Tuning the magnetic and electronic properties of monolayer SnS2 by 3d transition metal doping: A DFT study

Tin disulfide (SnS2) is a member of the layered metal dichalcogenides family. Monolayer SnS2 is a semiconductor with an indirect bandgap of 2.43 eV. It is a nonmagnetic semiconductor. In this article, we systematically study the electronic and magnetic properties of 3d transition metal atom-doped monolayer SnS2. The spin-polarized First-principles calculations reveal that Sn-poor condition is the energetically favourable condition to substitute all the 3d transition metal atoms into SnS2 monolayer at the Sn-site. We observe that, in all the doped systems, the denser valence bands are filled with the hybridized impurity 3d and S-3p orbitals. Here we show that, Sc-doped SnS2 is a nonmagnetic metal, and Ti and Ni-doped systems are nonmagnetic semiconductors. Single V, Cr, Mn, Fe, Co, Cu, and Zn atom doped systems with a dopant concentration of 6.25% are semiconductors with an induced magnetic moment of 1, 2, 3, 2, 1, 0.688, and 1.275 mu(B), respectively. Among them, Cu and Zn-doped systems are direct bandgap semiconductors. With a dopant concentration of 4.08%, the double Fe and Co-doped SnS2 monolayers are ferromagnetic half metals with 4 and 2 mu(B), respectively. The double V, Cr, Mn and Zn-doped SnS2 are ferromagnetic semiconductors with 2, 4, 6 and 2.56 mu(B), respectively. Ferromagnetic coupling between the two identical transition metal atoms is attributed to 90 degrees superexchange. These results emphasize the importance of 3d transition metal doped monolayer SnS2 for spin injection, spin polarized current generation and other spintronics device applications.