Size effect on the magnetic and electronic properties of the monolayer lateral hetero-junction WS ₂ -MoS ₂ nanoribbon

By using the VASP, we studied the magnetic and electronic properties of the monolayer lateral hetero-junction WS ₂ -MoS ₂ -nanoribbons (WS ₂ -MoS ₂ -NRs). Our results show that the NRs' edge chirality and width affect significantly its magnetic and electronic properties. The monolayer lateral hetero-junction ZZ-WS ₂ -MoS ₂ -NRs(ZZ: zigzag) exhibitmetallic behavior and have considerable magnetic moment. Their magnetic moments decrease in the order of N _z = 2, 6 and 4 (the width of NRs). While, the magnetic moment decreases with the increased r _z (the number of the Mo-S chains, r _z ≠ 0 and r _z ≠ N _z ) at the same width N _z . The N _A -AC-WS ₂ -NR (AC: armchair) and N _A -AC-WS ₂ -MoS ₂ -NR-1 (the number of the Mo-S chain is 1) show metallic behavior when N _A = 3 (the width of NRs). The other monolayer lateral hetero-junction AC-WS ₂ -MoS ₂ -NRs remain the nonmagnetic and semiconductingbehavior as bulk. But they are indirect band-gap except for the N _A = 3, r _A = 2 (the number of the Mo-S chains) and N _A = 7, r _A = 0 when N _A < 9. However they are direct band-gap when N _A ≥ 9. Their lowest and highest band gaps are 0.150 eV and 0.581 eV, respectively. These unique magnetic and electronic properties will provide guidanceon the WS ₂ -MoS ₂ hetero-junction application in nanodevice.