Yang Xueli, Guo Ankang, Yang Jie, Chen Jinyang, Meng Ke, Hu Shunhua, Duan Ran, Zhu Mingliang, Shi Wenkang, Qin Yang, Zhang Rui, Yang Haijun, Li Jikun, Guo Lidan, Sun Xiangnan, Liu Yunqi, Guo Yunlong
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, P. R. China.
Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Nat Commun. 2024 Sep 27;15(1):8368. doi: 10.1038/s41467-024-52770-z.
Organic semiconductors (OSCs) are featured by weak spin-orbit coupling due to their light chemical element composition, which enables them to maintain spin orientation for a long spin lifetime and show significant potential in room-temperature spin transport. Carrier mobility and spin lifetime are the two main factors of the spin transport performance of OSCs, however, their ambiguous mechanisms with molecular structure make the development of spintronic materials really stagnant. Herein, the effects of halogen substitution in bay-annulated indigo-based polymers on carrier mobility and spin relaxation have been systematically investigated. The enhanced carrier mobility with an undiminished spin lifetime contributes to a 3.7-fold increase in spin diffusion length and a record-high magnetoresistance of 8.7% at room temperature. By analyzing the spin-orbit coupling and hyperfine interaction, it was found that the distance of the substitution site from the conjugated center and the nitrogen atoms in the molecules play crucial roles in spin relaxation. Based on the above results, we proposed a molecular design strategy of halogen substitution far from conjugate center to enhance spin transport efficiency, presenting a promising avenue for advancing the field of organic spintronics.
有机半导体（OSCs）因其轻元素化学组成而具有较弱的自旋轨道耦合特性，这使得它们能够在较长的自旋寿命内保持自旋取向，并在室温自旋输运中展现出巨大潜力。载流子迁移率和自旋寿命是影响有机半导体自旋输运性能的两个主要因素，然而，它们与分子结构之间的关系尚不明确，这使得自旋电子材料的发展陷入停滞。在此，我们系统地研究了湾区稠合靛蓝基聚合物中卤素取代对载流子迁移率和自旋弛豫的影响。载流子迁移率的提高以及自旋寿命的保持，使得自旋扩散长度增加了3.7倍，并在室温下实现了8.7%的创纪录高磁电阻。通过分析自旋轨道耦合和超精细相互作用，发现取代位点与分子中共轭中心和氮原子的距离对自旋弛豫起着关键作用。基于上述结果，我们提出了一种远离共轭中心的卤素取代分子设计策略，以提高自旋输运效率，为推动有机自旋电子学领域的发展提供了一条有前景的途径。
