Electronic, magnetic and optical properties of (Fe, Mn, Cr) co-doped Janus monolayer SnSSe

Based on first principles, we have investigated the electronic structure, magnetic and optical properties of monolayer Janus SnSSe mono and co-doped Fe, Mn, Cr atoms. Without doping, the monolayer SnSSe is a nonmagnetic semiconductor, and with the doping of Fe, Mn, and Cr atoms, the bandgap of the monolayer SnSSe decreases significantly and succeeds in generating magnetic moments in the range of 2.18 μB–5.88 μB. We have specifically investigated five possible configurations of (Fe, Mn), (Fe, Cr) and (Mn, Cr) co-doping, and the results show that the (Fe, Mn) co-doped systems tend to be FM, and the different doped configurations of the (Fe, Cr) system and the Mn–Cr system have different couplings, and that most of the magnetic properties of the doped systems originate from the d-orbitals of the TM atoms, with a small fraction originating from the p-orbitals of the S atoms and Se atoms. The calculation of optical properties shows that the doping of TM atoms improves the absorption intensity of SnSSe in the visible range to a certain extent. Our study shows that the introduction of appropriate dopants is beneficial to improve the magnetic and optical properties of monolayer SnSSe, and our study is expected to provide theoretical guidance for the fabrication of SnSSe-based optoelectronic devices and spintronic devices.