title: In situ optical measurement of charge transport dynamics in organic photovoltaics.
abstract: We present a novel experimental approach which allows extraction of both spatial and temporal information on charge dynamics in organic solar cells. Using the wavelength dependence of the photonic structure in these devices, we monitor the change in spatial overlap between the photogenerated hole distribution and the optical probe profile as a function of time. In a model system we find evidence for a buildup of the photogenerated hole population close to the hole-extracting electrode on a nanosecond time scale and show that this can limit charge transport through space-charge effects under operating conditions.
authors.affiliation: Cavendish Laboratory, University of Cambridge , J. J. Thomson Avenue, Cambridge, United Kingdom.
authors.forename: Philip C Y
authors.initials: PC
authors.lastname: Chow
authors.forename: Sam L
authors.initials: SL
authors.lastname: Bayliss
authors.forename: Girish
authors.initials: G
authors.lastname: Lakhwani
authors.forename: Neil C
authors.initials: NC
authors.lastname: Greenham
authors.forename: Richard H
authors.initials: RH
authors.lastname: Friend
mesh_terms: D004566:Electrodes; D055668:Photochemical Processes; D012993:Solar Energy
keywords: Photovoltaics; charge transport; optical spectroscopy; organic; solar cells; transient absorption