PREPARATION OF GOLD-DISPERSED VANADIUM-OXIDE THIN-FILMS BY AN ALTERNATE SPIN-COATING METHOD FOR ELECTROCHROMIC APPLICATIONS

Thin films of V2O5 with dispersed gold particles were prepared from et hanol solutions of vanadyl isopropoxide and HAuCl4 by means of an alte rnate spin-coating method. The Au content was maintained at 12-36 atom % by selection of the appropriate concentration of the alkoxide soluti on. After calcination at 400-degrees-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 exhi bited by the Au (24 atom%)-V2O5 film. Owing to the plasma resonance of the Au particles, the film had a strong optical absorption band centr ed at 570 and 61 0 nm under cathodic and anodic polarization, respecti vely.