On‐Surface Synthesis of Nitrogen‐Doped Kagome Graphene

Abstract

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.

Halogenated Anthracenes as Building Blocks for the On-Surface Synthesis of Covalent Polymers: Structure Prediction with the Lattice Monte Carlo Method

“…At this stage, the adsorbed superstructure is alterable enough, so that weak metal–monomer bonds can be broken and re-formed to reach thermodynamically stable, defect-free, optimal configuration. In surface-assisted polymerization reactions, the morphology of this optimal metal–organic assembly is then transmitted to the final polymer in which, usually upon heating, coordination bonds are replaced by covalent bonds. , Understanding the ways in which metal–organic precursors are formed prior to the covalent bonding is thus an important task in custom designing and directing polymerization reactions on surfaces.…”

“…In surface-assisted polymerization reactions, the morphology of this optimal metal−organic assembly is then transmitted to the final polymer in which, usually upon heating, coordination bonds are replaced by covalent bonds. 23,24 Understanding the ways in which metal−organic precursors are formed prior to the covalent bonding is thus an important task in custom designing and directing polymerization reactions on surfaces.…”

Designer quantum matter in van der Waals heterostructures

“…These types of flat bands have been realized in artificial systems based on atomic lattices [127][128][129][130][131]. They can also be formed in suitable engineered, chemically synthesized lattices, where covalent organic frameworks and metal-organic frameworks are especially attractive systems for realizing these artificial models [132][133][134][135][136][137][138][139][140].…”

“…While there are extensive results on the formation of the onedimensional nanocarbons (graphene nanoribbons) [131,[143][144][145][146][147], challenges remain to create two-dimensional assemblies with very high quality [148][149][150]. However, there are recent experimental results that are pushing this field towards higher quality samples towards the formation of flat bands in the MOF or COF band structure [119,140,142,151]. The realized strategies rely on making a molecular network with a kagome lattice with one of the examples highlighted in Fig.…”

Mechanical Properties and Buckling of Kagome Graphene under Tension: A Molecular Dynamics Study

“…Although Kagome graphene has not been successfully synthesized yet, Chen et al suggested a self-assembly process (from cyclopropane) on single-layer boron nitride, as the lattice mismatch is only about 2% [7]. Additionally, Pawlak et al [11] recently published a successful synthesis process of nitrogen-doped graphene on an Ag (111) substrate, a 2D material that also has a Kagome pattern [11]. With growing interest in the synthesis of these types of material, it is evident that the actualization of materials with KG-like properties has merit, and understanding the mechanical properties of Kagome lattice structures may prove valuable.…”