Auger-Assisted Ultrafast Fluorescence Measurement of Semiconductor Single-Walled Carbon Nanotubes

Abstract

In the Auger process of a semiconductor nanostructure, the recombination energy of higher-order excitons would be nonradiatively transferred to the lower-order ones, and only the last exciton left could emit a photon. Here we show that this exciton–exciton annihilation effect can be positively employed to develop a novel optical technique for ultrafast fluorescence measurement. Upon excitation with two laser pulse trains continuously delayed in time, the fluorescence intensity of semiconductor single-walled carbon nanotubes increases accordingly, with two lifetime components of several and tens to hundreds of picoseconds being clearly resolved.