A modified empirical potential for energetic calculations of planar defects in GaN

The Stillinger-Weber empirical potential was modified and its parameters were determined to achieve a realistic description of the microscopic structure and the energetics of different planar defects and their interactions in wurtzite GaN. The formulation was based on the adjustment of the parameters in order to represent the Ga-Ga, N-N and GaN bonds. The input data comprises of the different crystalline phases of gallium, nitrogen and GaN. A satisfactory agreement on the values of the energy versus atomic volume per atom was obtained compared to those derived by ab initio calculations and experimental data for all the cases studied. By employing the modified Stillinger-Weber potential the energy of translation domain boundaries, which have been observed experimentally in GaN thin films, was calculated providing results comparable with ab initio calculations. (C) 2002 Elsevier Science B.V. All rights reserved.