With the development of low cost and low defects thin film, the thin film solar cells have been a predominant technology; however the absorber layer in thin film solar cell is thinner than c-Si solar cells, which exhibits less light absorption to result in the decrease of cell efficiency. In this article, we proposed Si quantum dot superlattice structure, nano-texturing and metal plasmonic effect to enhance the light absorption probability in absorber layer and increase the conversion efficiency.