Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 4: Carbon: Diamond, Nanotubes, and Graphene
HL 4.8: Talk
Monday, March 14, 2011, 12:15–12:30, POT 251
Localized defects in single carbon nanotubes imaged with high-resolution tip-enhanced Raman spectroscopy — •Carsten Georgi and Achim Hartschuh — Department Chemie & CeNS, Ludwig-Maximilians-Universität München, Germany
Raman spectroscopy is a powerful tool to study defects in sp2 carbon materials including carbon nanotubes, graphite and graphene [1]. Defects in the crystalline structure of these materials activate scattering by large momentum phonons giving rise to the characteristic D-band Raman signal. We imaged the D-band scattering in metallic single-walled carbon nanotubes with a spatial resolution of 15 nm using tip-enhanced Raman spectroscopy (TERS). The spatial extension of the D-band signal in the vicinity of localized defect sites was visualized and found to be about 2 nm. Furthermore, localized defects were intentionally photo-generated using the strong optical near-fields at the tip while simultaneously recording the temporal evolution of the local Raman spectrum. From these experiments, the relation between defect density and Raman D-band intensity could be derived for the investigated nanotubes. This relation is highly relevant for the characterization of carbon nanotubes via Raman spectroscopy [2].
[1] A. C. Ferrari et al., Phil. Trans. R. Soc. Lond. A 362, 2477 (2004)
[2] C. Georgi, A. Hartschuh, Appl. Phys. Lett. 97, 143117 (2010)