Recent research has focused on the heavy-atom effect in organic luminescent materials, especially in multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters. Traditional strategies involve directly conjugating heavy atoms to the chromophore, which often broadens the emission spectrum. This study explores an unconventional approach using the through-space heavy-atom effect, positioning heavy-atom moieties with nonconjugated short-range interaction with the chromophore. This method successfully demonstrates the “intramolecular external heavy-atom effect” proposed in the 1970s in cutting-edge high-efficiency emissive materials. Comparative analysis of these emitters confirms the spatial heavy-atom effect, maintaining the spectroscopic properties of MR chromophore while significantly improving external quantum efficiency in organic light-emitting diodes (OLEDs). These emitters also mitigate efficiency roll-off, showcasing the potential of spatial interactions to enhance MR-TADF materials for OLED applications.

中文翻译：

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通过空间重原子效应增强多共振热激活延迟荧光发射


最近的研究集中在有机发光材料中的重原子效应，特别是在多共振热激活延迟荧光 （MR-TADF） 发射器中。传统策略包括将重原子直接与发色团偶联，这通常会拓宽发射光谱。本研究探索了一种使用穿越空间重原子效应的非常规方法，通过与发色团的非共轭短距离相互作用定位重原子部分。该方法成功地证明了 1970 年代在尖端高效发射材料中提出的“分子内外重原子效应”。对这些发射器的比较分析证实了空间重原子效应，保持了 MR 发色团的光谱特性，同时显著提高了有机发光二极管 （OLED） 的外部量子效率。这些发射器还可以缓解效率滚降，展示了空间交互在增强 OLED 应用的 MR-TADF 材料方面的潜力。