Electric field screening in atomically thin layers of MoS2: the role of interlayer coupling

TL;DR

This study investigates how interlayer coupling affects electrostatic screening in atomically thin MoS2 layers, revealing the importance of interlayer interactions through combined experimental and theoretical analysis.

Contribution

It introduces a three-dimensional model with interlayer hopping to accurately describe electrostatic screening in MoS2, surpassing simpler continuum models.

Findings

Continuum model fails to explain experimental screening data.

Interlayer coupling significantly influences electrostatic screening.

3D model with interlayer hopping matches experimental results.

Abstract

The aim of this work is to study the electrostatic screening by single and few-layer MoS2 sheets by means of electrostatic force microscopy in combination with a non-linear Thomas-Fermi Theory to interpret the experimental results. We find that a continuum model of decoupled layers, which satisfactorily reproduces the electrostatic screening for graphene and graphite, cannot account for the experimental observations. A three-dimensional model with an interlayer hopping parameter can on the other hand successfully account for the observed electric field screening by MoS2 nanolayers, pointing out the important role of the interlayer coupling in the screening of MoS2.