Tunable Dirac states in doped B₂S₃ monolayers

Two-dimensional (2D) Dirac materials have been a research hotspot due to their intriguing properties, such as high carrier mobility and ballistic charge transport. Here, we demonstrate that the B₂S₃ monolayer with a hexagonal structure, which has been reported as a photocatalyst, can be tuned to new 2D Dirac materials by doping atoms. The Young's modulus can reach 65.23 N m^-1, indicating that the monolayer can be used as a buffer materials. The electronic structures of the pristine B₂S₃ monolayer show that some Dirac points appear but do not occur exactly on the Fermi level (E_F). Fortunately, we find that the Dirac cone can be tuned to the E_F by doping C, N, or Sn atoms. The C-doped B₂S₃ monolayer can be a half-metallic Dirac material, which has significant potential application in spintronics. For N- and Sn-doped B₂S₃ monolayers, the typical kagome bands are formed near the E_F, which arise from three molecular orbitals hybridized by B, S, and N (Sn) atoms. These outstanding properties render the doped B₂S₃ monolayers promising 2D Dirac materials for future nanoelectronic devices.