Neuromorphic Applications Realized by a Free-Standing Multilayer Molybdenum Disulfide Memristor

Recently, there has been growing interest in ultra-thin two-dimensional materials called transition-metal dichalcogenides (TMDs) for their potential use in compact electronic and optoelectronic devices. These materials are appealing because of their extremely thin structure and high data storage capacity. In this study, we introduce a type of memristor created using suspended multiple layers of molybdenum disulfide (MoS2). This memristor exhibits a substantial current on/off ratio of around ~1000 and maintains stable retention of data for at least ~3000 seconds. By adjusting the intensity of light shining on the suspended MoS2 channel, we can further enhance the on/off ratio to approximately 10⁵. Additionally, we demonstrate that these devices can replicate essential functions of the human brain related to memory, both short-term and long-term. We found that short-term memory (STM) can be transformed into long-term memory (LTM) by increasing the power of the light stimulus, the duration of the light pulses, and the number of pulses. Our electrical measurements, conducted in both vacuum and ambient air conditions, suggest that the observed change in resistance in these memristors is due to the presence of oxygen and water molecules on both sides of the MoS2 channel. Consequently, our free-standing two-dimensional MoS2-based memristors offer a facile approach to creating energy-efficient and reliable resistive switching devices suitable for neuromorphic applications.