Highly Effi cient Organic Light-Emitting Devices Prepared with a Phosphorescent Heteroleptic Iridium (III) Complex Containing 7,8-Benzoquinoline as the Cyclometalated Ligand

The performance of a heteroleptic bis-cyclometalated complex based on 7,8-benzoquinoline ligands is investigated as a new emitter in phosphorescent OLEDs. The devices show very high effi ciency at various dopant concentrations and maximum effi ciency is achieved at 8% dopant concentration. A comparison of the performance of PHOLEDs with the new emitter versus those with Ir(ppy)3 emitter reveals an improvement of effi ciency at all dopant concentrations. These preliminary results obtained with the fi rst bzq-based emitter indicate that this family of cyclometalated proligands is a promising compound for the development of highly emissive complexes.