F-doped cesium tungsten bronze has special optical properties such as photochromism, electrochromism and selective transmission of spectra so that it can be used to produce infrared ultraviolet shielding material for energy conservation in smart buildings. But why doped cesium tungsten bronze has these special optical properties? The special optical properties of cesium tungsten bronze doped with F atoms are due to its special tunnel structure and special carrier transport characteristics.

F-doped cesium tungsten bronze for transparent thermal insulation material has better near-infrared shielding properties than cesium tungsten bronze, which means that the doped cesium tungsten bronze is a better thermal insulation material than cesium tungsten bronze for building energy efficiency. And this is because the tungsten bronze doped with fluorine atoms exhibits higher concentration carriers and more excellent conductivity.

Electrochromic properties of MoO3 doped WO3 electrochromic film can be affected by the stability of tungstic acid sol. That is to say, a stable tungstic acid sol is suitable to be used as a precursor spin coating liquid for electrochromic materials. But is there any theory that can explain the stabilization process of tungstic acid sol system?

Doped tungsten oxide electrochromic film can be prepared by an ion exchange method and a spin coating method. Specifically, PEO, MoWO3 doped tungstic acid sol can be prepared by ion exchange method in sol-gel technique. Then, the film is prepared by spin coating on conductive glass (ITO/glass) and conductive polyester film (ITO/PET) respectively. After heat treatment at different temperatures, organic-inorganic multi-doped nanocomposite electrochromic film can be obtained.

Doped tungsten oxide thin film is an electrochromic film that can be prepared by multi-doping modification of the WO3 film. So, what substances can be selected as dopants?

Doped WO3 thin film is a nano-composite electrochromic film, which may be used to building glass for energy-saving. Wherein, an organic-inorganic multi-doped tungstic acid sol is prepared by a sol-gel technique. But why must the sol be doped?

Electrochromic properties of doped tungsten oxide electrochromic thin film are affected by the stability of the tungstic acid sol during the preparation process. Therefore, in order to improve the stability of the sol or to control the proper viscosity and film forming properties, experts have studied the effect of the addition of PEO on the tungstic acid sol. The figure below shows the viscosity curve of a member with the adding of PEO, that is, the effect of the amount of PEO added on the stability of a certain component sol. The composition of the sol is: WO3 is 0.0962mol; MoO3 is 0.0289mol; C2H5OH is 50mL; and isopropanol is 30mL.

Electrochromism can be referred to a phenomenon in which the reflectance, transmittance and absorptivity of doped WO3 film undergo a stable and reversible color change under the action of an applied electric field. Experts say that the electrochromic properties of tungsten trioxide will be effectively improved when the doping content is within a certain range.

Doped WO3 electrochromic thin film can be prepared by the following steps: preparation of a stable sol and preparation of a WO3 film by using the stable sol which has been subjected to aging treatment as a precursor liquid.

Electrochromism can be referred to the phenomenon that the optical properties of a doped tungsten oxide film undergo a stable and reversible color change under the action of an applied electric field, and its appearance is a reversible change in color and transparency. Wherein, the doped WO3 film is a kind of an inorganic oxide film that can causes electrochromic phenomenon.