Evolution of structural and electronic properties standardized description in rhenium disulfide at the bulk-monolayer transition
Document Type
Article
Publication Date
4-1-2024
Abstract
The structural and electronic properties of ReS 2 different forms - three-dimensional bulk and two-dimensional monolayer - were studied within density functional theory and pseudopotentials. A method for standardizing the description of bulk unit cells and ``artificial'' slab unit cells for DFT research has been proposed. The preference of this method for studying zone dispersion has been shown. The influence of the vacuum layer thickness on specified special high-symmetry points is discussed. Electron band dispersion in both classical 3D Brillouin zones and transition to 2D Brillouin zones in the proposed two-dimensional approach using the Niggli form of the unit cell was compared. The proposed two-dimensional approach is preferable for low-symmetry layered crystals such as ReS 2 . It was established that the bulk ReS 2 is a direct gap semiconductor (band gap of 1.20 eV), with the direct transition lying in the X point of the first Brillouin zone, and it is in good agreement with published experimental data. The reduction in material dimension from bulk to monolayer was conducted with an increasing band gap up to 1.45 eV, with a moving direct transition towards the Brillouin zone center. The monolayer of ReS 2 is a direct-gap semiconductor in a wide range of temperatures, excluding only a narrow range at low temperatures, where it comes as a quasi-direct gap semiconductor. The transition, situated directly in the Gamma -point, lies 3.3 meV below the first direct transition located near this point. The electronic density of states of ReS 2 in the bulk and monolayer cases of ReS 2 were analyzed. The molecular orbitals were built for both types of ReS 2 structures as well as the electron difference density maps. For all types of ReS 2 structures, an analysis of populations according to Mulliken and Voronoi was carried out. All calculated data is discussed in the context of weak quantum confinement in the 2D case.
Keywords
Rhenium disulfide, Slab, Monolayer, Density functional theory, Pseudopotential theory, electronic structure, Density of states, molecular orbitals, electronic density
Divisions
sch_ecs,advanced
Funders
King Saud University (RSP2024R301),State Program of Scientific Research "Material Science, New materials and Technology" in frame of assignment 2.14.3, Republic of Belarus
Publication Title
Heliyon
Volume
10
Issue
7
Publisher
Elsevier
Publisher Location
50 HAMPSHIRE ST, FLOOR 5, CAMBRIDGE, MA 02139 USA