Analog Resistance Switching in Single Tungsten Oxide Nanoparticle Devices

Analog resistance switching in single tungsten oxide (WOx) nanoplatelets (NPs) with similar to 100 nm edge length sandwiched in-between a tungsten (W) and a palladium (Pd) electrode is reported. The top contact, individually aligned to each NP, was fabricated using a combination of tailored planarization techniques, nanolithography and sputter deposition. Electrical characterization revealed pronounced analog resistive switching behavior of this material composition, with gradually increasing or decreasing maximum currents for a sequence of positive or negative voltage sweeps, respectively. The switching can be assigned to a formed oxygen vacancy path in the WOx layer. Chemically synthesized NPs with analog switching behavior are promising nanoscale building blocks for the bottom-up formation of 3D memristive structures, which may eventually self-assemble into complex neuromorphic computing circuitry.