Characterization of the Micro-Structural Properties of InAlN/GaN Epilayer Grown by MOCVD

An InAlN/GaN heterostructure has been successfully grown on GaN/sapphire and AlN/sapphire substrate by metal organic chemical vapor deposition. The whole epitaxial quality has been confirmed through X-ray diffraction, while some corresponding micro-structural propagation defects have been characterized by means of transmission electron microscopy. It can be concluded that these defects have been originating from the extended threading dislocation in GaN layer. In addition, with the increasing of acceleration voltage, a series of the cathodoluminescence peak shifting can be clearly observed, and the interesting phenomenon has been attributed to the several complex factors, such as inhomogeneous composition, internal absorption, and so on. Nevertheless, with further optimization of the structural parameters of the epilayers, it can be expected that these experimental results would promote a better epitaxy quality and the optoelectronic device design.