Controlling Half-Metallicity of Graphene Nanoribbons by Using a Ferroelectric Polymer

TL;DR

This study demonstrates a novel method to induce and control half-metallicity in zigzag graphene nanoribbons using ferroelectric polymer coatings, enabling reversible switching of electronic states with small external electric fields.

Contribution

The paper introduces a first-principles approach to achieve and manipulate half-metallicity in ZGNRs via ferroelectric polymer deposition, a noninvasive and reversible method.

Findings

Half-metallic state achieved with PVDF coverage on ZGNRs.

Switching between half-metallic and insulating states via small electric fields.

Electronic and magnetic properties controllable through ferroelectric polarization.

Abstract

On the basis of first-principles computational approaches, we present a new method to drive zigzag graphene nanoribons (ZGNRs) into the half-metallic state using a ferroelectric material, poly(vinylidene fluoride) (PVDF). Owing to strong dipole moments of PVDFs, the ground state of the ZGNR becomes half-metallic when a critical coverage of PVDFs is achieved on the ZGNR. Since ferroelectric polymers are physisorbed, the direction of the dipole field in PVDFs can be rotated by relatively small external electric fields, and the switching between half-metallic and insulating states may be achieved. Our results suggest that, without excessively large external gate electric fields, half-metallic states of ZGNRs are realizable through the deposition of ferroelectric polymers and their electronic and magnetic properties are controllable via noninvasive mutual interactions.