Diameter dependence of exciton-phonon interaction in individual single-walled carbon nanotubes studied by microphotoluminescence spectroscopy

We have investigated the diameter dependence of the exciton luminescence linewidth in individual single-walled carbon nanotubes (SWNTs) by means of microphotoluminescence (mu-PL) spectroscopy. The line shapes of mu-PL spectra for single SWNTs suspended on a patterned Si substrate at room temperature can be fitted by single Lorentzian functions. It is found that the mu-PL linewidth depends strongly on the diameter of SWNTs and the exciton-phonon interaction is enhanced with a decrease of the diameter.