The structural, magnetic and electronic properties of p-type and n-type doped monolayer WS2 systems

Abstract

The structural, magnetic and electronic properties of the p-type (group VA elements N, P, As or Sb) and n-type (group VIIA elements Cl, Br, I or At) doped monolayer WS2 systems have been systematically investigated using the spin-polarized first-principle calculations. The results show that whether p-type or n-type doped monolayer WS2 systems, the greater the atomic radius of the dopant X, the greater the bond length dX−W and height difference hS, but the smaller the bond angle θW-X-W. All doped systems are easier to form and more stable under W-rich condition than S-rich condition. Specially, the N- and Cl-doped cases are the most stable in p-type and n-type doped monolayer WS2 systems, respectively. The total magnetic moment Mtot of the N-doped system is 0.773μB contributed mainly by N-p orbitals, the total magnetic moments Mtot of the P-, As- and Sb-doped systems are all approximately zero, and the total magnetic moments Mtot of the Cl-, Br-, I- and At-doped systems are 0.543, 0.810, 0.989 and 0.999μB, respectively, contributed mainly by the first nearest-neighbor atom W-d orbitals. Although the pristine monolayer WS2 system is a nonmagnetic semiconductor, the doped system changes to magnetic semiconductor for N-doped system, nonmagnetic metal for P-, As- and Sb-doped systems, magnetic metal for Cl- and Br-doped systems and magnetic half-metal for I- and At-doped systems.