Evolution of polymorph and photoelectric properties of VO2 thin films with substrate temperature

Abstract

Abstract For specific application, direct deposition of high quality VO 2 films on common glass substrates is potentially promising and the work for controllable preparation of VO 2 films with different polymorphs is desirable. This work reports controllable preparation of VO 2 films with different polymorphs (B and M) optimizing physical and thermochromic properties of VO 2 thin films on amorphous glass via controlling the substrate temperature. By adjusting the substrate temperature, B-VO 2 films which can be formed at a relatively low temperature (400\u202f°C) possesses a comfortable sheet resistance and the value of temperature coefficient of resistance (TCR) is about 2.4%/K; M\u202f−\u202fVO 2 thin films are successfully prepared when the substrate temperature is higher than 400\u202f°C. It is found that the optimized VO 2 (M) thin film grown at 500\u202f°C has a favorable property such as ∼3 orders of magnitude change in sheet resistance during phase transition, high luminous transmittance of more than 62%, a solar switching efficiency of ∼7.5% and a Near-Infrared-Region switching efficiency of 52.4%. Our experimental results can provide technical supports for the practical application of VO 2 thin films.