A green emitting, alkoxy disubstituted poly(p-phenylene vinylene) for Electroluminescent Devices

We report the effects of the substitution of butoxy chains on the phenyl 2,3 positions of poly(p-phenylene vinylene) (PPV). We find that this substitution has a remarkable influence on the optical and electroluminescent properties of the resulting semiconductor (DB-PPV) which does not show the red-shift of the emission, typical of alkoxy substituted PPVs, such as poly(2-methoxy-5-(2′-ethyl-hexyloxy)-l, 4-phenylene vinylene), MEH-PPV, dominated by the influence of the π-electron rich oxygen atom. We report photoluminescence (PL), quantum efficiencies of 40%, electroluminescence (EL) efficiencies of 0.6 cd/A in 2-layer ITO/PPV/DB-PPV/Ca diodes, and luminances up to 4500 cd/m2.