Yellow tungsten oxide smart glass uses electrochromism of YTO, its principle is based on the exsit laminated glass manufacturing process, stick smart film between ordinary glasses. By changing electricity to adjust the luminousness from transparent to opacity. Smart window is a liquid crystal membrane between two ordinary glasses, liquid crystal film is covered in the middle by PVB, and put in high pressure autoclave to scoring under high temperature and pressure. Its working principle is when turning off power supply of smart glass, electronic control glass inside liquid crystal molecules will show an irregular spread of state, electronically controlled glass presents translucent and opaque appearance of the state. When charge smart glass, liquid crystal molecules will show an regular spread of state, light can penetrate freely. Smart glass is opaque. It can not only protect privacy but also has same characteristics of safety glass.
The most famous WO3 thin film electrochromism mechanism is inter valance transition theory came up with by Faughnan. It is under stimulating of applied electric field, electrons and cation ions inject into WO3 from both side of the film, electrons are captured by W atoms to form a localized state, metal ions M+ reside in this region to form dark blue tungsten bronze compound MxWO3. W ion exists as different valance state in MxWO3, transition of electrons between different W ions causes WO3 thin film color change. Chemical reaction process: WO3 (colorless) +xM+xe→Mx WO3（dark blue）