Quantitative investigation of reactions in copper-indium-gallium multilayer thin films

Abstract

Multilayer thin films of Cu-In, Cu-Ga, and Cu-In-Ga have been analyzed in order to understand thin film phase transformations that are relevant to the production of Cu(In,Ga)Se/sub 2/ (CIGS) photovoltaic solar cells. For example, the intermetallic phases present during selenization of precursor films will impact film microstructure and influence the resulting properties. In this research, phase formation sequences were predicted by application of the effective heat of formation model. The accuracy of these predictions was then explored experimentally. Through the use of differential scanning calorimetry (DSC), the reaction kinetics of product film formation were examined. X-ray diffraction (XRD) has been used to determine reactant and product phases. Auger electron spectroscopy (AES) has been used to explore segregation within the film.