ZnO单晶的微区光致发光特性研究

Study on the Photoluminescence Properties of ZnO Single Crystal

ZnO单晶材料以其优良的综合性能在光电子器件方面掀起了研究热潮,因此对ZnO单晶的研究具有重要的理论和实践意义。采用激光辐照的方式,对ZnO单晶进行了光致发光(photoluminescence,PL)光谱实验,分析研究了ZnO单晶在不同温度(低温)和不同激光能量强度照射下其光致发光特性。研究结果表明,ZnO单晶内存在少量杂质及表面氧缺陷,这些结构对其发光特性有一定的影响;在低温条件下,ZnO单晶具有良好的发光特性,且随着温度的提高,发光光谱峰的位置会向长波长方向移动,但强度会减小;当激光光源的强度增大,ZnO单晶的PL发射光谱的强度也会随之增大,且峰的位置和相对强度不变。结合拉曼(Raman)光谱实验,从分子及原子振动、转动类型验证了纤锌矿ZnO单晶的六方晶系结构;配合X射线衍射(X-ray diffraction,XRD)技术,得出ZnO单晶良好的结晶特性以及晶轴取向。

Zinc oxide （ZnO） single crystal is widely considered to be fabricated as a short wavelength light emitting device. In thsi paper temperature-dependent photoluminescence property of the ZnO single crystal was measured with laser irradiation method. Besides, the photoluminescence property was measured with different laser irradiation intensity. The results show that the peak of photoluminescence spectrum moves towards the ultraviolet region with the decreasing temperature. This phenomenon can be attributed to the stronger bound exciton combination in the lower temperature. The peak intensity of the photoluminescence is much stronger with stronger laser irradiation. Furthermore, the ZnO single crystal is hexagonal crystal from the X-ray diffraction pattern and Raman spectra. In addition, ZnO demonstrates good crystallization with C axis orientation. Furthermore, this paper has combined Raman scattering experimental and XRD technology to study the structure and energy level property of ZnO single crystal deeply.