Indexing of individual single-walled carbon nanotubes from Raman spectroscopy

Abstract

From combined Raman spectroscopy and electron diffraction studies on several freestanding single-walled carbon nanotubes (SWNTs), we define Raman criteria which correlate the main features of the Raman spectrum (radial breathing mode and G modes) and the optical transition energies with the structure of the SWNT under investigation. On this basis, we discuss the possibilities to determine the $(n,m)$ indices of an individual SWNT from a single wavelength Raman experiment. We show the efficiency of this approach in assigning the $(n,m)$ structure of different individual nanotubes including all types of achiral SWNTs. Finally, the limits and the accuracy of the method are discussed.