Use of the effective heat of formation model to determine phase formation sequences of In-Se, Ga-Se, Cu-Se, and Ga-In multilayer thin films

Abstract

Multilayer thin films of indium-selenium, gallium-selenium, copper-selenium, and gallium-indium have been analyzed for the purpose of understanding thin film phase transformations that are relevant to the production of Cu(In,Ga)Se2 photovoltaic solar cells. For example, the intermetallic phases that are present during selenization of precursor films will affect film microstructure and the resulting film properties. Throughout this research, the effective heat of formation model1 has been used to predict phase formation sequences. The accuracy of these predictions was explored experimentally. By using differential thermal analysis, the reactions of product film formation were examined. X-ray diffraction was used to determine reactant and product phases.