2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Chemical doping by sulfuric acid in double wall carbon nanotubes

P. Puech, A. Ghandour, A. Sapelkin, E. Flahaut, D. Dunstan, W. Bacsa
CEMES CNRS Univ Toulouse, FR

Keywords:
nanotubes, doping, Raman spectroscopy, doublle wall carbon nanotubes

Abstract:
Charge transfer due to chemical doping in carbon nanotubes [1] can be detected through changes in the band shape and spectral shifts of the Raman G-band. In double wall carbon nanotubes, the inner tube is well protected from the environment. Contributions of the inner tube to the Raman G-band can be detected and serve as a reference. Using the influence of sulfuric acid on G-band, a method has been proposed by Kim et al [2,3] to determine the purity of a sample and determining the ratio of DWNT to SWNT using Raman spectroscopy. We find that by combining doping with sulfuric acid and high hydrostatic pressure [4], we can determine the composition of our sample with higher accuracy and we propose empirical parameters to fit the G-band line shape. Our results reveal clearly electronic coupling of the two tube walls related to a spectral band at 1560cm-1 which changes with pressure at the same rate as the outer tube. [1] G. Chen et al Phys. Rev. Lett. 90, 257403 (2003) [2] Y.A. Kim et al. Chem. Phys. Lett. 420, 377 (2006) [3] W. Zhou et al. Phys. Rev. B 71, 205423 (2005) [4] P. Puech et al. Phys. Rev. B73, 233408 (2006)


Nanotech 2008 Conference Program Abstract