Highly efficient blue electrophosphorescent devices with a new series of host materials: polyphenylene-dendronized oxadiazole derivatives
作者:Shiyan Chen、Xinjun Xu、Yunqi Liu、Wenfeng Qiu、Gui Yu、Xiaobo Sun、Hengjun Zhang、Ting Qi、Kun Lu、Xike Gao、Ying Liu、Daoben Zhu
DOI:10.1039/b705515c
日期:——
A new series of oxadiazole derivatives TPO, PPO, MTPO, MPPO, BTPO, and BPPO have been designed and synthesized in high yields by a convenient synthetic procedure. A single crystal structure of TPO exhibited that this polyphenylene-dendronized material has a sterically crowded structure which efficiently prevents π–π stacking and endows it with good thermal stability. The photophysical properties of the materials show strong emission between 376 and 390 nm in the films. In addition, good reversible reductive waves in the cyclic voltammograms implied that these materials might have good electron transport properties. Blue electrophosphorescent devices fabricated using these materials as the host materials and iridium(III)bis[4,6-di-fluorophenyl-pyridinato-N,C2′]picolinate as the blue phosphorescent dopant emitter show very high efficiencies. A maximum luminance of 4484 cd m−2 and an external quantum efficiency of 6.20% were achieved under ambient conditions.
一系列新的氧杂二唑衍生物TPO、PPO、MTPO、MPPO、BTPO和BPPO已经通过一种方便的合成方法设计并合成,且产率很高。TPO的单晶结构显示出该聚苯甲烯树枝状材料具有立体拥挤的结构,这有效地阻止了π–π堆积,并赋予其良好的热稳定性。材料的光物理性质显示,在薄膜中在376到390 nm之间有强烈的发射。此外,循环伏安图中良好的可逆还原波表明这些材料可能具有良好的电子传输性能。使用这些材料作为主材料,铱(III)双[4,6-二氟苯基-吡啶-N,C2']皮克林酸盐作为蓝色磷光掺杂发射体制造的蓝色电致磷光器件表现出非常高的效率。在环境条件下,达到了4484 cd m−2的最高亮度和6.20%的外量子效率。