Spectroscopic characterization of functionalized graphene nanoribbon heterostructures

功能化石墨烯纳米带异质结构的光谱表征

• 批准号: 426882575
• 负责人: Professor Dr. Alexander Grüneis
• 金额: --
• 依托单位: Institut für Festkörperelektronik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/426882575?language=en
• 关键词: Spectroscopic; characterization; functionalized; graphene; nanoribbon

Graphene nanoribbons are the latest one-dimensional (1D) sp2-carbon allotrope and combine the best attributes from the nanotube and the graphene worlds, i.e. a variety in possible structures with the possibility of a uniform wafer coating. A key difference between graphene and graphene nanoribbons is that the latter possess a bandgap. Furthermore, the electronic and optical properties of GNRs can be tailored by controlling their width and edge structure. GNRs can be fabricated with atomic precision by a bottom-up approach on a catalytically active metal surface on which precursor molecules react to form the desired structure. The large variety in precursor molecules ensures that GNRs with different physical properties can besynthesized over large areas. Additionally, by using vicinal surfaces the ribbons can be aligned. Within this project we will synthesize, functionalize, and spectroscopically characterize novel graphene nanoribbons and heterostructures made thereof and evaluate their potential applicability in devices. For the synthesis of GNRs we employ on-surface polymerization and will optimize the synthesis parameters. Graphene nanoribbons will be further functionalized by for example evaporation of metals and earth alkali metals on them to achieve high electron doping. Heterostructures of GNRs will be prepared by co-evaporation of different precursors during the synthesis step or by stacking GNRs with different width or doping. The fabricated samples will be characterized using UHV optical spectroscopy, photoelectron spectroscopy, and fluorescence and Raman spectroscopy. Using these methods we will determine fundamental properties of graphene nanoribbons such as effective masses, exciton transition energies, and absorption spectra. We will additionally apply plasmonic enhancement to enhance the light-matter interaction of GNRs. Here a key goal is to reduce the probed area of the sample so that individual nanoribbons may be studied optically. Finally, we will explore the use of GNRs in devices and applications such as gas sensing.

石墨烯纳米带是最新的一维（1D）sp2-碳同素异形体，并且联合收割机结合了来自纳米管和石墨烯世界的最佳属性，即具有均匀晶片涂层的可能性的各种可能的结构。石墨烯和石墨烯纳米带之间的关键区别在于后者具有带隙。此外，可以通过控制它们的宽度和边缘结构来定制GNR的电子和光学性质。GNR可以通过自下而上的方法在催化活性金属表面上以原子精度制造，前体分子在该催化活性金属表面上反应以形成所需的结构。前体分子的多样性确保了具有不同物理性质的GNR可以在大面积上合成。另外，通过使用邻近表面，带可以对齐。在这个项目中，我们将合成，功能化和光谱表征新型石墨烯纳米带及其异质结构，并评估其在设备中的潜在适用性。对于GNRs的合成，我们采用表面聚合，并将优化合成参数。石墨烯纳米带将通过例如在其上蒸发金属和碱土金属来进一步官能化以实现高电子掺杂。GNR的异质结构将通过在合成步骤期间共蒸发不同前体或通过堆叠具有不同宽度或掺杂的GNR来制备。制造的样品将使用超高真空光学光谱，光电子能谱，荧光和拉曼光谱进行表征。使用这些方法，我们将确定石墨烯纳米带的基本性质，如有效质量，激子跃迁能和吸收光谱。我们还将应用等离子体增强来增强GNRs的光-物质相互作用。这里的一个关键目标是减少样本的探测面积，以便可以对单个纳米带进行光学研究。最后，我们将探讨GNRs在气体传感等设备和应用中的应用。