Dichalcogen Semiconductors for Optoelectronic and Spintronic Applications

Abstract

Semiconductors are the building blocks of electronics, optoelectronics, and spintronics technologies. Irrespective of unique electronic and optical attributes, the zero band gap of graphene stimulated the search for layered materials with semiconducting characteristics. Layered metal dichalcogenides have gained immense interest in this regard due to the sizable band gap. Tin disulfide (SnS2) is a layered metal dichalcogenide semiconductor that exhibits a wide electronic band gap in the bulk and monolayer environment.

The lack of unpaired electrons makes it a non-magnetic semiconductor.

Inspired by the highly tunable band gap and magnetism achieved via the transition metal doping on non-magnetic transition metal dichalcogenide semiconductors, the SnS2 crystal is doped with 3d series transition metal atoms. Our calculations are based on the framework of density functional theory. First, we discuss the structural, electronic, and optical properties of semiconductors induced by transition metal doping on SnS2. We continued our study to understand the formation of magnetic moments and possible magnetic ordering in these doped systems. These findings reveal the viable candidates for optoelectronic and spintronic applications.

Due to the unvarnished polarity between the dissimilar chalcogen atoms, Janus metal dichalcogenide monolayers are expected to exhibit the Rashba effect. We discuss the Rashba spin splitting in Janus SnXY and WXY (X, Y = S, Se, Te with X ≠ Y) monolayers along with their vertical heterostructures. SnSSe/WSSe heterostructure is a semiconductor that exhibits Rashba spin splitting energy of the order of room temperature energy and shows enhancement in the Rashba parameter up to 1 eVÅ with the vertical compressive strain. These results indicate that the SnSSe/WSSe heterostructure could be productive for spintronic applications.