Influence of oxidation degree on the resistive switching properties of graphene derivatives

In this work, we investigate the role of the oxidation degree of graphene on its resistive switching (RS) properties. Three graphene derivatives, graphene oxide (GO), selectively oxidized graphene (SOG), and exfoliated graphene (GEX), were fabricated and compared in the form of vertical Al/graphene derivative/Al structures. Electrical measurements revealed that only GO, with the highest oxidation level, exhibits reproducible RS, attributed to the abundance of oxygen functional groups and defects that facilitate the formation and rupture of conductive filaments. The GO devices show stable bipolar RS with an ON/OFF ratio > 10 4 , SET and RESET voltages of 2.2 ± 0.7 V and 0.66 ± 0.34 V, respectively, state retention >10 4 s, and potential to emulate synaptic behavior. In contrast, SOG and GEX devices lacked switching activity, highlighting the essential role of oxidation in filament dynamics. Furthermore, device area was observed to influence RS, as cells with a diameter < 120 μm exhibited reliable operation, whereas larger devices failed to consistently undergo RESET events. Compared to state-of-the-art GO-based RS, our devices show competitive ON/OFF ratios and operating voltages while offering the first direct comparison across different oxidation degrees. These insights establish oxygen functional group density and device scaling as key design parameters provide a pathway towards the optimization of graphene-based non-volatile memory and neuromorphic computing architectures.