F-doped Cesium Tungsten Bronze Applied for Thermal Insulation Masterbatch

F-doped cesium tungsten bronze may be used for the preparation of thermal insulation masterbatch, and then be applied for producing heat insulation film. Experts said that the energy bandgap of F-doping cesium tungsten bronze will be blue-shifted as the amount of HF added increases. But why?

More details, please visit:
http://www.tungsten-powder.com/tungsten-oxide.html

Experts say that this is due to the doping of fluoride ions into the WO3 lattice. It is reported that hexagonal tungsten bronze has a direct energy band gap. The 2p orbital of F is significantly hybridized with the 2p orbital of O in the [WO6-xFx] octahedron, and since fluorine has a higher electronegativity, the jump from the valence band to the conduction band in the [WO6-xFx] octahedron requires a higher energy than the [WO6] octahedron. So, F doping will increase the energy band gap of the cesium tungsten bronze. In addition, although two F doped cesium tungsten bronze samples of similar fluorine doping amount have almost the same energy band gap, one of the samples exhibits better visible light transmittance. This is because the homogeneous nanorod structure reduces the scattering of visible light, and therefore, one of the samples will have better visible light transmission.

• < Prev
• Next >