Direct Measurement of Electric Field-Assisted Charge Separation in Polymer:Fullerene Photovoltaic Diodes

Authors

  • R. Alex Marsh,

    1. Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE (U.K.)
    Current affiliation:
    1. These authors contributed equally to this work
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  • Justin M. Hodgkiss,

    1. Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE (U.K.)
    2. Current Affiliation: MacDiarmid Institute of Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600 (New Zealand)
    Current affiliation:
    1. These authors contributed equally to this work
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  • Richard H. Friend

    Corresponding author
    1. Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE (U.K.)
    • Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE (U.K.).
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Abstract

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The electric field dependence of transient optical absorption of photogenerated charge carriers in working organic photovoltaic cells is reported. Charge lifetimes are extended under reverse bias, revealing that the mechanism of photocurrent generation is the electric field-assisted separation of Coulombically bound charge pairs in kinetic competition with geminate charge recombination.

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