High efficiency blue phosphorescent organic light-emitting device

We have demonstrated a substantial enhancement in the efficiency of iridium (III) bis[(4,6-di-fluorophenyl)-pyridinate-N,C-2']picolinate based blue phosphorescent organic light-emitting devices (PHOLEDs). The efficiencies of PHOLEDs with conventional electron transport materials are low due to their low electron mobilities as well low triplet energies. High triplet energy electron transporting material with high electron mobility was used as a hole blocker to achieve efficient exciton confinement and good charge balance in the device thereby achieving a high current efficiency of 49 cd/A and an external quantum efficiency of 23%. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3000382]