中文摘要：

研究了不同温度和不同光激发强度下激光分子束外延方法生长的ZnO薄膜样品的发光性能，发现YAG脉冲激光激发，强度超过一定值时会在长波方向上出现一个新的发光峰，此峰可能起源于电子．空穴的复合。室温下氙灯激发的光谱中可以看到峰值位于381 nm的近带边紫外发射峰和位于450 nm的强的蓝绿带发射，根据光致发光激发光谱的特征给出了一个简单的蓝光发射模型。对比YAG脉冲激光激发和氙灯激发得到的实验光谱，我们认为不同的光谱特征和样品发光的激发机制有关，紫外峰发射需激发强度超过一定值才能观察到，而蓝带发射则在一定的激发强度下迅速饱和。

英文摘要：

Due to their wide potential applications in short-wavelength optoelectronic devices, ZnO and it＇s alloy have become one of the main topics in the research field of optoelectronic materials and devices. Although high quality ZnO films are available due to the improvement of material growth techniques, the luminescence behavior, mechanism and their relations with the structure of material are still unclear. Much work isneeded for further understanding of the optical properties of ZnO films. In this paper, the photoluminescence properties of ZnO film grown by Laser-MBE method have been experimentally investigated. The optical characterization methods we used include temperature-dependent and excitation-intensity-dependent photoluminescence. When using YAG pulse laser as the excitation source, a new emission band appeared on the low energy side, it might be originated from electron-hole-plasma （EHP） recombination. Stimulated emission can be detected both from the surface and the edge of the film, this shows that the film contains certainty quantity of defects. However, the spectrum excited by an Xe lamp under room temperature contains two emission bands： the violet band with a peak at 381 nm and the blue-green band with a peak at 450 nm, based on the information given by the PLE spectrum, a simple model for blue emission in ZnO was proposed. By comparison of the dif- ferent spectrum using different excitation sources, it is concluded that the violet band emission may require certain high excitation intensity, and the blue band emission saturates rapidly with the increasing excitation intensity.