Exploring synthetic approaches to non-alternant ring topologies in graphene nanostructures

探索石墨烯纳米结构中非交替环拓扑的合成方法

• 批准号: 429265950
• 负责人: Professor Dr. Xinliang Feng
• 金额: --
• 依托单位: Empa - Materials Science and Technology
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/429265950?language=en
• 关键词: Exploring; synthetic; approaches; non; alternant

Graphene has attracted extensive research interests since the ground breaking report by Geim and Novoselov in 2004. In the years to follow, graphene has been found to possess a number of exceptional properties. In particular, its excellent charge carrier mobility has rendered graphene one of the most promising materials for future use in nanoelectronics. However, graphene is a semimetal without a bandgap which precludes its application in digital transistors. This makes it crucial to find a way of opening a bandgap before graphene-based electronic devices can be developed. The most prominent way is to realize quantum confinement of charge carriers in one-dimensional semiconducting stripes of graphene with nanometer-scale width – namely, graphene nanoribbons (GNRs). Two main methods have been recently established to prepare GNRs, namely “top-down” and “bottom-up” approaches. The “bottom-up” approach, a convergent, total-synthetic approach inspired by organic chemistry, provides GNRs with atomically precise edge structures and well-defined width. This bottom-up approach can be conducted classically in a solution-mediated environment or on noble metal substrates such as gold, silver or copper. Another pathway to influence the electronic structure of graphene is to introduce the imperfections/defects in the basal plane of graphene. Theoretical calculations have described that topological defects in graphene strongly affect its electronic, optical, chemical, thermal and mechanical properties. The pentagon-heptagon pair is one of the reasonable defect models from the view point of energetic stability and can be induced by atom dislocation. Existence of topological defects have been experimentally confirmed using transmission electron microscopy (TEM) and scanning tunneling microscopy (STM) studies, and to this end, most such studies have hitherto focused only on their structural characterization. Consequently, physico-chemical aspects of topological defects in graphene remain poorly understood, which motivates a thorough understanding both from a fundamental and applied perspective. In this joint Swiss-German proposal, we bring together the TUD and EMPA, to establish a new line of research in atomically-precise synthesis of non-hexagonal rings in nanographenes and GNRs, both in the solution and on the surface, as a route to impart novel properties such as large open-shell biradical character, increased chemical activities and new electronic functionalities. This proposal aims at stimulating mobility of researchers between both countries within this key and strategic field of research with potential economic importance.

自 2004 年 Geim 和 Novoselov 发表突破性报告以来，石墨烯引起了广泛的研究兴趣。在接下来的几年里，人们发现石墨烯具有许多优异的性能，特别是其优异的载流子迁移率使石墨烯成为最重要的材料之一。然而，石墨烯是一种没有带隙的半金属，这阻碍了其在数字晶体管中的应用，因此找到一种打开带隙的方法至关重要。开发基于石墨烯的电子器件最突出的方法是在纳米级宽度的一维石墨烯半导体条中实现电荷载流子的量子限制，即石墨烯纳米带（GNR）。制备GNR，即“自上而下”和“自下而上”的方法“自下而上”的方法是一种受有机化学启发的聚合的全合成方法，为GNR提供了方法。这种自下而上的方法可以在溶液介导的环境中或在金、银或铜等贵金属基底上进行。另一种影响石墨烯电子结构的途径是引入原子级精确的边缘结构和明确的宽度。石墨烯基面的缺陷/缺陷从角度来看，石墨烯的拓扑缺陷强烈影响其电子、光学、化学、热和机械性能。使用透射电子显微镜（TEM）和扫描隧道显微镜（STM）研究已经通过实验证实了拓扑缺陷的存在，并且可以通过原子位错引起，为此，大多数此类研究迄今为止仅集中于其结构。经过检查，石墨烯拓扑缺陷的物理化学方面仍然知之甚少，这促使我们从基础和应用的角度进行彻底的理解，在这项瑞士-德国联合提案中，我们将 TUD 和EMPA 旨在建立纳米石墨烯和 GNR 中非六角环原子级精确合成的新研究路线，无论是在溶液中还是在表面上，作为赋予诸如大开壳双自由基特性等新特性的途径，增加了该提案旨在刺激两国研究人员在这一具有潜在经济重要性的关键和战略研究领域内的流动。