Influence of chain packing on the excitation transfer in perylene-end-capped polyindenofluorene

Summary form only given. We have investigated the excitation transfer in a novel polymer/dye system consisting of the blue-light-emitting conjugated polymer poly(6,6´-12,12´-tetra-2-ethylhexyl-2,8-indenofluorene) (PIFTEH) as a host and red-light-emitting perylene molecules covalently bonded to the PIFTEH chain ends as, a guest. The spectral overlap between the host emission and the guest absorption leads to an efficient Forster excitation transfer, such that photo-excitation of the host result in emission originating predominantly from the guest. Using femto-second time-resolved photoluminescence (PL) spectroscopy, we find that the transfer of excitations from isolated PIFTEH chains to perylene molecules is completed within the first 30-40 ps after excitation, and we extract a Forster radius of (1.8/spl plusmn/0.3) nm from fits to the PL transients.