Half-Metallic Silicon Nanowires: Multiple Surface Dangling Bonds and Nonmagnetic Doping

TL;DR

This study uses first-principles calculations to demonstrate that hydrogen-passivated silicon nanowires with surface dangling bonds and boron doping can achieve robust half-metallicity and tunable magnetic states, enabling spintronic applications.

Contribution

It reveals a new method to engineer half-metallic silicon nanowires without magnetic atoms by manipulating surface dangling bonds and doping.

Findings

Hydrogen-passivated SiNWs with SDBs and B doping exhibit half-metallicity.

Half-metallicity remains stable under external electric fields.

Surface passivation allows control over magnetic properties of SiNWs.

Abstract

By means of first-principles density functional theory calculations, we find that hydrogen-passivated ultrathin silicon nanowires (SiNWs) along [100] direction with symmetrical multiple surface dangling bonds (SDBs) and boron doping can have a half-metallic ground state with 100% spin polarization, where the half-metallicity is shown quite robust against external electric fields. Under the circumstances with various SDBs, the H-passivated SiNWs can also be ferromagnetic or antiferromagnetic semiconductors. The present study not only offers a possible route to engineer half-metallic SiNWs without containing magnetic atoms but also sheds light on manipulating spin-dependent properties of nanowires through surface passivation.