2D materials for neuromorphic devices

Biological synapses play an important role in the neural system, with a variety of functions, and operate with exceptionally low power consumption. Artificial synapses that can mimic biological functions are essential for next-generation electronics. Among various candidates, two-dimensional (2D) materials have been attracting significant attention due to their atomic-level thin body and potential capacity to mimic synaptic plasticity. In this chapter basic mechanisms and recent progress in neuromorphic devices based on 2D materials are reviewed. The different working mechanisms of neuromorphic devices are introduced, including metal ion migration, phase change, and tunneling effect. Different 2D neuromorphic device architectures are also summarized, ranging from two-terminal memristors to three-terminal transistors and, finally, 2D van der Waals heterostructures. This chapter will provide a view of the neuromorphic computing applications based on the emerging 2D synaptic devices.