PPV/TiO2 hybrid composites prepared from PPV precursor reaction in aqueous media and their application in solar cells

In this work, poly(phenylene vinylene) (PPV) and TiO2 nanocomposites containing different amounts of TiO2 were prepared through PPV precursor reaction in aqueous media. The TiO2 components were introduced into the systems by two methods, i.e. through in situ sol-gel reaction or by mixing commercially available TiO2 nanoparticles with the PPV precursor before reaction. The composite prepared by mixing commercially available TiO2 nanoparticles shows perfect crystal character of the anatase TiO2, but TiO2 particles severely agglomerate in the PPV matrix. The composite prepared by introducing TiO2 nanoparticles through the sol-gel reaction shows uniform nanoscale dispersion of anatase TiO2 in PPV matrix. The UV-vis and FL spectroscopic analyses confirm the formation of the TiO2/PPV composites and reveal the enhanced PL quenching effect as the TiO2 content increases. The PPV/TiO2 composites can show significant photovoltaic response. Better photovoltaic performance is observed for the solar cells prepared by using the in situ sol-gel reaction method.