Modulation of Gas Adsorption and Magnetic Properties of Monolayer-MoS₂ by Antisite Defect and Strain

The flexible nature and high surface-to-volume ratio make monolayer-MoS₂ a novel paradigm for tunable nanoelectronic devices. However, for further improvement in the performance of these devices, a new design strategy is essential to modulate the properties of an inert MoS₂ basal plane. Here, we demonstrate from first-principles that the gas adsorption and magnetic properties of MoS₂ can be modulated through Mo_S antisite doping and strain. The Mo_S defect with localized d-orbital electron density significantly promotes the catalytic activity which leads to highly enhanced adsorption of NO, NO₂, NH₃, CO, and CO₂ gas molecules. On application of a biaxial tensile strain, the adsorption of NH₃ is further enhanced for the antisite-doped MoS₂. In addition, strain-induced switching of magnetic states is also realized in antisite-doped MoS₂ with and without adsorbed gas species. The superior strain modulation of antisite-doped MoS₂ is explained by quantum confinement effect and strain-induced accumulation/depletion of charge density at the defect site. These results suggest that antisite-doped MoS₂ can be a promising avenue to design nanoscale spintronic devices and gas sensors