PHYSICO-CHEMICAL PROPERTIES OF ELECTROCHROMIC COMPLEX TUNGSTEN OXIDES

Abstract

A brief review of the problem of electrochromism in disordered thin films of complex tungsten oxides is given on the basis of experimental results published earlier. The problems of the ion-electron ordering in complex tungsten oxides MxWO3 (M=Na or K and x=0,3) are regarded as well as their relationship with the dynamics of the process of electrochromic coloring in these condensed systems. Possible ways of solving the indicated problems are considered. The starting point of our campaign to study the electrochromism and to develop the physical grounds of the technology of electrochromic devices was the rejection of the generally accepted electrochemical consideration of this phenomenon. We are convinced that the electrochromic effect is a purely solid-state one occurring in a condensed system with a strong electron correlation. The electronic structure of a solid at the solid-electrolyte interface largely controls the nature and rate of reactions that take place on its surface. In the case of oxides, the role played by the electronic structure is particularly complex. All of the above indicates the need to consider the effect of deep levels in the bulk of the oxide tungsten bronze and on its surface, bordering the electrolyte, on the process of electrochromic coloring.

Keywords

• complex tungsten oxides
• electrochromic effect
• tungsten oxide bronze
• thin film
• monocrystal