| abstract |
Iridium complexes comprising three different bidentate ligands and their use in OLEDs to enhance the device efficiency and lifetime are disclosed. The complexes have a structure of the formula Ir(LA)(LB)(LC), where ligand LA is selected from a variety of structures, ligand LB has the structureand LC has the structureIn these structures, rings A, B, C, and D are each independently a 5 or 6-membered carbocyclic or heterocyclic ring; R1, R2, R3, RA, RB, RC, and RD can be any of a variety of substituents, and Z1 and Z2 are each independently C or N. |