Sliding ferroelectric tunneling junctions with large electroresistance ratio

Sliding ferroelectric materials such as twisted hexagonal boron nitride (tw-hBN) have the advantages of fast switching and fatigue resistance compared with conventional ferroelectrics. However, their polarization is orders of magnitude lower than that of conventional ferroelectrics. Therefore, tunneling junctions based on sliding ferroelectrics usually have a low electroresistance ratio of order 1, due to a marginal modulation of the tunneling barrier by the weak polarization. Here we show that the polarization in tw-hBN can cause a significant shift of the band edges in a few-layer MoSe_2 electrode by \sim 0.2 eV and result in an electroresistance ratio of \sim 100. We clarify that the density of states in MoSe_2 instead of the tunneling barrier dominates the electroresistance ratio enhancement. Our study provides a viable route of utilizing sliding ferroelectrics in fast switching and high endurance non-volatile memories. In addition, the large band modulation capability of tw-hBN demonstrated in this work provides an attractive tool for engineering band structures in layered semiconductors.