Tungsten diselenide

Tungsten ( IV) selenide

Black, odorless solid

Fixed

9.2 g · cm -3

> 1200 ° C.

Insoluble in water

Risk

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Tungsten diselenide ( tungsten ( IV) selenide ) is a compound semiconductor with hexagonal symmetry and the molecular formula WSe2. It has a large anisotropy of electrical properties. Crystals of this material which are held together only by van der Waals forces of layers of the two elements ( tungsten, and selenium). Within each layer of the compound, all valence form covalent bonds so that there are no free valence, consequently, to the surface. Therefore, the compound ( such as other compounds which this type of chemical bonding have ) at their interfaces stable and relatively free of contamination, but can be very easily along the layer plane split.

Use

The compound is used as a solid lubricant, as a model for the investigation of semiconductor photoelectric effect in thin film solar cells and a base material for the self-assembly of the metal atoms on surfaces. Furthermore, it was discovered that the material is one through the layer structure of the best known thermal insulators.