Photovoltaic enhancement of organic solar cells by a bridged donor-acceptor block copolymer approach

The authors show that a photovoltaic device composed of a -donor-bridge-acceptor-bridge- type block copolymer thin film exhibits a significant performance improvement over its corresponding donor/acceptor blend (V-oc increased from 0.14 to 1.10 V and J(sc) increased from 0.017 to 0.058 mA/cm(2)) under identical conditions, where donor is an alkyl derivatized poly-p-phenylenevinylene (PPV) conjugated block, acceptor is a sulfone-alkyl derivatized PPV conjugated block, and bridge is a nonconjugated and flexible unit. The authors attribute such improvement to the block copolymer intrinsic nanophase separation and molecular self-assembly that results in the reduction of the exciton and carrier losses. (c) 2007 American Institute of Physics.