Laser annealing effect on the optical properties of CuAlO2 thin film


Transparent conducting oxides thin films of copper aluminium oxide (CuA1O2) were prepared from mixture of CuCl2 and Al2Cl3 salts by spray pyrolysis technique on a glass substrate at temperature (500oC). The as-deposited film show pure delaffosite phase of CuAlO2 by XRD spectra, also many peaks of CuAlO2 were appeared after annealing at different energy fluence. The optical transmission of thin films was measured by UV-VIS spectrometer and reach to 74% in visible region. The direct and indirect optical band gaps of the films are found in the range of (3.4-3.1) eV, and (2.1-1.5) eV, respectively depending on the annealing energy fluence at (300, 600, 900, 1200) mJ/cm2.