Exciton dissociation by a static electric field followed by nanoscale charge transport in PPV polymer films

The simultaneous study of the electric-field dependence of the photoluminescence and the photoinduced charge transport in the phenyl-substituted Super Yellow PPV derivative shows that charge carriers are created indirectly through field-induced ionization of excitons, and allows the identification of a free-carrier mobility larger than $\sim 3\times {10}^{-6}{\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$ that is valid for transport over a few nm during an apparent free-carrier lifetime of $\sim 50\mathrm{ns}$. The time dynamics of the photoluminescence and its temperature-quenching behavior indicate the presence of two species of excitons, which can be interpreted as intrachain and interchain excitons.