Ferroelectric ion gel-modulated long-term plasticity in organic synaptic transistors

Abstract

Motivated by the massive parallelism of the human neural system, an artificial neuromorphic system may emulate neural activities. Previous research endeavors have been devoted to mimicking various biological synaptic functions using ion gel-based organic synaptic transistors (IGOSTs). The design scheme for these devices has been pivoted on strategies for evaluating various biological synaptic functions, such as short-term plasticity and pulse paired facilitation. However, the implementation of the IGOSTs for mimicking long-term plasticity (LTP) remains challenging because of expeditious ion de-doping from the semiconductor channel after turning off the stimulus gate signal. Herein, we present a novel ferroelectricity-enabled ion gel dielectric platform, which is referred to as ‘ferro-iongel,’ capable of implementing a longer retention time of the pre-synaptic signal with low power consumption in the IGOSTs. The envisioned material platform comprises a blend of ferroelectric polymer, elastomer matrix, and ionic liquid. Consequently, highly reliable LTP at different applied voltages has been accomplished with the emergence of electric double layer (EDL) and the partial polarization switching of ferroelectric dipoles. The new class of the dielectric material suggested herein is anticipated to contribute toward the practical realization of LTP in the IGOSTs for the demonstration of future human-machine interfaces.