Convergent Modulation of Singlet and Triplet Excited States of Phosphine-Oxide Hosts through the Management of Molecular Structure and Functional-Group Linkages for Low-Voltage-Driven Electrophosphorescence
作者:Chunmiao Han、Zhensong Zhang、Hui Xu、Guohua Xie、Jing Li、Yi Zhao、Zhaopeng Deng、Shiyong Liu、Pengfei Yan
DOI:10.1002/chem.201203349
日期:2013.1.2
controllable tuning of the excited states in a series of phosphine‐oxide hosts (DPExPOCzn) was realized through introducing carbazolyl and diphenylphosphine‐oxide (DPPO) moieties to adjust the frontier molecular orbitals, molecular rigidity, and the location of the triplet excited states by suppressing the intramolecular interplay of the combined multi‐insulating and meso linkage. On increasing the number
通过引入咔唑基和二苯基膦氧化物(DPPO)部分来调节前沿分子轨道,分子刚度和三重激发态的位置,可以实现一系列膦氧化物主体(DPExPOCz n)中激发态的可控调节。通过抑制多重绝缘和内消旋结合的分子内相互作用 。随着取代基数量的增加,同时降低第一单重态能级(S 1)和提高第一三重态能级(T 1),达到约3.0 eV)。前者的变化主要是由于咔唑基对HOMO的贡献和扩展的共轭作用。后者的变化是由于分子刚性的增强和T 1态从二苯醚基向咔唑基部分的转变。这种激发态的会聚调制不仅有助于将放热能转移到磷光有机发光二极管(PHOLED)中的掺杂剂上,而且还可以实现电学性能的微调,以实现发光中平衡的载流子注入和输运层。结果,证明了发蓝光的PHOLED的良好性能,包括更低的驱动电压:开始时为2.6 V,在100 cd m -2时为3.0V。,并且EQE显着提高了12.6%。