Pyridine/isoquinoline-carbazole containing bipolar host materials for green phosphorescent organic light-emitting diodes.

We demonstrated the electroluminescent properties of bipolar host materials such as 9-(3-(6-methylpyridin-2-yl)phenyl)-9H-carbazole (Czpmpy), 9-(6-phenylpyridin-2-yl)-9H-carbazole (Czppy), and 9-(3-(isoquinolin-1-yl)phenyl)-9H-carbazole (Czpiq). Particularly, by using host (Czpiq) and dopant (bis[2-(1,1',2',1"-terphen-3-yl)pyridinato-C,N]iridium(III) (tphpy),2Ir(acac)) as the emitting layer, a green phosphorescent OLED was fabricated, showing a maximum luminance of 12780 cd/m2 at 10 V, maximum luminous efficiency of 45.0 cd/A, power efficiency of 47.1 Im/W, maximum external quantum efficiency of 12.3%, and CIE x, y coordinates of (0.34, 0.58) at 8 V.