Observation of rapid Auger recombination in optically excited semiconducting carbon nanotubes

Time-resolved fluorescence measurements of single-walled carbon nanotubes (SWNTs) reveal rapid electron-hole pair annihilation when multiple electron-hole pairs are present in a nanotube. The process can be understood as Auger recombination with a rate of similar to1 ps(-1) for just two electron-hole pairs in a 380-nm long SWNT. This efficient nonradiative recombination reflects the strong carrier-carrier interactions in the quasi-one-dimensional SWNTs. In addition to affecting nanotube fluorescence, Auger recombination imposes limitations on the sustained electron-hole density achievable within a SWNT.