Cerium Oxide Nanoparticles Embedded with Carbon Matrix for a Digital-Analog Integrated Memristor

The integration of digital and analog resistive switching (RS) within a single device holds significant promise for multifunctional memory and neuromorphic computing applications. In this work, we present a CeO₂-rGO nanocomposite-based memristor exhibiting bipolar RS behavior. The active layer, synthesized via a hydrothermal method, leverages the high oxygen vacancy concentration of CeO₂ and the excellent conductivity of rGO to achieve a relatively low voltage, forming free switching with an enhanced device stability. The fabricated CeO₂-rGO memristor device shows a large memory window and reliable endurance and retention time. Importantly, the coexistence of both digital and analog switching enables multilevel conductance states, essential for high-density storage and synaptic emulation. The possible mechanism for the presence of both switching behaviors is addressed by considering cation migration and oxygen vacancy redistribution. Additionally, the device exhibits a voltage pulse response during read-write-erase cycles for rewritable memory operations. These findings indicate CeO₂-rGO nanocomposites could be a potential candidate for next-generation nonvolatile memory devices that bridge conventional data storage and neuromorphic functionalities.