Effective Doping of Monolayer Phosphorene by Surface Adsorption of Atoms for Electronic and Spintronic Applications

TL;DR

This study uses density functional theory to explore how surface adsorption of various atoms modifies the electronic and magnetic properties of monolayer phosphorene, aiming to enhance its applications in electronics and spintronics.

Contribution

It systematically investigates the effects of 27 different adatoms on monolayer phosphorene, identifying specific elements that improve carrier density, mobility, and induce magnetism for spintronic use.

Findings

Group I and III adatoms increase n-type carrier density.

Transition metal adatoms induce magnetic moments.

Certain adatoms significantly alter electronic effective masses.

Abstract

We study the effect of surface adsorption of 27 different adatoms on the electronic and magnetic properties of monolayer black phosphorus using density functional theory. Choosing a few representative elements from each group, ranging from alkali metals (group I) to halogens (group VII), we calculate the band structure, density of states, magnetic moment and effective mass for the energetically most stable location of the adatom on monolayer phosphorene. We predict that group I metals (Li, Na, K), and group III adatoms (Al, Ga, In) are effective in enhancing the n-type mobile carrier density, with group III adatoms resulting in lower effective mass of the electrons, and thus higher mobilities. Furthermore we find that the adatoms of transition metals Ti and Fe, produce a finite magnetic moment (1.87 and 2.31 $\mu_B$) in monolayer phosphorene, with different band gap and electronic effective masses (and thus mobilities), which approximately differ by a factor of 10 for spin up and spin down electrons opening up the possibility for exploring spintronic applications.