Effects of composition and substrate temperature on the optical properties of CuInSe2 thin-film

Abstract

In this paper, the optical properties of CuInSe2 thin films prepared by Stacked Elemental Layers (SEL) technique have been studied. The thin films were deposited in an evacuated chamber (˂10-4 torr) by evaporating Cu, In and Se from electrically controlled heating appropriate crucible, then they were annealed under argon atmosphere at different temperatures and time. The band gap of CuInSe2 was measured from the absorption spectrum. It was observed that the values obtained were strongly dependent on the Cu/In ratio and the annealing time and temperature. The optical properties of the films were characterized by transmission spectrophotometer measurements. The band gap of the samples was estimated using optical transmittance and found to be ~ 1.03 eV.