Improved resistive switching performance of graphene oxide-based flexible ReRAM with HfOx buffer layer

Abstract

Flexible electronic devices have generated large research interest in recent years. Herein, we demonstrate a resistive random access memory (ReRAM) device fabricated on a flexible polyethylene terepthalate (PET) substrate using a bilayer of graphene oxide (GO) and HfOx films. The physical properties of GO and HfOx were characterized by a number of techniques such as X-ray diffraction (XRD), UV–Visible absorption spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The GO/HfOx-bilayered ReRAM devices exhibited good switching behavior at low SET/RESET voltages and showed improved cell-to-cell uniformity of switching parameters compared to the devices without HfOx layer, due to the oxygen vacancies within the HfOx film as confirmed by XPS. The switching mechanism was explained by the formation/rupture of the conductive filament through the migration-induced oxidation/reduction reaction of the oxygen vacancies at the interface of GO/HfOx. From the I–V curve fitting, the conduction in low resistance state (LRS) was found to be governed by the Ohmic mechanism and the trap-controlled space charge limited current (SCLC) in high resistance state (HRS) was observed for both the cycles.