Neuromorphic Device Based on Solution-Processed WSe2 Nanoflake Synaptic Transistors

Significant progress has been made in developing artificial synapses using transition metal dichalcogenides (TMDs)-based neuromorphic devices, but solution-processable TMDs remain underexplored, especially in utilizing intrinsic defects for synaptic functions. Here, we prepared electrochemically-exfoliated WSe2 nanoflakes with Se vacancies that enable charge trapping and detrapping. Using a solution-processed approach, we fabricated a high-performance WSe2 synaptic transistor with a large memory window, a significant trap density of $5\times 10^{{12}}$ cm ${}^{-{2}}$ , and high operating stability. This synaptic transistor also successfully mimics various synaptic behaviors such as potentiation and depression, spike-voltage-dependent plasticity, and spike-number-dependent plasticity. By integrating the device with an infrared ranging sensor, the neuromorphic sensory system achieves 94.7% accuracy in object classification task, demonstrating its potential for advanced sensory processing.