First-Principles Calculation of Defect Properties on Copper Doped KTaO3 Crystal

Abstract

A first-principles calculation is applied to perform a study of the Cu: KTaO3 system. The defect formation energy, the doping induced lattice distortion and the electronic structure properties have been calculated. The defect formation energy found that Cu is prefer to substitute K (CuK) at corresponding defect charge state +3(), +1() and 0 () with Fermi energy increase; The doping of Cu leads to an obvious distortion of the oxygen octahedron, along with the change of ionic bond characteristics; Further research on electronic structure shows that the doped Cu atom mainly occupies the top of the valence band, resulting in the decrease of the band gap.