Dye-sensitized solar cell

Abstract

A dye-sensitized solar cell with high conversion efficiency is provided. The dye-sensitized solar cell according to the present invention has, between an electrode (2) formed on a surface of a transparent substrate (1) and a counter electrode (6), a light-absorbing layer (3) containing light-absorbing particles carrying dye and an electrolyte layer (5), characterized in that the light-absorbing layer (3) containing light-scattering particles (4) different in size from the light-absorbing particles. In such a dye-sensitized solar cell according to the present invention, the energy of light, which passes through a light-absorbing layer in a conventional cell structure, can be strongly absorbed by the dye in the light-absorbing layer of the present invention. This will increase the conversion efficiency and output current of the dye-sensitized solar cell.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation of application Ser. No. 10 / 480,604, filed on Jul. 22, 2004, entitled SENSITIZING DYE SOLAR CELL which, in turn, claims priority under 35 U.S.C. 371 and 37 CFR 1.495 to PCT / JP03 / 04518, filed Apr. 9, 2003, which, in turn, claims priority to Japanese application No. JP2002-109408 filed Apr. 11, 2002.TECHNICAL FIELD [0002] The present invention relates to a dye-sensitized solar cell and particularly to a dye-sensitized solar cell with an improved conversion efficiency expressed by the ratio of the cell output to the quantity of incident light. BACKGROUND ART [0003] In Japan, photovoltaic power generation systems are now being commercially introduced and coming into widespread use. Although some p-n junction silicon solar cells are available on the market, their electricity prices are much higher than those of distribution lines. Accordingly, inexpensive solar cells are required for the proliferation of pho...

AI Technical Summary

Benefits of technology

[0009] In such a dye-sensitized solar cell according to the present invention, the addition of light-scattering particles that are different in size from the light-absorbing particles to the light-absorbing layer causes incident light on a light-collecting layer to be adequately scattered, thus increasing the optical path length through the light-absorbing layer. This enhances the absorption of the scattered light by the dye adsorbed on the light-absorbing particles and leads to greatly increased light absorption. As a result, the energy of light, which passes through the light-absorbing layer in the conventional cell structure, can be strongly absorbed by the dye in the light-absorbing layer. This will increase the conversion efficiency and output current of the dye-sensitized solar cell.

[0010] Moreover, the dye-sensitized solar cell that has such a structure according to this invention does not require a thicker light-absorbing layer for higher conversion efficiency; therefore, the series resistance of the light-absorbing layer is not increased and thus reduction in the conversion efficiency due to the increased thickness of the light-absorbing layer does not occur. Accordingly, the conversion efficiency can be improved while maintaining the small thickness of the light-absorbing layer.

[0011] Furthermore, these effects are particularly noticeable for long-wavelength light. Low conversion efficiency due to high transmission of long-wavelength light can be compensated for while maintaining the small thickness of the light-absorbing layer, and thus the conversion efficiency can be increased.

Problems solved by technology

While the dye-sensitized solar cell has such advantages, however, its low conversion efficiency stands in the way of commercialization.

However, a thicker light-absorbing layer 103 will cause a problem of further reduced conversion efficiency, because the light-absorbing layer 103 structurally has high series resistance.

In both cases, therefore, it is difficult to increase the conversion efficiency.

Consequently, a dye-sensitized solar cell that satisfies these contradictive requirements for conversion efficiency and light absorption efficiency as described above has not yet been developed.

Images