Carrier Dynamics in Single GaAs<sub>0.7 </sub>Sb<sub>0.3 </sub>/ InP Core-Shell Nanowires with Type II Band Alignment

ORAL

Abstract

Time-resolved optical measurements of single zinc-blende GaAs0.7Sb0.3 core-only and GaAs0.7Sb0.3/InP core-shell nanowires at 10K are obtained from pump-probe measurements. The core-shell nanowires exhibit a remarkably longer lifetime (≈ 600 times) compared with core-only nanowires. Measurements at 300K show only a factor of 6 enhancement. These results suggest that band alignment of the core-shell nanowire may be Type II with less than a 30meV off-set. Carrier thermalization and carrier density evolution obtained from fitting the nanowire spectra using Transient Rayleigh scattering (TRS) modeling provide supporting evidence for Type II band alignment. By modeling the energy loss mechanism of carriers based on longitudinal optical and acoustic phonon emission, we are able to simulate carrier thermalization. These results show that at early times optical phonon emission dominates the carrier energy loss rate. For core-shell nanowires at 10 K, the acoustic phonon emission dominates after 300 ps.

*We acknowledge the financial support of the NSF through grants DMR 1507844, DMR 1531373 and ECCS 1509706, and the financial support of the Australian Research Council.

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Presenters

  • Iraj Abbasian Shojaei

    • Department of Physics, University of Cincinnati

Authors

  • Iraj Abbasian Shojaei

    • Department of Physics, University of Cincinnati

  • Samuel Linser

    • Department of Physics, University of Cincinnati

  • Giriraj Jnawali

    • Department of Physics, University of Cincinnati

  • Howard Jackson

    • Department of Physics, University of Cincinnati

  • Leigh Smith

    • Department of Physics, University of Cincinnati

  • Xiaoming Yuan

    • Department of Electronics and Materials Engineering, Australian National University

  • Philippe Caroff

    • Lund University, Department of solid state physics
    • Department of Electronic and Materials Engineering, Austra
    • Department of Electronics and Materials Engineering, Australian National University

  • Hoe Tan

    • Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University
    • Department of Electronic and Materials Engineering, Austra
    • Department of Electronics and Materials Engineering, Australian National University
    • Department of Electronic and Materials Engineering, Australian National University
    • Australian Natl Univ

  • Chennupati Jagadish

    • Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University
    • Department of Electronic and Materials Engineering, Austra
    • Department of Physics, University of Cincinnati
    • Department of Electronic and Materials Engineering, Australian National University
    • Australian Natl Univ