Computational materials science at work: Density functional based study of structural and optical properties of tin oxide surface

State-of-the-art computational methods have been applied in order to dissect the subtle features affecting the structural and electronic properties of tin oxide nanocrystals. By describing the effects of oxygen vacancy formation and localization, we have been able to assign the 2.0eV emission of SnO2 photoluminescence spectrum to an electronic transition from an occupied state, mainly associated to a surface oxygen vacancy. Moreover, we report, preliminary results of an ongoing project devoted to study the effects of surface defects on the NO2 adsorption process onto tin oxide nano-crystals. A comprehensive analysis of the joint effects of surface oxygen vacancies and NO2 adsorption processes oil the SnO2 electronic properties is crucial in order to understand and control the potential use of this material as effective constituent of gas sensor devices.