| Photovoltaic technologies have get more and more attention in the world. It can change solar energy into electricity directly and is a kind of new energy with clear, safe, no pollution, no effect on entironment and reproducible. So solar energy has been understood and accepted by people gradually. At present, thin film solar cells is the most interesting project in the realm of solar cells research and development. The most promising thin film solar cells are Cadmium telluride (CdTe) thin film solar cells, copper-indium-diselenide (CIS) thin film solar cells and silicon thin film solar cells. A solar cell of cadmium telluride (CdTe) with high efficiency has been obtained, and it can be seen in the market of photovoltaic. But a big obstacle for large-scale application of CdTe thin film solar cells related to cadmium toxicity. Cadmium is a kind of heavy metal with toxicity, and cadmium compound is toxic too. The main danger is that its dust can harm human and another animals by breathing. Disuse and broken CdTe solar cell module has to be removed and recycled. CIS thin film solar cells have been studied and developed for many years, and has high efficiency. But serious problem is limitation of indium resource of whole world,which cannot fill the request for large-scale production. Among of many solar materials, silicon has abundant reserves in the earth. It has no toxicity and no pollution for environment. It has been studied for a long time and there are mature technologies to produce. Amorphous silicon thin film solar cell has light induce decay (S-W effect), which the conversion efficiency has serious decay after light irradiation. Mono-crystalline silicon thin film can be obtained by transfer technology, but its commercial application is probably limited by the complexity of the transfer process rather than by material constraints. So poly-Si thin films solar cells are becoming one of hot projects, because it has high efficiency and good stable performance. But thin film solar cells need a kind of substrate for support Good substrate is the key of solar cells gets high efficiency.In this thesis, we summarized the current status, tendency and unresolved of poly-si thin films solar cells. Performance of substrates for poly-Si thin films solar cells has been analyzed. We first put out ceramic silicon for the substrates of poly-Si thin films, and many researches and experiments have been done. Ceramic silicon has been prepared successfully, and the performance of ceramic silicon and mechanisms has been analyzed. Poly-Si thin films have been obtained by RTCVD on ceramic silicon, MgAl2O4 transparent ceramic, and graphite substrate respectively. Performance of poly-si thin films have been tested and analyzed. Poly-si thin films and poly-si thin films solar cells have been studied through electron irradiation. The following new results have been obtained.1 .The preparing methods and performance of ceramic silicon and mechanisms have been studied. Ceramic silicon materials were prepared first time by high-pressure low temperature method. The optimum prepare condition has been obtained. It was temperature 600@, pressure 2.3GPa, time 10 min. Under this condition, ceramic silicon materials with no dioxide silicon phase or a little dioxidesilicon phase were obtained. Ceramic silicon has high density and high hardness (6 |
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