title: Vacancies in wurtzite GaN and AlN.
abstract: Vacancies in wurtzite GaN and AlN are studied using a computational method which is based on the density functional theory (DFT) and takes into account the errors arising from use of finite-sized supercells and the DFT band gap underestimation. Negatively charged N vacancies in GaN and AlN are found to be stable, with formation energies similar to and higher than those of Ga and Al vacancies in n-type material under Ga- and Al-rich growth conditions, respectively. The localization and energies of the defect levels close to the computational conduction band edge are considered in detail.
authors.affiliation: Laboratory of Physics, Helsinki University of Technology, PO Box 1100, FI-02015 HUT, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Laaksonen
authors.forename: M G
authors.initials: MG
authors.lastname: Ganchenkova
authors.forename: R M
authors.initials: RM
authors.lastname: Nieminen