Patent attributes
A method for forming a thin film photovoltaic device. The method includes providing a transparent substrate comprising a surface region. The method forms a first electrode layer overlying the surface region of the transparent substrate. The method also forms a thin layer of indium material, using a sputtering target of indium material, overlying the first electrode layer to act as an intermediary glue layer to facilitate attachment to the first electrode layer. In a specific embodiment, the method forms a copper material overlying the thin layer of indium material. The method also forms an indium layer overlying the copper material to form a multi layered structure including at least the thin layer of indium material, copper material, and the indium layer. In a preferred embodiment, the multi-layered structure has a first thickness. In a specific embodiment, the method also subjects at least the multi-layered structure to thermal treatment process in an environment containing a sulfur bearing species to form a copper indium disulfide alloy material while consuming substantially all of the indium layer from at least the treatment process of the multi-layered structure. In a preferred embodiment, the copper indium disulfide alloy material comprises an atomic ratio of copper indium ranging from about 1.35 to about 3.00. In a specific embodiment, the copper indium disulfide alloy material has a second thickness of more than two times of the first thickness of the multi-layered structure. The method consumes substantially all of the thin layer of indium material into a portion of the copper indium disulfide alloy material during at least the thermal treatment process. The method causes formation of a copper sulfide material overlying the copper indium disulfide alloy material during at least the thermal treatment process.
