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 MoS2 can be a promising avenue to design nanoscale spintronic devices and gas sensors.