Structure, electronic and magnetic properties of 2D Graphene-Molybdenum diSulphide (G-MoS2) Heterostructure (HS) with vacancy defects at Mo sites

Abstract

First-principles calculations have been performed to study Structure, Electronic and Magnetic properties of 2D Graphene-Molybdenum diSulphide G-MoS2 heterostructure (HS) materials with vacancy defects at Mo sites. All the calculations have been performed within the framework of the first-principles Density Functional Theory (DFT) under the Perdew-Burke-Ernzerhof (PBE) form of the Generalized Gradient Approximation (GGA). The ven der Waals (vdW) interactions have been taken into account (considered via Grimme’s model) by DFT-D2 approach. The G-MoS2 heterostructure without Mo sites defects and with Mo sites defects have been optimized using BFGS methods implemented in Quantum ESPRESSO. Our investigations show that the defects materials are more compact than the pure material. Further, we have studied the Electronic and Magnetic properties of pure and defects G-MoS2 heterostructures from the band structure calculations and DOS-PDOS analysis. The results show that the pure and defects heterostructures are metallic in nature and they can be useful for low power consumption electronic devices. From the band structures calculation, it is seen that Fermi energy level shifted toward the valence band in single Mo atom and two Mo atoms vacancy defects both the cases means p-type Schottky defects. The analysis of the magnetic properties show that the nonmagnetic pure G-MoS2 heterostructure changes to magnetic materials by Mo sites defects. It is also found that total magnetism values of C-1Mo, L-1Mo and 2Mo atoms vacancy defects have 2.61 (Bohr-Mag/cell), 2.65 (Bohr-Mag/cell) and 5.25 (Bohr-Mag/cell) respectively and 2p orbital of C atoms, 3p orbital of S atoms and 4d orbital of Mo atoms have main contributions to the magnetism in all three configurations.