Yellow tungsten oxide electrochromic film can be applied to architectural glass to obtain an electrochromic smart window. Therefore people can actively adjust the optical properties of the glass, thus achieving dynamic adjustment of the lighting and heat insulation performance of the glass. This new type of smart glass is known as the new building energy-saving glass in the post-LOW-E era, and is the development direction of building energy-saving glass.

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?

Some experts used metal tungsten and tungsten-titanium alloy targets to prepare titanium-doped tungsten trioxide thin film by pulsed direct current reactive magnetron sputtering method. The experimental results are as follows:

Some experts have found that Ti-WO3 thin film is cubic phase before and after coloring, while WO3 film has a transition from monoclinic phase to cubic phase before and after coloring.

Ti-doped tungsten trioxide thin film is a new type of electrochromic thin film that is gradually used in the field of smart windows. Some experts used metal tungsten and titanium metal as sputtering targets to prepare Ti-doped WO3 electrochromic film on ITO glass. The results show:

Tungsten trioxide electrochromic film can realize intelligent heat insulation performance and dimming function in large-area building smart windows and automotive smart glass. However, it is not a common tungsten trioxide film that can satisfy the application requirements of smart windows.

Tungsten trioxide thin film has the advantages of large discoloration width and high coloring efficiency. Therefore, tungsten oxide has received more attention than other electrochromic materials. The architectural glass applying with tungsten trioxide thin film is a kind of smart glass, which is the development direction of building energy-saving glass in the future. So, what are the preparation methods of tungsten trioxide electrochromic film?