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

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 degrees 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 degrees basal dislocation introduces both shallow and deep states but the glide configuration with N polarity, which introduce only shallow states. (C) 2013 Elsevier B. V. All rights reserved.