HIGHLY EFFICIENT GREEN LIGHT-EMITTING-DIODES WITH ALUMINUM CATHODE

A novel silyl-substituted solvent processible poly(1,4-phenylenevinyle ne) (PPV) derivative, poly(2-dimethyloctylsilyl-1,4-phenylenevinylene) (DMOS-PPV) and copolymers of DMOS-PPV and y(2-methoxy-5-ethylhexyloxy -1,4-phenylenevinylene) (MEH-PPV) have been synthesized by the dehydro halogenation route, and the light-emitting properties of these polymer s have been studied. Electroluminescent devices were fabricated with t hese polymers as emitting layers, and ITO and Al as anode and cathode, respectively. A single layer device using DMOS-PPV as the emissive la yer showed 0.2% internal quantum efficiency. Single layer devices usin g the copolymers showed internal quantum efficiencies between 0.1 - 0. 02% depending on the copolymer compositions.