A soluble fused donor-acceptor conjugated polymer (fDA-CP) is prepared that absorbs light throughout nearly all the visible spectrum and is essentially black to the human eye when in the neutral state. The conjugated polymer has acceptor units that are isolated by a plurality of fused donor units. The fDA-CP assumes a conformation that results in a close π-stacking between adjacent lamella with a separation of less than 4.5 Å in the solid state and extended conjugation to promote high charge carrier mobilities. The fDA-CP is prepared by the polycondensation of a plurality of at least one fused donor-acceptor oligomer (fDA-oligomer) that has a flat internal acceptor unit and at least one fused donor unit incorporated in the oligomers, and optionally, an additional conjugated aromatic monomer or oligomer copolymerized with the fDA-oligomers.