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采用等离子体增强MOCVD方法生长出高质量的ZnO薄膜 ,并观察到了ZnO薄膜的光抽运紫外激射现象。在不同激发强度下进行了光荧光谱测量 ,发现紫外发光强度随着激发光强度的增加呈直线增强 ,证明此紫外发光峰来源于带边自由激子辐射复合。激发的激光器为 3倍频YAG激光器 ,脉宽 15ps,每秒 10个脉冲。抽运光达到样品的光斑直径约为 2 5 μm ,激射阈值为 0 .2 8μJ ,利用光纤连接到CCD来探测接收激射光。在 385～ 390nm之间的激射峰 ,其半峰全宽为 0 .0 3nm。所观察到的激射没有固定的方向 ,也就是说是往各个方向发射的。对于ZnO薄膜 ,由于我们并没有制作通常激光器的谐振腔 ,激射是通过晶粒强烈的散射导致的自形成谐振腔所产生的
High quality ZnO films were grown by plasma-enhanced MOCVD and the UV-induced optical pumping of ZnO thin films was observed. Fluorescence spectra were measured under different excitation intensities. It was found that the intensity of ultraviolet light increased linearly with the increase of excitation light intensity. It was found that the UV emission peak originated from the band edge free exciton radiation complex. The excited laser is a 3x frequency YAG laser with 15ps pulse width and 10 pulses per second. The spot diameter of the sample reaching the pump light was about 25 μm and the lasing threshold was 0.828 μJ. The fiber was connected to the CCD to detect the received laser light. In the 385 ~ 390nm lasing peak, the full width at half maximum of 0. 03nm. The lasing observed has no fixed direction, that is to say launches in all directions. For ZnO thin films, since we do not make resonant cavities for conventional lasers, lasing is caused by self-forming resonators due to the strong scattering of the grains