Reconfigurable Artificial Synapses between Excitatory and Inhibitory Modes Based on Single-Gate Graphene Transistors

Abstract Reconfigurable artificial synapse with synaptic responses modulated between excitatory and inhibitory modes is critical for building artificial intelligence systems. However, it is still a challenge to realize such reconfigurability with a simple single‐gated transistor. Here, hydrogen‐rich silicon nitride film is employed as the gate dielectric to construct a single‐gate controlled graphene‐based artificial synapse to realize the reconfigurable synaptic responses. In this dielectric, both traps and movable hydrogen ions are introduced to induce the carrier trapping effect and the capacitive gating effect, respectively. Comparatively, the capacitive gating effect needs stronger electrical fields excitation and can significantly modulate the graphene channel in a longer time. Utilizing the carrier trapping effect and the ambipolar property of graphene, the fundamental potentiation and depression behaviors can be emulated in each response mode. Then, utilizing the capacitive gating effect, the reconfiguration between excitatory and inhibitory response modes can be achieved. All synaptic responses only depend on the signals inputted through the back‐gate electrode, which is distinctively different from previous dynamic devices with additional modulating terminals. Such reconfiguration feature provides the artificial synapse the ability to emulate some complicated biological behaviors in future artificial intelligence systems, such as the adjustable perception of different external stimuli under different conditions.