Shizu Katsuyuki, Kaji Hironori
Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.
Nat Commun. 2024 Jun 3;15(1):4723. doi: 10.1038/s41467-024-49069-4.
Many phenomena in nature consist of multiple elementary processes. If we can predict all the rate constants of respective processes quantitatively, we can comprehensively predict and understand various phenomena. Here, we report that it is possible to quantitatively predict all related rate constants and quantum yields without conducting experiments, using multiple-resonance thermally activated delayed fluorescence (MR-TADF) as an example. MR-TADFs are excellent emitters because of its narrow emission, high luminescence efficiency, and chemical stability, but they have one drawback: slow reverse intersystem crossing (RISC), leading to efficiency roll-off and reduced device lifetime. Here, we show a quantum chemical calculation method for quantitatively obtaining all the rate constants and quantum yields. This study reveals a strategy to improve RISC without compromising other important factors: radiative decay rate constants, photoluminescence quantum yields, and emission linewidths. Our method can be applied in a wide range of research fields, providing comprehensive understanding of the mechanism including the time evolution of excitons.
自然界中的许多现象由多个基本过程组成。如果我们能够定量预测各个过程的所有速率常数，就可以全面预测和理解各种现象。在此，我们报告，以多共振热活化延迟荧光（MR-TADF）为例，无需进行实验就有可能定量预测所有相关速率常数和量子产率。MR-TADF因其发射窄、发光效率高和化学稳定性好而成为优异的发光体，但它们有一个缺点：反向系间窜越（RISC）缓慢，导致效率下降和器件寿命缩短。在此，我们展示了一种用于定量获得所有速率常数和量子产率的量子化学计算方法。这项研究揭示了一种在不影响其他重要因素（辐射衰减速率常数、光致发光量子产率和发射线宽）的情况下改善RISC的策略。我们的方法可应用于广泛的研究领域，为包括激子时间演化在内的机制提供全面理解。
