Assessing the reliability of the Raman peak counting method for the characterization of SWCNT diameter distributions: a cross-characterization with TEM

Abstract

Resonant Raman spectroscopy is a widely used technique for single-walled carbon nanotube (SWCNT) characterization, in particular in the radial breathing mode (RBM) range which provides direct information on the structure of the nanotube in resonance. The RBM peak counting method, i.e. acquiring Raman spectrum grids on a substrate with a select set of discrete laser lines and counting RBM peaks as single nanotubes, is frequently used to characterize SWCNT growth samples, despite the many factors that can induce errors in the results. In this work, we cross-characterize the diameter distributions obtained through this methodology with diameter distributions obtained by counting SWCNT diameters in transmission electron microscopy (TEM) and discuss the different results and biases between the techniques. This study is performed on a broad diameter distribution sample, and on two chirality-enriched samples whose chirality distributions are determined by photoluminescence excitation spectroscopy (PLE) and statistical analysis of high resolution TEM (HRTEM) images. We show that the largest differences between the Raman peak counting and TEM diameter distributions stem from the chirality-dependence of SWCNT Raman cross-sections and the patchy vision offered by the use of only a few discrete excitation wavelengths. The effect of the substrate and TEM-related biases are also discussed.

References in corpus (5)

• Radial breathing mode of single-walled carbon nanotubes: Optical transition energies and chiral-index assignment
• Interference enhancement of Raman signal of graphene
• Interference effect on Raman spectrum of graphene on SiO_2/Si
• A comprehensive model of the optical spectra of carbon nanotubes on substrate by polarized microscopy
• The strength of the radial-breathing mode in single-walled carbon nanotubes

Cited by in corpus (4)

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• The role of the bile salt surfactant sodium deoxycholate in aqueous two-phase separation of single-wall carbon nanotubes revealed by systematic parameter variations
• Ultrasonication-Induced Extraction of Inner Shells from Double-Wall Carbon Nanotubes Characterized via In Situ Spectroscopy after Density Gradient Ultracentrifugation
• Predicting the Thermal Conductivity Collapse in SWCNT Bundles: The Interplay of Symmetry Breaking and Scattering Revealed by Machine-Learning-Driven Quantum Transport