The edge of two-dimensional (2D) flakes of transition metal dichalcogenide (TMD) profoundly influences their optical, electronic, catalytic, and magnetic properties due to the asymmetric atomic configurations on the edge. As a reverse process of growth, the etching of monolayer MoS2 flakes can be modulated by tuning the sulfur stoichiometric ratio in chemical vapor deposition. Here, we report studies of the high-density formation of etched pores with defined orientations on MoS2 flakes. Structural analysis reveals that these pores are bound by zigzag edges. Our measurements show that the saturation magnetization of etched MoS2 flakes can be up to five times higher than that of unetched counterparts, indicating that increased zigzag edge density enhances the ferromagnetism of MoS2 flakes. These observations provide valuable insights for tailoring the edge density of 2D TMD flakes to optimize properties for targeted applications.
Keywords: anisotropic etching; chemical vapor deposition; edge structure; magnetism; monolayer MoS2 flakes; morphological evolution.