Verhage Michael, Bampoulis Pantelis, Preuss Marco D, Filot Ivo, Joosten Rick R M, Friedrich Heiner, Meijer E W, Flipse Kees
Molecular Materials and Nanosystems - Department of Applied Physics, Eindhoven University of Technology, Eindhoven, 5600 MB, The Netherlands.
MESA+ Institute, Physics of Interfaces and Nanomaterials, University of Twente, Drienerlolaan 5, Enschede, 7522 NB, The Netherlands.
Adv Mater. 2024 Oct;36(41):e2403807. doi: 10.1002/adma.202403807. Epub 2024 Aug 13.
The chirality-induced spin selectivity (CISS) effect is a fascinating phenomenon that correlates the molecular structure with electron spin-polarization (SP). Experimental procedures to quantify the spin-filtering magnitude have extensively used magnetic-field-dependent conductive AFM. In this work chiral crystals of imide-substituted coronene bisimide ((S)-CBI-GCH) are studied to explain the dynamics of the current-voltage I - V spectra and the origin of superimposed peaks are investigated. A dynamic voltage-sweep rate-dependent phenomenon can give rise to complex I - V curves. The redox group, capable of localization of charge, acts as a localized state that interferes with the continuum of the π - π stacking, giving rise to Fano resonances. A novel mechanism for dynamic transport is introduced, which provides insight into the origin of spin-polarized charge in crystallized CBI-GCH molecules after absorption on a metallic substrate, guided by transient charge polarization. Crucially, interference between charge localization and delocalization during transport may be important properties in understanding the magnetochiral phenomena observed by electrostatic force microscopy. Finally, it is observed that charge trapping sensitively modifies the injection barrier from direct tunneling to Fowler-Nordheim tunneling transport supporting nonlinearity in CISS for this class of molecules.
手性诱导自旋选择性(CISS)效应是一种引人入胜的现象,它将分子结构与电子自旋极化(SP)联系起来。量化自旋过滤幅度的实验程序广泛使用了依赖磁场的导电原子力显微镜。在这项工作中,对酰亚胺取代的并四苯双酰亚胺((S)-CBI-GCH)的手性晶体进行了研究,以解释电流-电压I-V谱的动力学,并研究叠加峰的起源。一种与动态电压扫描速率相关的现象会产生复杂的I-V曲线。能够使电荷局部化的氧化还原基团充当局部状态,干扰π-π堆积的连续性,从而产生法诺共振。引入了一种动态传输的新机制,该机制为由瞬态电荷极化引导的金属基底上吸收后结晶的CBI-GCH分子中自旋极化电荷的起源提供了见解。至关重要的是,传输过程中电荷局部化和离域之间的干扰可能是理解静电 force显微镜观察到的磁手性现象的重要特性。最后,观察到电荷俘获敏感地改变了从直接隧穿到福勒-诺德海姆隧穿传输的注入势垒,支持了这类分子在CISS中的非线性。