Dynamics of excitation transfer in dye doped Π-conjugated polymers

We present a time-resolved study of the transfer of optical excitations in conjugated polymers using luminescence spectroscopy with subpicosecond time resolution. In our experiments optical excitations are transferred from the initially excited polymers to admixtured dye molecules acting as acceptors. The temporal evolution of the emitted luminescence reveals transfer times of several picoseconds depending on the concentration of the dye molecules. From the dependence of the transfer time on the mean distance between excited polymer chromophores and acceptor dye molecules, we conclude the occurrence of a Fِrster-type energy transfer.