Surface Plasmon Based Engineering of Semiconductor Nanowire Optics

ORAL

Abstract

Emission from unthermalized (hot) excitons can be observed from high-quality crystals and quantum-well structures due to decreases in the exciton lifetimes but typically with low yields. By employing a plasmonic nanocavity, we observe efficient hot-exciton emission in core-shell CdS-SiO$_{2}$-Ag nanowires with intensities surpassing those from thermalized excitons [1]. These new spectral characteristics are mediated by whispering gallery plasmonic modes that yield highly intense electromagnetic fields. As a result, the exciton radiative lifetime is decreased by several orders of magnitude. The introduction of a high-quality hybrid plasmonic nanocavity structure significantly changes the photophysics of the host material, demonstrating an approach applicable to other material systems. \\[4pt] [1] Chang-Hee Cho, \textit{et al}, Nature Materials, \textbf{10}, 669 (2011).

*Transient optical work supported by the Department of Energy BES Award No. DESC0002158. Remaining work supported by ARO W911NF-09-1-0477, NIH Director's New Innovator Award Program, 1-DP2-7251-01, NSF-NSEC-DMR08-32802, and NSF IGERT DGE02-21664.

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Authors

  • Chang-Hee Cho

    • Department of Materials Science and Engineering, University of Pennsylvania
    • Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA

  • Carlos O. Aspetti

    • Department of Materials Science and Engineering, University of Pennsylvania

  • Michael E. Turk

    • Department of Physics and Astronomy, University of Pennsylvania

  • James M. Kikkawa

    • Department of Physics and Astronomy, University of Pennsylvania

  • Sung-Wook Nam

    • Department of Materials Science and Engineering, University of Pennsylvania

  • Ritesh Agarwal

    • Department of Materials Science and Engineering, University of Pennsylvania