Tunable filter Raman spectroscopy of purified semiconducting and metallic carbon nanotubes
single walled carbonnanotube (SWCNT), tunable Ramanspectroscopy, purity, metallicity
Tunable filter Raman spectroscopy is used to efficiently produce Raman excitationmaps of unpurified and type-purified single walled carbon nanotubes (SWCNTs).Maps with fine excitation resolution (1 nm) are created over a wide wavelengthrange (727 to 980 nm), extending from metallic to semiconducting resonances. Ata given wavelength, the wide bandwidth (>3,000 cm–1) allows the comparison ofthe G band with the radial breathing mode (RBM), and shows the 2D band andother less prominent bands. Materials examined included unsorted powders,aqueous sorted semiconductors, aqueous sorted metals, and polyfluorene sortedsemiconductors in toluene. The Raman excitation profiles of the G band arebroad, relative to the RBM bands. The maps offer evidence of minority speciescontamination, except in the case of the polyfluorene sorted semiconductors.Tunable Raman spectroscopy data help validate the simpler fixed wavelengthRaman spectroscopy approaches to purity assessment.
Tsinghua University Press
Paul Finnie, Tunable filter Raman spectroscopy of purified semiconducting and metallic carbon nanotubes. NanoRes.2016, 9(9): 2715–2728