Electrochromism in the composite material Au-WO3

Abstract
We have produced for the first time an electrochromic cermet composed of Au grains dispersed in the electrochromic WO3. The electrochromism arises from a shift in the wavelength of the dielectric absorption characteristic of gold cermets. The shift is due to a change in the dielectric constant of the WO3 matrix as a result of the coloring process. This is to be contrasted with the coloring in pure WO3 which results from the appearance of a broad absorption band in the red and infrared.