First-principles predictions of local charge distribution in few-layer 2D ferroelectrics

The structural stability of 2D materials at the nanoscale makes them particularly exciting for exhibiting the precise atomic rearrangements involved in ferroelectric switching down to the monolayer. Recent works have presented 2D materials such as SnS, In2Se3, and various transition metal dichalcogenides as promising candidates for exhibiting out-of-plane and/or in-plane ferroelectricity. In this work, we present our first-principles, density functional theory (DFT) predictions of the local electronic charge density at interfaces between multi-layered 2D ferroelectric materials. We rely on charge density predictions for uniformly oriented few-layer structures to draw conclusions on the charge density response observed at interfaces in heterogeneously oriented structures. In particular, we analyze the local charge distribution between ferroelectric domains in few-layer indium selenide (In₂Se₃), a material recently shown to exhibit out of plane ferroelectric switching and monolayer ferroelectricity. We compare these results with experimental measurements.