Raman spectra of single-walled carbon nanotubes with vacancies

Density-functional based tight-binding method in conjunction with nonresonant bond-polarization theory is used to predict Raman spectra of single-walled carbon nanotubes with vacancies. Calculations show that the high-energy Raman active modes are more sensitive to vacancies and their energy is generally lowered, while also the radial breathing mode may change in intensity and shape. The connection of these observations to experiments is discussed. The effect of vacancies on the spatial nature of Raman active eigenmodes is analyzed and discussed.