Efficient Polymer Light-emitting Diodes Utilizing Modified Al Cathode

We report the significant increases in the electroluminescence (EL) efficiency of poly(2-methoxy-5-(2'-ethylhe xyloxy)-1,4-phenylene vinylene)-based polymer light-emitting diode by a solution processible and interfacial modification 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).