Effect of rapid thermal annealing on photoluminescence and crystal structures of CdZnO films

Abstract

Abstract Hexagonal Cd x Zn 1− x O films with low and high Cd contents ( x =0.10 and 0.52) have been deposited by reactive direct-current magnetron sputtering, respectively. The as-deposited Cd x Zn 1− x O films hardly exhibit detectable photoluminescence (PL). Once subjected to rapid thermal annealing (RTA) at sufficiently high temperatures, the Cd x Zn 1− x O films exhibit pronounced PL. For the Cd 0.10 Zn 0.90 O films subjected to RTA at 500 °C and above, they are of single hexagonal phase. The enhanced near-band-edge (NBE) emission is somewhat blue-shifted with the increase of RTA temperature. While for the Cd 0.52 Zn 0.48 O films, they are transformed into hexagonal (Cd-incoporated ZnO) and cubic (Zn-incoporated CdO) phases due to the RTA at 500 °C and above. The NBE emissions from the two above-mentioned phases are well revealed in the PL spectra.