Patent ID: 8921151

Claim:
A method for forming a thin film photovoltaic device, the method comprising: co-depositing at least two materials on a surface of a substrate to form a layer on the surface of the substrate, the layer comprising the at least two materials, wherein a concentration of a first material of the at least two materials within the layer decreases as the layer extends from the surface of the substrate and a concentration of a second material of the at least two materials within the layer increases as the layer extends from the surface of the substrate, wherein the first material and the second material do not form an alloy, and wherein one of the first material and the second material comprises copper and the other of the first material and the second material comprises molybdenum; performing a heat treatment to the layer; applying a wet etch process to the layer after the performing of the heat treatment, wherein during the wet etch process, the second material is etched faster than the first material is etched such that a surface of the layer is textured after the applying of the wet etch process; and after applying the wet etch process, forming a back contact layer on the surface of the layer, wherein the back contact layer comprises copper, molybdenum, gold, zinc, tellurium, graphite, or a combination thereof; forming a p-type absorber layer on the back contact layer; forming an n-type buffer layer on the p-type absorber layer; and forming a front contact layer on the n-type buffer layer.