Gradual conductance modulation of Ti/WOx/Pt memristor with self-rectification for a neuromorphic system

In this study, we present an analysis of the gradually modulated conductance of the Ti/WOx/Pt memristor. The deposited material layers were verified by transmission electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. The results revealed that the current level and the rectification behavior differed depending on the presence or absence of the compliance current (CC). If the current is controlled low at a CC of 100 μA, the current is suppressed at the positive voltage bias. It was verified through array simulation that this can mitigate the sneak current in the crossbar array structure. Finally, we conduct the potentiation and depression characteristics for an in-mode and a self-compliance mode and evaluate the pattern recognition accuracy of Modified National Institute of Standards and Technology database through neuromorphic simulation. The synaptic device with a self-rectifying behavior has considerable potential for the synapse array structure in a neuromorphic system.