Optoelectronic synapses based on two-dimensional transition metal dichalcogenides for neuromorphic applications

Abstract

With the rapid advancement of information technology and artificial intelligence, the energy efficiency bottleneck of the von Neumann architecture and the scaling limits of silicon-based semiconductors are increasingly constraining improvements in computing performance. Neuromorphic computing, by emulating the cooperative behavior of neurons and synapses in the brain, enables the integration of computation and memory, offering a promising route toward next-generation low-power and high-performance computing. As a key strategy for artificial synapse implementation, optoelectronic synapses exhibit ultrafast response, broad bandwidth, and contactless optical signal transmission, conferring significant advantages in information sensing, transmission, and storage. In particular, two-dimensional (2D) transition metal dichalcogenides (TMDs) with their atomic-scale thickness, tunable bandgaps, and outstanding optoelectronic properties provide an ideal material platform for highly integrated optoelectronic synaptic devices. This review presents a comprehensive overview of the fundamental concepts of artificial synapses and synaptic plasticity, examines the device architectures and operating mechanisms of optoelectronic synapses based on 2D TMDs along with their applications in neuromorphic visual systems and neuromorphic computing, and further discusses the key challenges and future research directions in this area.