Enhanced photovoltaic performance of ZnO nanoparticle/poly(phenylene vinylene) hybrid photovoltaic cells by semiconducting surfactant

Hybrid films of ZnO nanoparticles and poly[2-methoxy-5-(3',7'-dimethyloctyloxyl)-1,4-phenylene vinylene] (MDMO-PPV) were investigated as a model hybrid bulk heterojunction (HBHJ) photovoltaic cell which combines the simple processability and excellent electrical characteristics of inorganic nanoparticle acceptors and conjugated polymer donors. Improved photovoltaic performance was observed when the ZnO nanoparticles were stabilized with a new semiconducting surfactant, 2-(2-ethylhexyl)-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinoline-6,7-dicarboxylic acid (BQ). We found that using the BQ surfactant increased the power conversion efficiency (1.23%) while a typical insulating surfactant, oleic acid (OA), decreased the efficiency (0.65%) despite the improvement of the ZnO dispersion, as compared to the HBHJ films prepared without a surfactant (0.75%). The underlying mechanism was delineated by hybrid-morphology study, photoluminescence spectroscopy, and photo-induced absorption spectroscopy. (C) 2010 Elsevier B.V. All rights reserved.