| 초록 |
We successfully synthesized the strong hole carrying bicarbazole derivative host materials with high triplet energy of about 2.8 eV which were suitable for blue phosphorescent organic light-emitting diodes. The host materials had strong hole carrying property which was proposed as the main factor for the high quantum efficiency. As good hole transport character of the bicarbazole derivatives compensated the hole trapping of the phenylimidazole type dopant, they could balance hole and electron density. In addition, the thermal and chemical stability of this compound contributed to long lifetime of the devices. The HOMO and LUMO levels of the compounds were -5.82/-2.52, -5.79/-2.58 and -5.83/-2.50 eV, respectively. A maximum quantum efficiency of 24.8% was achieved and the color coordinate of these host device were (0.19, 0.41), (0.19, 0.40) and (0.19, 0.41) at 1000cd/m2, respectively. |
