Giant Electroresistance in Ferroionic Tunnel Junctions

Summary Oxide-based resistive switching devices including ferroelectric tunnel junctions and resistance random access memory are promising candidates for the next generation non-volatile memory technology. In this work, we propose a ferroionic tunnel junction to realize a giant electroresistance. It functions as a ferroelectric tunnel junction at low resistance state and as a Schottky junction at high resistance state, due to interface engineering through the field induced migration of oxygen vacancies. An extremely large electroresistance with ON/OFF ratios of 5.1×10 7 at room temperature and 2.1×10 9 at 10 K is achieved, using an ultrathin BaTiO 3-δ layer as the ferroelectric barrier and a semiconducting Nb-doped SrTiO 3 substrate as the bottom electrode. The results point towards an appealing way for the design of high performance resistive switching devices based on ultrathin oxide heterostructures by ionic controlled interface engineering.