Electronic structure of electron doped SrTiO₃: SrTiO_3−δ and Sr_1−xLa_xTiO₃

Abstract

Electronic structures of electron-doped SrTiO_3−δ and Sr_1−xLa_xTiO₃ have been investigated within the ab initio band-structure approach using a supercell containing eight basic units. A small amount of electron doping is found to drive SrTiO₃ metallic, with the Fermi level moving into the conduction band in both the systems. Clustering of oxygen vacancies in the case of SrTiO_3−δ gives rise to distinct non-rigid-band-like evolution of the electronic structure, trapping doped charge carriers in midgap states; similar effects are not observed for Sr_1−xLa_xTiO₃, explaining the difference in the Hall measurements of these two closely related compounds.