Iron Pyrite Films Prepared By Sol-Gel Hydrothermal Method Combined With Electrophoretic Deposition (EPD)

An overview is given on development of photovoltaic materials at home and abroad, and set forth the principle,structure and efficiency of solar cell. We have also overviewed functional properties, recent development and preparation techniques of FeS₂ thin film based on solar cells material. Sol-gel hydrothermal method can find a wide application in the field of material synthesis, chemical reaction and processing. In this thesis, we have systematically described elementary principle and technical equipment of this method. Analysis instruments relating structure,electric and optical properties have also been introduced. The thesis is a summarization concerning research work during my graduate experience. During the first period, iron pyrite (FeS₂) crystalline particles was prepared using sol-gel hydrothermal method, which was characterized via XRD, FT-IR and SEM. It was found that reaction temperature and time, and sulfur pressure provided by some amount of sulfur could produce an impressive effect on controlling the formation of single-phase pyrite crystals, and the desirable reaction conditions was also concluded. A simplified mathematics model was established to analyze the crystal growth process. In the course of the second period, electrophoretic deposition (EPD) technique was used to deposit the as-prepared pyrite crystalline particles in an ethanol suspension. Furthermore, we have discussed the effects of deposit time, current density and deposit weight on structure, thickness and morphology of the pyrite films during the EPD process. Optical and electrical properties of the pyrite films prepared in this way indicate the superiority of this combined method.