红绿蓝三基色及单分子宽光谱环金属铱配合物液晶发光材料的分子构筑及其性能研究

液晶发光材料既具有液晶性能又具有发光性能，在偏振有机电致发光器件(OLEDs)领域具有潜在的应用价值。针对偏振OLEDs中高效液晶发光材料存在的分子构筑难、在固体薄膜中易聚集导致发光淬灭及偏振发光效率低等关键科学问题，本项目拟通过非平面结构的环金属铱配合物发光中心、外围液晶基元(联苯、噁二唑及芴衍生物)和聚集诱导发光基团的协同作用，构筑高效发光的红绿蓝三基色及单分子宽光谱(白光)环金属铱配合物液晶发光材料。通过改变液晶基元的种类与数量及配体的结构，系统研究环金属铱配合物的分子结构对液晶性能和光物理性能的影响，探索环金属铱配合物液晶发光材料的分子构筑规律。通过热处理等工艺制备取向发光层及偏振器件，研究材料结构和发光层的取向对偏振器件性能的影响；优化器件结构，获得高效的偏振单色光和白光器件。项目的实施对于促进环金属铱配合物液晶发光材料的发展及其在偏振OLEDs中的应用具有重要的理论和应用价值。

Luminescent liquid crystal materials are the promising family in the field of polarized organic light-emitting diodes (OLEDs) due to their possessing both liquid crystalline and luminescent features. However, it remains huge challenges for the high-efficiency luminescent liquid crystal materials in polarized OLEDs, such as the difficult molecular design, as well as emission quenching in the solid state and the low polarized efficiency for these luminescent liquid crystal materials. To address these issues, in this project, a series of cyclometalated iridium complexes-based luminescent liquid crystal materials with RGB (red, green and blue) and white emission will be designed and synthesized through the synergistic effect of the emission core (non-planar iridium complex), the mesogenic units (biphenyl, oxadiazole and fluorene derivatives) and the aggregation-induced emission group. The relationship between molecular structure and liquid crystal/photophysical properties will be systematically investigated by changing the structure and number of the mesogenic units, as well as the structure of the ligands. Furthermore, the molecular construction rule of the cyclometalated iridium complexes-based luminescent liquid crystal materials will be revealed. The aligned emitter and polarized OLEDs will be fabricated via thermal treatment procedures. The effect of both molecular structure and the aligned emission layer on the polarized performance in OLEDs will be studied in detail. After optimizing the device structure, high-efficiency polarized OLEDs should be achieved with RGB and white emission, respectively. Therefore, this project has significant theoretical and practical implications for promoting the development of cyclometalated iridium complexes used as the luminescent liquid crystal materials and their application in polarized OLEDs.