The structural and optical properties of (CuAlSe2 ) thin film compound Prepared by thermal evaporation technique

In the current investigation, (CuAlSe2) alloys were created by melting the stoichiometric weights of Cu, Al, and Se in a sealed quartz ampoule under a vacuum of approximately (3 × 102 mbar). (CuAlSe2) thin films were made by placing the alloy on a soda lime glass substrate, heating it at various temperatures, and employing a thermal evaporation process at a pressure of around (10-6 mbar). The thin film thickness was (1200±100A°). The (CuAlSe2) bulk had chalcopyrite structure, while the thin films are polycrystalline with sphalerite structure, according to X-ray examination. The optical measurements revealed that the (CuAlSe2) thin film had direct transitions, and the optical energy gape opt increased with increasing substrate temperature (Ts). It was discovered that the (E_opt=2.45 eV) at (Ts=150 °C) and (E_opt= 2.56 eV) at (Ts=350 °C) and also discovered the temperature annealing films at (200-400) °C at 2 hours annealing time the energy gap had risen with rising annealing temperature.