High-efficiency and multi-function blue fluorescent material for organic electroluminescent devices

We demonstrate one high-efficiency blue fluorescent material, N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine, emissive peak of 472 nm and the hole-transporting property speculated from different devices. It can function either as the single emissive layer or as the dye doped in N,N'-dicarbazolyl-4-4'-biphenyl (CBP). The former shows a maximum current efficiency and luminance of 7.06 cd/A (0.04 mA/cm(2)) and 16 930 cd/m(2), in contrast to 11.5 cd/A (4.35 mA/cm(2)) and 25 690 cd/m(2) for the latter. The better performance of the latter can be attributed to the bipolar carrier transport property of CBP and the hole-blocking and electron-transporting characteristic of 4,7-diphenyl-1,10-phenanthroline (BPhen), which resulting in a good balance of holes and electrons. Moreover, the Commission Internationale De L'Eclairage coordinates of the latter change slightly from (0.162, 0.3) to (0.148, 0.268) upon increasing the voltage from 3 V to 14 V. (C) 2008 Elsevier B.V. All rights reserved.