Topological states in MoS2 and WS2 monolayers with stacking faults induced period line defects: First-principles calculations

Abstract

Two-dimensional transition metal dichalcogenides monolayer can be tuned to topological insulators by introducing two adjacent stacking faults combined with first-principles calculations. Two-SFs consist of square-octagon defects in the rectangular structure. The phonon spectrum indicates dynamical stability. Band inversion occurs at the path G-X and S-Y, resulting in band crossing. The energy gap will be open with a sizable bulk gap and enter an insulating state in the presence of spin-orbit coupling. The Dirac points are mainly contributed by d orbits of Mo/W atoms. This result broadens the promising topological materials and improves the applications of researching systems in electronic and spintronic devices.