Efficient polymer light-emitting diodes utilizing modified Al cathode

We report the significant increases in the electroluminescence (EL) efficiency of poly(2'-ethylhexyloxy)-1,4-phenylene vinylene)-based polymer light-emitting diode by a solution processible and interfacial modifcation at the device cathode. An ultra thin polymer nano-layer was introduced to the contact interface between the device cathode and the polymer EL layer. The devices utilizing the high work function metal. Al, with an interfacial layer perform two orders of enhancement in the device performance, from 0.017 cd/A (Al cathode) to 1.50 cd/A (nano-layer/Al cathode).