Nonradiative exciton decay dynamics in hole-doped single-walled carbon nanotubes

Abstract

We studied exciton dynamics in hole-doped single-walled carbon nanotubes (SWNTs). The intensities of photoluminescence (PL) peaks decreased and the PL lifetimes became shorter with an addition of hole dopant tetrafluorotetracyano-p-quinodimethane (F4TCNQ). We found that the nonradiative decay of excitons induced by the F4TCNQ was of the order of a few tens of picoseconds for densities of ～0.1 hole/nm at room temperature. Our results suggest that the nonradiative exciton relaxation in the hole-doped SWNTs can be explained by phonon-assisted indirect ionization processes.