title: Chiral index dependence of the G+ and G- Raman modes in semiconducting carbon nanotubes.
abstract: Raman spectroscopy on the radial breathing mode is a common tool to determine the diameter d or chiral indices (n,m) of single-wall carbon nanotubes. In this work we present an alternative technique to determine d and (n,m) based on the high-energy G(-) mode. From resonant Raman scattering experiments on 14 highly purified single chirality (n,m) samples we obtain the diameter, chiral angle, and family dependence of the G(-) and G(+) peak position. Considering theoretical predictions we discuss the origin of these dependences with respect to rehybridization of the carbon orbitals, confinement, and electron-electron interactions. The relative Raman intensities of the two peaks have a systematic chiral angle dependence in agreement with theories considering the symmetry of nanotubes and the associated phonons.
authors.affiliation: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. hagen@lanl.gov
authors.forename: Hagen
authors.initials: H
authors.lastname: Telg
authors.forename: Juan G
authors.initials: JG
authors.lastname: Duque
authors.forename: Matthias
authors.initials: M
authors.lastname: Staiger
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Tu
authors.forename: Frank
authors.initials: F
authors.lastname: Hennrich
authors.forename: Manfred M
authors.initials: MM
authors.lastname: Kappes
authors.forename: Ming
authors.initials: M
authors.lastname: Zheng
authors.forename: Janina
authors.initials: J
authors.lastname: Maultzsch
authors.forename: Christian
authors.initials: C
authors.lastname: Thomsen
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Doorn
mesh_terms: D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012666:Semiconductors; D013059:Spectrum Analysis, Raman / Q000379:methods*