Gate Capacitance-Dependent Neuromorphic Functions of Organic Electrochemical Transistors

Neuromorphic functions of organic electrochemical transistors (OECTs) have attracted enormous research attention due to their promising application in the field of brain-mimicking computing and brain–computer interfaces. However, the essential role of gate electrodes in the neuromorphic functions of these synaptic transistors remains unclear. Herein, we systematically investigated the influence of gate electrodes on the neuromorphic functions of synaptic OECTs by rationally choosing four kinds of typical gate electrodes: bare glass carbon electrode (Bare-GCE), carbon nanotube-modified GCE (CNT-GCE), PEDOT:PSS modified GCE (PEDOT:PSS-GCE), and Ag/AgCl electrode. Evaluations of the neuromorphic functions indicated that gate capacitance controlled the performance of synaptic OECTs by tuning the electrical field distribution and doping kinetics in the ionic circuits. This systematic exploration of the gate electrode influences on the OECTs offers rational guidance for the structural design of synaptic OECTs.