A strategy to grow three dimensional InGaN/GaN heterostructure exclusively on non-polar m-plane of two-step etched GaN nanorods

Abstract

In this study, we present a strategy to prepare core–shell InGaN/GaN multiple quantum wells (MQWs) heterostructure exclusively on the m plane sidewalls using dielectric masking of the top-down processed GaN nanorods (NRs). Herein, we have utilized a two-step nanofabrication technique involving plasma as well as wet etching to prepare well-aligned GaN NRs. Furthermore, we have experimented with the surface morphology modification of prepared GaN NRs by the deposition of mask layers for the growth InGaN/GaN MQWs. Moreover, the role of GaN buffer layer in facilitating the formation of non-polar sidewalls on prepared GaN nanorods and variation in emission wavelengths from the active region grown on non-polar sidewalls is investigated through morphological as well as optical characterizations. Metrological analysis confirmed the formation of non-polar m-plane sidewalls on the NRs and subsequent conformal growth of the MQWs heterostructure while optical characterizations revealed the emission profile of the grown samples, showcasing influence of the mask layer on the emission profile. Moreover, cathodoluminescence and power dependent photoluminescence study elucidated the origin of the emission confirming the growth of active region on non-polar sidewalls along with absence of the polarization induced fields.