Vertical Organic Synaptic Transistor Based on Electrolyte Gate Dielectric for Emulating Short-Term Synaptic Plasticity and Pain Perception

Abstract

Inspired by biological neuromorphological systems, organic synaptic transistors (OSTs) have attracted wide attention due to their potential applications in the development of artificial intelligence. At present, the planar OSTs face great challenges in achieving low power consumption and short channel effect, while the vertical OSTs can simulate synaptic characteristics at low voltage owing to its short channel length and unique working principle. Here, we smoothly fabricated vertical structure transistors based on polyvinyl alcohol (PVA) gate dielectrics for the first time by solution method and achieved excellent electrical properties when the gate voltage was only −5 V. Subsequently, the conductivity and carrier transmission efficiency of the device were effectively improved by organic lithium salt-doped PVA gate dielectric, on the basis of which a neural morphological device based on vertical structure was constructed perfectly. By using the electric-double-layer (EDL) capacitance effect and electrochemical doping, the device can achieve low-voltage operation and typical synaptic functions successfully, including excitatory postsynaptic current (EPSC), paired pulse facilitation (PPF), long-term potentiation (LTP), and memory refresh. Moreover, the implemented PPF can be extended to simulate pain perception and sensitization. This work shows the great potential of PVA-gated OST based on vertical structure in neuromorphologic applications, facilitating the development of emerging neural morphological systems as well as future artificial neural networks.