Electronic, magnetic, and optical properties of pentagonal Pt2Se4 monolayer doped with metalloid elements

The electronic, magnetic, and optical properties of the pentagonal Pt₂Se₄ monolayer doped with metalloid elements (B, Si, Ge, As, Sb, Te, and At) as substitutes for Pt and Se atoms were explored using density functional theory. Our calculations of formation energies indicate that doping at the Se site is energetically preferred for all metalloids, with the Pt-site substitutions consistently exhibiting higher formation energies, averaging approximately 2.0 eV higher than the corresponding Se-site substitutions. Except for As, which induces a magnetic moment of approximately 0.5 μB in the system, the other dopants maintain the system's non-magnetic characteristics. The up-and-down-spin splitting of the As-pz orbital can be regarded as the primary reason for the emergence of the magnetic moment, a phenomenon absent in the other doped configurations. Apart from the B and Sb dopants, where new impurity states intersect the Fermi energy level, the remaining doped systems maintain semiconductor properties. All doped systems exhibit nearly transparent behavior in the visible energy range. However, incident light is effectively inhibited in the infrared region for B- and At-doped systems. The static dielectric constants ϵ₁(0) for Pt₂Se₄ doped with As, At, B, Ge, Sb, Te, and Si are reported as 1.08, 1.76, 1, 1.17, 1, and 1, respectively. These varied findings hold promise for applications in spintronics, optoelectronics, and the advancement of optical nanostructures.