Prismatic stacking faults in epitaxially lateraly overgrown GaN

摘要

We report on the presence of optically active stacking faults on basal and prismatic planes in epitaxially laterally overgrown GaN (ELOG) on {1122} facets. The structure of the faults has been analyzed using dffraction contrast electron microscopy. The prismatic plane stacking faults occur on {1120} planes, involving a lattice displacement of 1/2 < 1101 > , parallel to the fault plane. They appear as jogs connecting basal-plane stacking faults, the latter with a lattice displacement of 1/6 < 2023 > . These faults are observed only in laterally overgrown regions, which grow along {1122} planes, indicating that their formation is closely related to the orientation of the growth surface. Possible formation mechanisms of these faults are discussed. Cathodoluminescence observations indicate the absence of band edge emission at these faults.