Charge separation in conjugated-polymer/nanocrystal blends

Efficient charge separation has been observed in blends of conjugated polym ers and cadmium selenide nanocrystals. These composites, which can be used for photovoltaic applications, provide a unique medium for examining charge separation because the energy levels of both components can be tuned indep endently: those of the polymer by its side groups, and those of the nanocry stals by size-dependent quantum confinement effects. Here we study charge s eparation in such blends via photoluminescence quenching and photo-induced absorption measurements. The effects of polymer derivatization and nanocrys tal size are investigated.