In-plane ferroelectric tunnel junctions based on 2D α-In2Se3/semiconductor heterostructures

Abstract Ferroelectric tunnel junctions (FTJs) have been extensively studied due to their great potential in the application of high-density and non-volatile memories. Recently, α -In 2 Se 3 was found to exhibit robust in-plane and out-of-plane ferroelectric polarizations at a monolayer thickness, which is ideal to serve as a ferroelectric component in miniaturized ferroelectric devices. In this work, we design two-dimensional van der Waals heterostructures composed of an α -In 2 Se 3 ferroelectric and a hexagonal IV-VI semiconductor (SnTe and PbSe) and propose an in-plane FTJ based on these heterostructures. Our first-principles calculations show that the designed heterostructures exhibit a pronounced band tuning property, where ferroelectric polarization reversal leads to transition between insulating and metallic states. We demonstrate that the in-plane FTJ exhibits two distinct transport regimes, tunneling and metallic, for the OFF and ON states, respectively, leading to a giant tunneling electroresistance effect with the ON/OFF ratio exceeding 5 ´ 10 3 . Our results offer a promising approach for the high-density ferroelectric memory based on the 2D In 2 Se 3 /semiconductor heterostructures and ferroelectric tunnel junctions.