High efficiency and stable-yellow phosphorescence from OLEDs with a novel fluorinated heteroleptic iridium complex

Abstract The performance of a heteroleptic bis-cyclometalated iridium complex based on 2-(2,3,4-trifluorophenyl)benzo[d]thiazole [(tfbt)2Ir(acac)] was investigated as a new phosphorescent emitter in OLEDs. The devices showed very high efficiency at various dopant concentrations and maximum efficiency was achieved at 6 wt% dopant concentration. A comparison of the performances of phosphorescent OLEDs with the new emitter versus those with prototype-based (bt)2Ir(acac) emitter revealed a remarkable improvement of efficiency at all dopant concentrations. These preliminary results obtained with the tfbt-based emitter indicate that this family of cyclometalated ligands with multi-fluorine functionalization is a promising compound for the development of highly emissive complexes.