Elucidating the Structural, Electronic, Elastic, and Optical Properties of Bulk and Monolayer MoS₂ Transition-Metal Dichalcogenides: A DFT Approach

Abstract

Due to their outstanding properties for optoelectronic and versatile electronic applications, the atomically thin layers of transition-metal dichalcogenide (TMDC) materials have demonstrated a potential candidacy to succeed its analog silicon-based technology. Hence, the elucidation of the most important features of these materials is indispensable. In this study, we provide a theoretical elucidation of the structural, electronic, elastic, and optical characteristics of TMDCs. The study has been carried out by elucidating the material in its two particular forms, namely, bulk and two-dimensional (2D) layered (monolayer). The theoretical investigation was carried out within the framework of the density functional theory (DFT) method using first-principles calculations. The Perdew−Burke−Ernzerhof (PBE) variant of the generalized gradient approximation (GGA) scheme, as performed in the Quantum Espresso package, is used. Van der Waals density functional effects, involving the nonlocal correlation part from the rVV10 and vdW-DF2 methods, were treated to remedy the lack of the long-range vdW interaction. An illustration of the performance of both rVV10 and vdW-DF2 functionalities, with the popular PBE correlations, is elucidated. The Born stability criterion is employed to assess structural stability. The obtained results reveal an excellent stability of both systems. Furthermore, the theoretical results show that band-gap energy is in excellent agreement with experimental and theoretical data. Pugh's rule suggested that both the bulk and MoS 2 -2D layered systems are ductile materials. The refractive indices obtained herein are in good agreement with the available theoretical data. Moreover, the theoretical results obtained with the present approach demonstrate the ductility of both systems, namely, the bulk and the MoS 2 -2D layered. The results obtained herein hold promise for structural, elastic, and optical properties and pave the way for potential applications in electronic and optoelectronic devices.

Transition metal (Ti, Cu, Zn, Pt) single-atom modified graphene/AS2 (A = Mo, W) van der Waals heterostructures for removing airborne pollutants

“…As expected, there is no shared charge between graphene and the substrate. Some reports on MoS 2 and WS 2 66,67 show PDOSs similar to our dichalcogenides without graphene (Fig. 1), which supports the hypothesis that graphene on MoS 2 and WS 2 presents a weak interaction between both layers.…”

Effects of Exchange Correlation Functional (Vwdf3) on the Structural, Elastic, and Electronic Properties of Transition Metal Dichalogenides

“…To obtain significant results from our calculations, lattice parameters of MoTe2 were also studied, these were ensured to be 2.423 Å and 3.116 Å respectively. To further understand the vdW-DF3 effects, we calculated the formation energy based on the lattice parameters earlier reported [12,13]. The results are presented in Table 2.…”

“…Transition metal dichalcogenides are types of materials that can be metallic or semiconducting [6]. The semiconducting TMDs represent the layered materials [7], they can also be classified as direct or indirect energy band gap materials.…”

The potentials of boron-doped (nitrogen deficient) and nitrogen-doped (boron deficient) BNNT photocatalysts for decontamination of pollutants from water bodies

“…10 The analysis of the structural and elastic properties of the studied systems was performed using the Murnaghan equation of state, which describes the relationship between the volume of the pristine and N-doped systems and the tensile pressure. 11 where is the reduction in the volume of the nanotubes under stress and is the reduction of the force constant under stress. All calculations regarding electronic interactions were done using the generalized gradient approximation (GGA) method in terms of the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional.…”