title: Free-carrier generation in aggregates of single-wall carbon nanotubes by photoexcitation in the ultraviolet regime.
abstract: We present evidence for the generation of free carriers in aggregated single-wall carbon nanotubes by photoexcitation in the energetic range of the π→π(*) transition associated with the M saddle point of the graphene lattice. The underlying broad absorption culminating at 4.3 eV can be fit well with a Fano line shape that describes strong coupling of a saddle-point exciton to an underlying free electron-hole pair continuum. Moreover, it is demonstrated that transitions in this energetic region autoionize into the continuum by detecting features unique to the presence of free charges in the transient transmission spectra of the continuum-embedded second sub-band exciton, S(2).
authors.affiliation: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. jcrochet@lanl.gov
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Crochet
authors.forename: Sajjad
authors.initials: S
authors.lastname: Hoseinkhani
authors.forename: Larry
authors.initials: L
authors.lastname: Lüer
authors.forename: Tobias
authors.initials: T
authors.lastname: Hertel
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Doorn
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Lanzani