Abstract
Native point defects in anatase are investigated by using first-principles pseudopotential calculations based on density-functional theory (DFT). Antisite defects, namely, Ti-antisite and O-antisite , have high formation energies and are hence unstable. In contrast, all other fundamental native defects (, , , and ) have low formation energies. In particular, titanium interstitial is a quadruple donor defect with lowest formation energy in -type samples, whereas Ti vacancy is a quadruple acceptor defect with lowest formation energy in -type samples. Interstitial oxygen would spontaneously and strongly bind to lattice oxygen, resulting in a neutral dimer substituting on one O site. None of the four low-energy defects have energy levels inside the DFT band gap.
- Received 21 January 2006
DOI:https://doi.org/10.1103/PhysRevB.73.125205
©2006 American Physical Society