METHOD AND STRUCTURE FOR THIN FILM PHOTOVOLTAIC CELL USING SIMILAR MATERIAL JUNCTION

摘要

A method for forming a thin film photovoltaic device. The method provides a transparent substrate including a surface region. A first electrode layer overlies the surface region. A copper layer is formed overlying the first electrode layer and an indium layer is formed overlying the copper layer to form a multi-layered structure. At least the multi-layered structure is subjected to a thermal treatment process in an environment containing a sulfur bearing species to forming a bulk copper indium disulfide. The bulk copper indium disulfide material has a surface region characterized by a copper poor surface region having a copper to indium atomic ratio ofless than about 0.95:1 and n-type impurity characteristics. The bulk copper indium disulfide material excluding the copper poor surface region fonns an absorber region and the copper poor surface region fonns at least a portion of a window region for the thin film photovoltaic device.