Morphology and phase transformation of copper/aluminium oxide films

Abstract

© A. PANTHAWAN, T. KUMPIKA, W. SROILA, E. KANTARAK, W. THONGPAN, P. POOSEEKHEAW, R. SORNPHANPEE, N. JUMRUS, P. SANMUANGMOON, A. TUANTRANONT, P. SINGJAI, W. THONGSUWAN, 2018. Copper aluminium oxide (CuAlO2) was successfully prepared within the single-step sparking process at the atmospheric pressure. The as-deposited films were then annealed at 400, 900, 1000, and 1100∘C in an oven. The results have shown that the annealing temperature has direct effect on the morphology, phase transformation, and optical properties. CuAlO2in the delafossite phase was formed on the annealed films at temperatures higher than 900∘C. Furthermore, the energy band gaps of the annealed films were linearly increased from 3.3 to 3.8 eV with increasing the annealing temperature from 400 to 1100∘C due to a reduction of the oxygen deficit of films at high annealing temperatures.