First principles study of native defects in BeO

Abstract

Abstract Using first principles calculations within the formalism of the Density Functional Theory (DFT) and the Local Spin Density Approximation (LSDA) for the exchange-correlation term, we have studied native defects (vacancies and antisites) in wurtzite Beryllium Oxide (w-BeO). The stability of the defects was analyzed by calculating the formation energies (Eform) through total energy calculations (Et). Among all the defects studied, the oxygen vacancy (VO) is the most stable defect (lowest formation energy), while the Beryllium in the Oxygen site (BeO) is the less stable defect. For the vacancies we obtained formation energies of the 0.75 eV (7.88) and 9.16 eV (2.02) for the VO and VBe in a Be-rich (O-rich) growth condition. For the antisites we obtained formation energies of the 16.08 eV (1.76) and 6.69 eV (20.95) for the OBe and BeO in the Be-rich (O-rich) growth conditions. In addition, we observed that those defects introduce deep and localized electronic levels in the band gap. Those defects can be the responsible for luminescent properties of BeO. For the VBe a local spin magnetic moment of 2 μB is obtained.