A brief review of reconstructions and electronic structures of MoS2 zigzag edges

Abstract

Transition metal dichalcogenides, mainly focusing on MoS2, have attracted intensive studies in terms of their electronic and optical properties. Their lower-dimensional counterparts, such as nanoribbons and nanoclusters, gradually draw more research attention because of their potential applications in various electronic and spintronic devices. The edge states are essential to determine the intriguing electronic and magnetic properties of the nanocrystals. In this review, we mainly focus on the zigzag edges in the MoS2 system because they are more common in experiments. We first review the physical properties of the unreconstructed edges and then introduce the principles of edge reconstructions, the electron counting model (ECM). Then, based on the ECM, intrinsic edge reconstructions with different periodicities are discussed. The literature we reviewed suggests that the conductivities and magnetism of the edge states are highly related to the periodicities of the edges. Finally, the effects of the edge passivation with extrinsic atoms are reviewed. Edge passivation plays an important role in tuning the electronic and magnetic properties of the edge states and determining the morphology during the crystal growth. Furthermore, MoS2 zigzag edges could be an ideal platform to investigate the interplay between the edge states with different periodicities and magnetic dopants in the future.

Realization of quasi-1D topological magnetism at the V-alloyed MoS2 zigzag edge

“…[32][33][34] Specifically, in intrinsic MoS 2 systems, based on the electron counting model (ECM) 35 (see ESI † Section S3 for details) with different charge allocations of S-Mo bonds, edge reconstructions with different periodicities were proposed, especially, 1Â, 2Â, 3Â, and beyond. 32,[36][37][38][39] At the MoS 2 edge, 1Â periodicity is defined as a cell containing one cation at the single edge. For electronics, edge states of 1Â and 2Â periodicities-related reconstructions are metallic, 33,39 while those of 3Â periodicities-related reconstructions can be semiconducting because of the satisfaction of the ECM based on the distribution of 1.33e and 0.66e per S-Mo pair.…”