Self-assembled oxide films with tailored nanoscale ionic and electronic channels for controlled resistive switching

Resistive switches are non-volatile memory cells based on nano-ionic redox processes that offer energy efficient device architectures and open pathways to neuromorphics and cognitive computing. However, channel formation typically requires an irreversible, not well controlled electroforming process, giving difficulty to independently control ionic and electronic properties. The device performance is also limited by the incomplete understanding of the underlying mechanisms. Here, we report a novel memristive model material system based on self-assembled Sm-doped CeO2 and SrTiO3 films that allow the separate tailoring of nanoscale ionic and electronic channels at high density (∼1012 inch−2). We systematically show that these devices allow precise engineering of the resistance states, thus enabling large on–off ratios and high reproducibility. The tunable structure presents an ideal platform to explore ionic and electronic mechanisms and we expect a wide potential impact also on other nascent technologies, ranging from ionic gating to micro-solid oxide fuel cells and neuromorphics.
Metal oxide resistive switches rely on the migration of oxygen vacancies and electrons under applied voltage. Here, Cho et al. use nanocomposites to control the electronic and ionic conductivities in spatially distinct channels, and fabricate memristors with high on/off ratios and reproducibility.