Resistive Switching in ZnO Nanorods/Graphene Oxide Hybrid Multilayer Structures

Abstract

Multilayer structures of graphene oxide‐zinc oxide nanorods (GO‐ZnONRs) hybrids are successfully grown for use as an active material in resistive switching random access memory (RRAM) devices. A considerable reduction in the OFF current is achieved through a layer‐by‐layer growth of GO‐ZnONR multilayers up to three repeating layers as the active material. The scanning electron microscope images and X‐ray diffraction patterns of the hybrid multilayer structures reveal that vertically oriented ZnONRs are sandwiched between GO sheets. A Raman analysis shows that the G peak position in GO redshifts, due to the COZn bonding at interfaces of the hybrid multilayer structures. X‐ray photoelectron spectroscopy analysis of the hybrid multilayer structures also confirms the growth of GO on ZnONRs and secondary ZnONRs on GO, through a COZn bonding. This study realizes the growth of vertically oriented secondary and tertiary ZnONRs on GO, accompanying a tuning of photoluminescent emission wavelength. This hybrid multilayer structure‐based resistive memory device exhibits a stable resistive switching behavior with an ON–OFF ratio up to 3.3 × 105, which is higher by three orders of magnitude than the ON–OFF ratio of a single‐layer ZnONRs based device.