Efficient blue thermally activated delayed fluorescence emitters showing very fast reverse intersystem crossing
Efficient blue thermally activated delayed fluorescence emitters showing very fast reverse intersystem crossing
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DOI：
10.35848/1882-0786/ac06df
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发表时间：
2021-07-01
影响因子：
2.3
通讯作者：
Kaji, Hironori
中科院分区：
文献类型：
--
作者：
Ren, Yongxia;Wada, Yoshimasa;Kaji, Hironori
报道了一种高效的蓝色热激活延迟荧光（TADF）发射体MCz-TXO。MCz-TXO表现出三种状态的紧密能级匹配：电荷转移（CT）和局部激发三重态，以及CT单重态。由于分子结构中硫的良好能级匹配和重原子效应，MCz-TXO显示出非常大的反向系间穿越速率常数（k（RISC）），接近2 × 10（8）s（-1）。这是所有报道的纯有机TADF发射体中最大的k（RISC）值之一。MCz-TXO基有机电致发光器件具有蓝光发射，最大外量子效率为17.4%。
We report a highly efficient blue thermally activated delayed fluorescence (TADF) emitter, namely, MCz-TXO. MCz-TXO exhibits close energy level matching of the three states: charge transfer (CT) and locally excited triplet states, and a CT singlet state. Owing to the good energy level matching and heavy atom effect of sulfur in the molecular structure, MCz-TXO shows very large experimental rate constant of reverse intersystem crossing (k (RISC)) of similar to 2 x 10(8) s(-1). This is one of the largest k (RISC) values among all reported pure organic TADF emitters. The MCz-TXO based organic light-emitting diodes exhibit blue emission with maximum external quantum efficiency of 17.4%.