High Current-density Organic Electrochemical Diodes Enabled by Asymmetric Active Layer Design

Owing to outstanding electrical/electrochemical performance, operational stability, mechanical flexibility, and decent biocompatibility, organic mixed ionic-electronic conductors have shown great potential as implantable electrodes for neural recording/stimulation and as active channels for signal switching/amplifying transistors. Nonetheless, no studies exist on the general design rule for high-performance electrochemical diodes, which are essential for highly functional circuit architectures. Herein, we report on generalizable electrochemical diodes with very high current density over 30 kAcm-2 by introducing an asymmetric active layer based on organic mixed ionic-electronic conductors. The underlying mechanism on polarity-sensitive balanced ionic doping/dedoping is elucidated by numerical device analysis and in operando spectroelectrochemical potential mapping, while the general material requirements for electrochemical diode operation are deduced using various types of conjugated polymers. In parallel, analog signal rectification and digital logic processing circuits are successfully demonstrated to show the broad impact of organic electrochemical diode-incorporated circuits. We expect that organic electrochemical diodes will play vital roles in realizing multifunctional soft bioelectronic circuitry in combination with organic electrochemical transistors. This article is protected by copyright. All rights reserved.