Effects of line defects on spin-dependent electronic transport of zigzag MoS2 nanoribbons

Abstract

The nonlinear spin-dependent transport properties in zigzag molybdenum-disulfide nanoribbons (ZMNRs) with line defects are investigated systematically using nonequilibrium Green’s function method combined with density functional theory. The results show that the line defects can enhance the electronic transfer ability of ZMNRs. The types and locations of the line defects are found critical in determining the spin polarization and the current-voltage (I-V) characteristics of the line defected ZMNRs. For the same defect type, the total currents of the ribbons with the line defects in the centers are lager than those on the edges. And for the same location, the total currents of the systems with the sulfur (S) line defect are larger than the according systems with the molybdenum (Mo) line defect. All the considered systems present magnetism properties. And in the S line defected systems, the spin reversal behaviors can be observed. In both the spin-up and spin-down states of the Mo line defected systems, there are obvious negative differential resistance behaviors. The mechanisms are proposed for these phenomena.

The effect of structural defects on the electron transport of MoS2 nanoribbons based on density functional theory

“…Moreover, after unsaturated Mo(S) atoms at the lower (upper) edge, the row of Mo atoms after them shows the negative (positive) spin-density distribution. These investigations show that bridging line defects induce a little magnetic effect on the defect [28] and our obtained results about figure III′ show that the presence of Stone-Wales defect decreases the magnetic effect in the middle of edges and it can be seen that the distribution of spin-down electrons in the row of Mo atoms for the atoms placed after the lower edge has little increased.…”

“…7, it has been shown that in all the structures, the conductance for spin-up and spindown electrons is not equivalent, so it demonstrates the magnetic characteristic in these structures. Such magnetic characteristic is expectable for non-defect structure [24,36], and it also is observed in the presence of Mo-Mo and S bridges [28]. In Fig.…”

“…Such bond and also the bond forming inner edge of defect (S-Mo-S) will be effective for the transmission of charge carriers when the distribution of electrons around S-Mo-S bond increases. We expect that with increasing the width of nanoribbon and the distance of Mo-Mo bond defect of nanoribbon edges, the electron distribution changes and the S-Mo-S edges of this defect can act as a transmission channel [28]. Generally, the effect of line defect on the transmission of electrons significantly depends on the electron distribution on the atoms in the vicinity of inner edges of line defect and the coupling between the electron transport states (which the electron distribution is displayed in Fig.…”

“…Recently, a group of researchers investigated the effect of these two defects on the spin-dependent transport of MoS 2 nanoribbons. In order to increase the spin-dependent transport, they showed that the best position for defects is the middle part of nanoribbon [28]. However, the importance of edge effects in the presence of these types of defects has not been clearly investigated yet, so we calculated the density of energy states and found that the edge effects can play an important role in the electron transport of nanoribbon.…”

Modulating the spin transport behaviors in ZBNCNRs by edge hydrogenation and position of BN chain

“…A number of approaches have been suggested to tailor the electronic structure of graphene to introduce an appreciable band gap, which has been reviewed recently. [11][12][13][14][15] Owing to the unique physical properties and potential applications in nanoscale devices, many other 2D atomically thick materials, such as graphdiyne sheet, 16 silicene, 17,18 phosphorus 19,20 and layered transition-metal dichalcogenides 21,22 have attracted intensive attentions. The mono-layer boron nitride (BN) sheets known as hexagonal boron nitride (h-BN) have been fabricated in experiments 23,24 in 2009.…”