Dye-sensitized SnO₂ Solar Cell And Solid-state Electrolyte CuI's Preparation And Application

At present the world's primary energy sources are conventional energy sources, such as oil, coal, natural gas and other non-renewable energy sources. Their reserves are limited and they bring tremendous environment deterioration when they are used. The demand that looks for clean and economical substitutions spurs people to exploit and develop renewable energy resources, particularly solar energy. Photo-to-voltaic application is an irreversible trend. Photovoltaic industry is one of the fastest-growing industries. In the past five years, it increases annually at the speed of 40% in the world. Currently the main problems are how to reduce costs and increase the photo-to voltage conversion efficiency.Dye-sensitized solar cell (Gratzel cell) is a hot issue in the research area of nanotechnology and materials for photo-to-electricity. It provides an effective method to convert solar resource to electric power for its cheap costs, easy availability and better performance. SnO₂ is applied to preparation for dye-sensitized solar cell for the merits of low-cost, non-toxic, wide bandwidth (3.8eV). In second chapter, the SnO₂ nanospheres, nanospindles and nanorods prepared in different conditions by hydrothermal method were studied. The SnO₂ films with high BET were obtained by dip - coating from pre-prepared SnO₂ nanorod colloid. After dye sensitized, the SnO₂ films were used to assemble dye-sensitized solar cell. The solar cell' performance was investigated. To enhance their photoelectric conversion efficiency, the SnO₂ powders' surface was modified by zinc acetic. The results shows that surface modification significantly improve the cell's photoelectric conversion efficiency.Liquid-state dye-sensitized solar cells have a higher conversion efficiency and less working stability. To improve the stability, searching for appropriate solid-state electrolyte is another hot issue. CuI was introduced to build solid-state dye-sensitized solar cell. CuI is a P-type semiconductor material with 3.2eV bandwidth and stable performance in chemistry and physics. Its resistivity can be changed with [I^-] concentration, and CuI film is transparent for visible band of light. In third chapter, the experimental conditions of preparing CuI films by chemical deposition were discussed. The size of CuI nanoparticles can be adjusted in the range of 10²00nm in diameter.Based on the same TIO2 and dye electrodes, Cul was deposited on the electrodes surface to build different solid-state dye-sensitized solar cells identified by the ratio HO2 and Cul diameter. The optimum ration range of HO2 and Cul diameter was determined by the results of the solar cells performance measurement.