Light-emitting polymers and their LED devices

Highly luminous polymers have successfully been prepared by copolymerization of various arylene vinylene units. The random copolymerization of the monomers having different energy gaps or conjugation degrees can generate the irregularity in poly(arylene vinylenes) and enhance the fluorescence of the polymer. Among the copolymers synthesized, the m/p-phenylene vinylene copolymer showed fairly strong fluorescence and gave the most efficient polymer light-emitting diode (P-LED) device because of the good balance of the exciton confinement and the charge transporting property. The optimized P-LED device showed a maximum luminance of 70 000 cd/m(2).