containing 3,3´-dialkylbithiophene and bis(phenylquinoline) moieties in the main chain has led to a large improvement in performance of MEH-PPV-based light-emitting diodes. The good solubility of the copolymer in both aprotic organic solvents and protonic acid solvents has enabled the ready fabrication of multilayer light-emitting devices. (S. A. Jenekhe et al., August 5, Adv. Mater. 2002, 14, 1086-1090)