非平面结构加速了TADF发射器的反向交叉系统交叉:近40%的EQE和减轻的效率逐渐下降
He Liu1, Yang Liu1, Guohao Chen1
1National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment (Shenzhen), Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University 518055 Shenzhen P. R. China clyang@szu.edu.cn.
Chemical science
|August 9, 2024
概括
非平面结构显著提高了热激活延迟光 (TADF) 分子中的反向系统间交叉 (RISC) 速率. 这导致了效率的提高,并减少了电光发光器件的滚动.
科学领域:
- 材料科学 材料科学 材料科学
- 有机化学 有机化学
- 光物理学的光学物理学
背景情况:
- 高效的热激活延迟光 (TADF) 材料对于下一代有机发光二极管 (OLED) 至关重要.
- 提高反向系统间交叉 (RISC) 的速度是提高TADF效率的关键.
- 分子设计在控制光物理性质方面发挥着至关重要的作用.
研究的目的:
- 研究非平面分子几何学对TADF发射器RISC速率 (k_RISC) 的影响.
- 开发新型的TADF分子,结合不同程度的非平面性的螺旋氨酸捐赠体.
- 为了将分子结构与光物理性质和设备性能相关联.
主要方法:
- 三种基于螺旋基的TADF发射器 (S2-TRZ,S1-TRZ,O1-TRZ) 的合成,具有不同的结构特征.
- 光物理特征,包括光发光量产量 (PLQY) 测量.
- 使用瞬态光发光谱学评估RISC速率.
- 组合合成发射器的OLED设备的制造和测试.
主要成果:
- 所有合成的分子都表现出高的PLQY (96-98%) 由于刚性结构.
- 具有重原子效应和非平面几何学的S2-TRZ显示了最高的k_RISC (24.2 × 10^5 s^-1).
- OLED 设备显示出高的外部量子效率 (高达 40.1%) 和电流效率 (高达 124.7 cd A^-1).
- 带有S2-TRZ的设备表现出优越的性能,效率滚动率显著降低 (在1000cd m^-2时为7%).
结论:
- 非平面分子设计是加速TADF发射器RISC速率的高效策略.
- 非平面性和重原子的协同效应进一步增强了RISC.
- 这些发现为设计高性能TADF材料提供了宝贵的见解,用于高效的OLED,最小的滚动.
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