Insight into the Na adsorption on WSe_2xS_2(1-x)monolayers: a hybrid functional investigation

Monolayer WSe₂has 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 WSe₂monolayers and their WSe_2xS_2(1-x)alloys. Our results suggest that Na adsorption on defective WSe_2xS_2(1-x)monolayers would split and partially fill the empty defect states in the gap region inducing a local magnetic moment of 1μ_Bper alkaline atom. The efficient tuning of the electronic and magnetic properties of WSe₂monolayer by Na adsorption combined with the Se vacancy and S alloying would benefit its wide applications.