Abstract: With the rapid development of green sources of energy, silicon solar cells are playing a very important role, but due to material shortages and the high price of cells based on crystalline and poly-crystal Si, they cannot satisfy the needs of green energy demand. Thus, thin-film solar cells are regarded as the main potential area for future development. Although amorphous silicon thin-film cells have several unfavorable characteristics, with the improvements in film-depositing techniques and the rising quality of the cells, they are becoming more and more significant in the solar energy field. Alternatively, poly-silicon thin-film solar cells possess the dual properties of crystalline silicon and poly-silicon solar cells, and so are also making their mark in this field. On the other hand, as nano-technology progresses, the more recently developed nano-silicon film solar cells will be a promising highlight with their inherent advantages.