Self-rectifying resistance switching memory based on a dynamic p–n junction

Abstract

Although resistance random access memory (RRAM) is considered as one of the most promising next-generation memories, the sneak-path issue is still challenging for the realization of high-density crossbar memory array. The integration of the rectifying effect with resistance switching has been considered feasible to suppress the sneaking current. Herein, we report a self-rectifying resistance switching (SR-RS) by a newly discovered Li ions migration induced dynamic p–n junction at the Li-doped ZnO and ZnO layer interface. The Au/Li–ZnO/ZnO/Pt structure exhibits a forming-free and stable resistance switching with a high resistance ratio of R OFF/R ON ∼ 104 and a large rectification ratio ∼106. In the Li–ZnO/ZnO bilayer, the electric field drives the dissociation and recombination of the self-compensated complex pairs ( p-type substitutional defect; n-type interstitial defect) through the transport of between the two layers, thereby induces the formation of a dynamic p–n junction. Using this structure as a memory stacking device, the maximum crossbar array size has been calculated to be ∼16 Mbit in the worst-case scenario, which confirms the potential of the proposed device structure for the selection-device free and high-density resistance random access memory applications.