Blue tungsten oxide molecular graph is a kind of tungsten trioxide crystal with oxygen defect mode, the ideal structure tungsten trioxide is ReO3 structure which is consisted with eight tungsten ion and 24 oxygen ion, namely WO6 octahedral.
Blue tungsten oxide has very complicate composition, among them there are middle oxides of WO2 and WO4. Blue tungsten oxide if calculated with its its composition of WO2.9, then tungsten content is 82.13%, while the tungsten content in WO3 is 79.30%, that is to say tungsten content in blue tungsten oxide is more than tungsten trioxide. According to the standards of blue tungsten oxide product, its purity is suggested to be 99.95%, and among them the content of tungsten should reach 80.00% ~ 80.80%.
With the increasing of oxygen vacancy concentration, the distortion of WO6 octahedral becomes exacerbated, and eventually leading to defects from disorderly to orderly development and make WO6 octahedral structure change, thus the connection between cells will be changed from the previous point connection to edge connection and to form surface defect, which is known as crystallographic shear; this kind of surface defect will gradually turn to WO2.9 with the increasing of x in WO3-x. Single crystal of WO3-x can be changed and showed metallicity and semiconductor according to its internal oxygen hole concentration, wherein the semiconductor WO3-x has the forbidden band width of among 2.4~2.8eV, moreover the decrease of energy band will lead to absorption wavelength of light blue shift.