Investigation of the structure of tungsten oxide films obtained by chemical vapor deposition

Thin amorphous and polycrystalline tungsten oxide films have been prepared by Chemical Vapor Deposition (CVD) from metallorganic precursor - tungsten hexacarbonyl - at atmospheric pressure. The dependence of the composition a nd the structure of tungsten oxide films on the technological conditions ha s been investigated by XPS, XRD, DTA-TGA and Raman spectroscopy. As a resul t it has been established that: at high values of the flow-rates of the rea ction gases amorphous films of very low density have been obtained; in the XPS spectra of the understoichiometric WO3-y (0 < y < 0.3) films besides W6 +, also W5+ and W4+ states have been observed. First to observe in the Rama n spectra of amorphous CVD-WO3 films is the band at similar to 950 cm(-1), characteristic for terminal W6+=O bonds in result of the presence of struct ural water. The existence of structural water in the amorphous material has been established by thermal analyze, also.