The exciton decay dynamics in hole-doped single-walled carbon nanotubes (SWCNTs) has been studied by femtosecond pump-probe transient absorption (TA) spectroscopy. By the doping of SWCNTs with holes, a fast decay component with the lifetime of a few picoseconds appears in TA signals, which corresponds to exciton decay through the Auger recombination between an exciton and a hole and the trion formation. We revealed that this exciton decay rate is quantized by the number of holes in a single SWCNT. The number of holes of a hole-doped SWCNT is successfully evaluated on the basis of TA decay dynamics.

• Received 18 April 2012

DOI:https://doi.org/10.1103/PhysRevB.86.075449