New Paper: Defect-Free Axially Stacked GaAs/GaAsP Nanowire Quantum Dots with Strong Carrier Confinement

Transmission electron microscopy and room-temperature photoluminescence of a dot-in-wire structure.

In a new collaboration between Yunyan Zhang and Profs. Huiyun Liu (UCL), Ana Sanchez (Warwick) and David Mowbray (Sheffield) we report the fabrication and measurement of a GaAs/GaAsP quantum dot-in-wire structure in Nano Letters.

While many material architechtures have been explored for single photon emission, the GaAsP-GaAs system provides strong carrier confinement and sharp interfaces, and can be grown directly onto a silicon substrate. This is a new route to silicon integrated single photon devices.

Reference: Defect-Free Axially Stacked GaAs/GaAsP Nanowire Quantum Dots with Strong Carrier Confinement, Yunyan Zhang, Anton V. Velichko, H. Aruni Fonseka, Patrick Parkinson, James A. Gott, George Davis, Martin Aagesen, Ana M. Sanchez, David Mowbray, and Huiyun Liu, Nano Lett. (2021), DOI: 10.1021/acs.nanolett.1c01461

New Paper: Characterisation, Selection and Micro-Assembly of Nanowire Laser Systems

Our collaborative work on the selection, transfer and testing of semiconductor nanowire lasers has now been published in Nano Letters.

In this work, growth colleagues at ANU prepared nanowire lasers which were characterised at Manchester. This characterisation was used to select bins of nanowires, which were transferred using a cutting edge pick-and-place tool at the University of Strathclyde. The transferred wires were re-tested in Manchester; while some wires showed identical behaviour, some showed a change in lasing mode.

This work will guide the heterointegration of nanowire lasers with photonic circuits, targetting high-yield and industrial applicability.

Reference: Characterisation, Selection and Micro-Assembly of Nanowire Laser Systems, Jevtics et al., Nano Letters (ASAP), DOI: 10.1021/acs.nanolett.9b05078

New Paper – Optical Study of p-Doping in GaAs Nanowires for Low-Threshold and High-Yield Lasing

Our new work on large-scale statistical spectroscopy to optimize nanowire lasers is published today in Nano Letters. In this work, PhD student Arturo studied thousands of nanowires to identify the lowest threshold nanowire, as well as to model emission to identify the primary sources of non-radiative emission.

By quickly sorting nanowires by doping and length, he was able to demostrate sub-sets with over 90% yield and class-leading thresholds, pointing the way towards electrically injected nanolasers.

Congratulations Arturo!

nl-2018-04048u_0006
(Left) Far-field emission from a record breaking nanowire laser, emitting at room temperature and low exciation levels. (Right) Doping vs Quantum efficiency, showing two key limiting behaviours.

Reference: “Optical Study of p-Doping in GaAs Nanowires for Low-Threshold and High-Yield Lasing”, Juan Alanis et al., Nano Letters, ASAP 2018, DOI: 10.1021/acs.nanolett.8b04048