Facile fabrication of thermochromic VO2 (M) films on TiO2-buffered soda–lime glass via a one-step photo-assisted spray pyrolysis route

Abstract

VO2(M) films have been considered as promising thermochromic coatings for application in smart windows. Meanwhile, the comprehensive performance of the films required for practical smart windows and their large-scale preparation are still great challenges. In this study, a one-step ultraviolet (UV) photo-assisted spray pyrolysis route was developed to prepare thermochromic VO2(M) films on TiO2-buffered soda–lime glass substrates based on molecular dynamicsimulations and related experiments. According to the results, both the luminous transmittance and solar modulation efficiency of the film deposited at 450 °C and exposed to UV photo-irradiation increased by 17% and 40%, respectively, as compared to those of the non-irradiated films. In the case of VO2 and TiO2 single layers as well as bilayer VO2/TiO2 films deposited on substrates preheated to 350 °C-550 °C, it was found that UV irradiation could promote crystallization along with regulating the phase structure, orientation, and morphology, which enhanced thermochromic performance of the photo-treated films. Therefore, photo-assisted spray pyrolysis deposition is a facile, cost-effective and scalable technology for improving the comprehensive performance of as-obtained materials, which is appealing in the large-scale preparation of VO2 smart windows.