TY - GEN
T1 - Time resolved infrared spectroscopy for hot carrier dynamics in InAs-AlAsSb core-shell nanowires
AU - Sandner, Daniel
AU - Esmaielpour, Hamidreza
AU - del Giudice, Fabio
AU - Nuber, Matthias
AU - Kienberger, Reinhard
AU - Koblmüller, Gregor
AU - Iglev, Hristo
N1 - Publisher Copyright:
© 2023 SPIE.
PY - 2023
Y1 - 2023
N2 - Semiconductor nanowires (NWs) have shown robust hot carrier effects due to their small dimensions. Here, we study the cooling mechanisms of hot electrons in the time domain via transient absorption spectroscopy. Probe energies below the bandgap are used to determine the evolution of the carrier effective mass while probe energies above the bandgap track the conduction band occupation. From excitation intensity dependent measurements, we confirm that electron-hole interactions are a major cooling channel at large carrier density, given the high ratio of mh/me of InAs. Our experiments indicate that this cooling channel is amplified in passivated core-shell NWs. We associate this effect with spatial carrier separation caused by Fermi-level pinning in unpassivated NWs. In core-shell NWs, bands are considerably more flat which increases radiative recombination and electron-hole scattering with the latter cooling the hot electron population. Our results highlight the advantages of carrier separation if high carrier densities are to be used for hot phonon bottlenecks.
AB - Semiconductor nanowires (NWs) have shown robust hot carrier effects due to their small dimensions. Here, we study the cooling mechanisms of hot electrons in the time domain via transient absorption spectroscopy. Probe energies below the bandgap are used to determine the evolution of the carrier effective mass while probe energies above the bandgap track the conduction band occupation. From excitation intensity dependent measurements, we confirm that electron-hole interactions are a major cooling channel at large carrier density, given the high ratio of mh/me of InAs. Our experiments indicate that this cooling channel is amplified in passivated core-shell NWs. We associate this effect with spatial carrier separation caused by Fermi-level pinning in unpassivated NWs. In core-shell NWs, bands are considerably more flat which increases radiative recombination and electron-hole scattering with the latter cooling the hot electron population. Our results highlight the advantages of carrier separation if high carrier densities are to be used for hot phonon bottlenecks.
KW - Indium arsenide
KW - electron-hole scattering
KW - hot electrons
KW - semiconductor nanowires
KW - time-resolved infrared spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85159853322&partnerID=8YFLogxK
U2 - 10.1117/12.2648285
DO - 10.1117/12.2648285
M3 - Conference contribution
AN - SCOPUS:85159853322
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Physics, Simulation, and Photonic Engineering of Photovoltaic Devices XII
A2 - Freundlich, Alexandre
A2 - Collin, Stephane
A2 - Hinzer, Karin
PB - SPIE
T2 - Physics, Simulation, and Photonic Engineering of Photovoltaic Devices XII 2023
Y2 - 30 January 2023 through 1 February 2023
ER -