Chloride species surface treatment of thin film photovoltaic cell and manufacturing method

摘要

A method for forming a thin film photovoltaic device. The method includes providing a transparent substrate comprising a surface region. A first electrode layer is formed overlying 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. The method subjects at least the multi-layered structure to a thermal treatment process in an environment containing a sulfur bearing species to form a copper indium disulfide material. The copper indium disulfide material comprising a copper-to-indium atomic ratio ranging from about 1.2:1 to about 2:1 and a thickness of substantially copper sulfide material. The thickness of the copper sulfide material is removed to expose a surface region having a copper poor surface comprising a copper to indium atomic ratio of less than about 0.95:1. The copper poor surface is subjected to a chloride species to convert the copper poor surface from an n-type semiconductor characteristic to a p-type semiconductor characteristic. A window layer is formed overlying the copper indium disulfide material.