Study of heat treating on structure and properties of nanocomposite TiO₂-V₂O₅ thin films

TiO₂-V₂O₅ nano-composite thin films were prepared by sol-gel process with Ti (C₄H₉O)₄ and V₂O₅ powder as the starting materials. The thin films were characterized by Ellipsometer, AFM, XRD, TG-DSC and UV-VIS-NIR spectrophotometer. The results show that with increase of heating temperature, TiO₂ transforms from amorphous to anatase and then to rutile. The temperature at which rutile appeared and anatase turning into rutile completely decreases about 200°C. Crystallite size grows from 5.1nm to 227.3nm gradually. The refractive index of TiO₂-V₂O₅ composite thin films changes from 1.6 to 2.4, and the thickness reduces from 276nm to 187nm simultaneously. The transmittance of the films in the ultraviolet range falls remarkably while the absorption edges take a red shift with the increase of annealing temperature.