Effects of postdeposition annealing on the metal–insulator transition of VO2−x thin films prepared by RF magnetron sputtering

Abstract

We report the fabrication of textured VO2−x films on c-cut sapphire substrates by postdeposition annealing of V2O3 films prepared by RF magnetron sputtering using V2O3 as the target. Although the prepared VO2−x films are expected to be oxygen-deficient, overoxidation on the film surface was revealed by X-ray photoelectron spectroscopy. The metal–insulator transition (MIT) characteristics of the VO2−x films were investigated. MIT parameters including the transition temperature, transition sharpness, and hysteresis width of the VO2−x films were manipulated by varying the oxygen pressure during postdeposition annealing. The suppression of optical transmittance in the near-infrared region was observed by increasing the temperature through the MIT.