Overcoming Volatility in Ion Gel via Ag Doping for Nonvolatile Memristive Switching

Ion-gel-based memory devices can effectively change their resistance states even at low voltages, owing to the rapid mobility of ions and the formation of an electric double layer. However, their volatile characteristics limit their use in nonvolatile memory and neuromorphic applications. In this paper, we report an ion-gel-based memristive device capable of both digital data storage and analog data processing through the incorporation of silver nanoparticles (AgNPs). The memristive device exhibited reliable resistive switching behavior, characterized by forming-free and a butterfly shaped bipolar resistive switching (BRS) profile. Notably, the ion-gel-based memristive device with AgNPs demonstrated excellent data retention for over 10⁵ s even at 85 °C, attributed to the charge storage stability provided by Ag⁺-based ion pairing. In addition to memory functionality, the device successfully emulated various synaptic behaviors, including long-term potentiation (LTP), long-term depression (LTD), and the transition from short-term memory (STM) to long-term memory (LTM). Furthermore, it achieved clear digit classification results in learning and inference tasks, with a recognition accuracy of up to 96.4%.