Furo[3,2-c]pyridine-Based Iridium Complex Containing two Methoxy Groups for Efficient Solution-Processed Phosphorescent OLEDs

摘要

A furo[3,2-c]pyridine-based iridium complex, namely [(3,5-diMeOpfupy)(2)Ir(acac)], has been designed and synthesized by introducing two methoxy groups at the 3- and 5-positions of a phenyl ring. Such a small structure variation of the C^N ligand can not only avoid isomer production to favor easy purification, but also improve the solubility to ensure low-cost wet methods. Similar to the model complex [(3-MeOpfupy)(2)Ir(acac)] containing one methoxy group, [(3,5-diMeOpfupy)(2)Ir(acac)] possesses an orange emission peak at 598 nm together with a photoluminescence quantum yield (PLQY) of 0.32 and an exciton lifetime of 1.29 mu s. The corresponding solution-processed devices realize a maximum current efficiency of 17.2 cd/A (18.5 lm/W, 8.9 %) as well as Commission Internationale de L'Eclairage (CIE) coordinates of (0.60, 0.39). The result indicates that the multiple methoxy modification is a promising strategy towards isomer-free and solution-processable furo[3,2-c]pyridine-based iridium complexes.