Logo of Science Foundation Ireland  Logo of the Higher Education Authority, Ireland7 Capacities
Ireland's High-Performance Computing Centre | ICHEC
Home | News | Infrastructure | Outreach | Services | Research | Support | Education & Training | Consultancy | About Us | Login


Title:Polaronic trapping of electrons and holes by native defects in anatase TiO2
Authors:Benjamin J. Morgan and Graeme W. Watson, 2009
Abstract: We have investigated the formation of native defects in anatase TiO2 using DFT modified with on-site Coulomb terms (DFT+U) applied to both Ti d and O p states. Oxygen vacancies and titanium interstitials are found to be deep donors that trap two and four electrons, with transition levels that explain the two features seen in DLTS experiments. Titanium vacancies are deep acceptors accommodating four holes. Self-trapping of both electrons and holes is also predicted. In all cases both donor and acceptor trap states correspond to strongly localized small polarons, in agreement with experimental EPR data. Variation in defect formation energies with stoichiometry explains the poor hole-trapping of reduced TiO2.
ICHEC Project:Electronic structure studies of the defect chemistry of TiO2
Publication:Physical Review B 80, 233102 (2009) 10.1103/PhysRevB.80.233102
URL: http://link.aps.org/doi/10.1103/PhysRevB.80.233102
Status: Published

return to publications list