ZnO纳米材料的紫光发射研究

ZnO纳米材料的紫光发射研究(论文12000字)
摘要：
    ZnO为第三代直接带隙Ⅱ-Ⅵ族宽禁带的半导体，其自由激子结合能可以达到60meV，相比于其他半导体材料高出很多，在室温乃至更高的温度下其自由激子受激发射并具备很好的物理及化学稳定性。
本文首先介绍了ZnO的基本性质及应用，综述了引起其发光特性的结构与缺陷性质。其次对ZnO晶体薄膜几种常见的制备方法（脉冲激光沉积、原子层外延、磁控溅射、溶胶—凝胶）和表征方法（X射线衍射法、扫描电子显微镜法、原子力显微镜法、拉曼散射光谱、光致发光谱）进行了简要的表述。在本项研究中采用电子束蒸发于三种递增的衬底温度条件下生长了ZnO薄膜，通过实验发现：随着衬底温度由150℃到250℃升高，ZnO的结晶质量越来越好，其发光强度逐渐增强；ZnO的紫光发射源于电子由导带底到VZn和电子由Zni到价带发生的跃迁。ZnO材料在光电领域有广阔的应用前景，但可见区的发光严重影响了紫外发光效率，所以，对ZnO可见区发光机制的研究具有十分重要的意义。
关键词：ZnO薄膜；紫光发射；衬底温度；电子束蒸发法；ZnO缺陷

Study on violet emission of ZnO nanomaterial
Abstract：
  ZnO is the third generation direct band gap and II-VI group wide energy gap semiconductor with high free exciton binding energy of 60meV, which is much higher than that of others. The stimulated emission of free exciton contains a high physical and chemical stability at room temperature and even higher temperatures.
  Firstly, the basic properties and applications of ZnO are introduced in this paper, and the structure and defect properties causing the luminescence properties are reviewed. Secondly it describes several common deposition methods (such as PLD、ALE、MS、sol-gel) and characterization methods(such as X-ray diffraction、SEM、AFM、Raman scarrering spectra、PL). In the study, ZnO thin films were prepared by electron beam evaporation method under different substrate temperatures. It shows that with the substrate temperature increasing from 150℃ to 250℃, ZnO thin film crystalline quality and luminescent intensity both get better and better. The ZnO violet emission originates from the transition of electrons from conduction band to the VZn and the Zni to valence band. ZnO material has broad application prospects in the photoelectric field, but the visible area of the emission has a serious effect on the UV emission efficiency. Therefore, it is very important to study the mechanism of ZnO visible light emission.
Key words：ZnO thin films, violet emission, substrate temperature, electron beam evaporation, ZnO defects
 

目 录
摘要    1
Abstract    2
1 绪论    3
1.1 ZnO的基本性质及其应用    3
1.2 ZnO纳米薄膜的发光性质研究进展    3
1.2.1 ZnO的绿光发射    5
1.2.2 ZnO的紫外光发射    5
1.2.3 ZnO的紫光发射    6
1.3本文的研究内容    7
2 常用的薄膜沉积技术    7
2.1 脉冲激光沉积    7
2.2 原子层外延    8
2.3 磁控溅射    8
2.4 溶胶—凝胶法    9
3 常用的薄膜表征技术    10
3.1 X射线衍射    10
3.2 扫描电子显微镜    10
3.3 原子力显微镜    12
3.4 拉曼散射光谱    12
3.5光致发光谱    13
4 ZnO薄膜的制备及其结构与光学性质研究    15
4.1 电子束蒸发在不同衬底温度下制备ZnO薄膜    15
4.2 ZnO薄膜的结构性质分析    16
4.2.1 ZnO薄膜的晶相和晶向    16
4.2.2 ZnO薄膜的组分分析    17
4.3 ZnO薄膜的紫光发射性质分析    18
5 结论    19
参考文献    20
致谢    23