基片温度对ZnO薄膜结构和发光性能的影响

采用对靶直流反应磁控溅射方法，在不同温度的Si（100）基片上制备了一系列的ZnO薄膜．利用X射线衍射仪和荧光分光分度计对ZnO薄膜的结构和发光性能进行了研究．结果表明：所有的ZnO薄膜都具有六角纤锌矿结构，且都表现出了（002）织构．随基片温度增加，ZnO薄膜结晶质量提高，其颗粒尺寸单调增加，并且薄膜应力状态发生改变，由压应力转变为拉应力．同时光致发光谱实验结果表明：室温沉积的ZnO薄膜出现了365nm和389nm的紫外双峰，并且出现了弱的蓝光发射带．随着基片温度升高到350℃，365nm附近的紫外峰红移到373nm，并且强度增强，而389nm处的紫外峰强度明显减弱．当基片温度增加到500℃时，373nm的发光峰强度减弱并蓝移到366nm处，蓝光带强度减弱并红移到430nm-475nm处，并且出现了396nm的近紫峰．

The Impact of Substrate Temperature upon ZnO Thin Film Structure and Photoluminescence

A serious of ZnO films were prepared on the Si （100） substrate with various temperatures by using facing target direct current （DC） reacting magnetron sputtering system. The structure and photoluminescence （PL） spectrum of ZnO films were characterized by X-ray diffraction （XRD） and spectrofluorophotometer. The results indicated that all ZnO films formed wurtzite structure and exhibited （002） texture. With the increment of substrate temperature, the crystallizing quality of ZnO films was improved and the grain size increased monotonically. Meanwhile, the stress status of ZnO films changed from compress stress to tensile stress. In addition, PL spectrum showed that for ZnO films deposited on the Si （100） substrate at room temperatures, both a 365nm ultraviolet （UV） peak and a 389nm UV peak were observed, and a weak blue emission band was also found. With increasing the substrate temperature to 350℃, the 365 nm UV peak red-shifted to 373 nm and its intensity enhanced while the intensity of 389 nm UV peak diminished. As the substrate temperature elevated to 500℃, the 373 nm UV peak blue-shifted to 366 nm and its intensity decreased as the blue emission band red-shifted to 430 nm-475 nm and its intensity decreased. Besides, a 396 nm violet peak was found.