Pump-probe Spectroscopy of Single InGaAs and InGaAs/InP Nanowires: Shedding Light on the Wurtzite Band Structure and Carrier Dynamics

ORAL

Abstract

We use transient Rayleigh scattering to optically characterize the band structure and carrier dynamics of single wurtzite nanowires. We employ a 1.51 eV pump and a tunable near-infrared probe (0.79 to 1.16 eV) to study core-only InGaAs nanowires as well as strained core-shell InGaAs-InP heterostructures at 300 K and 10 K. We observe an electronic transition in low temperature core-only spectra at 0.86 eV, a higher energy than the fundamental bandgap of bulk zincblende InGaAs of similar composition. We observe a corresponding transition in core-shell spectra at 0.97 eV. The blue-shift of the transition energy for the core-shell nanowire relative to the core-only nanowire is consistent with compressive strain in the InGaAs core. We report an order of magnitude enhancement in the 10 K carrier lifetimes of the core-shell nanowires (2100 ps) compared to the core-only nanowires (90 ps). Numerical modeling of our TRS spectra provides further insight into the thermalization of charge carriers after photoexcitation.

*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

  • Samuel Linser

    • Department of Physics, University of Cincinnati

Authors

  • Samuel Linser

    • Department of Physics, University of Cincinnati

  • Iraj Abbasian Shojaei

    • 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

  • Amira Ameruddin

    • Department of Electronic and Materials Engineering, Austra

  • 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