VO₂Thin Film Prepared By Organic Sol-gel Method And Its Performance Study

Vanadium oxide has the property of co-existence of multiple valence. VO2was widely researched due to the unique and excellent optical property. Semiconductor phase VO2turns to metal phase VO2when the temperature rises to about68℃, and the optical performance of VO2will also have a mutation, this allowed the VO2films having a bright research prospect in temperature controlling. And research of VO2achieved considerable scientific payoffs in many areas these years such as smart windows for temperature controlling, laser protection and so on.The VO2thin films were successfully prepared by organic sol-gel method in this thesis, and they have a good phase transition properties when the temperature of the film changed. W6+doping had been tried to reduce the phase transition temperature of VO2film. The VO2film achieved has a low visible light transmittance, so TiO2/VO2multilayer structure was prepared to improve the transmittance after some research of the preparing of TiO2films. The phase, surface morphology and the thickness of films prepared were characterized by using X-ray diffractometry and scanning electron microscopy; the light transmittance under atmospheric temperature and high temperature were investigated by UV-Vis spectrophotometer, and phase transition temperature was also investigated by UV-Vis spectrophotometer. Results shows that the max visible light transmittance of VO2film reach45%, the preparing conditions are pulling at speed90mm/min and annealing at550℃for18min in N2atmosphere. The transmittance of infrared region is about55%in room temperature, when the film was heated to80℃, the transmittance of infrared region decrease to35%, the rate of the reduction reaches36.4%. The phase transition temperature of pure VO2thin film is about60℃, lower than68℃in theoretical. The transmittance in infrared region of TiO2/VO2multilayer structure is higher than that of VO2thin film.