摘要
Efficient deep-red organic light-emitting diodes （OLEDs） were investigated based on the blend of poly[2- methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene] （MEH-PPV） with 4,7-bis（5-（7-（9H-carbazol-9-yl）-9,9-dioctyl-9H- fluoren-2-yl）thiophen-2-yl）benzo[c] [1,2,5] thiadiazole （compound 1）. By optimizing the blend ratio, the turn-on voltage of the devices was significantly reduced from 4.9 V to 2.4 V. A highest external quantum efficiency of 2.56% was achieved at a blend ratio of 95：5 （wt） for compound 1： MEH-PPV. The CIE coordinate was measured to be （0.70, 0.30）, with the luminescence peak at around 680 nm. Based on experimental observations the improvement mechanism is described.
Efficient deep-red organic light-emitting diodes （OLEDs） were investigated based on the blend of poly[2- methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene] （MEH-PPV） with 4,7-bis（5-（7-（9H-carbazol-9-yl）-9,9-dioctyl-9H- fluoren-2-yl）thiophen-2-yl）benzo[c] [1,2,5] thiadiazole （compound 1）. By optimizing the blend ratio, the turn-on voltage of the devices was significantly reduced from 4.9 V to 2.4 V. A highest external quantum efficiency of 2.56% was achieved at a blend ratio of 95：5 （wt） for compound 1： MEH-PPV. The CIE coordinate was measured to be （0.70, 0.30）, with the luminescence peak at around 680 nm. Based on experimental observations the improvement mechanism is described.
基金
financially supported by the National Natural Science Foundation of China(Nos.61036007 and 60937001)
Ministry of Science and Technology of the People's Republic of China(Nos.2009CB930604 and 2009CB623604)
