Solution-processed high-performance orange-red organic light-emitting diode (OLED) based on ionic phosphorescent iridium(III) complex

A new and efficient ionic orange-red Ir(III) complex is rationally designed by utilizing 2-(4-chloro-3-(trifluoromethyl)phenyl)-4-methylquinoline and a large conjugated 2,2′-biquinoline as main ligand and ancillary ligand, respectively. The complex shows bright phosphorescence peaking at 583 and 626 nm (shoulder) with high absolute phosphorescent quantum efficiency of 81.3% and moderate emission lifetime of 1.54 μs in dichloromethane solution, which is suitable for fabricating high-performance solution-processed organic light-emitting diode. The device based on this ionic complex exhibits excellent electroluminescence performance, with the maximum luminance, external quantum efficiency, current efficiency, and power efficiency of up to 1209 cd/m2, 10.20%, 21.9 cd/A and 9.57 lm/W, respectively, thereby demonstrating that this new cationic Ir(III) complex possesses tremendous potentials for the future solution-processed electroluminescence.