Recombination and optical properties of dislocations gliding at room temperature in GaN under applied stress

The recombination and optical properties of dislocations in GaN introduced at room temperature by applied stress have been studied. It is observed that under the application of local shear stress of a few tens of MPa the dislocation glide in the parallel to the surface basal planes and in the planes intersecting the surface is activated at room temperature. It is shown that dislocations of dislocation half-loops gliding in the planes intersecting the surface can demonstrate both radiative and nonradiative recombination. Basal plane dislocations are shown to increase the nonradiative recombination rate. It is observed that the low-energy electron beam irradiation stimulates the dislocation glide both in the basal plane and the planes inclined to the surface, this effect being weaker for the basal plane. The analysis of electron irradiation effect on the dislocation related cathodoluminescence band suggests that this band is due to recombination involving complexes of point defects. These complexes are believed to be generated by gliding of the dislocation segments emerging at the surface.