Local electronic properties of functionalized graphene studied with scanning tunneling microscopy and spectroscopy

用扫描隧道显微镜和光谱学研究功能化石墨烯的局部电子特性

• 批准号: 233373995
• 负责人: Dr. Danny Haberer-Gehrmann
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/233373995?language=en
• 关键词: Local; electronic; properties; functionalized; graphene

Graphene, a two-dimensional single sheet of carbon atoms arranged in a honeycomb lattice, is attracting tremendous attention due to its remarkable physical properties. Particularly, its electronic structure, in which charge carriers near the Fermi level mimic massless relativistic particles (Dirac fermions), provides a perfect base for studying questions of quantum electrodynamics with experimental techniques commonly used in materials research. Furthermore, graphene is an ideal material for future electronic devices because of its outstandingly high charge carrier mobility, mechanical stability, room-temperature ballistic transport and scalability down to nanometer size. It is therefore of crucial importance to investigate the structural and electronic properties of graphene on an atomic scale which can be done by using scanning tunneling microscopy (STM) and spectroscopy (STS).This project´s major aim is exploring the influence of functionalization on the structure and local electronic properties of graphene using STM and STS. Particular emphasis will be laid on the impact of (charged) impurities on Dirac fermions in graphene and the influence of edges and individual shapes of graphene nanoribbons (GNR), small stripes of graphene, on the electronic structure. Especially the latter is of prime interest for device applications as nanoribbons are expected to exhibit a bandgap that scales with the ribbon width and, depending on the edge configuration, spin-polarized edge states as well as local magnetism. A controlled modification of graphene´s properties will be achieved by in-situ synthesis of (functionalized) graphene using chemical vapor deposition and by employing bottom-up fabrication routines transforming organic molecules into GNRs with defined shapes and edges. The results from this project will be an important contribution to the understanding of how functionalization modifies the properties of graphene and will provide valuable input for device physics based on graphene and GNRs.

石墨烯是一种二维的单层碳原子排列在蜂窝状晶格中，由于其卓越的物理特性而引起了人们的极大关注。特别是，它的电子结构，其中费米能级附近的电荷载流子模拟无质量的相对论粒子（狄拉克费米子），为研究量子电动力学问题提供了一个完美的基础，实验技术通常用于材料研究。此外，石墨烯因其极高的电荷载流子迁移率、机械稳定性、室温弹道传输和可扩展至纳米尺寸而成为未来电子设备的理想材料。因此，在原子尺度上研究石墨烯的结构和电子性质是至关重要的，这可以通过使用扫描隧道显微镜（STM）和光谱学（STS）来完成。本项目的主要目标是使用STM和STS探索功能化对石墨烯结构和局部电子性质的影响。特别强调的是（带电）杂质对石墨烯中狄拉克费米子的影响，以及石墨烯纳米带（GNR）的边缘和单个形状对电子结构的影响。特别是后者是最感兴趣的器件应用，因为纳米带预计表现出的带隙，该带隙的规模与带的宽度，并根据边缘配置，自旋极化的边缘状态以及局部磁性。石墨烯特性的可控改性将通过使用化学气相沉积原位合成（功能化）石墨烯以及采用自下而上的制造程序将有机分子转化为具有特定形状和边缘的GNR来实现。该项目的结果将对理解功能化如何改变石墨烯的性质做出重要贡献，并将为基于石墨烯和GNRs的器件物理提供有价值的输入。