Effect of tensile and compressive strains on the electronic structure of O-atom-doped monolayer MoS₂

We investigate the effects of biaxial tensile and compressive strains on the electronic structure of O-doped monolayer MoS2 by density functional theory (DFT) in this paper. O-doped monolayer MoS2 is an exothermic reaction. The doping of O leads to the transformation of the system from direct bandgap to indirect, and the bonding of Mo and O causes a large amount of charge transfer. The application of tensile strain leads to a decrease in the stability of the doped system, and the system always maintains the nature of indirect bandgap. The degree of interatomic charge transfer and bandgap value gradually decrease with the increase of tensile strain. The application of compression strain improves the stability of the doped system, and as the compressive strain increases, the bandgap of the doped system completes the indirect–direct–indirect transformation. The bandgap value shows a trend of increasing and then decreasing. Additionally, the degree of charge transfer between atoms is strengthened.