Programme

O.10 -- Oral, VCTP-47

Date: Tuesday, 2 August 2022

Time: 16:25 - 16:50

Halogenation effects in silicene and silicene nanoribbons: A DFT study

Duy Khanh Nguyen

High-performance computing laboratory (HPC Lab), Information Technology Center, Thu Dau Mot University, Binh Duong Province, Vietnam

In this talk, I will systematically present the various halogenation effects in structural, electronic, and magnetic properties of 2D silicene and 1D silicene nanoribbons, in which the halogen adatoms-enriched essential properties are fully identified under the complete DFT theoretical framework, including the cohesive energies, optimal structural parameters, phonon band structures, atom-and orbital-dominated electronic band structures, atom- and orbital-projected density of states (DOSs), spatial charge density distributions, charge density difference, magnetic moments, and spin density distributions. For 2D silicene systems, the double-side and single-side halogen effects are fully included in the calculations, whereas the former belongs to the concentration-depended finite gap semiconductors or p-type metals, while the latter display the valence energy bands with/without spin-splitting intersecting with the Fermi level. For 1D armchair silicene nanoribbons (ASiNR), the semiconducting behavior of the pristine system becomes the p-type metallic or semiconducting behaviors under the various halogen concentrations. For zigzag silicene nanoribbons (ZSiNR), the anti-ferromagnetic configuration of pristine ZSiNR transforms into the ferromagnetic one under the single adatom adsorption. Especially, under the double adatom adsorptions, whether the anti-ferromagnetic configuration becomes ferromagnetic or nonmagnetic ones that strongly depends on the adatom distributions across the zigzag edges. The ferromagnetic-nonmagnetic transition of the halogen-adsorbed ZSiNR is found at the critical concentration of 25%. The diverse structural, electronic and magnetic properties of halogenated silicene and silicene nanoribbons are very potential for a wide range of applications in high-performance electronic and spintronic devices.

Presenter: Nguyen Duy Khanh