Dendritic sidegroups as three-dimensional barriers to aggregation quenching of conjugated polymer fluorescence

We study the photophysics of poly-phenylenevinylene (PPV) polymers with lar ge dendritic sidegroups under both isolated chain and aggregated chain cond itions. Aggregation causes a substantial reduction in photoluminescence (PL ) quantum yield but that decrease is ameliorated by the attachment of an ad ditional generation of dendron to the PPV backbone. Three-dimensional separ ation of chromophores can be achieved with these sidegroups and the formati on of nearly nan-emissive interchain excitations leads to a factor of four enhancements in solid-state PL. (C) 2000 Elsevier Science S.A. All rights r eserved.