Structural, Electronic and Magnetic Properties of Defected Water Adsorbed Single-Layer MoS2

Abstract

Water adsorbed in MoS2 (wad-MoS2), 1S atom vacancy defect in wad-MoS2 (1S-wad-MoS2), 2S atoms vacancy defects in wad-MoS2 (2S-wad-MoS2), and 1Mo atom vacancy defect in wad-MoS2 (Mo-wad-MoS2) materials were constructed, and their structural, electronic, and magnetic properties were studied by spin-polarized density functional theory (DFT) based first-principles calculations. The wad-MoS2, 1S-wad-MoS2, 2S-wad-MoS2, and Mo-wad-MoS2 materials were found stable. From band structure calculations, wad-MoS2, 1S-wad-MoS2 and 2S-wad-MoS2 materials open energy bandgap of values 1.19 eV, 0.65 eV and 0.38 eV respectively. Also, it was found that the conductivity strength of the material increases with an increase in the concentration of S atom vacancy defects in the structure. On the other hand, the Mo-wad-MoS2 material has metallic properties because energy bands of electrons crossed the Fermi energy level in the band structure. For the investigation of magnetic properties, the density of states (DoS) and partial density of states (PDoS) calculations were used and found that wad-MoS2, 1S-wad-MoS2, and 2S-wad-MoS2 are non-magnetic materials, while Mo-wad-MoS2 is a magnetic material. The total magnetic moment of Mo-wad-MoS2 has a value of 2.66 µB/cell, due to the arrangement of unpaired up-spin and down-spin of electrons in 3s & 3p orbitals of S atoms; and 4p, 4d & 5s orbitals of Mo atoms in the material.

Electronic and magnetic performance of MoS2 monolayer via Tc & Nb impurities defect and water adsorption

“…We have also estimated the adsorption energy of water molecule with Tc-MoS 2 & Nb-MoS 2 by using equation (3), and found to be 2.17 eV & 2.08 eV respectively. They are comparable with the reported values of water adsorption on 2D materials [9,25,27]. Hence, water adsorbed defected materials are stable 2D materials.…”

“…Their structure is composed of a honeycomb pattern [4,5]in which the three atomic planes (chalcogen-metal-chalcogen) stack to create the individual layers of the material [6]. The MoS 2 monolayer is a semiconducting TMDs material that has Mo and S atoms stacked together in an S-Mo-S configuration, which results in a direct bandgap of 1.80 eV [5][6][7][8][9]. The unique properties of hexagonal TMDs materials include their atomic-scale thickness as well as their direct bandgap in its electronic band (wide bandgap exotic semiconductor), which can vary depending on the stacking order [3,7,10].…”

“…Previous studies have investigated the structural, electronic and magnetic characteristics of a pure MoS 2 monolayer [8,9], but the effect of impurities such as Tc, Nb on MoS 2 and water absorbed on impurities defected MoS 2 have not been reported. The current study aims to examine the impact of the impurity atoms on MoS 2 using firstprinciples calculations that combine spin-polarized density functional theory (DFT) method.…”

Adsorption of Water Molecule in Graphene/MoS2 Heterostructure with Vacancy Defects in Mo Sites

“…e molecular adsorption in vacancydefected HS can bring new properties because vacancy defects are very keen locations for molecular adsorption due to the configuration of atoms around the vacancy. ey play a particular role in determining the geometrical arrangement of layered materials [21][22][23]. Also, electronic and magnetic properties of defected materials can be modified by adsorbed water molecule [23].…”

“…ey play a particular role in determining the geometrical arrangement of layered materials [21][22][23]. Also, electronic and magnetic properties of defected materials can be modified by adsorbed water molecule [23]. us, it opens the way to tune novel properties of vacancy-defected HS materials.…”