Quantum dots tailored with poly(para-phenylene vinylene)

In polymer-nanoparticle composites, uniform dispersion of the nanoparticles carries advantages over cases where nanoparticle aggregation dominates. Such dispersion has been particularly difficult to obtain in the case of composites prepared from nanoparticles and conjugated polymers. Here, we show that cadmium selenide nanocrystals, or quantum dots, can be integrated into thin films of poly(paraphenylene vinylene) (PPV) without aggregation. The two key departures from previous studies of quantum-dot/electronic polymer composites are (1) the synthesis of high-quality quantum dots directly in novel, functional ligands, thus eliminating the need for ligand exchange, and (2) polymerization chemistry that grafts PPV to the quantum dot surface. Solid-state photoluminescence spectra of composite materials prepared by these novel techniques reveal the critical importance of the quantum dot-polymer interface that will enable new investigations in nanoparticle-based light-emitting devices.