Engineering Conducting Polymer Islands Toward High-Performance Solid-State Organic Electrochemical Transistors for Gas Recognition

Abstract

Fluent ion transport within conducting polymer channels can boost overall performance of organic electrochemical transistors (OECTs), which requires a highly accessible ion migration path. Here, we design highly crystalline Poly(3,4-ethylenedioxythiophene) (PEDOT) islands with an average lateral size of around 9.11 nm in channels of solid-state OECTs by in situ crosslinking poly(styrenesulfonate) chains via a progressive wet-spinning method. Compared with conventional condensed PEDOT channels, the reduced Warburg coefficient of 1299.4 Ω·s^−1/2 in island PEDOT confirms the enhancement of ion dynamics and the opening of ion transport path, while the crystalline regions enable durable ion exchange ability and long-term operation of devices, resulting in an ultra-high I_on/off ratio of 9.2 × 10³ and excellent stability over 3300 cycles. Meanwhile, the OECT also exhibits excellent short-term plasticity and multi-gas response capabilities. To simulate the capacity of olfactory receptors in encoding complex gases, we further fabricated an OECT sensor array including four functionalized gate materials. Combined with a convolutional neural network algorithm, the OECT sensor array achieved a high accuracy of 97.9% for identifying five gases. The engineered microstructure strategy of constructing island structures by controlling crystallization behavior offers a novel pathway for optimizing ion dynamics in conducting polymer and advancing high-performance bioelectronic devices.

Graphical Abstract

Keywords

Island PEDOT fibers / Ion dynamics / Organic electrochemical transistor array / Gas recognition

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Funding

The Hong Kong Polytechnic University

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