The 60° basal dislocation in wurtzite GaN: Energetics, electronic and core structures

Abstract

We have carried out computer atomistic simulations, based on an efficient density functional based tight binding method, to investigate the core configurations of the 60° basal dislocation in GaN wurtzite. Our energetic calculations demonstrate that the glide configuration with N polarity is the most energetically favorable over both the glide and the shuffle sets in nitrogen-rich growth conditions. However, in the case of gallium-rich growth conditions, the shuffle configuration with gallium polarity becomes the most favorable. Otherwise, we found that all the four configurations of the 60° basal dislocation introduces both shallow and deep states but the glide configuration with N polarity, which introduce only shallow states.