Configuration of dislocations in lateral overgrowth GaN films

The dislocation distribution and emission profile of sublimation lateral ov ergrowth GaN and metalorganic chemical vapor deposition films have been stu died using transmission electron microscopy and cathodoluminescence. A clos e relationship between the emission profile and the dislocation distributio n 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 mechanis m of the change in the propagation direction of dislocations has been discu ssed. (C) 1999 American Institute of Physics. [S0021-8979(99)06309-4].