Iridium Complexes with Cyclometalated 2-Cycloalkenyl-Pyridine Ligands as Highly Efficient Emitters for Organic Light-Emitting Diodes

Abstract

Iridium complexes containing cyclometalated 2-cyclohexenylpyridine derivatives with rigid and bulky cyclohexene units are synthesized, and found to be highly efficient materials in EL devices (see figure). Devices based on these iridium complexes emit yellowish- green light with the very high external quantum efficiency of 18.7%.