Theoretical perspective on the electronic, magnetic and optical properties of Zn-doped monolayer SnS₂

Highlights: • The Zn doping in monolayer SnS₂ is energetically favored under S-rich condition. • The room temperature ferromagnetism can be realized in Zn-doped monolayer SnS₂. • The Zn doping enhances the effective utilization in the near-infrared light region. • The Zn doping could lead to the red shift of absorption edge in monolayer SnS₂. • The Zn-doped monolayer SnS₂ is active for both the oxygen and hydrogen evolution. - Abstract: The electronic, magnetic and optical properties of Zn-doped monolayer SnS₂ have been theoretically investigated with the density functional theory. Numerical results reveal that monolayer SnS₂ can be easily synthesized by cleaving its bulk crystal. Besides, the Zn doping in monolayer SnS₂ is energetically favored under the S-rich with respect to the Sn-rich condition. The doped system exhibits the magnetic ground states due to the formation of defect states above the Fermi level, which are introduced by the hybridization between S-3p states and a small amount of Sn-4d states. The room temperature ferromagnetism can also be realized in Zn-doped monolayer SnS₂. The injection of Zn can enhance the absorption efficiency of solar spectrum, especially in the near-infrared light region. Moreover, the Zn doping can enhance the photocatalytic activity for both the oxygen and hydrogen evolution reactions in the monolayer SnS₂.