Buried Au nanoparticles-assisted enhancement of local electric field toward improved resistance switching in Au/ZnO/Si structures

In this work, we reported the fabrication of improved Au/ZnO/Si resistance switching (RS) devices achieved by introducing buried cone-like Au nanoparticles (NPs). The Au NPs were facilely obtained by thermally annealing a thin Au film grown on a Si substrate, which did not influence the subsequent growth of ZnO thin films. Electric measurements verified typical RS behaviors in the Au/ZnO/Si devices, which are related to the recovery and rupture of conductive filaments due to electric field-driven oxygen vacancy migration. Notably, COMSOL-based electrostatic field simulations on Au/ZnO/Au structures have shown that an enhanced local electric field with 4.5 times enhancement was produced at the tip of Au NPs, which facilitated the oxygen vacancies migration around the tip of Au NPs. Accordingly, controlled formation and rupture of conductive filaments are proposed in the Au/ZnO/Au NPs/Si devices, which greatly improved the RS window, stability, and endurance. The results shown in this work may pave the way for the fabrication of high-performance oxide-based RS devices in the future.