Optical properties of 0.4-nm single-wall carbon nanotubes aligned in channels of AlPO4-5 single crystals

Li, ZM., Liu, HJ., Ye, JT., Chan, CT. & Tang, ZK., May-2004, In : Applied Physics A: Materials Science & Processing. 78, 8, p. 1121-1128 8 p.

Research output: Contribution to journalArticleAcademicpeer-review

  • ZM Li
  • HJ Liu
  • JT Ye
  • CT Chan
  • ZK Tang

Single-walled carbon nanotubes (SWNTs) of 0.4 nm in diameter are produced inside channels of microporous zeolite single crystals. Three possible structures: (5,0), (4,2), and (3,3) contribute to three bands at 1.37, 2.1, and 3.1 eV in optical absorption spectra. The direct correspondence between chiralities and absorption bands is identified by density functional calculations. The resonant Raman spectrum shows the features that can be assigned to van Have singularities in calculated phonon density of states. In the low-frequency region, two peaks at 510 and 550 cm(-1) are attributed to the radial breathing modes (RBMs) of the (5,0) and (4,2) tubes. After removing the zeolite framework, the RBM frequencies downshift by similar to10 cm(-1). The charge-transfer behavior in lithium-doped 0.4-nm SWNTs is investigated. The Raman peak at 1558 cm(-1) couples with the electronic continuum, and shows a Breit-Wigner-Fano line shape.

Original languageEnglish
Pages (from-to)1121-1128
Number of pages8
JournalApplied Physics A: Materials Science & Processing
Issue number8
Publication statusPublished - May-2004



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