Patent ID: 8691618

Claim:
A method for forming a thin film photovoltaic device, the method comprising: providing a transparent substrate comprising a surface region; forming a first electrode layer overlying the surface region; forming a copper layer overlying the first electrode layer; forming an indium layer overlying the copper layer to form a multi-layered structure; subjecting at least the multi-layered structure to a thermal treatment process in an environment containing a sulfur bearing species; forming a copper indium disulfide material from at least the thermal treatment process of the multi-layered structure, the copper indium disulfide material comprising a thickness of substantially copper sulfide material having a copper sulfide surface region; removing the thickness of the copper sulfide material to expose a surface region having a copper poor surface; subjecting the copper poor surface to a metal cation species to convert the copper poor surface from an n-type semiconductor characteristic to a p-type semiconductor characteristic; subjecting the copper poor surface to a treatment process during a time period associated with the subjecting of the copper poor surface with the metal cation species; and forming a window layer overlying the copper indium disulfide material.