中国科学院宁波材料所葛子义团队通过控制分子膜形成工程来增强载流子的行为，从而显著改善电致发光。相关研究成果于2024年9月17日发表在《德国应用化学》。

有机薄膜的质量对有机半导体中的载流子动力学有着至关重要的影响。在纯/掺杂薄膜中，即使是微小的空隙也会被水或氧分子穿透，从而产生称为水/氧诱导陷阱的电荷陷阱状态，严重阻碍载流子迁移。虽然对非掺杂薄膜和晶态中的水/氧诱导陷阱进行了全面的研究，但对它们在掺杂态下的性质缺乏彻底的研究。因此，可以有效调节掺杂薄膜和实际器件中的分子堆叠行为，并提高这些薄膜的质量的分子设计策略需求很高。

该文中，研究人员提出了一种通用的分子设计原理，可以在目标分子10-（4-（4,6-二苯基-1,3,5-三嗪-2-基）苯基）-1'-（4-氟苯基）-10H-螺[吖啶-9,9'-黄原烯]（DspiroO-F-TRZ）中的，掺杂薄膜的表面和内部形成“纳米簇”结构，该分子用氟苯基修饰。

这些“纳米簇”结构在掺杂薄膜中表现出更均匀的形状，有效地降低了缺陷态密度，同时增强了载流子注入和传输性能，最终提高了器件性能。值得注意的是，由于“纳米簇”结构增强对提高电致发光性能的贡献，基于Dspiro-F-TRZ的TADF-OLED的效率几乎是其控制对应物的两倍。

附：英文原文

Title: Enhancing Carrier Behavior via Controlled Molecular Film Formation Engineering Leads to Significant Improvement in Electroluminescence

Author: Jiasen Zhang, Denghui Liu, Deli Li, Kexuan Sun, Wei Li, Yuanyuan Meng, Chang Liu, Yujie Wu, Kaibo Fang, Xilin Mu, Chunyu Liu, Shijian Su, Ziyi Ge

Issue&Volume: 2024-09-17

Abstract: The quality of organic thin films critically influences carrier dynamics in organic semiconductors. In neat/doped films, even tiny voids can be penetrated by water or oxygen molecules to create charge-trap states called water/oxygen-induced traps that significantly hinder carrier mobility. While the water/oxygen-induced traps in non-doped films and crystalline states have been investigated comprehensively, there is a lack of thorough examination regarding their properties in the doped state. Therefore, there is a high demand for a molecular design strategy that effectively modulates the molecular stacking behavior in doped films and practical devices and enhances the quality of these films. Herein, we proposed a versatile molecular design principle that enables the formation of "nano-cluster" structures on both the surface and interior of doped films in target molecule 10-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1'-(4-fluorophenyl)-10H-spiro[acridine-9,9'-xanthene] (DspiroO-F-TRZ), which is modified with a fluorophenyl group. These "nano-cluster" structures exhibit more uniform shapes within doped films and effectively reduce defective state densities while enhancing carrier injection and transport properties, ultimately improving device performance. Notably, TADF-OLED based on DspiroO-F-TRZ demonstrates nearly twice as much efficiency as its control counterpart due to contributions from 'nano-cluster' structure enhancements toward improved electroluminescence performance.

DOI: 10.1002/anie.202415856

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202415856