(III) 碳复合体具有金属至质电荷转移 (MLCT) 或通过空间的电荷转移 (TSCT) 蓝色发光
Jie Yan1, Yixin Wu1, Manli Huang2
1Department of Chemistry, Department of Materials Science and Engineering, and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong SAR, P.R. China.
Angewandte Chemie (International ed. in English)
|March 11, 2025
概括
新设计的Ir(III) 蓝色光器利用通过空间的电荷转移 (TSCT) 进行高效的发射. 这项研究探讨了新型复合体中TSCT与金属对联体电荷转移 (MLCT) 的对比,证明了有机发光二极管 (OLED) 的高外部量子效率.
科学领域:
- 材料科学 材料科学 材料科学
- 摄影化学的使用.
- 有机电子 有机电子
背景情况:
- (III) 复合物对于高效的有机发光二极管 (OLED) 来说至关重要.
- 了解激发状态过程,如金属到质电荷转移 (MLCT) 和通过空间的电荷转移 (TSCT) 是优化其性能的关键.
- 区分光和热激活延迟光 (TADF) 对于预测设备寿命和效率至关重要.
研究的目的:
- 为了研究穿越空间电荷转移 (TSCT) 在新型 (III) 蓝色中所扮演的角色.
- 合成和表征Ir(III) 复合物与[d]imidazolylidene pro-chelates,专注于替代剂对电子转换的影响.
- 评估这些复合体在有机发光二极管 (OLED) 设备中的性能,并探索它们的发射机制.
主要方法:
- 通过使用修饰的[d]imidazolylidene pro-chelates (L12H2+,L13H2+) 合成两系列的Ir(III) 复合物 (f-ct12b,c和f-ct13b,c).
- 谱分析以区分MLCT和TSCT过程,并确定S1-T1能量差距 (ΔE_ST).
- 温度依赖的排放研究,以调查光与热激活延迟光 (TADF) 机制.
- 使用合成的Ir (III) 复合物作为剂和敏感剂制造和测试OLED设备.
主要成果:
- 复合体f-ct12b,c表现出传统的MLCT,而f-ct13b,c表现出主导的TSCT,导致较小的DE_ST.
- 取决于温度的研究表明,TADF是TSCT占主导地位的复合体中长期发射的来源.
- 采用基于TSCT的剂f-ct13b的OLED设备达到22.2%的最大外部量子效率 (EQE) 和10,000 cd m-2.2的亮度.
- 使用f-ct13c作为感应剂的超级OLED达到28.2%的最大EQE.
结论:
- 穿越空间电荷转移 (TSCT) 是设计高效的Ir(III) 蓝色的可行机制,为MLCT提供了替代方案.
- TSCT复合体中的较小的 ΔE_ST 可能有助于 TADF,从而有助于有效的光发射.
- 这些发现为开发用于OLED应用的高性能蓝色发射器提供了一个有希望的新战略.
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