First-principles calculations to study the optical/electronic properties of 2D VS2 with Z doping (Z = N, P, As, F, Cl and Br)

Monolayer VS2 is expected to be an encouraging candidate for optoelectronic devices owing to its excellent optical/electrical performance. In this paper, first-principles calculations were conducted to figure out the optical/electrical performance of 2D VS2 doped with Z doping (Z ​= ​N, P, As, F, Cl and Br). The results show that there was a downward trend in formation energies when the doping element ranged from left to right and from bottom to top in the periodictable of elements. VS2 became more conductive with N, P and As doping, and transited from the semiconducting to metallic state with F, Cl and Br doping. For the optical properties, N, P, As and Br doping reduced the reflectivity of pristine VS2 in the near-infrared region (0.6 eV–1.6 ​eV). Moreover, P, F, Cl and Br-doping reduced the migration energy barrier of Li atoms in VS2, which may help to design the rechargeable Li ion batteries with high rate capability.