By Patrick Parkinson in ANU —

New Paper : Facet-Related Non-uniform Photoluminescence in Passivated GaAs Nanowires

(Left) SEM image of a single 250nm diameter GaAs nanowire with {112} facets highlighted and (Right) recombination measured in the {110} region (blue) and {112} region (red), showing emission quenching at these surfaces.

Our collaborative work on spatially inhomogeneous recombination in semiconductor nanowires has been published in a special issue of Frontiers in Chemistry. The work, led by Dr. Nian (Jenny) Jiang at the University of Cambridge reports the spatially varying emission intensity from passivated nanowires. By comparing the bulk emission to buried quantum well emission, we show that the a reduction in emission is related to {112}-faceted surfaces at the base of the wires.

This work solves a long-standing question in optoelectronic nanowires – why does the emission vary for nominally uniform structures? It provides two routes to avoiding this variation, through quantum well emission and by tuning the surface reconstruction to favour {110} side-walls.

Reference: Facet-Related Non-uniform Photoluminescence in Passivated GaAs Nanowires, Nian Jiang, Hannah Joyce, Patrick Parkinson, Jennifer Wong-Leung , Hark Hoe Tan and Chennupati Jagadish, Frontiers in Chemistry, 8, 1136 (2020), DOI: 10.3389/fchem.2020.607481