Blue-light emitting diodes and flat display based on poly (p-phenylenevinylene) copolymers

Copolymers containing alternating flexible aliphatic blocks and rigid poly (p-phenylenevinylene) (PPV) blocks were synthesized and characterized. It was found that the fluorescent intensity increases with increasing length of the flexible blocks. Bright blue-light emitting diodes were fabricated using PPV copolymers as electroluminescent layers. The devices show 190 cd/m2 light-emitting brightness at 460 nm and 15 V turn-on voltage. The effects of oxadiawle derivative PBD and tris(8-hydroxyquinoline) aluminum Alq3 electron-transporting layers on the luminance and stability of the devices are discussed.