Hybrid functional studies of the oxygen vacancy in TiO2

Author(s)
Anderson Janotti, Joel B. Varley, Patrick Rinke, N. Umezawa, Georg Kresse, Chris G. Van de Walle
Abstract

The electronic and structural properties of the oxygen vacancy (V-O) in rutile TiO2 are studied using generalized Kohn-Sham theory with the Heyd, Scuseria, and Ernzerhof (HSE) hybrid functional for exchange and correlation. The HSE approach corrects the band gap and allows for a proper description of defects with energy levels close to the conduction band. According to the HSE calculations, VO is a shallow donor for which the +2 charge state is lower in energy than the neutral and +1 charge states for all Fermi-level positions in the band gap. The formation energy of V-O(2+) is relatively low in n-type TiO2 under O-poor conditions but it rapidly increases with the oxygen chemical potential. This is consistent with experimental observations where the electrical conductivity decreases with oxygen partial pressure.

Organisation(s)
Computational Materials Physics
External organisation(s)
University of California, Santa Barbara
Journal
Physical Review B
Volume
81
No. of pages
7
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.81.085212
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/cdbe0805-360c-48ca-a905-aa87f8d4a74b