Résumé
We report a detailed study of changes in optical properties of single-walled carbon nanotubes caused by doping in acid medium and their comparison with those induced by other doping techniques. In this work, a hydrochloric acid was added to the aqueous suspension of nanotubes wrapped with sodium cholate. Additionally to the shift and suppression of several modes in the Raman spectrum and the suppression of the first optical transition in the optical absorption spectrum, we have observed an appearance of a trion band in the photoluminescence spectrum with the energy about 0.2 eV less than the main photoluminescence band.