Tungsten trioxide film is the right electrochromic material that is widely used to prepare large area electrochromic device currently. After decades of development, some companies have already prepared or are preparing to bring large-area electrochromic smart windows to the market.

WO3 film is the earliest and the most studied electrochromic material. And it is also an inorganic electrochromic film material that can be used to study and prepare a large area electrochromic glass. According to experts, the electrochromic glass technology can dynamically control the ray of light and the radiant heat of sun according to the actual needs of people as the season and time change.

Tungsten oxide film is considered to be the most promising inorganic electrochromic material for large-scale production of large area electrochromic glass. Therefore, WO3 powder and WO3 electrochromic film and even WO3 electrochromic device have received great attention. So why large area smart glass is a focus in the construction sector?

Tungsten trioxide, more precisely, WO3 film is often used to develop and produce a large area smart glass – an energy-efficient glass that is widely applied in building energy efficiency. As China's building energy efficiency is still at a very backward level, China's average building energy consumption is more than three times that of developed countries, and it consumes 500 million tons of standard coal per year.