Structure of [0001] tilt boundaries in GaN obtained by simulation with empirical potentials

Abstract

The atomic structures of [0001] tilt boundaries from 9.3\ifmmode^\circ\else\textdegree\fi{} to 44.8\ifmmode^\circ\else\textdegree\fi{} misorientation angles in wurtzite gallium nitride have been studied by atomic computer simulation using two interatomic potentials of the Stillinger-Weber and shell-model types. For each misorientation of the two adjacent crystals several periodic boundaries have been considered. A relation between the boundary structures and the cores of the prism a-edge dislocation has been established. The structures of some boundaries of larger periods found experimentally have been investigated, and it was found that in some cases they are energetically more favorable than the boundaries of shortest period.