An empirical potential approach to dislocation formation and structural stability in GaN xAs 1− x

Abstract

We study the feasibility of our empirical potential to dislocation formation and its contribution to structural stability in GaN x As 1− x . The feasibility is exemplified by the calculations of the dislocation core energy and core radius for various dislocation core structures in wurtzite structured GaN. Moreover, we carry out theoretical analyses of the structural stability for GaN x As 1− x with dislocation whose core structure is described by five- and seven-coordinated channels (5/7 core) over the entire concentration range. The GaN x As 1− x changes its structure from zinc blende to wurtzite at the concentration for phase transition x c = 0.3 with dislocation and x c = 0.4 without dislocation. This is because the 5/7 core favors the wurtzite structured GaN x As 1− x with lower core energy than that in zinc blende structured GaN x As 1− x .