In situ assessment of carbon nanotube diameter distribution with photoelectron spectroscopy
de los Arcos, T. × Garnier, M.G. Oelhafen, P. Seo, Jin Won Domingo, C. Garcia-Ramos, J.V. Sanchez-Cortes, V. #
American physical soc
Physical review b vol:71 issue:20 pages:-
In situ UV-photoelectron spectroscopy (He I and He it) was performed on multiwalled carbon nanotubes (CNTs) with clearly differentiated diameter distributions. A significant dependence of valence- and conduction-band characteristics on the mean CNT diameter was observed, which was determined by high-resolution TEM and micro-Raman spectroscopy. The decrease of relative intensity of the pi states at -3 eV in the He II experiments, indicative of increasing rehybridization between orbitals, was directly correlated with decreasing mean diameters. Furthermore, a progressive broadening of the unoccupied sigma* band at 7.6 eV was found in the He I spectra.