2016/05/27 by Saboura Salehi, Alireza Saffarzadeh · 1 citation
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1016/j.susc.2016.05.003
published as Surface Science 651, 215 (2016) · 16 pages, 7 figures
arxiv created 2016/05/27 · arxiv updated 2016/05/30
The influence of atomic vacancy defects at different concentrations on electronic properties of MoS2 and WS2 monolayers is studied by means of Slater-Koster tight-binding model with non-orthogonal sp3d5 orbitals and including the spin-orbit coupling. The presence of vacancy defects induces localized states in the bandgap of pristine MoS2 and WS2, which have potential to modify the electronic structure of the systems, depending on the type and concentration of the defects. It is shown that although the contribution of metal (Mo or W) d orbitals is dominant in the formation of midgap states, the sulphur p and d orbitals have also considerable contribution in the localized states, when metal defects are introduced. Our results suggest that Mo and W defects can turn the monolayers into p-type semiconductors, while the sulphur defects make the system a n-type semiconductor, in agreement with ab initio results and experimental observations.