Optical and Facet-Dependent Carrier Recombination Properties of Hendecafacet InGaN/GaN Microsized Light Emitters

Abstract

A hendecafacet (HF) microsized light emitter based on an InGaN/GaN multiple quantum well (MQW) is grown via selective area metalorganic chemical vapor deposition. The HF microsized light emitter is found to possess four crystallographic facets, (0001), {1 (1) over bar 01}, {11 (2) over bar2}, and {11-20}. Distinct facet-dependent emission properties, investigated by confocal scanning photoluminescence (PL) and cathodoluminescence (CL) measurements, are found to originate from differences in indium composition and InGaN quantum well thickness of the MQW. Facet-dependent recombination properties, examined by temperature-dependent micro-PL and PL streak images, suggest that the localization energy and nonradiative recombination of carriers at MQW on each facet are varied with the polarization fields and threading dislocations. Besides, scanning time-resolved PL measurements reveal that the recombination lifetime around the edge where different facets meet is shorter than that in the facet regions, implying such nonradiative recombination can be a significant obstacle for achieving high quantum efficiency microstructured light-emitting diodes.