Dresden 2017 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 83: Oxide Semiconductors (joined session with CPP, DS)

HL 83.7: Vortrag

Freitag, 24. März 2017, 11:45–12:00, POT 51

Hybrid functional calculations of oxygen mono- and di- vacancies in SrTiO3 — •Masud Alam, Liverios Lymperakis, and Jörg Neugebauer — Computational Material Design department, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck Str. 1, 40237 Düsseldorf, Germany

Perovskite-type oxides ABO3 have attracted considerable interest for their large variety of technologically appealing characteristics such as ferroelectricity, magnetism, as well their dielectric properties. Among these materials, SrTiO3 (STO) serves as a representative model for the class of large bandgap perovskites. Nevertheless, the properties of this material are dominated by the presence of oxygen vacancies which act as n-type dopants. In the present work we investigate the energetics, atomic geometry and electronic structures of oxygen mono- and di- vacancies by employing Heyd, Scuseria, Ernzerhof (HSE) hybrid density functional calculations. Based on these calculations we identify the energy levels and the formation energies of aforementioned point defects as well as the binding energies of the point defect complexes. Our calculations reveal that interactions between single and doubly ionized defects as expected are strongly repulsive. Based on the aforementioned results we will further discuss in details the effect of oxygen vacancies as a function of growth conditions and doping level on the electronic properties of STO.