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

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 HfO x films. The physical properties of GO and HfO x 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/HfO x -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 HfO x 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/HfO x . 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.