Insertion of a Graphene Oxide Layer into a Cu/SiO2/Pt Structure to Overcome Performance Degradation in a Vaporless Environment

Abstract

A Cu/SiO 2 /Pt structure is usually used to study the resistive memory properties of an electrochemical resistive random access memory. It can be reversibly switched between low-and high-resistance states by using DC voltages in the atmosphere. However, its resistive switching behavior disappears in a vaporless environment because no conducting filaments can be formed within the Cu/SiO 2 /Pt structure. This study inserted a graphene oxide (GO) layer to fabricate a Cu/GO/SiO 2 /Pt structure that could be resistively switched in a vaporless environment. The X-ray photoelectron spectra depth profile of the Cu/GO/SiO 2 /Pt structure showed that oxygen-related groups of the GO film reacted with the Cu electrode. The GO film assisted Cu ionization in a vaporless environment, and Cu ions could migrate in an electrical field to the Pt electrode. Cu conducting filaments were formed and ruptured by different polarity voltages, and the resistance of the Cu/GO/SiO 2 /Pt structure could be reversibly switched in a vaporless environment. A schematic model was proposed to explain the switching mechanisms in the atmosphere and a vaporless environment.were responsible for the reversible RS mechanism. One of the most severe issues is large switching dispersion, which would cause a small switching margin and a complex circuit for memory applications. Therefore, several methods have been proposed to reduce the occurrence of switching dispersion. Cu nanoparticles (Cu-NPs) were embedded into the SiO 2 layer of the Cu/SiO 2 /Pt structure to enhance the local electrical field near Cu-NPs during the forming process, which reduced the switching dispersion [10]. In our previous work [11], a graphene oxide (GO) layer with a folded, layered structure was used to limit the number of formation sites of Cu conducting filaments, which reduced the switching dispersion in the atmosphere [12]. Although the Cu/SiO 2 /Pt structure had good RS properties in the atmosphere, it had poor RS properties in a vaporless environment [13], which could have caused problems after device packaging. We have already conducted a study in which we fabricated a Cu/Cu x O/SiO 2 /Pt structure to investigate its RS in a vaporless environment [13].The Cu x O layer in the Cu/Cu x O/SiO x /Pt structure helped the dissolution of Cu ions from the Cu electrode into the SiO x layer, enabling electrochemical RS in a vaporless environment.Graphene is a two-dimensional material with superior electrical and mechanical properties [14], making it a very attractive material for many applications such as integrated circuits [15] and mechanical resonators [16]. Many methods, such as chemical vapor deposition [17] and reduced GO, attempt to fabricate low-price and large-area graphene layers. Oxygen functional groups within GO layers are influenced by synthesis methods and process parameters [18]. Therefore, GO is suitable for many applications. GO can be a surfactant due to its hydrophobic/hydrophilic property [19]. GO nanosheets are also a highly efficient and universal demulsifier [20]...

Special Issue: “Physics and Mechanics of New Materials and Their Applications”

“…Liu et al [1] inserted a graphene oxide (GO) layer, manufactured as a Cu/GO/SiO 2 /Pt structure, which could be resistively switched in a vaporless environment. The X-ray photoelectron spectra depth profile of this structure showed that the GO film caused Cu ionization in a vaporless environment with migration of Cu ions in an electrical field to the Pt electrode.…”