Photoluminescence properties of ZnO films grown by wet oxidation: Effect of processing

ZnO films were thermally grown on glass substrates by oxidation of magnetron sputtered Zn films in wet atmospheres. The processing conditions, including temperature, time, atmosphere, doping and oxygen content during sputtering, were varied systematically to see their influences on the room temperature photoluminescence (PL) properties of ZnO films. Oxidation in wet atmospheres in general favoured ZnO films with good mechanical properties and scale adherence to the substrates. PL studies indicated that a low oxidation temperature could fabricate films with a strong ultraviolet emission; while doping of Al or Ce would significantly suppress UV emission and enhance green emission. The influences of exposure time and gas atmosphere are much more complicated. The results therefore showed that the processing conditions should be carefully controlled in order to prepare films with desirable PL properties.