Effect of Substrate Temperature on Optical Properties of Aluminum Zinc Oxide Thin Films Deposited by DC Magnetron Sputtering

In the present work Aluminum doped Zinc Oxide (AZO) thin films have been deposited on glass substrates from room temperature to 300 degrees C by direct current (d.c) magnetron sputtering. The effects of substrate temperature on the crystallization behavior and optical properties of the films have been studied. The optical transmittance of aluminum zinc oxide films are obviously influenced by the substrate temperature. Optical constants such as absorption coefficient (alpha), extinction coefficient (k), optical band gap (E-g) and Urbach's energy (E-U) are evaluated from the transmission spectra. Optical absorption edge of aluminum zinc oxide films has a significant blue shift to the region of higher photon energy. The optical band gap of the Aluminium zinc oxide thin films is found to be in the range of 3.2-3.3 eV.