Abstract Blue organic emissive materials are still the most important bottlenecks for the development of organic light-emitting diodes (OLEDs). To enrich the material library, herin, three bipolar phenanthroimidazole derivatives, namely MePPIM-TPA, ClPPIM- TPA and BuPPIM-TPA, are synthesized using triphenylamine as electron-donor and phenanthroimidazole as the electron-acceptor. The photophysical, thermal and electrochemical properties of three compounds are investigated with high decomposition temperature up to 350 °C, and strong blue emission. Single-carrier devices are fabricated to show that three compounds have good bipolar carrier transport characteristic. The non-doped fluorescent OLEDs devices using three compounds as emitting layers are fabricated among which the devices based on MePPIM-TPA achieved the maximum luminance of 1743 cd/m2, the maximum external quantum efficiency (EQE) of 2.99% which is relatively comparable to commonly used blue emitters.

中文翻译：

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基于双极性菲咪唑-三苯胺衍生物的高效非掺杂蓝色荧光OLED

摘要 蓝色有机发光材料仍然是有机发光二极管（OLED）发展的主要瓶颈。为了丰富材料库，herin，使用三苯胺作为电子供体和菲咪唑作为电子受体合成了三种双极性菲咪唑衍生物，即 MePPIM-TPA、ClPPIM-TPA 和 BuPPIM-TPA。研究了三种化合物的光物理、热学和电化学性质，分解温度高达 350 °C，并发出强烈的蓝光。制造单载流子器件以显示三种化合物具有良好的双极载流子传输特性。制作了使用三种化合物作为发光层的非掺杂荧光 OLED 器件，其中基于 MePPIM-TPA 的器件达到了 1743 cd/m2 的最大亮度，