Modification of the stoichiometric and the reduced SnO2 (110) surface by transition metal doping: density functional study

Abstract

SnO₂ is a wide gap semiconductor, which has excellent properties for selective detection of various gases, catalysis and optoelectronic devices. Many experimental studies showed that the transition metal (TM) doping is a way to enhance its performances. Using the modified density functional calculations we study the relative stability of the stoichiometric and the reduced SnO₂ (110) surfaces, as well as the influence of transition metals doping on their stability and electronic structure. In our study we consider models of the surface with different positions and concentrations of oxygen vacancies. We find that the substitutional doping of TM for Sn induces the structural relaxation and the charge modification around the involved atoms. In some of the investigated cases it also introduces surface states within the band gap. The obtained results for the structural relaxations and energetics are compared with available previous theoretical and experimental data.