Synthesis, Structures, and Luminescent Properties of a Yellow-Emitting Iridium Complex

The synthesis, structure and luminescent properties of a cyclometalated iridium (ΙΙΙ) complex are reported. The cyclometalated ligand and auxiliary ligand are 2-(2-fluorophenyl)-benzothiazole (F-BT) and acetylacetone (Hacac), respectively. The complex (F-BT)2Ir(acac) exhibits bright photoluminescence (PL) at room temperature with a high solution PL quantum efficiency of 0.62. Organic electroluminescent (EL) devices are fabricated employing (F-BT)2Ir(acac) as an emissive dopant in 4,4′-N,N′-dicarbazole-biphenyl (CBP) host. EL efficiency shows weak dependence on doping concentration and current density. While the optimized device exhibits a peak efficiency of 28.5 cd/A and a maximum brightness of 49880 cd/m2. An efficiency of 22.7 cd/A at 100 mA/cm2, 80% of the maximum, can be achieved.