The thermally activated delayed fluorescence (TADF) originating from high-level intersystem crossing (hRISC) presents great potential in realizing a more full utilization of triplet excitons. In this study, DPA-FBP and TPA-FBP were doped in a PMMA film with different weight fractions to study the effect of aggregation on the luminescence properties. As a result, the TADF feature from hRISC was only found in the 50 wt % doped film, whereas the 1 wt % doped film only shows prompt fluorescence. The fs-TA spectroscopy results reveal that the 50 wt % film will generate charge transfer species to lower the energy gap, so that the high-lying triplet exciton can transition back to the singlet state, whereas that of the 1 wt % film will quickly transition to the lowest triplet state due to the unfavorable energy splitting. This study provides a new insight into aggregation effects on the excited-state properties of hot exciton materials and the solid-state photodynamic.

中文翻译：

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来自高水平反向系统间交叉的聚集诱导 TADF 的超快光谱研究


源自高水平系统间交叉 （hRISC） 的热激活延迟荧光 （TADF） 在实现更充分地利用三重态激子方面具有巨大潜力。在本研究中，DPA-FBP 和 TPA-FBP 掺杂在不同重量分数的 PMMA 薄膜中，以研究聚集对发光性能的影响。因此，hRISC 的 TADF 特征仅在 50 wt % 掺杂的薄膜中发现，而 1 wt % 掺杂的薄膜仅显示出快速荧光。fs-TA 光谱结果表明，50 wt % 的薄膜将产生电荷转移物质以降低能隙，因此高位三重态激子可以跃迁回单重态，而 1 wt % 薄膜的激子由于不利的能量分裂而迅速跃迁到最低的三重态。这项研究为聚集对热激子材料的激发态特性和固态光动力学的影响提供了新的见解。