铂配合物磷光材料在OLED中的应用研究进展

Research Progress on Application of Platinum Complex Phosphorescent Materials in OLED

有机发光二极管(OLED)开发和商业化的一项关键突破是将磷光材料用作发光材料,与荧光材料相比,磷光材料的内部量子效率提高了3倍。在所有磷光材料中,方形平面铂(Ⅱ)配合物由于高的结构刚性而表现出磷光量子产率高、磷光寿命短以及化学和热稳定性高等优点,这对于实现具有长使用寿命的OLED至关重要。另一方面,铂(Ⅱ)配合物由于其平面配位几何形状,可以轻松构建二齿、三齿或四齿配体,从而可显著调控铂(Ⅱ)配合物的光物理性质。除此之外,含多个Pt中心可以进一步增强分子的自旋轨道耦合作用从而增强其磷光发射。基于以上考虑,该文对含二齿、三齿和四齿配体的单核及多核铂(Ⅱ)配合物在OLED发光材料中的应用进行了总结,并讨论了配体结构对器件性能的影响。最后,对铂(Ⅱ)配合物材料的研究难点进行了分析,对其未来的发展趋势进行了展望。

A key breakthrough in the development and commercialization of organic light-emitting di⁃odes(OLEDs)is to use phosphorescent substances as light-emitting materials,which have a three⁃fold increase in internal quantum efficiency compared to fluorescent materials.Among all phospho⁃rescent materials,square planar platinum(Ⅱ)complexes have such advantages,namely,high structural rigidity,superior phosphorescent quantum yield,short decay lifetime and good chemical and thermal stability,which are important for realizing long-lifetime phosphorescent OLEDs.Mean⁃while,platinum(Ⅱ)complexes could easily construct bidentate,tridentate or tetradentate ligands due to their planar coordination geometry,which may significantly affect the photophysical properties of platinum(Ⅱ)complexes.In addition,the employment of multiple Pt centers could further en⁃hance the spin-orbit coupling and thus enhance phosphorescence emission.Based on the above con⁃siderations,the application of mononuclear and polynuclear platinum(Ⅱ)complexes containing bi⁃dentate,tridentate and tetradentate ligands in OLED luminescent materials is summarized in this pa⁃per,and the influence of ligand structure on device performance is discussed.Finally,the future development of platinum(Ⅱ)complex materials is also prospected.