Efficient red phosphorescent iridium complexes for organic light-emitting diodes based on 5-benzoyl-2-phenylpyridine ligands with fluorine and methyl moieties

Red phosphorescent emitters for OLEDs were synthesized using Ir(III) complexes based on 5-benzoyl-2-phenylpyridine ligands with fluorine and methyl substitution. Their electroluminescence, when doped in the emitting layers of multilayer OLEDs, was sensitive to their structural features. In particular, a highly efficient orange-red OLED showed a maximum luminance of 18,740 cd/m(2) at 11 V. with a luminous efficiency of 25.9 cd/A, power efficiency of 8.74 lm/W, external quantum efficiency of 9.25% at 20 mA/cm(2), and CIEx,y coordinates of (0.53, 0.47) at 8.0 V, respectively. A red OLED with CIEx,y coordinates of (0.66, 0.34) at 8.0 V exhibited a luminous efficiency, power efficiency and external quantum efficiency of 5.98 cd/A, 2.06 lm/W and 5.77% at 20 mA/cm(2), respectively. (C) 2012 Elsevier B.V. All rights reserved.