Reinforcing Synaptic Plasticity of Defect-Tolerant States in Alloyed 2D Artificial Transistors

초록

While two-dimensional (2D) materials possess the desirablefutureof neuromorphic computing platforms, unstable charging and de-trappingprocesses, which are inherited from uncontrollable states, such asthe interface trap between nanocrystals and dielectric layers, candeteriorate the synaptic plasticity in field-effect transistors. Here,we report a facile and effective strategy to promote artificial synapticdevices by providing physical doping in 2D transition-metal dichalcogenidenanomaterials. Our experiments demonstrate that the introduction ofniobium (Nb) into 2D WSe2 nanomaterials produces chargetrap levels in the band gap and retards the decay of the trapped charges,thereby accelerating the artificial synaptic plasticity by encouragingimproved short-/long-term plasticity, increased multilevel states,lower power consumption, and better symmetry and asymmetry ratios.Density functional theory calculations also proved that the additionof Nb to 2D WSe2 generates defect tolerance levels, therebygoverning the charging and de-trapping mechanisms of the synapticdevices. Physically doped electronic synapses are expected to be apromising strategy for the development of bioinspired artificial electronicdevices.

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