Functionalization of BN Honeycomb structure by Adsorption and Substitution of Foreign atoms

TL;DR

This study uses first-principles calculations to explore how adsorbing and substituting foreign atoms in BN honeycomb structures affect their electronic, magnetic, and structural properties, revealing potential for electronic and optical applications.

Contribution

It provides a detailed analysis of how adatom adsorption and atom substitution modify BN monolayer properties, highlighting the emergence of magnetic and metallic states at high coverage.

Findings

High coverage of transition metals induces magnetic and metallic states.

Low coverage results in localized impurity states in the band gap.

Substituting C creates donor and acceptor magnetic states.

Abstract

We carried out first-principles calculations within Density Functional Theory to investigate the structural, electronic and magnetic properties of boron-nitride (BN) honeycomb structure functionalized by adatom adsorption, as well as by the substitution of foreign atoms for B and N atoms. For periodic high density coverage, most of $3d$ transition metal atoms and some of group 3A, 4A, and 6A elements are adsorbed with significant binding energy and modify the electronic structure of bare BN monolayer. While bare BN monolayer is nonmagnetic, wide band gap semiconductor, at high coverage of specific adatoms it can achieve magnetic metallic, even half-metallic ground states. At low coverage, the bands associated with adsorbed atoms are flat and the band structure of parent BN is not affected significantly. Therefore, adatoms and substitution of foreign atoms at low coverage are taken to be the representative of impurity atoms yielding localized states in the band gap and resonance states in the band continua. Notably, the substitution of C for B and N yield donor and acceptor like magnetic states in the band gap. Localized impurity states occurring in the gap give rise to interesting properties for electronic and optical application of the single layer BN honeycomb structure.