METHOD and material FOR INDIUM SPUTTERING AND FOR FORMING CHALCOPYRITE-BASED SOLAR CELL ABSORBER LAYERS

The present invention discloses a method and a material for indium sputtering and for forming chalcopyrite-based solar cell absorber layers. A solar cell includes an absorber layer formed of a CIGAS, copper, indium, gallium, aluminum, and selenium. A method for forming the absorber layer provides for using an indium-aluminum target and depositing an aluminum-indium film as a metal precursor layer using sputter deposition. Additional metal precursor layers such as a CuGa layer are also provided and a thermal processing operation causes the selenization of the metal precursor layers. The thermal processing operation/selenization operation converts the metal precursor layers to an absorber layer. In some embodiments, the absorber layer includes a double graded chalcopyrite-based bandgap.