First-Principles LDA plus U Study of Hydrogen Impurities in Anatase TiO2

Abstract

The microscopic structures of hydrogen impurities in anatase TiO2 are investigated through first-principles LDA+U calculations. We find that the shallow-donor-like interstitial H (H-int) in anatase TiO2 is stabilized by the formation of a hydroxyl OH- ion. We examine the interaction between H and the oxygen vacancy (V-O) and found that the H-int can be captured by a donor-like V-O defect with a large binding energy of 1.12 eV by using U - J = 5.0 eV. It is important that there is no gap state for the H circle plus V-O complex, contrary to the deep donor-like V-O.