Supramolecular self-assembly and opto-electronic properties of semiconducting block copolymers

With continuous and nanometre-scale interpenetrating phases of electron donor and acceptor components, a novel diblock copolymer, in which one block is poly(p-phenylene vinylene) (PPV) and the other is a C60-functionalized polystyrene, is designed to be an efficient photovoltaic material. The synthesis involves the polymerization of a styrene derivative from a PPV-based macroinitiator via living free radical polymerization, and its subsequent functionalization with C60 via atom transfer radical addition. In selective solvents for the polystyrene block, aggregation is detected by means of optical spectroscopy and small-angle neutron scattering. Solid films exhibit honeycomb-structuring at the micrometre level when cast from CS2. As active layer in a device, the donor–acceptor diblock copolymer shows enhanced photovoltaic response relative to a blend of its constituent polymers.