Influence of deposition temperature (Ts), air flow rate (f) and precursors on cathodoluminescence properties of ZnO thin films prepared by spray pyrolysis

Semiconducting metal oxide such as ZnO films were prepared by the spray pyrolysis technique on glass substrates. The cathodoluminescence properties of these films were investigated with respect to deposition temperature (Ts) and air flow rate (f). The luminescent films had a polycrystalline hexagonal wurtzite-type structure. Cathodoluminescence intensity was critically dependent on substrate temperature and spray rate. The best films had three emissions: near ultra-violet (UV) band gap peak at 382 nm, a blue-green emission at 520 nm and a red emission at 672 nm. These films were deposited at optimum condition: Ts=450 °C and f=5 ml/min.