Electronic and magnetic properties of MoS2 nanoribbons with sulfur line vacancy defects

Motivated by the recent experimental result that single sulfur vacancies in monolayer MOS2 are mobile under the electron beam and easily agglomerate into the sulfur line vacancy defects [Physical Review B 88, 035301(2013)], the structural, electronic and magnetic properties of one dimensional zigzag (ZZ) and armchair (AC) edge MOS2 nanoribbons with single or double staggered sulfur line vacancy defects (hereafter, abbreviated as SV or DV, respectively), parallel to their edges, have been investigated systematically by density functional theory calculations. It is very interesting to find that the bond strains induced by the sulfur line vacancy defect can cause a much larger out-of plane distortions in the ZZ edge MOS2 nanoribbon than in the AC edge counterpart. Besides, the defective ZZ edge MOS2 nanoribbons with SV or DV are both metals, having their two respective degenerate ground states with the same energy, among which one is ferromagnetic (FM + +) and the other is antiferromagnetic (AFM + -). But the AC edge MOS2 nanoribbons with SV or DV are both nonmagnetic semiconductors, having very different gap values. Finally, the sulfur line vacancy defects would induce some defect states in the electronic structures of the defective MOS2 nanoribbons. All these important results could provide a new route of tuning the electronic properties of MOS2 nanoribbons and its derivatives for their promising applications in nanoelectronics and optoelectronics. (C) 2015 Published by Elsevier B.V.