Vanadium oxides for solar control applications

Solar control window coatings are those which can respond in a desired way to an external stimulus. These are materials such as the vanadium dioxide that can control the amount of daylight and solar heat that can pass through the windows of buildings with temperature. Chemical vapour deposition is an attractive method for thin film deposition since it is capable of achieving high deposition rates. The properties of the as-deposited samples can be simply tuned by altering the vapour composition and flow in the coating zone. This can be beneficial for the thermochromic coatings since stoichiometric vanadium dioxide coatings are required. Finally, when CVD is performed at atmospheric pressure, it has the advantage of a relatively simple apparatus (no vacuum system required), which can be easily integrated into float-glass production lines. Results obtained demonstrate the excellent thermochromic properties of undoped vanadium dioxide coatings as illustrated by switching temperature as low as 51 oC. Finally, from the in-situ monitoring analysis it can be possibly concluded that in the absence of oxygen, anhydride species may form with some evidence of ester species. While, in the presence of oxygen, there is indication for the enhanced production of CO and the suppression of the C-H species.