First-Principles Study of Metal Adatom Adsorption on Black Phosphorene

Abstract

We have investigated the structure, adsorption energy, growth mode, diffusion barrier, magnetic property, dipole moment, and work function of Li, Na, Mg, Al, Cr, Fe, Co, Ni, Mo, Pd, Pt, and Au adsorption on phosphorene using first-principles density-functional theory. We have found that all the adatoms favor the hollow site of hexagonal. It seems that the Mg, Cr, Mo, and Au adatoms may have three-dimensional (3D) growth mode on phosphorene substrate, whereas all other adatoms prefer two-dimensional (2D) growth mode. The metallic state is observed in Li, Na, Al, and Cr doped systems, and the Cr doped phosphorene displays magnetic state. The other eight metal doped systems still preserve semiconducting band gap. Among them, we obtained spin polarized band structures in Fe, Co, and Au doped systems with a band gap. In particular, the Fe doped phosphorene can be a potential candidate for dilute magnetic semiconductor material because no clustering problem will take place. We found a variation in dipole moment and work functions in each impurity doped layer. Both dipole moment and the shift of the Fermi level could account for the change of work function semiquantitatively.