论文标题
多孔石墨烯纳米纤维中的电荷密度波传输
Charge Density Wave Transport in Porous Graphene Nanoribbons
论文作者
论文摘要
多孔石墨烯(PG)形成一类带有纳米方面架构的石墨烯相关材料。它们独特的原子布置呈现具有较高表面积和较高孔隙体积的相互联系的网络。 PG的某些显着特性,例如高机械强度和良好的热稳定性,已被广泛研究。但是,它们的电导率,最重要的是,它们的电荷运输机制仍未完全理解。本文中,我们采用了一种基于2D紧密结合模型哈密顿量的数值方法,首先揭示了PG纳米骨中电荷传输机制的性质。结果表明,这些材料中的电荷传输是由电荷密度波介导的。这些载体物种动态稳定,并呈现非常浅的晶格扭曲。孔隙率允许替代极性荷载体的通常产生,即使在较宽的纳米骨中,也可以保留PG半导体特征。电荷密度波在光学状态内的PG中移动,终端速度从0.50到1.15 a/fs不等。这些速度低于传统石墨烯纳米纤维(2.2-5.1 A/fs)中极性的速度。
Porous graphene (PG) forms a class of graphene-related materials with nanoporous architectures. Their unique atomic arrangements present interconnected networks with high surface area and high pore volume. Some remarkable properties of PG, such as high mechanical strength and good thermal stability, have been widely studied. However, their electrical conductivity, and most importantly, their charge transport mechanism are still not fully understood. Herein, we employed a numerical approach based on a 2D tight-binding model Hamiltonian to first reveal the nature of the charge transport mechanism in PG nanoribbons. Results showed that the charge transport in these materials is mediated by charge density waves. These carrier species are dynamically stable and present very shallow lattice distortions. The porosity allows for an alternative to the usual arising of polaron-like charge carriers and it can preserve the PG semiconducting character even in broader nanoribbons. The charge density waves move in PG within the optical regime with terminal velocities varying from 0.50 up to 1.15 A/fs. These velocities are lower than the ones for polarons in conventional graphene nanoribbons (2.2-5.1 A/fs).