title: Raman doping profiles of polyelectrolyte SWNTs in solution.
abstract: We present a resonance Raman study of electrochemical charge transfer doping on polyelectrolyte single-walled carbon nanotubes (SWNTs) in solution. Changes in the intensity of the radial breathing modes of well-identified SWNTs are measured as a function of the electrochemical potential. The intensity is maximum when the nanotubes are neutral. Unexpectedly, the Raman signal decreases as soon as charges are transferred to the nanotubes, leading to intensity profiles that are triangular for metallic and trapezoidal for semiconducting nanotubes. A key result is that the width in energy of the plateaus for the semiconducting nanotubes is roughly equal to the optical gap (rather than the free carrier gap). While these experiments can be used to estimate the energy levels of individual nanotubes, strong dynamical screening appears to dominate in individual SWNT polyelectrolytes so that only screened energy levels are being probed.
authors.affiliation: Département de chimie, Université de Montréal, C.P. 6128 Succursale Centre-Ville, Montréal, Québec H3T 1J4, Canada.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Dragin
authors.forename: Alain
authors.initials: A
authors.lastname: Pénicaud
authors.forename: Matteo
authors.initials: M
authors.lastname: Iurlo
authors.forename: Massimo
authors.initials: M
authors.lastname: Marcaccio
authors.forename: Francesco
authors.initials: F
authors.lastname: Paolucci
authors.forename: Eric
authors.initials: E
authors.lastname: Anglaret
authors.forename: Richard
authors.initials: R
authors.lastname: Martel
mesh_terms: D003460:Crystallization / Q000379:methods*; D004595:Electroplating / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon