Probing electronic structure of stoichiometric and defectiveSnO2

Abstract

The electronic structure of stoichiometric tin dioxide (SnO 2 ) is studied by probing its unoccupied states using the fine structure in the electron energy-loss spectra (EELS) at the oxygen K-edge. The spectral measurements were made both at room-and high temperature (773 K), and compared to ab initio calculations carried out using real-space multiple scattering and linearized augmented-plane wave methods. Important many-body effects are included via quasiparticle corrections calculated within the many-pole GW self-energy approximation. An additional energy dependent damping is calculated to account for vibrational effects. Results from this study demonstrated that quantitative agreement between theoretical and experimental spectra can be obtained when non-spherical potentials and quasiparticle self-energy effects are considered, and vibrational broadening is included. Modifications of the electronic structure by single oxygen vacancies, both in the bulk and at the (110) surface, are also predicted. Our predictions support the use of O-K EELS as a probe of defect structure in SnO 2 surfaces and nanoparticles.