Thermochromic vanadium dioxide thin films prepared by electric field assisted atmospheric pressure chemical vapour deposition for intelligent glazing application and their energy demand reduction properties

Abstract

Thermochromic vanadium dioxide thin films were deposited from the electric field assisted atmospheric pressure chemical vapour deposition reaction of vanadyl acetylacetonate and 2%O2/98%N2 at temperatures between 350 and 530°C on to fluorine doped tin oxide coated glass substrates. A potential difference was applied between the top plate and substrate during the deposition to generate an electric field with a positive bias applied to the substrate. The films produced were analysed and characterised by X-ray diffraction, scanning electron microscopy, atomic force microscopy Raman spectroscopy, contact angle and variable temperature UV/Visible spectroscopy. It was found that the presence of an electric field during deposition could lead to a marked change in the microstructure particularly a reduced crystallite size and a reduced thermochromic transition temperature. The optical data collected in this study is used in building energy demand simulation to predict the potential energy savings achievable by using these novel thin films compared to standard industrial products, for locations with different climates. The results suggest that such glazing can have a significant energy saving effect compared to current approaches across a wide range of climate types.