Cathodoluminescence and scanning transmission electron microscopy study of InGaN/GaN quantum wells in core-shell GaN nanowires

Abstract

InGaN/GaN quantum wells (QWs) on GaN nanowire are expected for applications in high efficiency optoelectronic devices. To improve efficiency, it is important to clarify the relation between optical and structural properties. A systematical optical and structural characterization of QWs in core-shell GaN nanowires is performed by cathodoluminescence and scanning transmission electron microscopy. The QWs grown on the m-facet show varied optical behavior with respect to height position: main-body region (2.82 ∼ 3.10 eV), upper region (3.26 eV), and corner region (2.88 ∼ 3.20 eV). The variant luminescence behaviors are attributed to interface quality and In diffusion.