| Since the beginning of the 20th century, it has been an important way to solve the energy crisis and environmental pollution by exploiting and using solar energy. And so the solar cell that converts the sunlight into electricity has become the focus of the researches. In this thesis, the history of the wet-type solar cells is summarized and the previous researches about the electrode material TiO2 semiconductor are particularly reviewed, based on which, the significant subject of compounding narrowband semiconductor CdS with TiO2 to improve the photoelectric conversion efficiency of the solar cells is presented.Oxide semiconductor TiO2 is considered as the most promising electrode materials because of the particular optic, electric and chemical properties, nice chemical stability and anti- erosion, cheap as well as the good ability of utilization of the solar energy. However it can just absorb the ultraviolet radiation and almost cannot use the visible light of the solar spectra. For this problem, using the narrowband semiconductor CdS to compound with TiO2 will be an effective solution. Because it will not only enlarge the region of the absorption with the proper narrow band of CdS but also improve the photoelectric conversion efficiency on account of the band overlap of the two, which makes the photo induced electron and holes separate more easily.Sol-gel method is a good way of coating. Here, with the materials Ti(OC4H9)4,Cd(COOCH3)2 and SCN2H4,the TiO2,CdS and CdS/TiO2 films were prepared, respectively, by sol-gel method. The process of the coating was analyzed and the structure, the absorption of sunlight and the photoelectric conversion of the films were researched with the advanced tests of SEM, EDAX, UV-VIS absorption and photocurrent. At the same time, the influences of the atmosphere and temperature of the heat treatment, the concentration of the sols and the ratio Cd/Ti on the properties of the films were discussed. It is revealed that (1) The appropriate parameters for preparation of the films are: the concentration of TiO2, CdS are 0.6mol/L and 0.1 mol/L, respectively; the mol ration of Cd/Ti is 0.45 ;under N2 atmosphere; 480℃,lh.(2) The formation of thecompound semiconductor CdS/TiO2 films improves the absorption of the visible region and the photoelectric conversion property of the TiO2 film to an extent.Moreover, based on the analytically pure TiO2 and K2CO3 powder, the layered metal oxide K2Ti4O9 powder was synthesized, and then with the suspension of K2Ti4O9, the films of K2Ti4Oo on the glass substrate was made by spin coating. The ion-exchange property of KiTi4O9 powder and film was studied. Also through ion exchange, the compound semiconductor powder CdS /K2Ti4O9 was synthesized and by coating its slurry on the ITO glass substrate, the photoelectric conversion property was researched. It is summarized as follows: (1) The feasible parameters for synthesizing the K2Ti4O9 powder are: temperature is 850℃, time is Ih and the mol ration of the TiO2 to KiCO3 is 4 ; (2) Both the KiTi^Q powder and the films have the ion-exchange ability (3) The appropriate particle diameter of the suspension for spin coating is less than 440nm;(4) This new method provides a possible way to design and prepare the interlayer-modified compound films and materials with the excellent optic, electric and photocatalytic performances.
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