Optical properties of H2S-annealed CuInSe2 films

Thin polycrystalline CuInSe2 films have been grown in a range of composition and deposited on the glass substrate by two-source vacuum evaporation of CuInSe2 and Se powders. These films were annealed into H2S. The optical study shows an increase in the energy band gap after annealing. The films were examined by x-ray diffraction, energy dispersive x-ray analysis, and scanning electron microscopy. The optical constants of the films were determined by transmission and reflection at normal incidence in the energy range 0.83–1.77 eV.