodes that is transparent. In the photochemical cell illustrated in FIG. 1, the electrode 1 and the semiconductor 2 are transparent, and the dye layer 3 and the After the dye layer 4 absorbs the incident light 7, photoelectric conversion occurs by passing electrons and holes to the semiconductor 2 and the charge transport layer 5.

FIG. 1 shows a model diagram of the cross-sectional shape of the photochemical cell of the present invention, which has a structure other than that drawn therein, for example, an intermediate layer provided between each layer. Can also.

<Semiconductor electrode> The semiconductor electrode is composed of an electrode and a semiconductor layer laminated on the surface thereof. Any electrode can be used as long as it is a conductive material.
Such materials include metals such as platinum, gold, silver,
When the semiconductor electrode is a transparent semiconductor electrode, tin oxide, zinc oxide, and other transparent conductive materials that have low absorption in the visible light region and are conductive, such as fluorine and indium, are used. The body is preferred.
These conductive materials may be those formed with a suitable polymer binder or inorganic binder.

The semiconductor electrode has a semiconductor layer laminated on the surface of the electrode. As the semiconductor forming the semiconductor layer, any semiconductor can be used as long as it receives electrons excited by the light absorption of the dye in the dye layer.

In the case where the semiconductor electrode is a transparent semiconductor electrode, it is common to use a semiconductor which absorbs little in the visible light region. Such semiconductors include metal oxides,
Preferable examples include oxides of transition metals, and specifically, oxides of titanium, zirconium, hafnium, strontium, zinc, indium, yttrium, lanthanum, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, SrTiO ₃ , CaTiO 2 ₃ , BaTiO
₃ , perovskites such as MgTiO ₃ and SrNb ₂ O ₆ , or composite oxides or oxide mixtures thereof. Other semiconductors are also useful, for example G
aN, InP, ZeSe, ZnS, InGaP, and others are preferred.

The surface of the semiconductor layer is preferably not smooth in order to increase the area of the dye layer formed thereon and increase the amount of light absorption. Usually, the semiconductor is laminated on the electrode as fine particles, but is formed to have a non-uniform thickness, for example, as depicted in FIG. Although the shape is not particularly limited, the semiconductor surface may be a fractal shape having self-similarity like a resinous structure.

The roughness of the surface can be changed within a range that does not impair the effects of the present invention. In particular, the roughness factor of the semiconductor layer is preferably less than 20. By setting the surface roughness of the semiconductor layer in this manner, it is possible to sufficiently maintain the junction between the dye layer formed substantially uniformly on the semiconductor surface and the charge transport layer. This effect is particularly remarkable when a solid material is used for the charge transport layer.
Obstacles to charge transport are reduced and light energy conversion efficiency can be increased.

<Laminated Dye Layer> The photochemical cell of the present invention comprises a laminated dye layer in which at least two dye layers each comprising a different dye are laminated. By having such a structure, the amount of light absorption can be greatly increased as compared with a single dye layer. The use of at least two dye layers can broaden the range of the absorption spectrum.

The number of dye layers constituting the laminated dye layer cannot be determined unconditionally depending on the kind of dye used and the roughness factor of the semiconductor layer, but generally two to four layers are preferable. Attention should be paid to the case where the number of layers is five or more, since there is a possibility that charge transfer with the charge transport layer may not be performed sufficiently.

The dye layers forming these laminated dye layers are:
Although they may be adjacent to each other, any intermediate layer may be provided between the respective dye layers as long as the effect of the present invention is not impaired. For example, an intermediate layer as an adhesive layer that suppresses separation of the two dye layers can be provided.

As the dye that can be used in the present invention, any dye can be selected as long as it absorbs light that can generate an electromotive force in a photochemical cell. Such dyes include visible-near infrared light absorbing dyes, ultraviolet light absorbing dyes, far infrared light absorbing dyes, and others. More specifically, (1) as a visible-near infrared light absorbing dye, for example, ruthenium-tris, ruthenium-bis,
Osmium-Tris, osmium-bis type transition metal complex, or ruthenium-cis-diaqua-bipyridyl complex, or so-called metal chelate complex such as phthalocyanine, porphyrin, dithiolate complex, acetylacetonate complex, and cyanine dye, merocyanine dye, rhodamine Oxadiazole derivatives, benzothiazole derivatives, coumarin derivatives, stilbene derivatives and others as organic dyes such as dyes and other (2) ultraviolet light absorbing dyes, and (3) aromatic rings as far-infrared light absorbing dyes Is preferred. These dyes preferably have a large extinction coefficient and are stable against repeated oxidation-reduction. The dye molecule may be a low-molecular compound or a polymer having a repeating unit.

Further, in the photochemical battery of the present invention, the laminated dye layer is charged or has an adsorptive dye layer having a functional group which is easily charged, and is charged to the opposite polarity to the dye layer, or is charged. It is preferable to have a structure in which an adsorption dye layer having a functional group which is easily formed is alternately stacked.

By using a charged dye or a dye having a functional group that is easily charged, repulsion occurs between dyes of the same kind, and a monomolecular adsorption layer is easily formed. If the dye layer is a single dye in which a single dye is adsorbed by multiple molecules, the conversion efficiency may be reduced. Therefore, such a single molecule adsorption layer is preferably used.

On the other hand, if another dye having a functional group that is charged or has an opposite polarity is used for the dye layer formed as described above, electrostatic attraction is generated between the different dyes, and the laminated structure is formed. It can be easily formed and can prevent problems such as peeling. In addition, the formed dye layer is charged to the opposite polarity, or a polymer having a functional group that is easily charged, and further charged to the opposite polarity to the polymer (that is, the same polarity as the dye forming the first dye layer), Alternatively, when another dye having a functional group which is easily charged is used, a monomolecular layer is formed in each layer by repulsion, and a suction force acts between adjacent layers, so that a robust layer structure can be formed.

Here, the functional group which is easily charged negatively includes, for example, a carboxyl group, a sulfonic acid group, a phosphoric acid group,
Examples include an amide group and other functional groups that easily dissociate protons. On the other hand, functional groups that are easily charged positively include an amino group, a carbonyl group, a phosphine group, and others. It is preferable that a plurality of such functional groups are present in the dye or polymer molecule.

In the photochemical cell of the present invention, it is preferable that each of the dye layers constituting the laminated dye layer is made of a dye having a different absorption spectrum. More specifically, in the photochemical battery of the present invention, it is preferable that the laminated dye layer includes a combination of dyes having a difference in absorption edge on the long wavelength side of the absorption spectrum of 100 to 400 nm. The difference between the absorption edges on the long wavelength side is
If it is less than 100 nm, the overlapping portion of the spectrum is too large, and if it is more than 400 nm, there is a gap in the spectrum, so that the efficiency of light absorption tends to decrease. Here, the long-wavelength-side absorption edge in the absorption spectrum of the dye refers to the long-wavelength side of the wavelength at which the absorbance is 0.5% or less of the absorbance at the peak of the absorption spectrum. Due to the different absorption spectra, light of a wide range of wavelengths can be efficiently absorbed.

In the photochemical cell of the present invention, by using a combination of dyes in which energy transfer occurs between the dyes, energy transfer occurs between the dye layers and light energy can be concentrated on the dye layer where charge separation occurs. Energy conversion efficiency can be improved. For example, compared to the case where only visible light is absorbed by receiving energy transfer from a dye that absorbs ultraviolet light or infrared light,
The output as a photocell increases. For energy transfer to occur efficiently, it is necessary that the fluorescence spectrum of one dye overlaps with the absorption spectrum of the other dye.

In the photochemical cell of the present invention, it is preferable that at least two dyes constituting the laminated dye layer have different oxidation-reduction potentials. By adjusting the oxidation-reduction potential as shown in FIG. 2, the charge transfer occurs promptly in the direction of the arrow, and the light energy conversion efficiency can be increased. More specifically, the difference in oxidation-reduction potential is preferably 0.1 to 0.6 V, and more preferably 0.2 to 0.4 V.

In particular, in an all-solid-state photochemical cell, the distance between the solid charge transport layer and the dye tends to be large, and the charge transfer speed is slow. However, by adjusting the oxidation-reduction potential of the two dyes, the charge injected into the semiconductor is reduced. Since the recombination rate of charges generated in the dye can be reduced, the conversion efficiency can be increased.

The photochemical cell of the present invention is further characterized in that the charge transport layer is solid at an operating temperature. If it is solid, it can be easily shot, and the influence on the environment due to the damage of the battery can be reduced. In the photochemical cell of the present invention, the conversion efficiency is improved by using at least two dyes, and the roughness factor of the surface of the semiconductor layer is adjusted as necessary. The poor joining defect is improved.

<Charge Transporting Layer> As the electrolyte contained in the charge transporting layer, any material generally used for a charge transporting layer of a photochemical cell can be used arbitrarily. For example, iodide including iodine, bromide, quinone complex , TCNQ complexes, dicyanoquinone diimine complexes, and others are preferred.

In the photochemical cell of the present invention, a solid charge transport layer can be used. Such a charge transport layer is preferable because there is no possibility of liquid leakage that may occur when a liquid charge transport layer is used.

The solid charge transporting layer is, for example, an organic molecule which forms an amorphous substance having a glass transition temperature higher than 25 ° C., for example, having a donor skeleton or an acceptor skeleton.
Low molecular compound having a molecular weight of 300 to 1000
It is preferable that the compound is a spherical and rigid simple compound having no flexible substituent. Here, as the donor skeleton, the oxidation potential with respect to the saturated calomel electrode is
A voltage of 0 to +0.8 V is preferable, and a voltage of +0.2 to +0.7 V is more preferable. As the acceptor skeleton, those having a reduction potential of −0.2 to +0.6 V are preferable, and those having a reduction potential of 0 to +0.4 V are more preferable.

Specific examples of the material which can be used for the solid charge transport layer include, as a donor skeleton, aromatic amine compounds such as triphenylamine, diphenylamine and phenylenediamine; condensed polycyclic hydrocarbons such as naphthalene, anthracene and bilen; Examples of the acceptor skeleton include azo compounds such as azobenzene, compounds having a structure in which aromatic rings such as stilbene are connected by an ethylene bond or an acetylene bond, heteroaromatic compounds substituted with amino groups, porphyrins, and fukurosyans. Examples include quinones, tetracyanoquinodimethanes, dicyanoquinone diimines, tetracyanoethylene, viologens, and dithiol metal complexes. Other materials that can be used for the solid charge transport layer include CuI,
There are AgI, TiI, and other metal iodides.
These materials can be used in any combination as needed.

<Counter Electrode> As the counter electrode, any conductive material can be used, and the same materials as those usable for the above-mentioned semiconductor electrode, such as metals such as platinum, gold and silver, and transparent conductors can be used. Things. .

<Method of Manufacturing Photochemical Battery> The method of manufacturing a photochemical battery according to the present invention is the same as the method of manufacturing a photochemical battery described above.
The semiconductor layer surface of the semiconductor layer electrode is charged, or a solution containing a dye or polymer having a functional group that is easily charged, or charged to the opposite polarity to the dye or polymer contained in the solution, Alternatively, by alternately contacting with a solution of a dye or a polymer having a functional group which is easily charged, at least two of
The present invention is characterized in that a laminated dye layer in which dye layers made of different dyes are laminated is formed.

Here, by contacting a dye or polymer having a functional group which is charged or has an easily-charged polarity with a polarity opposite to that of the already formed dye layer or polymer layer, electrostatic attraction and electrostatic force can be obtained. A monomolecular layer can be easily formed by repulsion.

Here, when the dye or the polymer is adsorbed on the multilayer to cause unevenness, it is preferable to remove excess dye molecules by washing with a suitable solvent that dissolves the dye or the polymer.

Except for the laminated dye layer, any method generally used in the production of conventional photochemical cells can be used in any combination.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples are intended to illustrate the present invention in detail and do not limit the present invention.

Example 1 A dispersion in which fine particles of titanium oxide having a diameter of 10 nm were dispersed in water at a concentration of 1% by weight was applied on a transparent electrode 1 made of fluorine-doped tin oxide and the like.
For 5 hours to obtain an n-type transparent semiconductor layer 2. The roughness factor was 1000. After immersing the transparent semiconductor layer 2 in an acetonitrile solvent containing a dye represented by the following formula (1) for 1 hour, washing excess dye with the solvent, the dye represented by the following formula (2) is removed. After immersion in the contained solvent for 1 hour, excess dye was washed with the solvent.

Embedded image

The electrode on which the dye layer was formed was sealed with a sealant via a 7 μm spacer on the glass substrate on which the platinum counter electrode was formed. Under vacuum, a propylene carbonate solution (charge transport layer) in which iodine and tetraethylammonium iodide were dissolved was injected to prepare a photochemical cell. The oxidation potential of the first dye is 0.8 V with respect to the saturated calomel electrode, the absorption edge wavelength is 800 nm, and the oxidation potential of the second dye is
0.6V, and the absorption edge wavelength was 1020 nm.

The photochemical cell thus obtained was irradiated with light of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. . As a result, the energy conversion efficiency of this photochemical cell was 20%.

Comparative Example 1 Photochemistry was performed in the same manner as in Example 1 except that only the dye represented by the chemical formula (1) was used instead of using the two dyes represented by the chemical formulas (1) and (2). Battery was created. The photochemical battery obtained in this manner was used for a 750 m
Light irradiation was performed at a light amount of W / cm ² , and the photoelectric conversion efficiency was measured by a source measure unit 236 manufactured by Keithley. As a result, the energy conversion efficiency of this photochemical cell is
10%.

Example 2 In the same manner as in Example 1, a semiconductor layer and a laminated dye layer were formed on the electrode. Further, on the laminated dye layer, the following formula (3) having a glass transition temperature of 78 ° C.
Apply a chloroform solution of the donor molecule shown in
It was dried to form a charge transport layer.

Embedded image

A gold electrode was deposited on the formed charge transport layer to obtain a photochemical cell. The oxidation potential of the charge transport layer was 0.1 V with respect to the saturated calomel electrode. The photochemical cell obtained in this manner was used for 75 W
Light irradiation was performed at a light amount of 0 mW / cm ² , and the photoelectric conversion efficiency was measured by a source measure unit 236 manufactured by Keithley. As a result, the energy conversion efficiency of this photochemical cell was 13%.

Comparative Example 2 Photochemistry was performed in the same manner as in Example 2 except that only the dye represented by the formula (1) was used instead of using the two kinds of dyes represented by the formulas (1) and (2). Battery was created. The photochemical cell thus obtained was irradiated with light at a light amount of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. As a result, the energy conversion efficiency of this photochemical cell was 5%.

Example 3 A photochemical cell was prepared in the same manner as in Example 1 except that the dye represented by the following formula (4) was used instead of using the dye represented by the formula (2). . The oxidation potential of the dye represented by the chemical formula (4) is 0.1.
7V, the absorption edge wavelength was 550 nm.

Embedded image

The dye of the formula (4) showed visible light fluorescence, but no fluorescence was observed in the photochemical cell, indicating that the excitation energy was transferred to the dye of the formula (1). The photochemical cell thus obtained was irradiated with light at a light amount of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. As a result, the energy conversion efficiency of this photochemical cell was 22%.

Example 4 A dispersion medium in which titanium oxide fine particles having a diameter of 10 nm were dispersed in water at a weight ratio of 1% was applied on a transparent electrode 1 such as fluorine-doped tin oxide, and was heated at 400 ° C.
For 5 hours to obtain an n-type transparent semiconductor layer 2. The roughness factor was 1000. The transparent semiconductor layer 2 is immersed in an acetonitrile solvent containing the dye represented by the formula (1) for 1 hour, and then the excess dye is washed with the solvent. After immersion for 1 hour, the excess dye was washed with the solvent. Further, after immersing in a solvent containing a dye represented by the following formula (5) for 1 hour,
Excess dye was washed with the solvent.

Embedded image

The electrode on which the laminated dye layer was formed was sealed with a sealing agent via a 7 μm spacer on a glass substrate on which a platinum counter electrode was formed. Under vacuum, a propylene carbonate solution (charge transport layer) in which iodine and tetraethylammonium iodide were dissolved was injected to prepare a photochemical cell. The oxidation potential of the dye represented by the formula (5) was 0.3 V with respect to the saturated calomel electrode, and the absorption edge wavelength was 1000 nm. The photochemical cell thus obtained was irradiated with light at a light amount of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. As a result, the energy conversion efficiency of this photochemical cell was 24%.

Example 5 Titanium oxide fine particles having a diameter of 10 nm
A dispersion, which is dispersed in water at a concentration of 1% by weight, is applied on a transparent electrode 1 made of fluorine-doped oxide or the like, and heated at 350.degree.
By baking for an hour, an n-type transparent semiconductor layer 2 was obtained.
The roughness factor was 19. This transparent semiconductor layer 2
Is immersed in an acetonitrile solvent containing a dye represented by the formula (1) for 1 hour, washed with the solvent, and then immersed in a solvent containing a dye represented by the formula (4) for 1 hour. ,
Excess dye was washed with the solvent. Further, after immersing in a solvent containing a dye represented by the following formula (6) and having an oxidation potential of 0.2 V and a long-wavelength absorption end of 460 nm containing a dye, excess dye was washed with the solvent.

Embedded image A chloroform solution of a donor molecule represented by the formula (3) was applied onto the layered dye layer of the electrode having the layered dye layer thus formed, and dried to form a charge transport layer. A gold electrode was further deposited thereon to obtain a photochemical cell.

The photochemical cell thus obtained was irradiated with light at a light amount of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. did. As a result, the energy conversion efficiency of this photochemical cell was 15%.

[Embodiment 6] In the embodiment 5, the formula (4)
Was obtained in the same manner as in Example 5, except that a polymer represented by the following formula (7) was used instead of The photochemical cell thus obtained was irradiated with light at a light amount of 750 mW / cm ² using a pseudo solar light source manufactured by Wacom, and its photoelectric conversion efficiency was measured by a source measure unit 236 of Keithley. As a result, the energy conversion efficiency of this photochemical cell was 13%.

Embedded image

[0055]

According to the present invention, there is provided a photochemical cell capable of absorbing light in a wider wavelength range with a larger amount of light absorption by a dye layer than a conventional dye-sensitized type photochemical cell. Alternatively, there is provided a photochemical cell in which there is no problem of liquid leakage, and there is no decrease in energy conversion efficiency due to an increase in electric resistance due to the use of a solid charge transport layer and no decrease in conversion efficiency due to poor junction between a charge transport layer and a dye layer. The thing is
It is as described in the section of [Summary of the Invention].

[Brief description of the drawings]

FIG. 1 is a model diagram showing a cross-sectional shape of an example of a photochemical cell of the present invention.

FIG. 2 is a model diagram showing an example of an energy level of the photochemical cell of the present invention.

[Explanation of symbols]

 Reference Signs List 1 transparent electrode 2 transparent semiconductor layer 3 first dye layer 4 second dye layer 5 charge transport layer 6 counter electrode 7 incident light

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigenori Tanaka 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba R & D Center Co., Ltd. (72) Inventor Akihiro Horiguchi Sachi-ku, Kawasaki-shi, Kanagawa Komukai Toshiba 1 F-term in Toshiba R & D Center (reference) 5F051 AA14 5H032 AA06 AS16 BB10 EE07 EE16 EE18 HH07

Claims (4)

[Claims] 1. A structure in which (1) a semiconductor electrode composed of a conductor layer and a semiconductor layer laminated thereon, (2) a dye layer, (3) a charge transport layer, and (4) a counter electrode are sequentially laminated. Wherein the at least one electrode is transparent, and wherein the dye layer is a stacked dye layer in which at least two dye layers made of different dyes are stacked. 2. The photochemical battery according to claim 1, wherein the laminated dye layer contains a combination of dyes having a difference in absorption edge on the long wavelength side of the absorption spectrum of 100 to 400 nm. 3. The photochemical cell according to claim 1, wherein the laminated dye layer comprises a combination of dyes having different oxidation-reduction potentials. 4. A structure in which (1) a semiconductor electrode comprising a conductor layer and a semiconductor layer laminated thereon, (2) a dye layer, (3) a charge transport layer, and (4) a counter electrode are sequentially laminated. A method for producing a photovoltaic cell, wherein at least one electrode is transparent, wherein a solution containing a first dye charged to a predetermined polarity is brought into contact with the semiconductor layer surface of the semiconductor layer electrode, Adsorbing the dye, and contacting the solution containing the second dye charged to the opposite polarity to the first dye with the first dye, and adsorbing the second dye on the first dye. A method for producing a photochemical battery, comprising: