Tailoring the electronic properties of graphene by functionalization: Insights through optical and electron spectroscopy

自从二维和亚稳态石墨烯片的发现以来，致力于探索其物理性质的研究急剧增加。这可以归因于以下两个原因。首先，石墨烯允许人们解决量子电动力学的基本问题，例如相对论性的狄拉克费米子或在台式凝聚态实验中的克莱因悖论。其次，纳米尺寸、可扩展性和室温弹道输运特性使石墨烯成为未来具有高载流子迁移率的纳米电子器件的有希望的候选者和自旋电子学的理想材料。在这个项目中，功能化单层和多层石墨烯（FLG）的光谱学研究将结合光学和电子光谱学以及理论计算进行。特别强调的是通过控制功能化，如氢化和碱金属和有机分子的吸附来定制电子性能。控制石墨烯的电子特性对其作为晶体管材料、自旋阀、气体传感器或分子膜的应用至关重要。我们的多学科方法确保所获得的结果不仅有助于理解掺杂效应，而且为基于石墨烯的器件物理学提供有价值的输入。

Since the discovery of two-dimensional and metastable graphene sheets, a dramatic increase in the research dedicated to explore its physical properties took place. This can be attributed to the two following reasons. First, graphene allows one to address basic questions of quantum electrodynamics, such as relativistic Dirac fermions or the Klein paradox in a bench-top condensed-matter experiment. Second, the nanometer size, the scalability and room-temperature ballistic transport properties make graphene a promising candidate for future nanoelectronic devices with high charge carrier mobilities and an ideal material for spintronics. In this project, the spectroscopic investigation of functionalized mono- and few-layer graphene (FLG) will be carried out using a combination of optical and electron spectroscopies as well as theoretical calculations. Particular emphasis will be paid to tailoring the electronic properties via controlled functionalization such as hydrogenation and adsorption of alkali metals and organic molecules. Controlled modification of the electronic properties of graphene is of prime importance for its applications as a transistor material, spin valve, gas sensor or molecular membrane. Our multi-disciplinary approach ensures that the results obtained will not only contribute to the understanding of doping effects but also yield valuable input for device physics based on graphene.