First-principles study of different levels of Mg-doped Janus WSSe monolayer
Two-dimensional Janus WSSe,as a novel transition metal dichalcogenide(TMDs)material,has great potential for application in spintronic devices due to its unique out-of-plane asymmetric structure and no-vel physical properties.In this paper,by using the first-principles plane wave pseudopotential method of the density functional theory,the electronic structures and optical properties of four Mg-doped models of W9-xMgxS9Se9(x=0,1,2,3)were calculated separately,and their energy band structures,densities of states and optical properties were analyzed.The results show that doping makes WSSe change from a direct band gap semiconductor to an indirect band gap semiconductor.Furthermore,with the increasing of doping concentration,the band gap gradually decreases,the Fermi level passes through the valence band,and the doping system becomes a P type semiconductor.When x=3,the doping system presents a metallic property.In addition,the static dielectric constant of the doping system increases and the polarization degree is significantly enhanced with the increasing doping concentration.Both the imaginary part of the dielectric function and the light absorption peak are red-shifted,indicating that the doping is beneficial to the absorption of visible light.The static refractive index increases with the increasing doping concentration,and the peak value of extinction coefficient is positively correlated with the doping concentration of Mg atoms.
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维普
