Structural and Electronic Properties of Silicene on MgX₂ (X = Cl, Br, and I)

Abstract

Silicene is a monolayer of Si atoms in a two-dimensional honeycomb lattice, being expected to be compatible with current Si-based nanoelectronics. The behavior of silicene is strongly influenced by the substrate. In this context, its structural and electronic properties on MgX2 (X = Cl, Br, and I) have been investigated using first-principles calculations. Different locations of the Si atoms are found to be energetically degenerate because of the weak van der Waals interaction with the substrates. The Si buckling height is below 0.55 Å, which is close to the value of free-standing silicene (0.49 Å). Importantly, the Dirac cone of silicene is well preserved on MgX2 (located slightly above the Fermi level), and the band gaps induced by the substrate are less than 0.1 eV. Application of an external electric field and stacking can be used to increase the band gap.

3D Hollow α‐MnO2 Framework as an Efficient Electrocatalyst for Lithium–Oxygen Batteries

“…[37] Beyond hollow and porous structure, moreover, 3D hierarchical structure is also an effective morphology for the air cathode, considering the large inner contact area between the catalyst and electrolyte and a huge open space for O 2 diffusion. [13,36,43,44] Nevertheless, most of 3D hierarchical structure, usually assembled by active catalyst grown on the supporting network, only exposed part of active sites on network surface with limited catalytic ability. Increasing available surface area and boundaries could effectively create more exposed catalytically active sites for the high durability and capacity of Li-O 2 batteries.…”

Quantum valley Hall states and topological transitions in Pt(Ni, Pd)-decorated silicene: A first-principles study

“…In experiments, silicene is generally deposited on a substrate, such as metallic Ag (111) To maintain the exotic Dirac-electron behaviors in silicene, some insulating substrates, including hexagonal BN, 38,39 SiC (0001), 38 and MgBr 2 (0001), 40 have been proposed to support the silicene. The lattice mismatch between the silicene and these substrates is usually small (<2.5%).…”

“…More importantly, the interactions between them are generally the weak van der Waals type, leading to the unbroken Dirac-cone-like electronic structure of silicene. [38][39][40] Here, we took MgBr 2 (0001) (Ref. 40) as an example to check the influence of the substrate on the topologically phase transition obtained in the Pt-decorated silicene.…”

“…[38][39][40] Here, we took MgBr 2 (0001) (Ref. 40) as an example to check the influence of the substrate on the topologically phase transition obtained in the Pt-decorated silicene. As shown in Fig.…”

Hierarchical Polyaniline‐MnO2‐Reduced Graphene Oxide Ternary Nanostructures with Whiskers‐Like Polyaniline for Supercapacitor Application

“…[16] To address such issues, considerable research efforts have been made to improve the conductivity of MnO 2 -based electrodes with simultaneous optimization of their electrochemical performance through exploring hybrid composite structures with highly conducting materials like metal nanostructures, [16] conducting polymers, [17][18][19][20][21] carbon nanotubes [22][23] and graphene. [24][25][26][27][28] Among various hybrid materials developed so far, graphene/PANI, PANI/MnO 2 , graphene/MnO 2 binary and graphene/MnO 2 /PANI ternary nanostructure based SCs electrode materials are found to be promising for large scale energy storage system due to their low cost, scalable synthesis and processability. [5,[29][30][31][32][33][34][35][36][37] It has been reported [5] that the electrochemical capacitance performance of MnO 2 /graphene composite electrodes can be further improved significantly by wrapping MnO 2 /graphene sheets three dimensionally with conducting polymers.…”