Characterizations of GaN nanowires and GaInN/GaN multiquantum shells grown by MOVPE

Structural characterizations of core-shell type nanowire-based materials are difficult because of their tiny 3D structure. In this paper, we prepared the GaInN/GaN multi quantum shell (MQS) grown on the sidewall of the n-GaN nanowire, and scanning transmission micro-scope (STEM) and 3D atom probe are employed for detailed structural characterization of such samples. Furthermore, cathodoluminescence (CL) measurement is carried out for characterization of optical properties. As a result of 3D atom probe measurement, an out-diffusion-like profile of In, where In atoms move from the wells to the outer barriers, was observed. This is considered that the incorporated In atoms in the outer barriers come from In–droplets caused on the top c-plane during the growth of GaInN.