Ti缓冲层及退火处理对Si(111)基片上生长的ZnO薄膜结构和发光特性的影响

采用反应磁控溅射法在Si（111）基片上制备了带有Ti缓冲层的高c轴取向ZnO薄膜.通过X射线衍射分析和光致荧光光谱测量，研究了Ti缓冲层厚度和退火处理对ZnO薄膜结晶质量和光致荧光特性的影响.研究结果表明，Ti缓冲层的引入可以有效改善Si基片上ZnO薄膜的发光性能，但缓冲层存在一个最佳的厚度.薄膜应力是影响ZnO薄膜紫外荧光发射性能的重要因素，较小的残余应力对ZnO薄膜的紫外荧光发射是有利的，残余应力的存在可以改变ZnO薄膜紫外荧光发射能量.随着退火温度的增加，薄膜中的张应力增大，导致带隙宽度减小以及激子复合跃迁峰逐渐向低能方向移动. 关键词： ZnO薄膜 缓冲层 退火处理 应力分析

Photoluminescence of as-grown and annealed ZnO films on Ti-buffered Si(111) substrates

ZnO thin films with strong c-axis preferred orientation have been deposited on Ti buffered Si （111） substrate by reactive ratio-frequency magnetron sputtering. With X-ray diffraction analysis and photoluminescence （PL） measurement， the structure， residual stress and PL emission properties of Ti-buffered ZnO films are studied and effects of Ti-layer thickness and annealing temperature are discussed. It is found that the PL properties of the films are improved after the introduction of Ti buffer layer and an optimized thickness of Ti buffer layer is given. Annealing treatment can improve the properties of Si（111）/Ti-buffer/ZnO films further. The residual stress is found to be an important factor influencing the emission properties of ultraviolet light. It is helpful for the emission of ultraviolet light if the films have a small residual stress. The residual stress can also change the transition energy of excitons. With the increase of annealing temperature， the increase of tension strain in films reduces the band gap of ZnO， hence results in the shift of the excitonic peak to lower energy.