VO_2/TiO_2复合薄膜的结构和红外光学性质研究

Structure and infrared optical properties of VO_2/TiO_2 multilayer film

采用溶胶凝胶法在白云母沿(001)方向的解理表面制备VO2/TiO2热致相变复合薄膜。利用X射线衍射仪(XRD),X射线光电子能谱仪(XPS),原子力显微镜(AFM)等手段分析了薄膜的微观结构和表面形貌,通过原位傅里叶变换红外光谱(in-situ FTIR)分析复合薄膜在不同温度下的红外透过率,研究其热致相变特性。结果表明,复合薄膜在云母解理面表面呈VO2(011)/TiO2(101)取向生长,表面致密平整。复合薄膜在金属-半导体相变前后表现出优异的光学开关效应,相变过程中的红外光(波长为4μm)透过率变化(ΔTr)为75.5%;相变过程陡然,透过率变化率(-dTr/dT)达15.7%/℃,滞回温宽减小到8℃。

The VO2/TiO2 films were fabricated by a sol-gel method on the（001） oriented cleavage surface of muscovite slices. The X-ray diffractometer（XRD）, X-ray photoelectron spectroscopy（XPS） and atomic force microscopy （AFM） were used to investigate the microstructure and describe the morphology of the films. The infrared transmittance spectrums of the VO2/TiO2 films at different temperatures were determined by in-situ Fourier transform infrared spectroscopy （FTIR）, and the spectrums were used to analyze the thermochromic properties of the VOJTiO2 films. The results show that the composite films are preferred VO2 （011）/TiO2 （101） orientated on the muscovite substrate with compact structure and smooth surface. The VO2/TiO2 films exhibit a significant infrared optic switching of 75.5% at the wavelength of 4 μm during the metal-semiconductor phase transition （MST） process. The phase transition process of the composite film is quite sharp with a dTr/dT of 15.7%/℃, and the hysteresis width of films decreases to 8 ℃.