蓝色荧光材料在作为有机发光器件(OLED)的蓝光发光层材料方面具有很大的商业应用潜力。本文将4-(9H-咔唑-9-基)苯胺(CzPA)作为电子给体单元、三氟甲基苯基(FMP)作为电子受体单元, 通过在CzPA和FMP之间分别引入苯, 9,9'-二辛基-9H-芴和双(9,9′-二辛基-9H-芴)作为π-共轭桥, 设计并合成了一系列基于扭曲A-π-D-π-A构型的蓝色荧光材料(CzPA-B-FMP, CzPA-F-FMP, CzPA-DF-FMP), 并研究π-共轭桥与材料光物理性质之间的关系。通过对材料的相关光物理性质以及电荷转移特性的详细比较, 可以分析得出: CzPA和FMP之间的π-共轭桥长度的增加可以增强激发态的局部激发特性, 进而提高这些材料的荧光量子效率和器件的外量子效率。但是, 过长的π-共轭桥将导致更大的分子间共轭效应, 不利于材料光物理性质的优化。

Blue light-emitting fluorescent materials have great commercial application potential as blue-light emitter for organic light-emitting devices(OLEDs). In this work, a series of blue light-emitting fluorescent materials with twisting A-π-D-π-A configuration were designed and synthesized, in which 4-(9H-carbazol-9-yl)benzeneamine(CzPA) as electron donor unit and trifluoromethylphenyl (FMP) as electron acceptor unit. To investigate the relationship between π-conjugated bridge and photophysical properties, the benzene, 9,9′-dioctyl-9H-fluorene and di(9,9′-dioctyl-9H-fluorene) are introduced as π-conjugated bridge between CzPA and FMP, which are named as CzPA-B-FMP, CzPA-F-FMP, CzPA-DF-FMP, respectively. By comparing photophysical properties in detail, it can be concluded that combining with charge transfer characteristic, the local excitation characteristic of excited state can be enhanced with increasing length of π-conjugated bridge between CzPA and FMP, which can improve the fluorescent quantum efficiency of these materials and external quantum efficiency of blue light OLED. But, too longer π-conjugated units will also deteriorate photophysical properties for bigger intermolecular conjugating effect.