Ultrafast Dynamics of Single-Walled Carbon Nanotubes Dispersed in Polymer Films

Abstract
Wavelength-resolved femtosecond transient absorption spectroscopy is used to follow the electronic dynamics of single-walled carbon nanotubes in polymers following visible photoexcitation. Electron−hole (e−h) pairs give rise to sharp features in the transient spectra that decay in amplitude and exhibit rapid spectral shifts. The decay reflects (e−h) recombination on both short (1.3 ps) and long (35 ps) time scales. Transient spectra also exhibit a broad photobleach at early times that arises from the cooling of a hot electron gas created via excitation at the red edge of a π-plasmon band.