Preparation of nanostructured tungsten trioxide thin films by high pressure sublimation and condensation

In the present work we have carried out a systematic study of the nanostructured WO3 thin films by using a novel technique of varying the source-substrate distance in a high pressure sublimation and condensation method. This technique has been found to be very efficient in controlling the grain size and thus the nanostructure of the deposited films. A correlation is established between the optical and electrochromic properties of the WO3 films and the induced nanostructure. The electrochromic properties are studied by a dry lithiation process developed in our laboratory. The results indicate a strong dependence of the film nanostructure on the source-substrate distance which influences quite sensitively the electrochromic properties. These results are expected to help design electrochromic devices suitable for different applications.