Original Paper
Atomic structure and relative stability of gallium and nitrogen interstitials in GaN [0001] grain boundaries
Abstract
The atomic and electronic structures of gallium and nitrogen interstitial created at the 8-interface of the (2
30) Σ = 19 (θ = 13.2°) tilt grain boundary in GaN were investigated by density-functional based tight-binding calculations. We found that the structure of lowest energy of the Ga- or N-interstitial boundary is formed by a mixture of 6- and 5/7-atom rings (Gai- or Ni-interface) which is comparable to that of the 5/7-interface. The calculations show that the non stoichiometric Gai-interface is energetically more stable than the stoichiometric 5/7-interface, suggesting that both configurations may exist. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
