Thermally Activated Delayed Fluorescence in an Organic Cocrystal: Narrowing the Singlet-Triplet Energy Gap via Charge Transfer
Thermally Activated Delayed Fluorescence in an Organic Cocrystal: Narrowing the Singlet-Triplet Energy Gap via Charge Transfer
复制标题
有机共晶中的热激活延迟荧光：通过电荷转移缩小单线态-三线态能隙
DOI：
10.1002/anie.201904427
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Hu Wenping
中科院分区：
文献类型：
--
作者：
Sun Lingjie;Hua Weijie;Liu Yang;Tian Guangjun;Chen Mingxi;Chen Mingxing;Yang Fangxu;Wang Shufeng;Zhang Xiaotao;Luo Yi;Hu Wenping
收集有机半导体的非发射自旋三重态电荷转移（CT）激子对于提高未来器件的运行效率至关重要。在反式- 1,2 -二苯乙烯（TSB）和1,2,4,5 -四苯基苯（TCNB）的1:2 CT共晶体中，我们观察了热激活延迟荧光（TADF）。该共晶系统通过吸收光谱、变温稳态和时间分辨光致发光光谱、单晶X射线衍射和第一性原理计算来表征。这些数据表明，共晶中的分子间CT缩小了单线态-三重态的能隙，从而促进了TADF的反向系统间交叉（RISC）。这些发现为未来新型TADF材料的设计和开发开辟了一条新的途径。
Harvesting non‐emissive spin‐triplet charge‐transfer (CT) excitons of organic semiconductors is fundamentally important for increasing the operation efficiency of future devices. Here we observe thermally activated delayed fluorescence (TADF) in a 1:2 CT cocrystal oftrans‐1,2‐diphenylethylene (TSB) and 1,2,4,5‐tetracyanobenzene (TCNB). This cocrystal system is characterized by absorption spectroscopy, variable‐temperature steady‐state and time‐resolved photoluminescence spectroscopy, single‐crystal X‐ray diffraction, and first‐principles calculations. These data reveal that intermolecular CT in cocrystal narrows the singlet–triplet energy gap and therefore facilitates reverse intersystem crossing (RISC) for TADF. These findings open up a new way for the future design and development of novel TADF materials.