[85] Vacancy‐ and doping‐dependent electronic and magnetic properties of monolayer SnS₂

We have performed first-principles calculations to investigate the formation and migration of vacancies and doping with M (M = Ti, V, Co, Mo, W, Re) at the Sn sites and X (X = O, Se, Te) at the S sites in monolayer SnS₂. We find that the formation energies for S vacancy under both Sn- and S-rich environments are lower than those for Sn vacancy, indicating that the vacancies at the S sites are likely to be formed during the synthesis. Reducing the possibility of vacancy cluster formation, both the vacancies at the Sn and S sites remain robust due to high migration barrier. Additionally, SnS₂ with the vacancies at the Sn sites induces magnetic ground states with a magnetic moment of 4.00 μB. Both the Sn- and S-sites vacancies preserve the semiconducting nature of pristine SnS₂ with band gaps of 2.47 eV and 0.30 eV, respectively. Furthermore, we find that the dopants Ti, V, Mo, W, Re can be easily incorporated at the Sn sites in monolayer SnS₂ due to the low formation energies under the S-rich environment. However, Co may not be easily incorporated into SnS₂. The doping with M at the Sn sites induces magnetic ground states in non-magnetic SnS₂. Additionally, a long-range magnetic ordering is observed in SnS₂ doped with V, Co, and Mo. In contrast, easy incorporation of O, Se, and Te at the S sites under the Sn-rich environment has been observed while the semiconducting nature of SnS₂ preserves with small band gaps.