| 摘要 |
A solar cell with a heightened open-circuit voltage and improved junction quality of the interface between an interfacial layer (or buffer layer) and a thin-film light absorbing layer is disclosed. A thin-film solar cell is fabricated on a glass substrate and includes a metallic back electrode, a light absorbing layer, an interfacial layer, a window layer, and an upper electrode. The solar cell is characterized by the light absorbing layer. The light absorbing layer is a thin film of p-type Cu(InGa)Se2 (CIGS) of the Cu-III-VI2 chalcopyrite structure and has such a gallium concentration gradient that the gallium concentration gradually (gradationally) increases from the surface thereof to the inside, thereby attaining a heightened open-circuit voltage. The light absorbing layer has on its surface an ultrathin-film surface layer of Cu(InGa)(SeS)2 (CIGSS), which has such a sulfur concentration gradient that the sulfur concentration abruptly decreases from the surface thereof (i.e., from the interfacial layer side) to the inside, thereby improving interfacial junction characteristics. <IMAGE> |
