Programmable electronic synapse and nonvolatile resistive switches using MoS₂ quantum dots

Brain-inspired computation that mimics the coordinated functioning of neural networks through multitudes of synaptic connections is deemed to be the future of computation to overcome the classical von Neumann bottleneck. The future artificial intelligence circuits require scalable electronic synapse (e-synapses) with very high bit densities and operational speeds. In this respect, nanostructures of two-dimensional materials serve the purpose and offer the scalability of the devices in lateral and vertical dimensions. In this work, we report the nonvolatile bipolar resistive switching and neuromorphic behavior of molybdenum disulfide (MoS₂) quantum dots (QD) synthesized using liquid-phase exfoliation method. The ReRAM devices exhibit good resistive switching with an On-Off ratio of 10⁴, with excellent endurance and data retention at a smaller read voltage as compared to the existing MoS₂ based memory devices. Besides, we have demonstrated the e-synapse based on MoS₂ QD. Similar to our biological synapse, Paired Pulse Facilitation / Depression of short-term memory has been observed in these MoS₂ QD based e-synapse devices. This work suggests that MoS₂ QD has potential applications in ultra-high-density storage as well as artificial intelligence circuitry in a cost-effective way.