Cui Mingkuan, Rui Hongsong, Wu Xiaoming, Sun Zhe, Qu Weixin, Qin Wenjing, Yin Shougen
Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education; Tianjin Key Laboratory of Photoelectric Materials and Devices; National Demonstration Center for Experimental Function Materials Education; School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China.
School of Chemistry & Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin 300384, P. R. China.
J Phys Chem Lett. 2021 Sep 9;12(35):8533-8540. doi: 10.1021/acs.jpclett.1c02281. Epub 2021 Aug 31.
Understanding the mechanism of interaction between organic polymers and dopants is of great significance to further enhance the performances of flexible electronics. Here, the two doping mechanisms of charge transfer complex (CTC) and integer charge transfer (ICT) are found to coexist in p-π conjugated PTAA doped with the strong acceptor F4-TCNQ, and their correlation is affected by the HJ-aggregate state of the doped polymer. The growth of the J-aggregate caused by the increase of CTC would lead to a corresponding formation of ICT. The doping efficiency was dominated by the CTC/ICT ratio. On the basis of the analysis of the optical, electrical, and morphological properties of PTAA:F4-TCNQ films, we optimized the CTC/ICT ratio to achieve the efficient hole transport layers that are used in solution-processed flexible phosphorescent organic light-emitting diodes with p-i-n structure. The optimal device presents a very high current efficiency (CE) of 31.12 cd/A and a low turn-on voltage of 3.6 V.
理解有机聚合物与掺杂剂之间的相互作用机制对于进一步提高柔性电子产品的性能具有重要意义。在此，发现电荷转移络合物（CTC）和整数电荷转移（ICT）这两种掺杂机制在掺杂强受体F4-TCNQ的p-π共轭PTAA中共存，并且它们的相关性受掺杂聚合物的HJ-聚集体状态影响。由CTC增加引起的J-聚集体的生长将导致相应的ICT形成。掺杂效率由CTC/ICT比率主导。基于对PTAA:F4-TCNQ薄膜的光学、电学和形态学性质的分析，我们优化了CTC/ICT比率，以实现用于具有p-i-n结构的溶液处理柔性磷光有机发光二极管的高效空穴传输层。最佳器件呈现出31.12 cd/A的非常高的电流效率（CE）和3.6 V的低开启电压。
