Two-Terminal Neuromorphic Devices Based on Organic Electrochemical Diodes

Although various types of neuromorphic devices base on memristive, phase-change, and ferroelectric characteristics are proposed, there exist few examples of two-terminal neuromorphic behaviors driven by ion-intercalated modulation. Herein, we report the organic electrochemical diode (OECD)-based two-terminal neuromorphic device architecture. The proposed devices operate via key principles based on polarity-dependent current-rectification and activity-dependent electrochemically-floated potential shift of organic mixed ionic-electronic conductors with low oxidation potentials. The actual potential of a given active channel layer could be effectively modulated by repeated electrical stimulations through the input node so that the non-conductive channel became conductive under the forward bias below 0.8 V and vice versa. We also demonstrated that patterned devices in series/parallel could show the behaviors of programmable AND or OR logic gates as a proof-of-principle of integrated digital circuits.