Localization of edge states at triangular defects in periodic Mo S 2 monolayers

What happens to the electronic properties of a two-dimensional material when it is not ideal anymore? In order to answer this question, the authors studied more than 150 different structural triangular defects in periodic MoS${}_{2}$ monolayers by means of density-functional calculations, thereby varying the defect size and their distance within the monolayer. The resulting energetic properties can be viewed as a combination of edge and bulk properties dominated by the defect size. Mid-gap edge-localized states are introduced into the density of states by the defects. The grade of orbital localization was quantified by a newly defined localization parameter.