ZnSe/SiO2复合薄膜光学常数与荧光光谱的研究

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ZnSe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、ZnS关键词：2复合薄膜')" href="#">ZnSe/SiO₂复合薄膜光学性质椭偏光度法荧光光谱

Luminescence and optical constant of ZnSe/SiO2 composite thin films

The ZnSe/SiO₂ composite thin films were prepared by sol-gel process a nd in-situ growth technique. X-ray diffraction results showed that the phase str ucture of ZnSe particles embedded in ZnSe/SiO₂ composite thin films i s the sphalerite (cubic ZnS). X-ray fluorescence results revealed that the molar ratio ofZn/Se is about 1∶1.01—1∶1.19. Scanning electron microscopy results r evealed that the size of ZnSe crystal particles is about 400nm, while some parti cles are less than 100nm in size. The dependence of ellipsometric angle Ψ, Δ w ith wavelength λ of ZnSe/SiO₂ composite thin films was investigated with spectroscopic ellipsometers. The optical constant, thickness, porosity and the concentration of ZnSe in ZnSe/SiO₂ composite thin films were fitt ed according to Maxwell-Garnett effective medium theory. The photoluminescence p roperties of ZnSe/SiO₂ composite thin films were investigated with fl uorescence spectrometer. The photoluminescence results indicated that the emissi on peak at 487nm under 395nm 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.