Tungsten oxide electrochromic film can be prepared by a constant potential deposition method in a solution of peroxo-tungstic acid in ethanol. By setting annealing temperatures of 60°C, 100°C, 250°C and 500°C, the experts studied the effects of different annealing temperatures on the crystal structure and electrochromic properties of WO3 thin films. They found that:

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.

The electrochromic mechanism of yellow tungsten oxide thin film can be explained by the dual injection model currently accepted and applied by academics. The dual injection model, also known as the dual injection model of cations and electrons, the Faughnan model, was proposed by Faughnan in 1975.

Amorphous tungsten trioxide film is superior in electrochromic properties to the crystalline tungsten trioxide film. But why?