Monte Carlo calculations were used to determine charge accumulation, on threading edge dislocations, as a function of the dislocation density and background dopant density. Four possible core structures were examined, each of which produced defect levels in the gap and could therefore act as electron or hole traps. The results indicated that charge accumulation, and the resultant electrostatic interactions, could change the relative stabilities of the various core structures. Structures with Ga and N vacancies at the dislocation core were predicted to be stable under N-rich and Ga-rich growth conditions, respectively. Due to dopant depletion at high dislocation densities, and the many charge states, the line-charge exhibited a complex cross-over behavior as the dopant and dislocation densities varied.

Charge Accumulation at a Threading Edge Dislocation in Gallium Nitride. K.Leung, A.F.Wright, E.B.Stechel: Applied Physics Letters, 1999, 74[17], 2495-7