Abstract: The invention relates to novel conjugated polymers comprising in their backbone one or more divalent donor units, like for example benzo[1,2-b:4,5-b?]dithiophene-2,6-diyl (BDT), that are linked on both sides to an acceptor unit, to methods of preparing the polymers and educts or intermediates used in such preparation, to polymer blends, mixtures and formulations containing the polymers, to the use of the polymers, polymer blends, mixtures and formulations as semiconductors organic electronic (OE) devices, especially in organic photovoltaic (OPV) devices and organic photodetectors (OPD), and to OE, OPV and OPD devices comprising these polymers, polymer blends, mixtures or formulations.