“Nanostructured thin films of titanium dioxide, tungsten trioxide and vanadium dioxide have been deposited using a novel electric field assisted chemical vapour deposition methodology onto glass and gas sensor substrates. Electric fields were generated during the deposition reaction by applying a potential difference across the inter-digitated electrodes of the gas sensor substrate or by applying an electric field between two transparent conducting oxide coated glass substrates. The deposited films were analysed and characterized using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. It was found that applying an electric field led to large changes in film microstructure, preferential orientation and an increase in the film growth rate.
This led to improved materials properties such as increased photo-catalytic activity, enhanced wetting behaviour, reduction in thermochromic transition temperature and improved supercapacitor electrode behaviour. The gas sensor properties of the films were also tested and it was found that by tuning the microstructure of the films a two to three fold enhancement in sensor response could be obtained compared to sensors deposited in the absence of an electric field. Electric field assisted chemical vapour deposition shows great promise as a method for nano-structuring and tailoring the properties of metal oxide thin films.”