Surface barrier modulation and diffuse reflectance spectroscopy of MoO3–WO3 thick films

Diffuse reflectance spectroscopy in the UV–vis–NIR is employed to study the electronic transitions in MoO3–WO3 mixed oxide. The spectroscopic results were then related to the temperature profile of the surface barrier. The electronic absorptions appear to increase after reducing treatments and to decrease after oxidation. This variation of oxygen-related defects changes the doping level, which in turn, affects the dependence of surface barrier on temperature. The latter is strictly connected to the sensing properties of the mixed oxide.