Artificial Synapse Based on Back-Gated MoS(2)Field-Effect Transistor with High-kTa(2)O(5)Dielectrics

Herein, a multilayer MoS2-based low-power synaptic transistor using Ta(2)O(5)as a back-gate dielectric for mimicking the biological neuronal synapse is reported. The use of high-kdielectric allows for a lower-voltage swing compared with using conventional SiO2, thus offering an attractive route to low-power synaptic device architectures. Exfoliated MoS(2)is utilized as the channel material, and the hysteresis in the transfer characteristics of the transistor is exploited to demonstrate excitatory and inhibitory postsynaptic currents, long-term potentiation, and long-term depression (LTP/LTD), indirect spike timing-dependent plasticity (STDP) based on single and sequential gate (V-g) pulses, respectively. The synapse had achieved a 35% weight change in channel conductance within 15 electrical pulses for negative synaptic gate pulse and 28% change for positive synaptic gate pulse. A complete tunability of weight in the synapse by spike amplitude-dependent plasticity (SADP) at a low voltage of 4 V is also demonstrated.