Elevating the Triplet Energy Levels of Dibenzofuran-Based Ambipolar Phosphine Oxide Hosts for Ultralow-Voltage-Driven Efficient Blue Electrophosphorescence: From DA to DπA Systems
作者:Chunmiao Han、Zhensong Zhang、Hui Xu、Jing Li、Yi Zhao、Pengfei Yan、Shiyong Liu
DOI:10.1002/chem.201203719
日期:2013.1.21
energy levels (T1) of DBFxPOPhCzn are elevated to about 3.0 eV, 0.1 eV higher than their DA‐type analogues. Nevertheless, the electrochemical analysis and DFT calculations demonstrated the ambipolar characteristics of DBFxPOPhCzn. The phenyl π spacers hardly influenced the frontier molecular orbital (FMO) energy levels and the carrier‐transporting ability of the materials. Therefore, these DπA systems
设计并设计了一系列由苯基咔唑,二苯并呋喃(DBF)和二苯基膦氧化物(DPPO)部分组成的供体(D)–π–受体(A)型氧化膦主体(DBF x POPhCz n),合成的。苯基π间隔基插入到咔唑基和DBF基之间,有效地削弱了电荷转移和三重态激发态的扩展。作为结果,第一三线态能级(T 1)的DBF X POPhCz Ñ升高到约3.0eV,0.1eV的比它们的d更高A型类似物。然而,电化学分析和DFT计算证明了DBF x POPhCz n的双极性特性。苯基π间隔基几乎不会影响材料的前沿分子轨道(FMO)能级和载流子传输能力。因此,这些d π A系统中被赋予高于或等于该1状态,以及可比较的电特性d A系统中。基于DBF x POPhCz n的磷光蓝光发光二极管(PHOLED)不仅继承了超低驱动电压(起始电压为2.4 V,200 cd m -2时约为2.8 V和<3.4V的在1000cd