HIGHLY EFFICIENT LIGHT-EMITTING-DIODES BASED ON AN ORGANIC-SOLUBLE POLY(P-PHENYLENEVINYLENE) DERIVATIVE CARRYING THE ELECTRON-TRANSPORTING PIED MOIETY

Communication: Balanced charge injection and mobility are required for efficient electroluminescence (EL) in light-emitting diodes (LEDs). H ere a novel approach towards this end is described-the direct attachme nt of the electron transporting material -(4-biphenyl)-5-(4-t-butylphe nyl)-1,3,4-oxadiazole (PBD) to the backbone of poly(p-phenylenevinylen e) (PPV). The fabrication and performance efficiency of devices based on this polymer are reported. It is found that the EL efficiency is im proved to a remarkable extent, which is ascribed to a more facile elec tron injection and an enhancement of the electron transporting propert ies of the polymer.