Highly efficient phosphorescent organic light-emitting diodes based on novel bipolar iridium complexes with easily-tuned emission colors by adjusting fluorine substitution on phenylpyridine ligands

Two novel heteroleptic iridium complexes’ emitting colors can be tuned easily by adjusting F/CF₃-substituted cyclometalated ligands, which achieved very high EL efficiency level with peak EQE values of >20% at wide concentration range of 8-25%.