Theoretical study of oxygen-deficient SnO2(110) surfaces -: art. no. 245428

Theoretical consideration of recently proposed ordered stoichiometric and oxygen-deficient (110) surfaces of SnO2 crystal with 1x1, 1x2, 2x1, and 1x4 symmetries have been done. We use a first-principles density-functional method and plane-wave basis, combined with pseudopotentials to calculate surface electronic structures, surface geometries, and energetics. Calculated surface formation energies suggest that stability of the oxygen-deficient surfaces decrease with increasing oxygen deficiency. At oxygen-deficient 1x2 and 1x4 surfaces tin atoms similar to those in SnO crystal were found to appear. In all cases, the highest occupied orbitals were considerably localized at the sites of surface oxygen vacancies. The 2x1 added row surface structures were found to be relatively stable and associated with the decrease of the band gap due to jagged surface. Also, ultraviolet optical absorption coefficients for different surface structures were determined by using the electric dipole approximation with a scissor correction.