【摘要】 采用溶胶-凝胶工艺与原位生长技术,制备了ZnSe/SiO₂复合薄膜.X射线衍射分析表明薄膜中ZnSe晶体呈立方闪锌矿结构.X射线荧光分析结果显示薄膜中Zn与Se摩尔比为1∶1·01—1∶1·19.利用场发射扫描电子显微镜观察了复合薄膜的表面形貌,结果表明复合薄膜表面既存在尺寸约为400nm的ZnSe晶粒,也存在尺寸小于100nm的nSe晶粒.利用椭偏仪测量了薄膜椭偏角Ψ,Δ与波长λ的关系,采用Maxwell-Garnett有效介质理论对薄膜的光学常数、厚度、气孔率、ZnSe的浓度进行了数据拟合.利用荧光光谱分析了薄膜的光致发光,结果表明在波长为395nm的激发光下,487nm的发射峰对应着闪锌矿型ZnSe的带边发射,同时也观测到薄膜中ZnSe晶体增强的自由激子发射及伴随着ZnSe晶体缺陷而产生的辐射发光.更多还原

【Abstract】 The ZnSe/SiO-2 composite thin films were prepared by sol-gel process and in-situ growth technique. X-ray diffraction results showed that the phase structure of ZnSe particles embedded in ZnSe/SiO-2 composite thin films is the sphalerite (cubic ZnS). X-ray fluorescence results revealed that the molar ratio of Zn/Se is about 1∶1.01—1∶1.19. Scanning electron microscopy results revealed that the size of ZnSe crystal particles is about 400?nm, while some particles are less than 100?nm in size. The dependence of ellipsometric angle Ψ, Δ with wavelength λ of ZnSe/SiO-2 composite thin films was investigated with spectroscopic ellipsometers. The optical constant, thickness, porosity and the concentration of ZnSe in ZnSe/SiO-2 composite thin films were fitted according to Maxwell-Garnett effective medium theory. The photoluminescence properties of ZnSe/SiO-2 composite thin films were investigated with fluorescence spectrometer. The photoluminescence results indicated that the emission peak at 487?nm under 395?nm excitation corresponds to the band-to-band emission of sphalerite ZnSe crystal. The strong free exciton emission and other emission peaks correlated with ZnSe lattice defect were also observed.更多还原