Janus Doping of Sulfur into Platinum Diselenide Ribbons

2D platinum diselenide (PtSe₂), a novel member of the transition metal dichalcogenides (TMDCs) family, possesses many excellent properties, including a layer-dependent bandgap, high carrier mobility, and broadband response, making it promise for applications in technologies like field-effect transistors and room-temperature photodetectors. Doping represents an effective method to modify the electrical properties of 2D TMDCs and to bestow upon them additional functions. However, to date, little research has been conducted on the successful doping of 2D PtSe₂ for modification. In this study, sulfur (S) powder is utilized during the chemical vapor deposition growth process of 2D PtSe₂ ribbons and successfully integrated into the PtSe₂ lattice through substitutional doping. The Au substrate significantly decreases the substitution energy of Se atoms in the lower layer of PtSe₂, resulting in the formation of the Janus PtSSe structure. S-doped PtSe₂ ribbons demonstrate significant symmetry breaking and enhanced electrical properties, showcasing a strong nonlinear optical response and certain synaptic plasticity, further simulating some neuromorphological processes. This study not only demonstrates a viable method for controllable doping and modification of 2D PtSe₂ but also establishes a platform for exploring the characteristics of Janus TMDCs.