Local strain engineering in Janus MoSSe nanoribbons induces tunable electronic structures and remarkable magnetic moments

Abstract

Local strain, as a small degree and single direction strain method, can effectively regulate the structures and electronic properties of armchair Janus MoSSe nanoribbon, so that the system can be transformed from the original 0.467 eV indirect band gap into 0.259 eV (3-zig), 0.117 eV (3-arm), 0.080 eV (6-arm) and 0.139 eV (9-zig) direct band-gap semiconductor according to the different strain degrees and directions. Compared with traditional MoS2 and MoSe2 nanoribbons, Janus MoSSe nanoribbon shows relatively stable band structure under local strain. The structure and electronic properties of Janus MoSSe nanoribbon are anisotropic when the local strain is along different directions. Due to the broken mirror symmetry of the Janus system and the appearance of in-plane local polarization, the spin polarization effect of Janus nanoribbon under local strain is more remarkable. When the local strain degree C = 0.167 is along the zigzag direction and the local strain C ⩾ 0.056 is along the armchair direction, the Janus nanoribbon exhibits half-metallic properties and surprisingly induces a magnetic moment. For the local strain along the armchair direction, the total magnetic moment of the system can be up to 2.05 μB when C = 0.111. A local strain method is applied to the nanoribbon system, which can effectively regulate the geometric configuration and electronic structure without external doping, and introduce magnetism, providing the possibility for expanding nanoribbons as potential nanoelectronic and spintronic materials.