Efficient red phosphorescent OLEDs using Ir(III) complexes based on bezoylphenylpyridine and the various ancillary ligands.

A series of red phosphorescent Ir(III) complexes 1-5 based on benzoylphenylpyridine and various ancillary ligands were synthesized and their photophysical properties were investigated. The EL efficiencies were quite sensitive to the structural features of the dopants in the emitting layers. Particularly, using complex 5 as a dopant in emitting layer, a high-efficiency orange-red OLED was fabricated, showing the maximum luminance of 16,900 cd/m2 at 12 V, the luminous efficiency of 12.8 cd/A, the power efficiency of 4.48 lm/W, the external quantum efficiency of 9.65% at 20 mA/cm2 and CIE x,y coordinates of (0.609, 0.390) at 12 V.