Structure, Electronic Properties, Defects and Doping of AlN Using a Self-Consistent Molecular Dynamics Method

ABSTRACTMolecular dynamics simulations are employed to study native defects and dopants in AlN. We use local basis density functional theory within the local density approximation where charge transfer between the ions is included in a self-consistent fashion. Employing this code we find reasonable agreement for the band structure compared to other recent calculations, suggesting the suitability of our method to adequately describe AlN.Wurtzite and zincblende 96 atom AlN cells are used to study the relaxations and electronic properties of common defects in the crystal structure, including vacancies and antisites. We investigate the electronic signatures of these defects. The local topology of column-IV impurities in anion and cation sites is studied. We analyze the lattice relaxations and electronic consequences of these impurities and identify midgap defect, donor and acceptor levels.