ABSTRACT
The role of dislocation for luminescence in InGaN grown on sapphire substrate
by metal organic chemical vapor deposition (MOCVD) method was investigated by cathodoluminescence (CL), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The CL emission area and dark spots between InGaN and GaN layers in InGaN/GaN single quantum well (SQW) and multiple quantum well (MQW) structures showed completely one to one correspondence indicating that dislocations in InGaN act as non-radiative recombination centers. It was confirmed that the phase separation in InGaN occurs when InGaN layer is thick and the growth temperature is low. The phase separation growth mechanism which is caused by spiral growth due to mixed dislocations was discussed.
