| 摘要 |
PROBLEM TO BE SOLVED: To increase the yield and throughput of a thin silicon film solar cell and reduce the cost of the cell by reducing the number of processes by fixing the total number of supplied metal atoms at a specific ratio to the total number of supplied silicon atoms. SOLUTION: The structure of, for example, a thin polycrystalline Si film 11 changes from a high Al-concentration layer to a low Al-concentration layer from a glass substrate 1 side. The thin film 11 has such a film structure that the thin film is composed of large-grain polycrystalline silicon containing an impurity at a high concentration near the boundary with a substrate and the impurity concentration becomes lower as going toward the upper surface while the gain size is maintained. When the total number of supplied metal atoms is adjusted 1/2,000 to 1/100 of that of supplied silicon atoms at the time of forming a metallic thin film, the adjustment is equivalent to the adjustment of the film thickness of the thin metallic film to 1/2,000 to 1/100 of the film thickness of that of the thin polycrystalline silicon film. In such a way, a base layer which becomes a seed crystal having a large grain size and a highly pure active layer taking over the crystallinity of the base layer can be manufactured. |
