发光材料的发展是有机发光二极管（OLED）技术发展的一个重要环节，其中磷光铱(III)配合物是一类备受关注的发光材料。在铱(III)配合物中配位基团振动和转动引起的非辐射跃迁是导致发光效率降低的一个重要因素。本项目拟通过π桥联基团连接二齿或三齿配位单元来增强铱(III)配合物整体结构的刚性，从而提高发光效率、稳定性和色纯度，同时抑制浓度淬灭效应和减少异构体的形成。本项目拟研究多齿刚性配体的结构和性能（配体的刚性和共面性、配体的配位性能、配位基团的共轭尺度和电子能级、辅助基团的位阻效应等）对铱(III)配合物发光性能的影响，并归纳总结新型刚性铱(III)配合物结构与OLED器件性能之间的关系。本项目的研究内容主要包括（1）新型刚性多齿配体的设计与合成；（2）新型铱(III)配合物的制备、提纯与表征；（3）主客体材料的能级匹配以及能量传输；（4）OLED器件制备、性能分析与材料结构的优化。

The development of emissive materials is one of the key steps for the advances in organic light emitting diode (OLED) technology. Phosphorescent Ir(III) complexes are one type of most popular emitters. Within Ir(III) complexes, the vibration and rotation of ligands around metal ion could lead to the non-radiative decay, which could account in part for the low quantum yields. Herein the rigid bidentate or tridentate ligands were linked together through rigid π bridges to enhance the overall rigidity of Ir(III) complexes, which could lead to high quantum yields, high stability and good color purity, and at meantime reduce concentration-induced luminescence quenching and the production isomers. This project intends to study the dependence of the emission properties of novel Ir(III) complexes on the rigid ligands and to investigate the relationship between the structures of Ir(III) complexes and device performance via the optimization of the structures and electronic properties of multiple-dentate ligands such as the rigidity, planarity and the size of the conjugation system of ligands, and the steric effect of ancillary ligands. This study includes the following sections: (1) the design and synthesis of novel rigid ligands; (2) the preparation and purification of Ir(III) complexes; (3) the selection of suitable host materials to enhance the energy transfer from hosts to dopants; (4) the fabrication and optimization of OLED devices, and the interrogation of the device data and the redesign of novel rigid ligands.