High efficiency deep blue phosphorescent organic light-emitting diodes

Deep blue phosphorescent organic light-emitting diodes have been developed by using tris((3,5-difluoro-4-cyanophenyl)pyridine) iridium (FCNIr) as a blue phosphorescent dopant. The FCNIr showed a wide triplet bandgap of 2.8 eV for deep blue emission due to a strong electron withdrawing CN substituent in addition to F unit. Doping of the FCNIr in N,N’-dicarbazolyl-3,5-benzene gave a high quantum efficiency of 9.2% with a CIE color coordinate of (0.15, 0.16).