Resonance Raman Signature of Intertube Excitons in (6,5)-Enriched Carbon Nanotube Bundles

ORAL

Abstract

Electronic interactions in low-dimensional nanomaterial heterostructures can lead to novel optical response arising from exciton delocalization over the constituent materials. Similar phenomena have been suggested to arise between closely interacting semiconducting single wall carbon nanotubes (SWCNTs) of identical structure. We use resonance Raman spectroscopy (RRS) to probe intertube interactions in (6,5)-enriched SWCNTs, dispersed in aqueous solutions and separated using density gradient ultracentrifugation into fractions of increasing bundle size. A continuously tunable dye laser coupled to a triple-grating spectrometer affords measurement of Raman resonance excitation profiles (REPs) over a range of wavelengths, (505 to 585)nm, covering the (6,5)-E22S excitation. REPs of both the radial breathing mode (RBM) and GLO+ display a previously unobserved sharp feature that is superimposed on the typical intrinsic exciton resonance response. This sharp feature provides evidence for the creation of intertube excitons, with the response being generated as the result of the interaction between the intratube and intertube excitons whose spectral responses overlap.

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Presenters

  • Jeffrey Simpson

    • Engineering Physics, National Institute of Standards and Technology
    • Physics, Towson University
    • Physics, Astronomy, and GeoSciences, Towson University
    • Towson University
    • Department of Physics, Astronomy, and Geosciences, Towson University
    • Physics, Astronomy, and Geosciences, Towson Univ and NIST

Authors

  • Jeffrey Simpson

    • Engineering Physics, National Institute of Standards and Technology
    • Physics, Towson University
    • Physics, Astronomy, and GeoSciences, Towson University
    • Towson University
    • Department of Physics, Astronomy, and Geosciences, Towson University
    • Physics, Astronomy, and Geosciences, Towson Univ and NIST

  • Oleksiy Roslyak

    • Physics and Engineering Physics, Fordham University
    • Fordham University

  • Andrei Piryatinski

    • Theoretical Division, Los Alamos National Laboratory
    • Los Alamos National Lab

  • Angela Hight Walker

    • Engineering Physics, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • NIST - Natl Inst of Stds & Tech
    • Physical Measurements Laboratory, National Institute of Standards and Technology
    • Physical Measurment Division, NIST
    • NIST -Natl Inst of Stds & Tech
    • Physical Measurement Laboratory, National Institute of Standards and Technology
    • NIST - National Institute of Standards and Technology
    • National Institute of Standards and Technology (NIST)
    • National Institute of Standards & Technology

  • Stephen Doorn

    • Center for Integrated Nanotechnologies, Los Alamos National Laboratory
    • Los Alamos National Lab