Oxadiazole based bipolar host materials employing planarized triarylamine donors for RGB PHOLEDs with low efficiency roll-off
作者:Paul Kautny、Daniel Lumpi、Yanping Wang、Antoine Tissot、Johannes Bintinger、Ernst Horkel、Berthold Stöger、Christian Hametner、Hans Hagemann、Dongge Ma、Johannes Fröhlich
DOI:10.1039/c3tc32338b
日期:——
Employing the developed materials, red (o-TPATOXD: CEmax: 28.8 cd A−1, EQEmax: 16.9%), green (o-PCzPOXD: CEmax: 62.9 cd A−1, EQEmax: 17.1%) and blue (o-PCzPOXD: CEmax: 29.8 cd A−1, EQEmax: 13.4%) devices were achieved showing remarkably low efficiency roll-off for planarized donors. Hence, this is the first report of efficient blue devices for this specific class of host materials. It is proposed that
已设计,合成和表征了一系列6种新颖的含三芳基胺的恶二唑化合物(o -PCzPOXD,o -ICzPOXD,o -TPATOXD,o -PCzTOXD,o -ICzTOXD和o- CzTOXD),并作为应用在PHOLED器件中用作基质材料进行了表征。为了进一步改进邻位键合概念,研究了引入平面化的供电子三芳基胺(TAA)结构对分子内电荷转移的影响。评估了两个系列的电子接受的恶二唑支架的效果,实现了邻位-在苯(POXD)和噻吩(TOXD)核上的键合。热分析表明,平面化结构的玻璃化转变温度升高,表明其形态稳定性得到改善。较高的平面化程度还导致单线态和三线态能量值显着增加,从而揭示了对分子内电荷转移的影响。使用已开发的材料,红色(o -TPATOXD:CE max:28.8 cd A -1,EQE max:16.9%),绿色(o -PCzPOXD:CE max:62.9 cd A -1,EQE max:17