In this work, the possibility to induce hole doping in monolayer SnO by intrinsic and extrinsic defects is investigated, using first-principles simulations, based on density functional theory. It is found that Sn vacancies generate spin-polarized gap states near the valence band edge of monolayer SnO, and that these point defects are behaving like acceptors. A typical density of 5x1013/cm2 of Sn vacancies induces a paramagnetic to ferromagnetic phase transition in the material, with a magnetic moment density of 1 Bohr magneton/hole. Substitutional doping of Sn atoms by e.g. In or Zn atoms is also predicted to result in hole-doping of monolayer SnO, and also leads to a ferromagnetic order in the 2D material. The possibility to induce a ferromagnetic phase transition in monolayer SnO by electrostatic doping will also be discussed.
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