Phase transition characteristics of vanadium oxide films under the CO2 laser irradiation

Abstract

Vanadium oxide is a type of thermochromic material. At a certain temperature it undergoes a phase transition, The phase transition temperature of VO2 is about 68°C.Using the magnetron sputtering method, vanadium oxide thin films were prepared on glass substrates. Heat treatment was carried out. The film was analysed using X-ray diffraction (XRD) spectrum. The result shows that the main constituents of the film are VO2 and V2O3. A beam of CO2 laser was directed to the film. A laser power meter was used to measure the specular reflection power from the film. The test results showed that the temperature of the film and its base rose fast when the laser irradiated on it and a semiconductor-metal phase transition occurred in the film. As a result, the film's reflectivity grew high. The specular reflectivity of 10.6 μm laser from the film rose 76.4% after the phase transition.