(Li,Mg)∶ZnO薄膜的溶胶-凝胶法制备及特性表征

Preparation and Characterization of (Li,Mg)∶ZnO Thin Films Derived by Sol-Gel Method

利用溶胶-凝胶旋涂制膜方法制备了具有良好表面形貌及c轴择优取向性的(Li,Mg)∶ZnO薄膜。重点研究了该法制膜时不同膜厚(Li,Mg)∶ZnO薄膜的结构及光学性质。扫描电子显微镜(SEM)图像及X射线衍射(XRD)图谱分析结果表明随着膜厚的增加,薄膜晶粒尺寸逐渐增大,薄膜的晶化程度及c轴择优取向性增强。但薄膜厚度的增加是有一定范围的,当薄膜厚度过大时,薄膜均匀性、致密性及c轴择优取向性显著下降。样品的荧光光致发光(PL)谱表明,Mg的掺入使近紫外发光峰出现了蓝移,恰当膜厚的(Li,Mg)∶ZnO薄膜发光特性主要以深能级发射(DLE)为主,蓝绿发光峰强度很高。

（Li,Mg）∶ZnO thin films with good surface morphology and c-axis preferred orientation were prepared on pyrex glass substrates by sol-gel spin-coating method.The structural and optical properties of the films with different depths were studied.The results investigated by the scanning electron microscopy（SEM）and X-ray diffraction（XRD）show that the crystal size extent along with c-axis preferred orientation of the films increase with the increasing depth of the films.The depth of the films increase within a certain range,if the films is over thick,the uniformity,density and c-axis preferred orientation are all decrease obviously.The photoluminescence（PL）spectra of the samples demonstrate that doping of Mg results in a blue shift in the near ultraviolet emission peak.The luminous property of the films with appropriate depth is mainly contains deep energy level（DLE）emission,and the intensity of blue green emission peak is very high.