Electronic Structure Modulation of VS Monolayers through Cr, Ni, Nb, Zr and Te Doping: A DFT Investigation

In this study, first-principles density functional theory (DFT) calculations were performed to investigate the structural stability, elastic response and electronic properties of pristine and doped vanadium disulfide (VS2) monolayer. Transition-metal dopants Chromium (Cr), Nickel (Ni), Niobium (Nb), Zirconium (Zr) and the non-transition-metal dopant tellurium (Te), were substituted at the vanadium site to examine their influence on the host lattice. Doping induces notable changes in lattice parameters, elastic properties and electronic structures, as reflected in the band structure and density of states. Equation-of-state analysis indicates that all systems are mechanically and energetically favourable, with positive bulk moduli (~32-58 GPa) and negative cohesive energies (-3.27 to -3.79 eV per atom). Nb and Zr-doped VS2 exhibit complete metallisation with finite density of states at the Fermi level, whereas Cr and Ni-doped systems show pronounced band-gap narrowing, resulting in semimetallic behaviour. In contrast, Te doping preserves the semiconducting nature of VS while reducing the band gap. These results show that the method of dopant engineering is effective for the control of elastic as well as electronic properties of VS highlighting its potential as a conductive and mechanically stable platform for future energy-storage-related investigations.