Enhanced tunneling electroresistance through interfacial charge-modulated barrier in α-In2Se3-based ferroelectric tunnel junction

Abstract

The manipulation of tunneling resistance is critical for ferroelectric tunnel junction (FTJ) devices. In this work, we propose a mechanism to manipulate tunneling resistance through interfacial charge-modulated barrier in two-dimensional (2D) n-type semiconductor/ferroelectric FTJs. Driven by ferroelectric reversal, different effective tunneling barriers are realized by the depletion or accumulation of electrons near the n-type semiconductor surface in such devices. Thus, the tunneling resistance in FTJs undergoes significant changes for different polarization orientations, resulting in a giant tunneling electroresistance (TER) effect. To illustrate this idea, we construct 2D FTJs based on n-InSe/α-In2Se3 van der Waals (vdW) heterostructures. Based on the electronic transport calculations, it is found that TER ratio can reach 4.20 × 103% in the designed FTJs. The physical origin of the giant TER effect is verified through analysis of the effective potential energy of the n-InSe/α-In2Se3 vdW heterostructures and the real-space transmission eigenstates of the designed FTJs. This work contributes to the knowledge of carrier tunneling mechanisms at the interface of semiconductor/In2Se3 vdW heterostructures, and providing a significant insight into the TER effect of this FTJ systems, also presenting an alternative approach for the design of FTJ-based devices.