Different characteristics of InGaN/GaN multiple quantum well heterostructures grown on m- and r-planes of a single n-GaN nanowire using metalorganic chemical vapor deposition

Abstract

The growth behavior of coaxial nonpolar (m-plane) and semipolar (r-plane) oriented multiple quantum well (MQW) heterostructures simultaneously deposited under the same experimental conditions on core n-GaN nanowires (NWs) were investigated in this study. The core–shell-type InGaN/GaN MQW/n-GaN heterostructure NWs were grown on Si(111) substrates via the metalorganic chemical vapor deposition technique. We characterized these MQW NW heterostructures and discussed the comparative analyses of the formation of m-plane and r-plane oriented NW structures. Temperature-dependent photoluminescence (PL) measurements showed a distinct InGaN well structure emission wavelength at the m- and r-plane regions owing to the variation of the In composition. Further, the polarization-induced effects of the MQW NW structure were investigated by using power-dependent cathodoluminescence (CL) measurements. The non-radiative recombination located at the defective interface between the m- and r-planes was correlated with the CL mapping image profile and was also evidenced by scanning transmission electron microscopy (STEM) observations. This investigation addresses the understanding of the formation of nonpolar and semipolar oriented MQW NWs and offers insightful details of the structural and optoelectronic characterization of these core–shell NWs.