JP2002075479A - Pigment sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment sensitized solar cell enabled to improve the photoelectric conversion rate per unit area by widening a wave length region usable for a pigment sensitized photoelectric generation. SOLUTION: A multi-layered porous semiconductor films of metal oxide or the like, holding a light absorbing material like a pigment having a different wave length absorbing region within the wave length region of sun light, and an electrolyte layer, are interposed between transparent insulation substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solar cell, and more particularly to a dye-sensitized solar cell using a light absorbing substance such as a dye.

[0002]

2. Description of the Related Art In a conventional dye-sensitized solar cell, a metal oxide such as titanium oxide is formed as a semiconductor layer on a glass substrate coated with a transparent conductive film, and a dye is carried thereon to form a working electrode. The structure was such that a glass substrate coated with a conductive film was used as a counter electrode and an electrolyte solution was sealed between the two electrodes.

[0003] Since a solar cell having such a structure can be manufactured at low cost, if a photoelectric conversion efficiency comparable to that of a silicon solar cell can be achieved, the manufacturing cost per unit output can be greatly reduced. No one that can achieve a photoelectric conversion efficiency comparable to a battery has been obtained. One of the reasons is that the light absorption region is very narrow compared with semiconductors such as silicon and the solar energy cannot be sufficiently absorbed by using only one kind of dye conventionally used (for example, ruthenium dye). It is considered to be one.

In order to improve the photoelectric conversion efficiency,
The first and second dye-sensitized semiconductor electrodes are spaced apart and opposed to each other, and a carrier transfer layer is formed between the two dye-sensitized semiconductor electrodes (JP-A-2000-90989), an electrode layer, A light conversion layer, which is formed by laminating a semiconductor layer composed of a metal oxide to which a sensitizing dye is adsorbed, an electrolyte layer, and an electrode layer in this order, is alternately laminated into a plurality of layers with a light-transmitting insulating substrate interposed therebetween (see (Heihei 11-277353) has been proposed.

[0005]

The above-mentioned prior arts each have a configuration in which a plurality of unit cells are stacked, so that the unit cells must be connected to each other by a metal wire or the like. However, there is a problem that the photoelectric conversion efficiency of the solar cell module is reduced with the increase in the resistance, and the manufacturing process is complicated.

[0006] As the area of the unit cell becomes larger, electricity flows in the intermediate layer in a relatively high-resistance transparent conductive film in a planar direction for a longer distance, so that a higher internal resistance is generated and the module per unit area of the module is increased. This causes a reduction in conversion efficiency. Therefore, there is a problem that it is difficult to increase the area of the unit cell.

[0007] The present invention has been proposed in view of the above point, the wavelength range that can be used for dye-sensitized photovoltaic power generation is expanded,
It is an object of the present invention to provide a dye-sensitized solar cell capable of improving photoelectric conversion efficiency per unit area.

[0008]

Means for Solving the Problems In order to achieve the above object, the invention described in claim 1 comprises a pair of transparent members formed by coating a transparent insulating substrate such as glass with a transparent conductive film.
A porous semiconductor film such as a metal oxide carrying a light absorbing substance such as a dye having an absorption wavelength range in the wavelength range of sunlight,
A dye-sensitized solar cell composed of an electrolyte solution or an electrolyte solution supported by an insulating porous film or an electrolyte layer made of a solid electrolyte or a conductive polymer, and having different absorption wavelength regions within the wavelength region of sunlight. A unit intermediate layer consisting of a porous semiconductor film such as a metal oxide carrying a light-absorbing substance such as a dye and a transparent conductive film and an electrolyte layer having a light wavelength such as a dye having an absorption wavelength range within the wavelength range of sunlight. It is characterized in that one or more layers are inserted in addition to a porous semiconductor film such as a metal oxide carrying an absorbing substance.

According to a third aspect of the present invention, there is provided a pair of transparent members each having a transparent insulating substrate made of glass or the like coated with a transparent conductive film, and a light-absorbing material such as a dye having an absorption wavelength range within the wavelength range of sunlight. A dye-sensitized solar cell composed of a porous semiconductor film such as a metal oxide carrying a metal oxide and an electrolyte solution or an electrolyte solution supported by an insulating porous film or an electrolyte layer composed of a solid electrolyte or a conductive polymer. In addition, a porous semiconductor film such as a metal oxide is formed by supporting two or more types of light-absorbing substances such as dyes having different absorption wavelength regions in the wavelength region of sunlight in a layered manner. .

According to a fifth aspect of the present invention, there is provided a pair of transparent members in which a transparent insulating film such as glass is coated with a transparent conductive film, and a light-absorbing material such as a dye having an absorption wavelength range within the wavelength range of sunlight. In a dye-sensitized solar cell composed of a porous semiconductor film such as a metal oxide carrying a metal oxide and an electrolyte solution or an electrolyte solution supported by an insulating porous film or an electrolyte layer made of a solid electrolyte or a conductive polymer. In addition, two or more types of light-absorbing substances such as dyes having different absorption wavelength regions within the wavelength region of sunlight are dispersed and supported on a porous semiconductor film such as a metal oxide.

[0011]

According to the present invention, a semiconductor porous film in which a plurality of light-absorbing materials having different absorption wavelength regions within the wavelength region of sunlight are carried on a porous material in an intermediate layer serving as a photoelectric conversion layer is formed into a layer. Or, since a plurality of light-absorbing substances having different absorption wavelength regions are arranged in layers or dispersed in the wavelength region of sunlight in the semiconductor porous film, the wavelength region of sunlight that can be used for photoelectric conversion Can be expanded.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual structural view of a dye-sensitized solar cell according to the first invention. In the drawing, reference numeral (1) denotes a transparent insulating material formed of a transparent material such as a glass plate or a plastic plate. A substrate, (2) a transparent conductive film composed of tin oxide, fluorine-doped tin oxide, indium oxide, aluminum-doped zinc oxide, etc., coating one side surface of the transparent insulating substrate (1); Is a porous semiconductor film made of a metal oxide or the like carrying a light absorbing substance such as a sensitizing dye having an absorption wavelength range within the wavelength range of sunlight, and (4) is supported by an electrolyte solution or an insulating porous film. (5) is a second transparent conductive film, (6) is a second porous semiconductor film, (7) is a second electrolyte layer, (5) is a second electrolyte layer made of an electrolyte solution, a solid electrolyte, or a conductive polymer. 8) is a third transparent conductive film,
(9) is a third porous semiconductor film, (10) is a third electrolyte layer, (11)
Is the other transparent insulating substrate coated on one side with a transparent conductive film (12).

In this case, the transparent conductive film, the porous conductive film and the electrolyte layer each constitute a unit intermediate layer (13).
In the three porous conductive films (3), (6) and (9), light absorbing substances such as sensitizing dyes having different absorption wavelength ranges within the wavelength range of sunlight are supported on the metal oxide. is there. Then, in this case, it is desirable that the porous conductive film holding the light-absorbing substance having a high charge transfer efficiency from the light-absorbing substance to the porous semiconductor film be located on the sunlight incident side (surface side). .

In the case where a plurality of unit intermediate layers (13) are arranged in a laminated state between the transparent insulating substrates (1) and (11), a plurality of cell units are formed while being a single cell. Since the structure is connected in series, the electromotive force as a single cell can be mentioned.

FIG. 2 is a conceptual structural view of a dye-sensitized solar cell according to the second invention, which has a transparent conductive film (22) on one side.
Between a pair of transparent insulating substrates (21) and (21) coated with (22), plural kinds of light absorbing substances such as sensitizing dyes having an absorption wavelength range within the wavelength range of sunlight (3 in the figure). (Type) A porous semiconductor film (23) made of a metal oxide carried thereon is arranged, and an electrolyte layer (24) is arranged.

In this case, the porous semiconductor film (23) in each layer carries a light-absorbing material having a different absorption wavelength range, and the efficiency of charge transfer from the light-absorbing material to the porous semiconductor film is reduced. It is desirable that the porous conductive film holding the high light-absorbing substance be disposed in a state where the porous conductive film is located on the sunlight incident side (surface side).

FIG. 3 is a conceptual structural view of a dye-sensitized solar cell according to the third invention, which has a transparent conductive film (32) on one side.
Plural types of light-absorbing substances (three types in the figure) such as sensitizing dyes having an absorption wavelength range within the wavelength range of sunlight between a pair of transparent insulating substrates (31) and (31) coated with (32) A porous semiconductor film made of a metal oxide supported in a dispersed state (3
3) and an electrolyte layer (34).

In the above embodiments, three light absorbing materials having different absorption wavelength ranges are used. However, two types of light absorbing materials having different absorption wavelength ranges may be used. Alternatively, four or more light absorbing substances may be used.

As the light absorbing substance to be carried on the porous semiconductor film, a ruthenium-tris, ruthenium-bis, osmium-tris, osmium-bis type transition metal complex,
Alternatively, metal phthalocyanines such as copper phthalocyanine, polycyclic aromatic compounds such as porphyrin, and charge transfer complex materials such as tetracyanoquinodimethane are conceivable.

As a porous conductive film, a ruthenium dye supported on a titanium oxide porous membrane using an ethanol solution, a pheophorbide (Pheophorbide) supported on a titanium oxide porous membrane using an ethanol solution, And a solar cell was created using a titanium oxide porous membrane supported using an ethanol solution in which both dyes were mixed,
FIGS. 4 and 5 show the results obtained by injecting monochromatic light into the solar cell using a spectroscope and examining the wavelength dependence of collection efficiency from the short-circuit current.

FIG. 4 shows a ruthenium dye, pheophorbide
(Pheophorbide) shows the standardized collection efficiency of the solar cell using each. In addition, in order to clarify the wavelength dependence, the data was standardized at each collection efficiency at 400 nm. Here, the collection efficiency refers to a ratio of a photocurrent to the number of incident photons. According to FIG. 3, when a ruthenium dye was used, pheophorbide (Phe
It can be seen that when using ophorbide), each has a peak at 650 to 700 nm.

FIG. 5 shows a ruthenium dye and pheophorbide.
(Pheophorbide) and the standardized collection efficiency of a solar cell formed. In the solar cell in which the two dyes were mixed, both a peak at 500 nm derived from ruthenium and a peak at 670 nm derived from pheophorbide appeared, and the peak ratio changed according to the mixing ratio of the dye. As a result, by using a plurality of sensitizing dyes in one cell, it is possible to overcome the weak point of a narrow light absorption region, which has been an obstacle to improving the efficiency of the dye-sensitized solar cell.

[0023]

According to the present invention, since a plurality of light absorbing materials having different absorption wavelength regions are arranged between transparent insulating substrates, power can be generated from light in a wide wavelength range. Since sunlight is a collective light of monochromatic light in a very wide wavelength range, the photoelectric conversion efficiency can be improved. In addition, since a dye-sensitized solar cell has an advantage that it can be manufactured at low cost, the solar cell of the present invention can produce a high-efficiency solar cell at low cost.

[Brief description of the drawings]

FIG. 1 is a conceptual structural diagram of a dye-sensitized solar cell according to a first invention.

FIG. 2 is a conceptual structural diagram of a dye-sensitized solar cell according to a second invention.

FIG. 3 is a conceptual structural diagram of a dye-sensitized solar cell according to a third invention.

FIG. 4 is a diagram showing the normalized collection efficiency of a solar cell using a ruthenium dye and pheophorbide, respectively.

FIG. 5: Ruthenium dye and pheophorbide
FIG. 9 is a diagram showing the normalized collection efficiency of a solar cell formed by mixing ide).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Komiyama 5-2-4 Daida, Setagaya-ku, Tokyo (72) Inventor Manabu Ihara 4- 20-naka-812, Nakayama 812-812, Nakayama, Aoba-ku, Sendai City, Miyagi Prefecture (72) Inventor Koichi Izumi 3-21-8 Nishi-Shimbashi, Minato-ku, Tokyo Iwatani Industrial Co., Ltd. Tokyo Head Office F-term (reference) 5F051 AA14 5H032 AA06 AS16 CC06 CC11 CC17 EE04 EE07 EE08 EE16 EE18 HH07

Claims (5)

[Claims] 1. A pair of transparent members each comprising a transparent insulating substrate such as glass coated with a transparent conductive film, and a metal oxide carrying a light-absorbing substance such as a dye having an absorption wavelength range within the wavelength range of sunlight. In a dye-sensitized solar cell composed of a porous semiconductor film such as an electrolyte solution or an electrolyte solution supported by an electrolyte solution or an insulating porous film, or an electrolyte layer composed of a solid electrolyte or a conductive polymer, the wavelength within the wavelength range of sunlight A unit intermediate layer consisting of a porous semiconductor film such as a metal oxide carrying a light absorbing substance such as a dye having a different absorption wavelength region, a transparent conductive film, and an electrolyte layer within the wavelength region of the sunlight. A dye-sensitized solar cell characterized in that one or more layers are inserted in addition to a porous semiconductor film such as a metal oxide carrying a light-absorbing substance such as a dye having a dye. 2. A light absorbing material having high charge transfer efficiency from the light absorbing material to the porous semiconductor film is disposed on the surface side.
The dye-sensitized solar cell described in 1. 3. A pair of transparent members formed by coating a transparent insulating substrate such as glass with a transparent conductive film, and a metal oxide carrying a light-absorbing substance such as a dye having an absorption wavelength range in the wavelength range of sunlight. In a dye-sensitized solar cell composed of a porous semiconductor film such as an electrolyte solution and an electrolyte solution supported by an electrolyte solution or an insulating porous film or an electrolyte layer made of a solid electrolyte or a conductive polymer, a porous material such as a metal oxide is used. A dye-sensitized solar cell characterized in that the porous semiconductor film is formed by supporting two or more types of light-absorbing substances such as dyes having different absorption wavelength ranges in the wavelength range of sunlight in a layered manner. 4. A light absorbing material having a high charge transfer efficiency from the light absorbing material to the porous semiconductor film is disposed on the surface side.
The dye-sensitized solar cell described in 1. 5. A pair of transparent members in which a transparent conductive film is coated on a transparent insulating substrate such as glass, and a metal oxide carrying a light-absorbing substance such as a dye having an absorption wavelength range in the wavelength range of sunlight. In a dye-sensitized solar cell composed of a porous semiconductor film such as an electrolyte solution or an electrolyte solution supported by an electrolyte solution or an insulating porous film, or an electrolyte layer composed of a solid electrolyte or a conductive polymer, a porous material such as metal oxide is used. A dye-sensitized solar cell characterized in that two or more types of light-absorbing substances such as dyes having different absorption wavelength ranges within the wavelength range of sunlight are dispersed and supported on a porous semiconductor film.