Preparation of Thermochromic Vanadium Dioxide Thin Films by Pulsed-Magnetron Sputtering

Abstract

High quality VO 2 films have been successfully deposited by pulsed magnetron sputtering. In the preparation of vanadium dioxide films, the stoichiometry, structure and orientation of vanadium dioxide can be influenced by the process parameters. In this study, sputtering power and oxygen partial and substrate temperature were controlled accurately during experiment. Between X-ray diffraction and X-ray photoelectron spectroscopy were used to analyze the composition, phase structure, crystalline and valence state of the film. Atomic force spectroscopy was used to identify the film surface morphology. Electrical transition characteristics were also measured by four probes. Thermal radiative property was measured on a Calorimetric Emissometer. These investigations reveal that VO 2 films have high purity, monophase and the sharp variation of resistance of films from semiconductor to metal state at 293K~373K temperature. Thermal emissivity of VO 2 films vary widely from 0.82 to 0.35, which can meet requirement of future space thermal design.