Spatial distribution of triplet excitons formed from charge transfer states at the donor/acceptor interface
Spatial distribution of triplet excitons formed from charge transfer states at the donor/acceptor interface
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供体/受体界面处的电荷转移态形成的三线态激子的空间分布
DOI：
10.1039/d2ta02068h
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发表时间：
2022
影响因子：
11.9
通讯作者：
Hiramoto Masahiro
中科院分区：
文献类型：
--
作者：
Izawa Seiichiro;Morimoto Masahiro;Naka Shigeki;Hiramoto Masahiro
在有机半导体界面处的三重态激子形成在电子器件（例如有机发光二极管（OLED）和有机光致发光器件）中的电子物理过程中，以及在光学功能（例如基于三重态-三重态湮灭（TTA）的光子上转换（PUC））中起着至关重要的作用，所述光子上转换产生具有高能量的光子，所述光子结合具有低能量的两个光子。在这里，我们报告的三重态激子的空间分布后产生的电荷复合在有机半导体界面。三重态激子的分布进行评估，通过检查TTA发射的变化时，三重态淬灭剂掺杂在OLED和PUC系统的界面附近。结果表明，90%的三重态激子被限制在离施主/受主界面小于10 nm的范围内，在施主/受主界面处发生电荷复合并形成电荷转移态，这是三重态激子的前体.三重态激子的限制导致有效的TTA发射，其效率是三重态浓度依赖性的，在OLED和PUC系统中利用界面三重态形成的机制。
Triplet exciton formation at an organic semiconductor interface plays a crucial role in photophysical processes in electronic devices, such as organic light-emitting diodes (OLEDs) and organic photovoltaics, and in optical functions, such as photon upconversion (PUC) based on triplet–triplet annihilation (TTA), which produces a photon with high energy combining two photons with low energy. Herein, we report the spatial distribution of the triplet exciton generated after charge recombination at the organic semiconductor interface. The triplet exciton distribution is assessed by examining the variation in TTA emission when the triplet quencher is doped near the interface in the OLED and PUC systems. The obtained result indicates that 90% of the triplet excitons are confined to less than 10 nm from the donor/acceptor interface, where charge recombination occurs and a charge transfer state forms, which is a precursor of the triplet exciton. The confinement of triplet excitons leads to efficient TTA emission, whose efficiency is triplet concentration-dependent, in OLED and PUC systems utilizing the mechanism of interfacial triplet formation.