我们以钯为催化剂、通过一步交联耦合反应合成了一系列以螺[芴-9,9’-氧杂葸](SFX)为基本构建单元的新型主体材料,这些材料具有较高的三线态能级和产率,可用作蓝色磷光材料的主体。接着,以这砦材料和空穴传输型材料TAPC作为双主体、以Flrpic为发光客体,制作了蓝色磷光有机发光器件fPHOLED)。SFX主体材料可以向Flrpic提供有效的能量转移,而TAPC可以提高发光层的空穴迁移率、同时降低器件工作电压,因此我们制备的蓝色发光器件具有良好的性能。其中,以TAPC:PF-SFX和TAPC:C80PF-SFX为双主体的两个PHOLED,最大电流效率和亮度分别达到22.56、25.93cd·A-1和6421、6196cd.m-2。上述实验结果表明,只存在C、H、O时,SFX是构建高效蓝色磷光主体材料的有效结构单元。
We synthesized a series of novel spiro[fluorene-9,9'-xanthene] (SFX)-based host materials via a one-step palladium-catalyzed cross-coupling reaction. These materials have high triple energy levels and high yield, and thus can be used as hosts for blue phosphors. Blue phosphorescent organic light-emitting devices (PHOLEDs) with a bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyri-dyl)iridium(Ⅲ) (Flrpic) emission were fabricated. Furthermore, we applied cohosts composed of one of the new synthesized materials and the hole transport material di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane (TAPC) to the blue PHOLEDs to successfully acquire efficient blue emissions. The SFX-based material provided efficient energy transfer while TAPC improved the mobility of the cohost as well as reduced the working voltage. Maximum current efficiencies of 22.56 and 25.93 cd.A-1 and the maximum brightnesses of 6421 and 6196 cd.m 2 were obtained for the PHOLEDs with TAPC: 2-(9-phenyl-fluoren-9-yl)spiro[fluorene-9,9'-xanthene] (PF-SFX) and TAPC: 2-(9-(4-(octyloxy)-phenyl)- 9H-fluoren-9-yl)spiro[fluorene-9,9'-xanthene] (C8OPF-SFX) cohosts, respectively. The experimental results obtained for the four SFX-based host materials were enough to declare that SFX is an effective main unit that can be used to build efficient host materials for blue phosphors containing only C, H, and O basic elements.