Tunable oxygen vacancy defects for high-performance electrolyte-gated synaptic transistors

Synaptic transistors are regarded as promising components for advanced artificial neural networks and hardware-based learning systems because they can emulate the fundamental biological synapse functions. One-dimensional indium zinc oxide (InZnO) nanowires, owing to their excellent charge transport and trapping properties, demonstrate tremendous potential in synaptic transistors. However, the carrier concentration in InZnO nanowires is susceptible to oxygen vacancies, which can severely influence the performance of the synaptic transistors. Herein, we present a facile and reliable scheme to control the synaptic transistor properties via an Ar plasma-assisted oxygen vacancy defect-tunable strategy. This adjusting strategy is based on the thermal diffusion of oxygen atoms bombarded by Ar ions, which increases the oxygen vacancy concentration on the surface of InZnO nanowires and further regulates the carrier concentration in the device channel. Compared with the untreated devices, the responsivity of the Ar plasma-treated devices is increased by 400%, and the memory effect is also enhanced by 230%. This oxygen vacancy regulation strategy provides a new avenue for fabricating high-performance neuromorphic computing systems.