Giant Excitonic Transport in GaN/AlGaN Surface Quantum Wells

ORAL

Abstract

A huge progressive spatial expansion of photoluminescence (PL) area over a few 100 $\mu $m with decreasing the GaN/Al$_{0.2}$Ga$_{0.8}$N surface quantum well width in the range of 2.9 - 1.51 nm has been observed by focusing 4.66 eV laser light (170 fs pulses) into the spot on the sample surface. The out-of-spot PL spectra reveal higher energy bands which are separated from the free exciton peak by multiples of optical phonon energy. The effect is explained as a dipolar excitonic explosion followed by nonequilibrium-optical-phonon-mediated lateral transport. The PL is observable due to radiative recombination of high-energy excitons accompanied by inelastic scattering with surface ionized acceptors.

*YDG acknowledges Welch Foundation (grant F-1662) for travel support.

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Authors

  • Y.D. Glinka

    • Department of Physics, University of Texas at Austin, Austin, TX

  • S.V. Goupalov

  • T.V. Shahbazyan

    • Department of Physics, Jackson State University, Jackson, MS

  • H.O. Everitt

    • U.S. Army Aviation and Missile RDEC, Redstone Arsenal, AL

  • J. Roberts

  • P. Rajagopal

  • J. Cook

  • E. Piner

  • K. Linthicum

    • Nitronex Corporation, Raleigh, NC