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 highdensity 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 ROFF/RON 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 Li-Zn - Li+i complex pairs (Li-Zn: p-type substitutional defect; Li+i : n-type interstitial defect) through the transport of Li+i 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.