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

With continuous and nanometre-scale interpenetrating phases of electron don or and acceptor components, a novel diblock copolymer, in which one block i s poly(p-phenylene vinylene) (PPV) and the other is a C-60-functionalized p olystyrene, is designed to be an efficient photovoltaic material. The synth esis involves the polymerization of a styrene derivative from a PPV-based m acroinitiator via living free radical polymerization, and its subsequent fu nctionalization with C-60 via atom transfer radical addition. In selective solvents for the polystyrene block, aggregation is detected by means of opt ical spectroscopy and small-angle neutron scattering. Solid films exhibit h oneycomb-structuring at the micrometre level when cast from CS2. As active layer in a device, the donor-acceptor diblock copolymer shows enhanced phot ovoltaic response relative to a blend of its constituent polymers. (C) 2001 Elsevier Science Ltd. All rights reserved.