Tungsten oxide thin film is an electrochromic material with electrochromism performance. The essence of electrochromism is a typical electrochemical redox reaction, but the electrochemical redox reaction only reflects the basic chemical process. And there is no uniform conclusion about the intrinsic electrochromic mechanism of electrochromic materials. The following is an theoretical model of electrochromism phenomenon that is widely accepted and widely used by people - the small polaron model.
More details, please visit:
http://www.tungsten-powder.com/tungsten-oxide.html
The small polaron model is also called the Schirmer model, which is a new theoretical model based on the dual injection model of ions and electrons. Schirmer believes that ions and electrons inject into the thin film material and interact with the crystal lattice to form small polarons, which are confined to a certain position. Small polarons can absorb the energy of photons and transition between different lattice positions. The energy during the transition is released in the form of photons. The Schirmer model is consistent with the light absorption curve of tungsten oxide.
