Effect of Aluminium Concentration on Physical Properties of ZnO Films Synthesized by Spray Pyrolysis Method

Abstract

The present work study, the effect of aluminum concentration (0%, 1%, 3%, 5%, 7.5% and 10%) on some physical properties of zinc oxide (ZnO) films. All ZnO doped Al (ZnO: Al) thin films were deposited on optical glass substrates at 350°C by spray pyrolysis method. Polycrystalline films with a hexagonal würtzite phase present a strong (002) preferred orientation parallel to the c-axis. This direction that gradually disappear with increasing aluminum concentration (>7.5%). The grain size obtained values was satisfactory for 1%, 3% and 5% Al-concentrations. In addition, the highest transmittance (95%) was detected at 5% and 7.5% Al concentration. The best obtained value of the Eg is 3.44 eV for an aluminum concentration of 7.5%. Finally, all results confirm that the film deposited with 7.5% Al concentration is the better suited as a window layer in solar cells application.