向热激活的延迟光活性子[c][1,2,5]thiadiazole发射器的直接化方法,用于近红外溶液处理的OLED
Sonny Brebels1,2, Emma V Puttock3, Tom Cardeynaels1,2,4
1Institute for Materials Research (IMO-IMOMEC), Hasselt University, Martelarenlaan 42, Hasselt B-3500, Belgium.
概括
一种新的同位素发射体,2TPA-iCNBT,显示了增强的热激活延迟光 (TADF) 特性. 这种近红外 (NIR) 发射器实现了更高的量子产量和更快的动力学,超越了以前的设计.
科学领域:
- 有机化学 有机化学
- 材料科学 材料科学 材料科学
- 光物理学的光学物理学
背景情况:
- 近红外 (NIR) 发射器对于先进的光电子应用至关重要.
- 热激活延迟光 (TADF) 材料在有机发光二极管 (OLED) 中提供高效率.
- 优化供体-接受体 (D-A) 结构是增强TADF特性的关键.
研究的目的:
- 设计和合成一种具有改进的NIR-TADF特征的新型同位素发射器 (2TPA-iCNBT).
- 调查DA替代模式和捐赠群体数量对发射器性能的影响.
- 探索一种新的直接配合策略,以有效合成TADF发射器.
主要方法:
- 合成了四种新型发射剂,包括2TPA-iCNBT,2TPA-CNBT,1TPA-CNBT和1TPA-iCNBT,使用直接配合策略.
- 使用光谱技术进行表征 (稳态和时间分辨率的辐射光谱).
- 使用密度函数理论 (DFT) 模拟分子几何和激发状态的计算建模.
- 解决方案加工OLED的设备制造和测试,以评估外部量子效率 (EQE).
主要成果:
- 在没有氧气的情况下,2TPA-iCNBT显著增强了TADF特性,光发光量产率从27%增加到55%.
- 最快的TADF发射动力学 (k_RISC ~ 10^5 s^-1) 已被观察到2TPA-iCNBT在片中.
- 2TPA-iCNBT在OLED中实现了2.49%的最大EQE,超过了参考2TPA-CNBT (1.16%) 并在更高的电流密度下保持高EQE (1.98%在10mA cm^-2).
结论:
- D-A替代模式和捐赠群体的数量极大地影响了NIR-TADF发射器的性能.
- 设计的同位素发射器2TPA-iCNBT与参考设备相比,具有优越的TADF特性和设备效率.
- 直接合策略为合成功能化的TADF发射器提供了一条有效的途径.
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