C60 Filling Rate in Carbon Peapods: A Nonresonant Raman Spectra Analysis

We calculated the nonresonant Raman spectra of peapods to determine the concentration of fullerenes inside single-walled carbon nanotubes. We focus on peapods with large diameters for which molecules can adopt a double helix configuration or a two-molecule layer configuration. Our calculations are performed within the framework of the bond-polarizability model combined with the spectral moment’s method. The changes in the Raman spectra as a function of filling rate and the configuration of molecules inside the nanotubes are identified and discussed. Our calculations support the experimental method proposed by Kuzmany to evaluate the concentration of molecules inside nanotubes.