Low voltage and very high efficiency deep-blue phosphorescent organic light-emitting devices.

We report on very high efficiency deep-blue phosphorescent organic light-emitting devices (PHOLEDs) based on iridium(III) bis(4′,6′-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6). Dual emissive layers consisting of an N,N′-dicarbazolyl-3,5-benzene layer doped with 4 wt % FIr6 and a p-bis(triphenylsilyly)benzene layer doped with 25 wt % FIr6 were employed to maximize exciton generation on FIr6 molecules. Combined with the p-i-n device structure, we achieved a low turn-on voltage of 3.2 V and very high power efficiencies of 25±2 lm/W at 100 cd/m2 and 20±2 lm/W at 1000 cd/m2 for such deep-blue PHOLEDs with peak emission at a wavelength of 458 nm. [ABSTRACT FROM AUTHOR]