Dependence of Effective Doping Concentration on the Molecular Structure of Dopant: ABCV-P Doped OLEDs with Broad Range of and High Doping Concentration

A new red fluorescent material, (2Z,2′Z)-3,3′-[4,4″-bis(dimethylamino)-1,1′:4′,1″-terphenyl-2′,5′-diyl]bis(2-phenylacrylonitrile) (ABCV-P), preventing concentration quenching in solid state was synthesized. Studies on the device performance of ABCV-P doped OLEDs with variation of the doping concentration and thickness of the emitting layer as well as the optical properties of ABCV-P were carried out. The effective doping concentration of ABCV-P dopant was in the range of 40%–50%. ABCV-P doped OLEDs showed maximum luminance of 11000 cd/m2 (40%) and 6800 cd/m2 (50%), CIExy coordinates of (0.588, 0.410) (40%) and (0.597, 0.402) (50%) and full width at half maxima of 71 nm and 72.5 nm, respectively. Accordingly, ABCV-P doped OLED showed much lower sensitivity to doping concentration than the typical red doped ones.