title: Direct observation of sub-100 fs mobile charge generation in a polymer-fullerene film.
abstract: The formation of mobile charges in a roll-to-roll processed poly-3-hexylthiophene-fullerene bulk heterojunction film is observed directly by using transient terahertz spectroscopy with sub-100 fs temporal resolution. The transient terahertz ac conductivity reveals that 20% of the incident pump photons are converted into highly delocalized charges within the 40 fs, 3.1 eV pump pulse duration, which then rapidly becomes localized within 120 fs. Approximately 2/3 of these carriers subsequently decay, possibly into an exciton, on a 1 ps time scale.
authors.affiliation: Department of Physics, McGill University, Montreal, Canada H3A 2T8.
authors.forename: D G
authors.initials: DG
authors.lastname: Cooke
authors.forename: F C
authors.initials: FC
authors.lastname: Krebs
authors.forename: P U
authors.initials: PU
authors.lastname: Jepsen