Ab Initio Thermodynamics of Oxygen Vacancies and Zinc Interstitials in ZnO.
ZnO is an important wide band gap semiconductor with potential application in various optoelectronic devices. In the current contribution, we explore the thermodynamics of oxygen vacancies and zinc interstitials in ZnO from first-principles phonon calculations. Formation enthalpies are evaluated using hybrid DFT calculations, and phonons are addressed using the PBE and the PBE+U functionals. The phonon contribution to the entropy is most dominant for oxygen vacancies, and their Gibbs formation energy increases when including phonons. Finally, inclusion of phonons decreases the Gibbs formation energy difference of the two defects and is therefore important when predicting their equilibrium concentrations and the electrical activity of ZnO at finite temperatures.
†Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Norway, FERMiO, Gaustadallén 21, 0349 Oslo, Norway.
Tor S
TS
Bjørheim
‡Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany.|§Institute for Solid State Physics, University of Latvia, Kengaraga 8, 1063 Riga, Latvia.
Eugene
E
Kotomin
DFT; ZnO; defects; oxygen vacancy; phonons; thermodynamics; zinc interstitial