Insight into the Na adsorption on WSe2xS2(1-x)monolayers: A hybrid functional investigation

Monolayer WSe2 has aroused strong interest as a semiconducting 2D material. The tuning of its electronic properties is important for expanding the range of applications. In this work, by hybrid density functional theory calculations, we investigate the effect of Na adsorption on the electronic and magnetic properties of stoichiometric and defective WSe2 monolayers and their WSe2xS2(1-x) alloys. Our results suggest that Na adsorption on defective WSe2xS2(1-x) monolayers would split and partially fill the empty defect states in the gap region inducing a local magnetic moment of 1 μ B per alkaline atom. The efficient tuning of the electronic and magnetic properties of WSe2 monolayer by Na adsorption combined with the Se vacancy and S alloying would benefit its wide applications.