Enhanced tunneling electroresistance through polarization-controlled band alignments in α-In2Se3-based ferroelectric tunnel junctions

Abstract

The manipulation of tunneling resistance is of paramount importance in the realm of ferroelectric tunnel junction (FTJ) devices. In this work, we propose a novel mechanism that enables the manipulation of tunneling resistance through polarization-controlled band alignments in α-In2Se3-based FTJs. This mechanism exploits the transition between metallic and insulating states, induced by polarization-controlled band alignments, thus resulting in the emergence of a significant tunneling electroresistance (TER) effect. To investigate this intriguing possibility, we have designed two-dimensional (2D) FTJs based on a PtTe2/α-In2Se3 van der Waals heterostructures. By employing first-principles calculations, we demonstrate that the manipulation of band alignments between insulating and metallic states can be achieved via ferroelectric polarization. Leveraging nonequilibrium Green's function methods, we have successfully achieved a remarkably large TER effect with a ratio reaching up to 2.40 × 104. This work unveils substantial potential for the development of nano-field high-density memories and ferroelectric field-effect transistors utilizing 2D layered ferroelectric/semiconductor heterostructures.