TiO2 sensitized with an oligo(p-phenylenevinylene) carboxylic acid: a new model compound for a hybrid solar cell

The interaction of an acid-functionalized oligo(p-phenylenevinylene) (OPV3-COOH) with nanocrystalline TiO2 has been studied as a model for semiconducting polymer-inorganic material hybrid solar cells. Langmuir adsorption studies show that the monolayer coverage of OPV3-COOH on nc-TiO2 results in 35% filling of the nanopores. Photoluminescence quenching and near steady-state photoinduced absorption spectroscopy demonstrate that an efficient forward photoinduced electron transfer occurs from OPV3-COOH to TiO2. Photovoltaic cells based on OPV3-COOH/nc-TiO2 and a liquid electrolyte as a medium for hole transport provide an incident photon-to-electron conversion efficiency of 55%, comparable to the values obtained with the best ruthenium dyes, and show that the majority of the photogenerated charges can be collected.