Mist CVD of vanadium dioxide thin films with excellent thermochromic properties using a water-based precursor solution

Abstract

Mist chemical vapor deposition (mist CVD), which is capable of producing oxide films over large areas at a high productivity and low cost, has been proposed as a fabrication method for VO₂ thin films for smart windows. However, the thermochromic properties of the VO₂ films previously prepared by mist CVD are not sufficient for application in smart windows. In this study, to obtain a high-quality VO₂ film, we investigated the effects of the solvent of the precursor solution on the resulting film in mist CVD. Films consisting of a single phase of VO₂ were obtained when a water-based precursor solution was used. In contrast, V₂O₃ films are formed when a methanol-based precursor solution is used. The VO₂ film deposited from water solution exhibited high visible transmittance along with a large change in the infrared transmittance with temperature change. The high quality of the VO₂ film indicates that mist CVD is an effective method for the fabrication of VO₂-based smart windows.