First principle study of the effect of doping on the optoelectronic properties of Cr-adsorbed MoS.

CONTEXT

This study explores, for the first time, using first principles, the impact of substitutional doping with boron (B), carbon (C), and nitrogen (N) on the adsorption of chromium (Cr) on monolayer MoS. The effects of doping on the Cr adsorption behavior of MoS were investigated using four MoS systems, namely, pure, boron (B)-doped, carbon (C)-doped, and nitrogen (N)-doped, in order to gain an in-depth understanding of the mechanism of the effects of doping on the electronic structure and optical properties of Cr adsorbed by MoS, to optimize the properties of MoS, to explore new areas of application, and to promote the development of materials science. Four MoS adsorption systems of Cr adsorption on pure, B-doped, C-doped, and N-doped MoS were optimized, and the optimized results showed that the stable adsorption location of Cr on both pure and doped MoS was the hollow location at the top of the folded hexagon. The findings reveal that pure MoS has an adsorption effect on Cr, and doped elements B, C, and N can promote the adsorption of Cr on MoS, and the strong and weak order of this promotion is B > C > N.

METHODS

In this paper, we use the CASTEP module in the simulation software Materials Studio to perform simulation calculations and analyses to optimize the simulation of Cr adsorption by MoS doped with B, C, and N atoms using the generalized gradient approximation (GGA) plane-wave pseudo-potential method (Perdew et al. Phys Rev Lett 77(18):3865-3968, 1996), as well as Perdew-Burke-Ernzerhof (PBE) generalized functionals (Segall et al. J Phys: Condens Matter 14(11):2717-2744, 2022). The convergence test reveals that it is more reasonable to set the K-point network to 3 × 3 × 1 and the truncation energy to 400 eV. In this paper, a 3 × 3 × 1 supercell structure with 18 S atoms and 9 Mo atoms is selected. The convergence value of the iteration accuracy is 1.0e - 5eV/atom, and all the atomic forces are less than 0.02eV/Å. Additionally, to prevent MoS interlayer interaction, a vacuum layer with a thickness of 18 Å is set in the C direction. The geometrical optimization of the model is performed first, and then the corresponding adsorption energies of the model and the nature of the electronic structure are analyzed.