Potentiation and depression behaviour in a two-terminal memristor based on nanostructured bilayer ZrO <sub>x</sub> /Au films
Filippo Profumo, Francesca Borghi, Andrea Falqui, Paolo Milani
Abstract
Abstract The emulation of synaptic functions such as potentiation and depression is of strategic importance for the development of artificial neuromorphic architectures. Memristors can qualitatively reproduce the short-term plasticity behaviour of biological synapses by exploiting the gradual relaxation of resistance levels upon the removal of the switching signals. Various types of memristors based on nanofabricated metal-oxide-semiconductor stacks have been proposed for this purpose. Here we present a different fabrication approach based on cluster-assembled nanostructured zirconia and gold films (ns-Au/ZrO x ) deposited in a bilayer planar configuration. This device shows memristive behaviour with short-term memory and potentiation/depression. The observed relaxation can be described by a stretched-exponential function. Furthermore, the characteristic time of the short-term phenomena dynamically changes under repeated pulses application. Our nanostructured device is characterised by a substantially larger conductive path length with respect to other nanoscale memristive devices; the use of a zirconia nanostructured film makes the device compatible with neuronal cell culture.