Resistive switching memory using titanium-oxide nanoparticle films

In this work we present symmetric metal-insulator-metal bipolar memristors based on room-temperature deposition of titanium-oxide nanoparticles (TiO NPs) formed in vacuum by a physical process. We report that deposition under substrate biasing conditions strongly affects the structural and electrical properties of the produced TiO-NP films including their bipolar switching behaviour. The application of an external electric field during deposition enhances the mean size and oxygen content of the TiO NPs as well as the high-to-low resistance (HLR) ratio of the memristive films. Under the substrate-biasing deposition conditions examined so far, we successfully achieved bistable devices with a HLR ratio increased by two orders of magnitude compared to devices using TiO-NP films formed without electric-field assisted NP deposition.