NIR-luminescence mapping and Raman spectroscopy of single-walled carbon-13 nanotubes

Photoluminescence and Raman scatterings of single-walled carbon nanotubes (SWNTs) synthesized from isotopically-modified ethanol were studied. Using Alcohol catalytic CVD (ACCVD) technique optimized for the efficient production of SWNTs from very small amount of ethanol, SWNTs consisting of carbon-13 isotope (SW$^{13}$CNTs) were synthesized in addition to normal SWNTs consisting of mainly $^{12}$C. The vibrational features of SW$^{13}$CNTs were compared with those of normal SWNTs through NIR-luminescence mapping and Raman spectroscopy. There was almost no change in Raman spectra shape of SW$^{13}$CNTs except for the Raman shift frequency down-shifted as much as square-root of mass ratio 12/13. In addition to Raman spectroscopy, we have mapped the NIR-luminescence of D$_{2}$O-surfactant dispersions of both SW$^{13}$CNTs and SW$^{12}$CNT. By comparing the two maps, luminescence peaks corresponding to electronic transitions with vibrational excitation were identified.