Ab initio DFT computation of SnO2 and WO3 slabs and gas–surface interactions

Slabs of SnO2 and WO3 were computed by ab initio DFT technique, in order to model nanoribbons. Atomic positions, electron density and electronic density of states were calculated for perfect, vacancy free materials. In these conditions, oxygen is shown to adsorb as a neutral species, but this adsorption creates acceptor states in the gap which can trap the electrons due to O vacancies in real materials.