Nanometer TiO2 thin films are prepared by a sol-gel method and the effects of preparation technique on the microstructure and surface morphology of the obtained materials are studied using X-ray Diffraction [XRD,IR spectrum[IR], UV-VIS spectrum [UV-VIS,AFM and X-ray photoelectron spectroscopy[XPS]. The results show that the TiO2 thin films are of anatase and rutile phase structures when annealed in a temperature range from 450°C to 600°C. When heated up to 700°C, the structure of TiO2 film changed into rutile completely. In the TiO2 thin films, there is some residual carbon from the starting organometallic components and a small amount of sodium ions diffused from the glass substrates. During heat-treatment, the absorption peak of water become weak gradually and the organic groups are disappeared completely at 500°C. Optimum film layers are obtained for the UV absorbance index. AFM result shows that the rough morphology of surface [RMS] of films is about 2-3nm or so.
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