Ab Initio Study of Electronic Properties on WS 2 Monolayer and Transition Metal Doped WS 2

Two-dimensional materials have attracted the attention of many researchers. Especially transition metal dichalcogenides (TMDs) like MoS 2 , WS 2 , etc., grants a wide scale of the band gap. TMDCs, MoS 2 and WS 2 monolayers have similar electronic and structural properties. WS 2 has a great surface to volume ratio, a wide band gap range, high thermal and oxidative stability. It also has the peak carrier mobility and least effective mass than other TMDCs. So, it has been used in many applications like solar cells, LED, rechargeable batteries and sensors. In this work, we have analysed the stability and the electronic properties of monolayer and doped WS 2 with Cobalt (Co), Iron (Fe) and Nickel (Ni) using density functional theory (DFT). The stability of the system has been studied by the formation energy. The electronic properties are analysed by band structure, the density of states, charge transfer, chemical potential, and total energy of the systems. These results show that the formation energy of the doped system is increasing with a negative magnitude which proves that the doped structures are more stable. We have observed reasonable changes in the band structure and density of states for transition metal doped WS 2 while comparing with WS 2 monolayer. We concluded that the doped WS 2 shows better results than monolayer WS 2 in the stability and improved electronic properties. These results may provide a prospective insight for making gas sensing devices.