Raman spectroscopy of optical transitions and vibrational energies of ∼1 nm hgte extreme nanowires within single walled carbon nanotubes

Joseph H. Spencer, John M. Nesbitt, Harrison Trewhitt, Reza J. Kashtiban, Gavin Bell, Victor G. Ivanov, Eric Faulques, Jeremy Sloan, David C. Smith

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

This paper presents a resonance Raman spectroscopy study of ∼1 nm diameter HgTe nanowires formed inside single walled carbon nanotubes by melt infiltration. Raman spectra have been measured for ensembles of bundled filled tubes, produced using tubes from two separate sources, for excitation photon energies in the ranges 3.39-2.61 and 1.82-1.26 eV for Raman shifts down to ∼25 cm-1. We also present HRTEM characterization of the tubes and the results of DFT calculations of the phonon and electronic dispersion relations, and the optical absorption spectrum based upon the observed structure of the HgTe nanowires. All of the evidence supports the hypothesis that the observed Raman features are not attributable to single walled carbon nanotubes, i.e., peaks due to radial breathing mode phonons, but are due to the HgTe nanowires. The observed additional features are due to four distinct phonons, with energies 47, 51, 94, and 115 cm-1, respectively, plus their overtones and combinations. All of these modes have strong photon energy resonances that maximize at around 1.76 eV energy with respect to incident laser.

Original languageEnglish
Pages (from-to)9044-9052
Number of pages9
JournalACS Nano
Volume8
Issue number9
DOIs
StatePublished - Sep 23 2014
Externally publishedYes

Keywords

  • DFT
  • HRTEM
  • HgTe@SWCNT
  • carbon nanotubes
  • nanowires
  • resonant Raman spectroscopy

Fingerprint

Dive into the research topics of 'Raman spectroscopy of optical transitions and vibrational energies of ∼1 nm hgte extreme nanowires within single walled carbon nanotubes'. Together they form a unique fingerprint.

Cite this