基于新型螺氧杂蒽主体的高效蓝色磷光有机发光二极管

摘要

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'-氧杂蒽](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,以这些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(PHOLED).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:C8OPF-SFX为双主体的两个PHOLED,最大电流效率和亮度分别达到22.56、25.93 cd· A-1和6421、6196 cd·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(lll) (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 efflciencies 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.