Tungsten Oxide

Tungsten oxides exist in many forms, which offer great opportunities for chemical modifications to adapt the products properties. Keeling & Walkers extensive knowledge in solid state chemistries provided the background for developing a range of oxides with novel properties.

The stoichiometric WO3 has a yellow colour. With increasing oxygen deficiency, the colours change from yellow to blue to purple to brown. Reduced Tungsten oxides are sub stoichiometric compounds, which absorb infrared light – albeit at a low rate.

Manipulation of the crystal structure and doping with other metals increases the IR absorption efficiency significantly. The doped tungsten oxides are the most effective materials of their class. Absorption of NIR Light starts already at around 900 nm, an area where the highest solar intensity of the near Infrared range is recorded. The transparency in the visible range can be adjusted by varying the concentration of the doped Tungsten Oxides, which can improve the solar shading effect even further.

As a result, only small quantities of doped Tungsten Oxides provide excellent rates of heat absorption in coatings, films, polymeric plates for glazing applications.