Nano-composite thermochromic thin films and their application in energy-efficient glazing

A hybrid atmospheric pressure and aerosol-assisted chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nanoparticles and the use of a surfactant Molecule, tetraoctylammonium bromide, is discussed. The films were fully characterised using a wide variety of techniques, including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV/vis/NIR spectroscopy. It is shown that micro-structural Changes brought about by careful control of film growth conditions, and/or the use of surfactant, lead to an enhancement of thermochromic properties. Gold nanoparticle incorporation leads to a significant change in the colour of the films from a yellow-brown colour to a variety of greens and blues depending oil the gold nanoparticle concentration. The films become more reflective in the infra-red with increased gold nanoparticle incorporation. Optical data are used in energy modelling Studies to elucidate the film potential as an energy-saving coating in architectural glazing. The energy modelling results suggest that for warmer climates the thermochromic nanocomposites investigated here lead to significant energy savings when compared with plain glass and other standard industry products. (C) 2009 Elsevier B.V. All rights reserved.