Selenophene Substitution Enabled High‐Performance n‐Type Polymeric Mixed Ionic‐Electronic Conductors for Organic Electrochemical Transistors and Glucose Sensors

Abstract

High‐performance n‐type polymeric mixed ionic‐electronic conductors (PMIECs) are essential for realizing organic electrochemical transistors (OECTs)‐based low‐power complementary circuits and biosensors, but their development still remains a great challenge. Herein, by devising two novel n‐type polymers (f‐BTI2g‐SVSCN and f‐BSeI2g‐SVSCN) containing varying selenophene contents together with their thiophene‐based counterpart as the control, we demonstrate that gradually increasing selenophene loading in polymer backbones can simultaneously yield lowered lowest unoccupied molecular orbital (LUMO) levels, boosted charge‐transport properties, and improved ion‐uptake capabilities. Therefore, a remarkable volumetric capacitance (C*) of 387.2 F cm−3 and a state‐of‐the‐art OECT electron mobility (μe,OECT) of 0.48 cm2 V−1 s−1 are synchronously achieved for f‐BSeI2g‐SVSCN having the highest selenophene content, yielding an unprecedented geometry‐normalized transconductance (gm,norm) of 71.4 S cm−1 and record figure of merit (μC*) value of 191.2 F cm−1 V−1 s−1 for n‐type OECTs. Thanks to such excellent performance of f‐BSeI2g‐SVSCN‐based OECTs, a glucose sensor with a remarkably low detection limit of 10 nM and decent selectivity was further implemented, demonstrating the power of selenophene substitution strategy in enabling high‐performance n‐type PMIECs for biosensing applications.This article is protected by copyright. All rights reserved

Effects of selenium incorporation on the performance of polythiophene based organic electrochemical transistors

“…The newly reported f-BSeI2g-SVSCN achieved a record μC * of 191.2 F cm −1 V −1 s −1 with a remarkable C * value of 387.2 F cm −3 and μ e,OECT of 0.48 cm 2 V −1 s −1 for n-type OECTs. 24 However, the mechanisms underlying this performance gain are unclear, and Se substitution for p-type OMIECs is rarely used.…”

Amphiphilic Interface-Mediated Ion Doping for High Performance Organic Electrochemical Transistors with Hydrophobic Polymers

“…In recent years, organic electrochemical transistors (OECTs) have attracted significant attention in the fields of bioelectronics, − flexible sensors, − and neuromorphic computing, , due to their low operation voltage, high output signal, and compatibility with aqueous environments and flexible processes. ,, OECTs typically consist of substrates, patterned source-drain electrodes, conducting polymers or organic semiconductor films, electrolyte solutions, and gates. The main operation modes of OECTs can be divided into two categories: depletion-type devices and accumulation-type devices .…”