Short-term and long-term synaptic plasticity of Au/Al:WO<i>x</i>/Ti memristive synapse from 25 to 125 °C

Abstract

WOx-based memristors can effectively emulate short-term and long-term synaptic plasticity, making them promising for artificial synapse and neuromorphic computing chip. The high-temperature environment or the inevitable self-heating effect in chip is inescapable. However, the temperature dependence of the synaptic plasticity in WOx-based memristive synapses remains underexplored. This study investigates the effect of temperature on the short-term and long-term synaptic plasticity characteristics in Au/Al (9 at. %):WOx/Ti memristive synapses. From 25 to 125 °C, the memristive synapses maintain stable semi-volatile resistive switching properties and synaptic plasticity, including Excitatory Postsynaptic Current, Spike Amplitude-Dependent Plasticity, Spike Number-Dependent Plasticity, Long-Term Potentiation (LTP), Long-Term Depression (LTD), and Bienenstock–Cooper–Munro (BCM) sliding frequency threshold characteristics. As temperature increase, EPSC shows saturating enhancement, and post-tetanic potentiation increases. Notably, the linearity of LTP and LTD remains consistent, while the BCM frequency threshold range expands significantly (by 263.6% at 125 °C compared to 25 °C). These changes are attributed to accelerated oxygen vacancy diffusion at higher temperatures. The results confirm the feasibility of using WOx-based memristive synapses in high-temperature environments or neuromorphic computing chip.