Hybrid functional studies of the oxygen vacancy in TiO2

Autor(en)

Anderson Janotti, Joel B. Varley, Patrick Rinke, N. Umezawa, Georg Kresse, Chris G. Van de Walle

Abstrakt

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(en)

Computergestützte Materialphysik

Externe Organisation(en)

University of California, Santa Barbara

Journal

Physical Review B

Band

81

Anzahl der Seiten

7

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.81.085212

Publikationsdatum

2010

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/cdbe0805-360c-48ca-a905-aa87f8d4a74b