Preparation Of Vanadium Dioxide Thin Films And Study Of Optical Properties

In this thesis,high quality VO₂ thin films are deposited on verities of substrates. Analysis of the phase transition mechanism and the impact on the process of phase transition.The microstructures of VO₂ thin films are studied with XRD.The properties of thermochromic VO₂ thin films have been investigated by FT-IR spectroscopy.Thermally induced phase transition of VO₂ thin films occurred at a certain temperature,associated with abrupt changes in optical properties.Temperature and transmission change caused by heating-induced phase transition of the vanadium dioxide thin films were measured on real time under the irradiation of a 1.319μm continuous wave laser beam.The experimental results indicate that after 480ms laser irradiation,the temperature of vanadium dioxide thin film is raised from room temperature to about 100℃,phase transition occurs and transmittance decreases from 48%before the phase transition to 28%after the phase transition.We can see that,in order to improve the usefulness of the VO₂ thin films,can be realized by reducing the phase transition temperature,increasing the change of transmittance before and after the phase transition.The key to achieve the purpose is the preparation of high quality films.Influence of nonstoichiometry on Raman scattering of VO₂ thin films has been analyzed.The experimental evidence is presented and the reason for nonstoichiometry dependence on Raman spectra of VO₂ thin films is discussed.Finally,optical and electrical properties of VO₂ thin films are introduced.Associated problems and developing trend of laser protection with VO₂ thin films are also described.