Multiple Exciton Generation in Single-Walled Carbon Nanotubes

Upon absorption of single photons, multiple excitons were generated and detected in semiconducting single-walled carbon nanotubes (SWNTs) using transient absorption spectroscopy For (6,5) SWNTs, absorption of single photons with energies corresponding to three times the SWNT energy gap results in an exciton generation efficiency of 130% per photon Our results suggest that the multiple exciton generation threshold in SWNTs can be close to the limit defined by energy conservation