Electronic, optical and magnetic properties of molybdenum disulfide monolayer in the presence of point defects using first principles

This study investigates the defects of molybdenum disulfide substitutions based on first principles. The first principle-based computational method based on density functional theory (DFT) studies the electronic structure of atoms, molecules and solids and is an accurate and intelligent method for substituting multiparticle problems. The supercell considered in this structure consists of 36 atoms and a generalized gradient approximation is used for the exchange-correlation potential. Intrinsic molybdenum disulfide has a direct band gap with an energy of 1.82 eV. Defects in this structure lead to significant changes in the electronic and magnetic properties of the material. The results show that the removal of one molybdenum atom or the removal of one molybdenum atom with two sulfur atoms leads to a change in the spin states and magnetization of the material. In addition, the removal of one or two sulfur atoms results in a band gap energy lower than its intrinsic. By removing a sulfur atom, the first imaginary part of the dielectric function occurs around the band gap energy. Removal of two sulfur atoms or one molybdenum atom with one sulfur atom also causes the band gap to be indirect. The study of structural defects can provide new opportunities for approaches to the growth and synthesis of nanomaterials.