Synaptic Transistor Arrays Based on PVA/Lignin Composite Electrolyte Films

With the development of information society, the traditional von Neumann-based computing system is facing significant challenges. The search for an intelligent computing system similar to the biological brain would be a very effective solution to the present-day von Neumann bottleneck. Electrolyte-gated transistors (EGTs) have received much attention because they can simulate biological synaptic behavior very effectively. However, large-scale EGTs arrays are still lacking because most of the existing reported EGTs use organic or liquid electrolytes, which poses a significant challenge to the current production methods for manufacturing integration using photolithography. Although synaptic transistor arrays using solid-state electrolytes have the potential for large-scale fabrication, the power consumption required for individual transistors is relatively high. In this work, an electrolyte transistor array ( $10\times10$ ) fabricated by the photolithography process was successfully proposed, where the individual transistors in the array used a composite polyvinyl alcohol (PVA)/lignin electrolyte as the gate dielectric layer. The switching ratio of a single transistor can reach 106, and the maximum gate leakage current is 43.96 pA in the voltage range of −3 to 3 V. In addition, the synaptic properties, such as excitatory postsynaptic current (EPSC) and paired-pulse-facilitation (PPF), were successfully achieved. When the pulse duration is 100 ms, the energy consumption of the transistor is 0.63 nJ. The number's dynamic memory and forgetting functions were also successfully simulated by the artificial synaptic transistor array. This work will provide a useful idea for large-scale array integration of EGTs using organic and liquid electrolytes as gate dielectric layers.