Bilayers of Ni₃C₁₂S₁₂and Pt₃C₁₂S₁₂: graphene-like 2D topological insulators tunable by electric fields

Abstract

In the present work we predict, through first-principles calculations, that bilayers of the recently synthesized Ni<sub>3</sub>C<sub>12</sub>S<sub>12</sub> and Pt<sub>3</sub>C<sub>12</sub>S<sub>12</sub> layered materials are topological insulators upon electron doping, and that that their topological insulator properties can be modulated by the application of electric fields with magnitudes achievable in devices. The electronic structures of both bilayers are characterized by spin-orbit split graphene-like bands, with gap magnitudes that are three orders of magnitude larger than graphene's. In ribbon geometries, chiral edge modes develop at each side with band dispersions similar to that of Kane-Mele graphene model. Surprisingly, the edge states' spin-propagation locking occurs even for very thin ribbons. We also find that the response of the electronic structure of both materials to applied electric fields are similar to both graphene and the Kane-Mele model with a Rashba term. All these findings indicate that these bilayer systems can be considered as large-spin-orbit graphene analogues with a strong sensitivity to applied electric fields.

Synthetic Routes for a 2D Semiconductive Copper Hexahydroxybenzene Metal–Organic Framework

“…As a class of crystalline, solid materials, MOFs have an outstanding degree of synthetic tunability in their structure, composition, and functionality. , Unlike in insulating MOFs, the long-range electronic coupling in c-MOFs can exemplify how local changes in the building blocks affect the material’s bulk properties. Tuning the structure of c-MOFs with atomic precision is therefore a powerful strategy to study the structure–property relationship in 2D materials while simultaneously providing more candidates for electronic applications. − …”

Structures and electronic properties of functional molecules on metal substrates: From single molecule to self‐assemblies

“…The π‐d conjugated system possesses exotic electronic properties, 151–154 which relies on the constructed structures. For example, the 2D organic network consisting of three Cu atoms and one benzenehexathiol molecule (Cu 3 (C 6 S 6 )) has high electrical conductivity 155 and superconductivity, 156,157 while the one consisting of three Ni atoms and two benzenehexathiol molecules (Ni 3 (C 6 S 6 ) 2 ) has topological non‐trivial band structure 158,159 . In this part, we start from the 2D metal–organic systems with topological insulator states, then we introduce the 2D metal–organic network with superconductivity.…”

“…The other type has a Kagome lattice, 159,164–167 in which three metal atoms form a Kagome lattice and bond the adjacent two organic molecules, as shown in Figure 6b (Ni 3 (C 6 S 6 ) 2 ) 158 . Figure 6e shows the band structure of Ni 3 (C 6 S 6 ) 2 with SOC around the Fermi level.…”

Layertronic control of topological states in multilayer metal-organic frameworks

“…Indeed, the energetic preference of 2ML-AA was also verified in Refs. [39,40] using different approaches to describe the long range vdW interactions [41][42][43]. In contrast, while Ref.…”