A tungsten oxide electrochromic film composed of tungsten oxide powder can be used to assemble an electrochromic glass - a smart heat insulation window glass. According to experts, such heat insulation glass has five thin film layers sandwiched between two layers of glass. And the five-layer contains a transparent conductive layer, an electrochromic layer, an ion conducting layer (electrolyte layer), an ion storage layer, and another transparent conductive layer. So, do you know what the electrochromic mechanism of tungsten oxide heat insulating glass is?
More details, please visit:
http://www.tungsten-powder.com/tungsten-oxide.html
When no voltage is applied across the device, the initial state of tungsten oxide electrochromic layer is colorless or light colored. When a voltage is applied across the device, the lithium ions stored in ion storage layer are injected into the lattice gap of WO3 film through electrolyte layer under the action of electric field to form tungsten bronze, which causes W6+ to be reduced to W5+. The transition of electrons from W6+ to W5+ absorbs photons and causes discoloration. This electrochromic mechanism is a theoretical model of inter-valency transition caused by double injection of ions/electrons that is now widely accepted. However, there are still some disputes and problems that have not been completely resolved, so more in-depth theoretical discussions are needed.
