Thermochromic characteristics of WO3-doped vanadium dioxide thin films prepared by sol–gel method

Thin films of tungsten-doped vanadium oxide were fabricated on an alumina substrate by spin coating technology. A V2O5 solution was prepared by an inorganic sol–gel method, which was a fairly cheap and effective process. As-coated V2O5 films turned to VO2 films during heat treatment in a reducing gas flow. Non-doped VO2 film exhibited the best switching property of 4.0 orders of magnitude of electrical resistance and a small hysteresis of approximately 5 °C width. Tungsten in VO2 led to a diffuse phase transition and weak jump of electrical resistivity. A reduction of the transition temperature by 15.5 °C/mol was observed for the tungsten doping in this study.