A needle in a needlestack: exploiting functional inhomogeneity for optimized nanowire lasing

Abstract

III-V semiconductor nanowires allow easy hetero-integration of optoelectronic components onto silicon due to efficient strain relaxation, well-understood design approaches and scalability. However continuous room temperature lasing has proven elusive. A key challenge is performing repeatable single-wire characterization-each wire can be different due to local growth conditions present during bottom-up growth. Here, we describe an approach using large-scale population studies which exploit inherent inhomogeneity to understand the complex interplay of geometric design, crystal structure, and material quality. By correlating nanowire length with threshold for hundreds of nanowire lasers, this technique reveals core-reabsorption as the critical limiting process in multiple-quantum-well nanowire lasers. By incorporating higher band-gap nanowire core, this effect is eliminated, providing reflectivity dominated behavior.

Sub‐Picosecond Carrier Dynamics Explored using Automated High‐Throughput Studies of Doping Inhomogeneity within a Bayesian Framework

“…The image processing followed the procedure outlined in Ref. [ 78 ] , using image‐processing tools available in MATLAB (namely regionprops ).…”

Holistic Determination of Optoelectronic Properties using High-Throughput Spectroscopy of Surface-Guided CsPbBr3 Nanowires

“… 4 This allows correlations to be drawn between measured properties and can establish those with the greatest impact on performance. 6 In this study, this approach is applied to holistically characterize microstructures by studying each individual element with multiple techniques, including photoluminescence spectroscopy, time-correlated single photon counting (TCSPC), and excitation power-dependent TCSPC, with a typical characterization time of a few seconds per NW. A self-consistent analysis is applied to this multimodal data set, of 15576 individual measurements, to correlate all of the measured properties and establish the coupling between geometry, strain, and carrier recombination processes.…”

“…This fundamental approach has been used for materials spanning tens of microns in length, down to micron scale . This allows correlations to be drawn between measured properties and can establish those with the greatest impact on performance . In this study, this approach is applied to holistically characterize microstructures by studying each individual element with multiple techniques, including photoluminescence spectroscopy, time-correlated single photon counting (TCSPC), and excitation power-dependent TCSPC, with a typical characterization time of a few seconds per NW.…”