Deposition of CuInAlSe2 films using co-sputtered precursors and selenization

Abstract

CuInAl precursor films with varying Al/(Al+In) ratios were co-sputtered onto Mo coated soda-lime glass substrates. Samples were then selenized under high vacuum using thermally evaporated elemental selenium. Single-step and two-step selenization heating profiles were investigated. Single-step samples resulted in better Mo-CuInAlSe2 adhesion than those selenized using the two-step approach. Precursor and selenized films were characterized for composition, crystalline structure, surface morphology, and composition with depth. The development of a method to co-sputtered CuInAl precursors is discussed, as well as the effect of selenization temperature and heating profile on selenized film properties.