Excitons in semiconducting single-walled carbon nanotubes

Hongbo Zhao, Sumit Mazumdar

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

We report correlated-electron calculations of optically excited states in 10 semiconducting single-walled carbon nanotubes with a wide range of diameters. Optical excitation occurs to excitons whose binding energies decrease with the increasing nanotube diameter, and are smaller than the binding energy of an isolated strand of poly-(paraphenylene vinylene). The ratio of the energy of the second optical exciton polarized along the nanotube axis to that of the lowest exciton is smaller than the value predicted within single-particle theory. The experimentally observed weak photoluminescence is an intrinsic feature of semiconducting nanotubes, and is consequence of dipole-forbidden excitons occurring below the optical exciton. Excited states absorption calculations show photoinduced absorption energies are lower than or comparable to the binding energy of the lowest exciton.

Original languageEnglish (US)
Pages (from-to)250-253
Number of pages4
JournalSynthetic Metals
Volume155
Issue number2
DOIs
StatePublished - Nov 15 2005

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Keywords

  • Carbon nanotubes
  • Photoluminescence
  • Semiempirical models and model calculations

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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