Configuration of dislocations in lateral overgrowth GaN films

Abstract

The dislocation distribution and emission profile of sublimation lateral overgrowth GaN and metalorganic chemical vapor deposition films have been studied using transmission electron microscopy and cathodoluminescence. A close relationship between the emission profile and the dislocation distribution has been observed. The results show that the dislocations not only affect the band edge emission, but also the yellow emission. It is observed that the dislocations propagate laterally in the overgrowth region. The mechanism of the change in the propagation direction of dislocations has been discussed.