Tuning Electronic and Magnetic Properties of Janus MoSSe Monolayers via Non-magnetic Atoms Substituted Doping Se atoms by First-principles Calculation

Abstract

First-principles calculations is employed to systematically investigate the structural stability, electronic, and magnetic properties of Janus MoSSe monolayers via substitutional doping with non-magnetic atoms (B, Al, C, Si, N, P, F, Cl) at Se site. All doped configurations exhibit excellent structural and thermal stability, with negative formation energies comparable to the pristine monolayer. It is found that doping with B, Al, N, P, F, and Cl atoms effectively induces stable ferromagnetic ground states at room temperature, while C and Si doping results in paramagnetic semiconductors. Crucially, B-, Al-, and Cl-doped systems demonstrate half-metallic behavior, characterized by a metallic spin channel coexisting with a semiconducting one. The origin of magnetism and half-metallicity is traced to the local bonding environment of Mo atoms at the doping center, which attributed to the the incomplete passivation of Mo d-orbitals electrons in B/Al/Cl-doped systems, and primarily from the dopant's pz orbitals in N/P-doped systems. Furthermore, the study explores dual Cl doping, revealing that the magnetic ground state is critically dependent on the Cl-Cl separation, governed by the competition between localized moment formation and antiferromagnetic coupling. This work establishes non-magnetic element doping as a potent and structurally benign strategy for tailoring magnetism and achieving half-metallicity in two-dimensional Janus materials, presenting a promising avenue for developing ultrathin spintronic and quantum devices.