Preparation of gold-dispersed vanadium oxide thin films by an alternate spin-coating method for electrochromic applications

Abstract

Thin films of V2O5 with dispersed gold particles were prepared from ethanol solutions of vanadyl isopropoxide and HAuCl4 by means of an alternate spin-coating method. The Au content was maintained at 12–36 atom% by selection of the appropriate concentration of the alkoxide solution. After calcination at 400 °C, the mean diameter of dispersed Au particles was 7.0 nm, as observed for the film containing 24 atom% Au. Violet (cathodic)↔green (anodic) electrochromism was exhibited by the Au (24 atom%)–V2O5 film. Owing to the plasma resonance of the Au particles, the film had a strong optical absorption band centred at 570 and 610 nm under cathodic and anodic polarization, respectively.