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

Abstract

Tin disulfide (SnS) is a member of the layered metal dichalcogenides family. Monolayer SnS 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 SnS. 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 SnS 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 SnS 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 , 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 , respectively. The double V, Cr, Mn and Zn-doped SnS are ferromagnetic semiconductors with 2, 4, 6 and 2.56 , respectively. Ferromagnetic coupling between the two identical transition metal atoms is attributed to 90° 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.