Electronic Structures of Silicene Nanoribbons: Two-Edge-Chemistry Modification and First-Principles Study.
Electronic Structures of Silicene Nanoribbons: Two-Edge-Chemistry Modification and First-Principles Study.
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硅烯纳米带的电子结构：两端化学修饰和第一性原理研究
DOI：
10.1186/s11671-016-1584-5
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发表时间：
2016-12
影响因子：
--
通讯作者：
Wang R
中科院分区：
文献类型：
--
作者：
Yao Y;Liu A;Bai J;Zhang X;Wang R
在本文中，我们利用从头算密度泛函理论方法和局域自旋密度近似研究了边缘化学修饰的H、F、OH和O修饰的锯齿状硅烯纳米带（ZSiNRs）的结构和电子性质。考虑三种自旋极化配置：非自旋极化（NM）、所有电子的铁磁自旋耦合（FM）、沿每个边缘的铁磁排序以及两个边缘之间的反平行自旋方向（AFM）。 H、F 和 OH 基团修饰的 8-ZSiNR 具有 AFM 基态。由于相同的 sp2 杂化，直接边缘氧化 (O1) ZSiNR 对于 NM、FM 和 AFM 配置产生相同的能量和能带结构。并用 O 原子 (O2) 替换两个边缘上的 Si 原子，产生 FM 基态。边缘化学改性的 ZSiNR 均表现出金属能带结构。并且这些修改引入了特殊的边缘态，强烈集中在边缘的 Si 原子上，除了 O1 形式。硅烯纳米带锯齿形边缘的修饰是将硅烯应用于场效应晶体管（FET）的关键问题，并为更好地理解实验结果提供了更多必要。
In this paper, we investigate the structural and electronic properties of zigzag silicene nanoribbons (ZSiNRs) with edge-chemistry modified by H, F, OH, and O, using the ab initio density functional theory method and local spin-density approximation. Three kinds of spin polarized configurations are considered: nonspin polarization (NM), ferromagnetic spin coupling for all electrons (FM), ferromagnetic ordering along each edge, and antiparallel spin orientation between the two edges (AFM). The H, F, and OH groups modified 8-ZSiNRs have the AFM ground state. The directly edge oxidized (O1) ZSiNRs yield the same energy and band structure for NM, FM, and AFM configurations, owning to the samesp2hybridization. And replacing the Si atoms on the two edges with O atoms (O2) yields FM ground state. The edge-chemistry-modified ZSiNRs all exhibit metallic band structures. And the modifications introduce special edge state strongly localized at the Si atoms in the edge, except for the O1form. The modification of the zigzag edges of silicene nanoribbons is a key issue to apply the silicene into the field effect transistors (FETs) and gives more necessity to better understand the experimental findings.