Shao Jingjing, Paulus Beate
Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany.
Nanomaterials (Basel). 2021 Dec 30;12(1):125. doi: 10.3390/nano12010125.
A systematic examination of the electronic and transport properties of 1D fluorine-saturated zigzag graphene nanoribbons (ZGNRs) is presented in this article. One publication (Withers et al., , , , 3912-3916.) reported a controlled synthesis of fluorinated graphene via an electron beam, where the correlation between the conductivity of the resulting materials and the width of the fluorinated area is revealed. In order to understand the detailed transport mechanism, edge-fluorinated ZGNRs with different widths and fluorination degrees are investigated. Periodic density functional theory (DFT) is employed to determine their thermodynamic stabilities and electronic structures. The associated transport models of the selected structures are subsequently constructed. The combination of a non-equilibrium Green's function (NEGF) and a standard Landauer equation is applied to investigate the global transport properties, such as the total current-bias voltage dependence. By projecting the corresponding lesser Green's function on the atomic orbital basis and their spatial derivatives, the local current density maps of the selected systems are calculated. Our results suggest that specific fluorination patterns and fluorination degrees have significant impacts on conductivity. The conjugated π system is the dominate electron flux migration pathway, and the edge effect of the ZGNRs can be well observed in the local transport properties. In addition, with an asymmetric fluorination pattern, one can trigger spin-dependent transport properties, which shows its great potential for spintronics applications.
本文对一维氟饱和锯齿形石墨烯纳米带（ZGNRs）的电学和输运性质进行了系统研究。一篇文献（Withers等人，……，3912 - 3916。）报道了通过电子束可控合成氟化石墨烯，揭示了所得材料的电导率与氟化区域宽度之间的相关性。为了理解详细的输运机制，研究了不同宽度和氟化程度的边缘氟化ZGNRs。采用周期密度泛函理论（DFT）来确定它们的热力学稳定性和电子结构。随后构建所选结构的相关输运模型。应用非平衡格林函数（NEGF）和标准朗道尔方程的组合来研究全局输运性质，如总电流 - 偏置电压依赖性。通过将相应的较小格林函数投影到原子轨道基及其空间导数上，计算所选系统的局部电流密度图。我们的结果表明，特定的氟化模式和氟化程度对电导率有显著影响。共轭π体系是主要的电子通量迁移途径，并且在局部输运性质中可以很好地观察到ZGNRs的边缘效应。此外，具有不对称氟化模式时，可以引发自旋相关的输运性质，这显示了其在自旋电子学应用中的巨大潜力。
