Tunable magnetism and electronic properties in 3D transition metal-doped blue phosphorene via charged defect engineering

Blue phosphorene (BP), a novel two-dimensional material, has garnered considerable attention owing to its distinct atomic configuration, intriguing electronic characteristics, and high carrier mobility. However, its inherent non-magnetic character restricts its applicability in spintronics. To overcome this limitation and induce magnetism, we propose the strategic incorporation of 3d transition metal (TM) atoms (from Sc to Zn) via substitutional doping under various charged states. Using first-principles density functional theory, we systematically assess the structural stability, electronic structure, and magnetic characteristics of 3d TM-doped BP under various charge states. Our findings indicate that Sc substitution is most thermodynamically favorable in the neutral lattice, and its 1+ charge state exhibits magnetism. The Mn doping system consistently exhibits substantial magnetic moments and significant magnetic anisotropy across all charged states. Across all dopants, defect states introduced near the band edges modulate BP’s bandgap, and changes in electron occupation directly correlate with variations in local magnetic moments. These results deepen our understanding of charged defect physics mechanism in two-dimensional materials and offer practical guidance for defect-engineering strategies aimed at spintronic and nano-electronic applications.