Defects mediated electronic and magnetic properties of monolayer Janus SnSSe

Abstract

Based on first-principles simulations, we have studied the effect of vacancy, anti-site and Mo/W doping on the physical properties of Janus SnSSe. We find that the formation energies for Vs are more favorable than VSn, suggesting that the VS are more likely to be exist in the experiments. In order to reduce the clustering in vacancies both vacancies VSn and VS retain its robustness due to high migration barriers. Additionally, both the vacancies remain non-magnetic with band gap of 0.28 eV and 0.04 eV for VSn and VS respectively. Furthermore, we find that the anti-site doping Se@S (− 2.65 eV) is more stable than S@Se (− 2.54 eV). Both the anti-site doping retain the semiconductor nature of SnSSe. Moreover, the dopant Mo and W can be easily incorporated in SnSSe. The spin-polarization is induced with Mo (2.0 μB)/W (2.0 μB) doping in SnSSe. Interestingly, the doping keeps the semiconducting nature of SnSSe. Our calculations show that the defects significantly tune the band gap of Janus SnSSe. Thus, we expect that our results can pave a route to potential applications like energy storage devices.