Asymmetric Carrier Transport in Two-Dimensional Ferroelectric Layers

Ferroelectric tunnel junctions can offer low power and non-destructive readout for memory based applications, but are currently limited by their low tunneling electro-resistance (TER). Recent experimental study has shown greatly enhanced tunneling barrier and TER of hetrostacks based on ferroelectric CuInP₂S6 (CIPS). However, microscopic mechanisms underlying the observed asymmetric charge carrier transport in CIPS remain unknown. We perform nonadiabatic quantum molecular dynamics simulations to study carrier dynamics in a graphene-CIPS interface under high electric fields. Simulations results exhibit a high asymmetry in carrier transport due to CIPS polarization, which is likely related to the observed tunneling barrier enhancement. Better understanding of the asymmetry in the charge carrier transport will give valuable insight into the design of novel ferroelectric tunneling junctions.