Exploring the Nature of Exciton Localization in Quasi One-Dimensional GaAs/AlGaAs Quantum Well Tube Nanowires

ORAL

Abstract

We explore the nature of exciton localization in single GaAs/AlGaAs nanowire quantum well tube (QWT) devices using photocurrent (PC) spectroscopy combined with simultaneous photoluminescence (PL) and photoluminescence excitation (PLE) measurements. Excitons confined to GaAs quantum well tubes of 8 and 4 nm widths embedded into an AlGaAs barrier are seen to ionize at high bias. Spectroscopic signatures of the ground and excited states confined to the QWT seen in PL, PLE and PC data are consistent with simple numerical calculations. The demonstration of good electrical contact with the QWTs enables the study of Stark effect shifts in the sharp emission lines of excitons localized to quantum dot-like states within the QWT. Atomic resolution cross-sectional TEM measurements, an analysis of the temperature dependence of PL and time-resolved PL as well as the quantum confined Stark effect of these dots provide insights into the nature of the exciton localization in these nanostructures.

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Authors

  • Howard Jackson

    Department of Physics, University of Cincinnati, University of Cincinnati

  • Bekele Badada

    Department of Physics, University of Cincinnati

  • Teng Shi

    Department of Physics, University of Cincinnati

  • Leigh Smith

    Department of Physics, University of Cincinnati, University of Cincinnati

  • Changlin Zheng

    Monash Centre for Electron Microscopy, Monash University

  • Joanne Etheridge

    Monash Centre for Electron Microscopy and Department of Materials Engineering, Monash University

  • Nian Jiang

    Department of Electronic Materials Engineering, Australian National University

  • Hoe Tan

    Department of Electronic Materials Engineering, Australian National University

  • Channupati Jagadish

    Department of Electronic Materials Engineering, Australian National University