Top-Gated Organic Synaptic Transistor With PS/PVA Hybrid as Trapping Layer for Excitatory Behavior Modulation

Organic synaptic transistor (OST) has received considerable attention in the era of artificial intelligence. However, to simplify the process, most of the ion-conducting polyelectrolyte-based devices use the bottom-gate structure and adopt a single organic or organic/inorganic composite material as the charge trapping/blocking layer, which limits their biocompatibility and synaptic plasticity. Here, a novel OST based on the hybrid gate dielectric consisting of porous PS and proton-conducting PVA electrolyte is proposed and fabricated. The OST with the hybrid trapping layer exhibits a large hysteresis window up to 10.7 V for the gate voltage ranging from -15 V to 15 V, indicating appreciable memory performance. The clockwise hysteresis phenomenon in gate voltage dual-sweep operation reveals that the polarization/depolarization of mobile protons and the defect reaction of channel interface layer are the dominant effects. Moreover, the OST was adopted to mimic the typical synaptic functions successfully, including excitatory postsynaptic current, paired-pulse facilitation, and long-term potentiation, short-term memory to long-term memory. Therefore, the OST based on the hybrid layer could promote the development of emerging neuromorphic systems and compact artificial neural networks.