DISLOCATIONS IN GaN/SAPPHIRE: THEIR DISTRIBUTION AND EFFECT ON STRESS AND OPTICAL PROPERTIES

摘要

Recent Raman experiments show that strain in GaN layers grown on the c-plane of sapphire is low at the surface, increases with depth, and is maximum at the interface. We show that this stress distribution can be attributed to the presence of a large number of threading dislocations. GaN photonic devices work in spite of large density of dislocations present in the GaN epilayers. We describe a model which shows that the effect of saturation of traps in the dislocations with increasing number of injected carriers can explain the high performance of the GaN devices containing the dislocations.