Faraday-like Screening by Two-Dimensional Nanomaterials: A Scale-Dependent Tunable Effect

The modulation of electric fields by mono- or few-layer two-dimensional (2D) nanomaterials embodies a major challenge through vast technological areas, including 2D nanoscale electronics, ultrathin cable shielding, and nanostructured battery and supercapacitor electrodes. By a quantum-mechanical analysis of Faraday-like electrostatic screening due to diverse 2D nanolayers we demonstrate that electric field screening is triggered by charge response nonlocality. The effective screening factor is not only influenced by average polarizability but further exhibits nontrivial scalings with respect to surface distance: while ideal 2D metallic systems cause complete Faraday-cage screening, semimetallic graphene yields a finite, roughly scale-independent field reduction factor. Conversely, screening by finite-gap MoS2 appears most effective in the vicinity of the surfaces, gradually vanishing in the long-distance limit because of the intrinsic finiteness of the charge-response length scale. The variability of screening effects and of their scaling laws with respect to accessible physical parameters opens novel pathways for experimental modulation of electric fields, ionic interactions, and adsorption of charged or polar moieties.