First-principles study on electronic structure of the (001) surface of SrTiO3.

Abstract

Electronic structures of ${\mathrm{SrTiO}}_{3}$ (001) surfaces are calculated by the use of self-consistent pseudopotential method with plane-wave basis. The effect of surface defects, which are introduced by removing a surface oxygen in a 1\ifmmode\times\else\texttimes\fi{}1 or a \ensuremath{\surd}2 \ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}2 cell, are studied in detail. Levels induced by the defect appear in the bulk band-gap region. The wave funciton of the defect level is localized around surface Ti ion, forming the Ti(3d)-O vacancy complex.