Carrier Dynamics in Single GaAs0.7 Sb0.3 / 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.

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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