Stable orange and white electrophosphorescence based on spirobifluorenyltrifluoromethylpyridine iridium complexes

Abstract Novel complexes bis[2-(9,9′-spirobifluoren-2-yl)-5-trifluoromethylpyridinto-C 3 , N] iridium (acetylacetonate) ( 8 ) and bis[2-(9,9′-spirobifluoren-2-yl)-5-trifluoromethyl-pyridinto-C 3 , N] iridium (2-picolinic acid) ( 9 ) were synthesized. Trifluoromethyl group and 2-picolinic acid were incorporated to tune luminescent color and spirobifluorene with supramolecular steric hindrance was introduced to suppress intermolecular interaction. The orange-emissive electrophosphorescent devices for 8 and 9 exhibited stable electroluminescent (EL) peaks at 580 (or 584) and 568 (or 572) nm at the different voltages, and maximum current efficiencies of 21.6 and 35 cd/A. The white-emissive devices of the dual emitting layer based on the orange ( 8 or 9) and blue (FIrPic) phosphor showed CIE coordinates of (0.32, 0.37) and (0.33, 0.39), and maximum current efficiencies of 10.6 and 13.8 cd/A. The CIE coordinates with the increasing of the operating voltage were stable. High efficiency and slow decay of devices indicated that 8 and 9 were highly efficient orange emitters.