Finite size effects of hysteretic dynamics in multi-layer graphene on ferroelectric

TL;DR

This paper investigates how finite size effects influence the nonlinear charge dynamics and resistivity in multi-layer graphene on ferroelectric substrates, revealing size-dependent hysteresis and conductivity changes.

Contribution

It introduces a self-consistent continuum model to analyze size effects on charge dynamics and hysteresis in graphene-ferroelectric systems, highlighting the impact of layer thicknesses.

Findings

Size effects depend on the relative thicknesses of graphene, ferroelectric, and dielectric layers.

Hysteresis loops are influenced by polarization reversal and incomplete screening.

Conductivity dramatically increases when transitioning from multi to single ferroelectric domains.

Abstract

The origin and influence of finite size effects on the nonlinear dynamics of space charge stored by multi layer graphene on ferroelectric and the resistivity of graphene channel were analyzed using self-consistent continuum media approach. Revealed size effects peculiarities are governed by the relations between the thicknesses of multi layer graphene, ferroelectric film and dielectric layer between them. Appearance of charge and electroresistance hysteresis loops and their versatility steam from the interplay of polarization reversal dynamics in alternating electric field and its incomplete screening, which features are mostly determined by the dielectric layer thickness. We further investigate the effects of spatially nonuniform ferroelectric domain structures on graphene layer conductivity and predict its dramatic increase under the transition from multi to single domain state in ferroelectric. The intriguing effects can open new possibilities for graphene based sensors and explore the physical mechanisms underlying the operation of graphene field effect transistor with ferroelectric gating.