不同衬底上的ZnO薄膜紫外光致发光

用射频磁控溅射法在蓝宝石、硅和石英衬底上沉积出具有好的择优取向的多晶ZnO薄膜. 在270 nm波长的光激发下室温下可观察到显著的紫外光发射（波长为356 nm）和较弱的蓝光发射（波长为446 nm）. 经高温退火后薄膜的结晶质量显著提高, 在蓝宝石、石英衬底上沉积的薄膜，其积分发光强度分别增加了7倍和14倍.而硅衬底上的膜发光强度增强不太显著.紫外光发射源于电子的带间跃迁，而蓝光发射是由电子从氧空位浅施主能级到价带顶的跃迁引起的. 关键词： ZnO薄膜 射频磁控溅射 紫外发光 退火

Ultra violet photoluminescenc of ZnO films on different substrates

Polycrystalline ZnO films with a good preferred orientation were deposited on sapphire, Si and quartz substrates by rf magnetron sputtering. A 356 nm Ultraviolet (UV) photoluminescence (PL) peak and a 446 nm blue peak were observed at room temperature when excited with 270 nm light. After high-temperature annealing in oxygen, the crystallinity of the films was improved. The intensity of the UV emission increased by 7 and 14 times, respectively, for the films on sapphire and quartz substrates respectively. We conclude that the UV emission originates from the inter-band transition of electrons and the blue emission is due to the transition of electrons from the shallow donor level of the oxygen vacancies to the valence band.