Sol-gel strontium titanate nickelate thin films for flexible nonvolatile memory applications

Abstract

Bipolar resistive switching random access memory (RRAM) devices on a plastic substrate are investigated. Strontium titanate nickelate (STN) thin film prepared by sol-gel method served as insulator on an Al/STN/ITO/PET structure. The STN-based flexible RRAM shows a high ON/OFF resistance ratio (≥ 105) and a retention ability of over 105 s. The characteristics of Ni in the STO thin films demonstrate that spin casting without doping other elements or any complex processes can be used to fabricate thin films with higher density of oxygen vacancies, less particles, and smoother surface. In addition, the fabricated devices on a flexible plastic substrate exhibit excellent durability upon repeated bending tests, demonstrating the potential for flexible and low-cost memory applications.