Electrochromism of gold-vanadium pentoxide composite thin films prepared by alternating thermal deposition

The composite thin films of Au-V2O5 were prepared by means of an alternating thermal deposition technique. The electrochromic properties of the films were dependent on Au contents and calcination temperature. The composite film containing 26 at. % Au calcined at 400 °C gave clear electrochromism of reddish-violet (cathodic polarization) ↔ green (anodic). The film had a strong optical absorption peak ascribable to the dispersed Au particles at 615 nm (cathodic) or 555 nm (anodic). The shift of this absorption peak, coupled with that of the absorption edge of the V2O5 matrix, was responsible for the new electrochromism.