Comparative study of first- and second-order Raman spectra of MWCNT at visible and infrared laser excitation

Growth of carbon nanotubes at temperatures compatible with integrated circuit technologies

“…Given the short length of the nanotubes, it is possible that there is a strong contribution from the dome tips of the aligned nanotubes, giving rise to a stronger D band, as suggested by Antunes et al 14 .…”

“…Second order Raman peaks are associated with well developed multiple scattering optical interactions 14,15 , as seen in fullerites (Fig. 4b) The Raman spectrum shows a slightly higher D-band than G-band, resulting in a higher I D /I G ratio (1.01) -see Supplementary information for a description of the Raman spectral features.…”

“…The 2705, 2945 and 3244 cm -1 bands can all be attributed to long-range order. They have also observed that aligned carbon nanotubes have a strong D-line 14,15 .…”

Comparison of structure and yield of multiwall carbon nanotubes produced by the CVD technique and a water assisted method

“…From the Raman spectra, we can see that the lo!IG ratio for MWNTs produced by the CVO method is higher than the lo!IG ratio for MWNTs produced by the water assisted method. A high value of IDll c ratio indicates more number of defects and more amount of amorphous carbon in the sample [29,30]. Infact, the intensity of 0 band is considered defect dependent [30].…”

“…A high value of IDll c ratio indicates more number of defects and more amount of amorphous carbon in the sample [29,30]. Infact, the intensity of 0 band is considered defect dependent [30]. Hence, MWNTs produced by the CVD method contain more defects as compared to MWNTs produced by the water assisted method.…”