New Paper: Heterostructure and Q-factor engineering for low-threshold and persistent nanowire lasing

Group PhD student Stefan Skalsky’s paper on semiconductor nanowire lasing has just been published in Light: Science and Applications. In this new work, Stefan used his newly developed Interferometric Time-Correlated Single Photon Counting system (i-TCSPC) to measure the coherence length of laser emission from nanowires grown by the Liu group at UCL. These measurements allowed the direct calculation of the nanowire mirror reflectivity.

During this study, Stefan found that it was possible to use indirect bandgap materials as a holding state for carriers before they relax into the emissive wells; this finding both allows multi-nanosecond lasing after a sub-picosecond excitation, and record low lasing thresholds through resonant excitation.

This work was supported by TEM provided by the Sanchez group at Warwick.

Reference: Heterostructure and Q-factor engineering for low-threshold and persistent nanowire lasing, Skalsky et al., Light: Science and Applications, 9, 43 (2020) https://doi.org/10.1038/s41377-020-0279-y

New Paper – Threshold reduction and yield improvement of semiconductor nanowire lasers via processing-related end-facet optimization

Arturo has had a paper accepted for publication in Nanoscale Advances, describing the impact of the transfer process on the morphology and threshold of semiconductor nanowire lasers.

While many studies have sought to improve the threshold for lasing in semiconductor nanowire lasers, the role of process has not been significantly considered. By applying a large-scale population study to this system, Arturo has used statistical tools to identify the optimal processing methods which is transferrable to a wide varity of nanowire laser structures.

(Left) Threshold as a function of processing conditions, showing the improvement arising from PDMS or ultrasound transfer. (Right) A typical laser, showing coherent emission and lasing onset.

Reference: “Threshold reduction and yield improvement of semiconductor nanowire lasers via processing-related end-facet optimization“, J. A. Alanis et al., Nanoscale Advances, 2019 (10.1039/C9NA00479C)