Pawlak Rémy, Liu Xunshan, Ninova Silviya, D'Astolfo Philipp, Drechsel Carl, Liu Jung-Ching, Häner Robert, Decurtins Silvio, Aschauer Ulrich, Liu Shi-Xia, Meyer Ernst
Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland.
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
Angew Chem Int Ed Engl. 2021 Apr 6;60(15):8370-8375. doi: 10.1002/anie.202016469. Epub 2021 Mar 3.
Nitrogen-doped Kagome graphene (N-KG) has been theoretically predicted as a candidate for the emergence of a topological band gap as well as unconventional superconductivity. However, its physical realization still remains very elusive. Here, we report on a substrate-assisted reaction on Ag(111) for the synthesis of two-dimensional graphene sheets possessing a long-range honeycomb Kagome lattice. Low-temperature scanning tunneling microscopy (STM) and atomic force microscopy (AFM) with a CO-terminated tip supported by density functional theory (DFT) are employed to scrutinize the structural and electronic properties of the N-KG down to the atomic scale. We demonstrate its semiconducting character due to the nitrogen doping as well as the emergence of Kagome flat bands near the Fermi level which would open new routes towards the design of graphene-based topological materials.
氮掺杂的 Kagome 石墨烯（N-KG）在理论上被预测为可能出现拓扑带隙以及非常规超导性的候选材料。然而，其物理实现仍然非常难以捉摸。在此，我们报道了在 Ag(111) 上的一种底物辅助反应，用于合成具有长程蜂窝 Kagome 晶格的二维石墨烯片。利用低温扫描隧道显微镜（STM）和原子力显微镜（AFM），结合由密度泛函理论（DFT）支持的 CO 端接针尖，在原子尺度上仔细研究了 N-KG 的结构和电子性质。我们证明了由于氮掺杂导致的半导体特性，以及在费米能级附近出现的 Kagome 平带，这将为基于石墨烯的拓扑材料设计开辟新途径。
