Enhancement of Luminescence in Polymer Nanocomposites

The effect of supramolecular structure and morphology on the solid state luminescence of polymers is explored through a rod-coil copolymer system, poly(benzobisthiazole-1,4-phenylene-co-benzobisthiazole decamethylene), which forms nanocomposites at compositions below 50 mol% rods. The composition dependence of the photoluminescence quantum efficiency exhibited a sharp change corresponding to a change in supramolecular structure of the copolymers. The photoluminescence quantum efficiency of the polymer nanocomposites was as high as 37% which represents over sixfold enhancement compared to the corresponding 'bulk' conjugated polymer. These results have implications for the fundamental understanding of the origin of luminescence quenching in conjugated polymers and they also suggest that control of supramolecular structure and morphology is key to efficient solid state luminescence in polymers.