Thin Solid Films, Vol.516, No.1, 47-51, 2007
White polymer light-emitting diodes based on poly(2-(4'-(diphenylamino) phenylenevinyl)-1,4-phenylene-alt-9,9-n-dihexylfluorene-2,7-diyl) doped with a poly(p-phenylene vinylene) derivative
Efficient white polymer light-emitting diodes based on the polymer blend of poly(2-(4'-(diphenylamino)phenylenevinyl)-1,4-phenylene-alt-9,9-n-dihexy lfluorene-2,7-diyl) doped with poly 2-[3',5'-bis(2"-ethylhexyloxy) benzyloxy]-1,4-phenylenevinylenel-co-poly(2-methoxy-5-(2'-ethyl-hexyloxy )-1,4-phenylene vinylene) were fabricated. The electroluminescence (EL) spectrum is easily controlled by changing the dopant concentration. A white light emission was realized on the device with the dopant concentration of 0. 194%. and the emission light is less sensitive to the applied voltage in a wide voltage range. The maximum luminance and the maximum EL efficiency of the single-layer device were 2330 cd/ m 2 and 0.29 cd/A, respectively. By introducing an Alq(3) layer as an electron transporting and hole blocking layer, the overall performance of the double layer device was dramatically improved, the maximum luminance and the maximum EL efficiency reached 3300 cd/m(2) and 2.37 cd/A, respectively. (C) 2007 Elsevier B.V All rights reserved.
Keywords:white polymer light-emitting diodes;polyfluorene derivatives;poly(p-phenylene vinylene) derivatives;8-hydroxyquinoline aluminum