title: Encounter-limited charge-carrier recombination in phase-separated organic semiconductor blends.
abstract: The theoretical effects of phase separation on encounter-limited charge carrier recombination in organic semiconductor blends are investigated using kinetic Monte Carlo simulations of pump-probe experiments. Using model bulk heterojunction morphologies, the dependence of the recombination rate on domain size and charge carrier mobility are quantified. Unifying competing models and simulation results, we show that the mobility dependence of the recombination rate can be described using the power mean of the electron and hole mobilities with a domain-size-dependent exponent. Additionally, for domain sizes typical of organic photovoltaic devices, we find that phase separation reduces the recombination rate by less than one order of magnitude compared to the Langevin model and that the mobility dependence can be approximated by the geometric mean.
authors.affiliation: Experimental Physics VI, Julius-Maximilians-University of Würzburg, 97074 Würzburg, Germany.|Institut für Physik, Technische Universität Chemnitz, 09126 Chemnitz, Germany.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Heiber
authors.affiliation: Institut für Physik, Technische Universität Chemnitz, 09126 Chemnitz, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Baumbach
authors.affiliation: Experimental Physics VI, Julius-Maximilians-University of Würzburg, 97074 Würzburg, Germany.|Bavarian Centre for Applied Energy Research (ZAE Bayern), 97074 Würzburg, Germany.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Dyakonov
authors.affiliation: Institut für Physik, Technische Universität Chemnitz, 09126 Chemnitz, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Deibel