Quantitative composition of a single-walled carbon nanotube sample: Raman scattering versus photoluminescence

We investigated the spectral data of three carbon nanotube (CNT) species obtained by Raman spectroscopy and photoluminescence (PL) measurements. The corresponding relative signal intensities without further corrections yielded significantly different relative distributions of the CNT species. Theoretical calculations of optical transition probabilities and electron-phonon coupling were included, providing simple models in order to estimate the relative distribution of the three species within the sample. We proposed the product of PL and PL excitation intensities to be a candidate for quantitative analysis of CNT species. Applying the models, we confirmed that both spectroscopic methods agree on one nanotube species dominating the distribution.