Defect engineered magnetism induction and electronic structure modulation in monolayer MoS2

Abstract

The electronic, magnetic, and optical characteristics of a defective monolayer MoS2 were examined by employing density functional theory (DFT)-based first-principles calculations. The effects of several defects on the electrical, magnetic, and optical properties, including Mo vacancies, MoS3 vacancies, and the substitution of a single Mo atom by two S atoms were studied in this work. Our first-principles calculations revealed that different types of defects produced distinct energy states within the band gap, leading to a band gap reduction after the introduction of various types of defects, which caused a change from semiconducting to metallic behavior. The spin-up and spin-down states were separated in the case of MoS3 vacancy. The total magnetization was ∼ −0.83 μB/cell, and the absolute magnetization was ∼ 1.23 μB/cell. Moreover, spin-up states had a 0.45 eV band gap, whereas spin-down states were metallic. Consequently, it can be promising for spin filter applications. It was disclosed that the broadband part of the electromagnetic spectrum has a high absorption coefficient, which is necessary for applications including impurity detection, photodiodes, and solar cells. Designing spintronic and optoelectronic devices will benefit from the modification of the electrical, optical, and magnetic properties by defect engineering of MoS2 monolayers presented here.