Organic Electrochemical Transistors Based on the Conjugated Polyelectrolyte PCPDTBT‐SO₃K (CPE‐K)

Abstract

PCPDTBT-SO3K (CPE-K), a conjugated polyelectrolyte, is presented as a mixed conductor material which can be used to fabricate high transconductance accumulation mode organic electrochemical transistors (OECTs). OECTs have been utilized in a wide range of applications such as analyte This article is protected by copyright. All rights reserved. 2 detection, neural interfacing, impedance sensing and neuromorphic computing. We demonstrate the use of interdigitated contacts to enable high transconductance in a relatively small device area in comparison to standard contacts. Such characteristics are highly desired in applications such as neural activity sensing, where device area must be minimized to reduce invasiveness. The physical and electrical properties of CPE-K have been fully characterized to allow a direct comparison to other top performing OECT materials. CPE-K demonstrates an electrical performance that is among the best that have been reported in the literature for OECT materials. In addition, CPE-K OECTs operate in the accumulation mode, which allows for much lower energy consumption in comparison to commonly used depletion mode devices.

Porous Semiconducting Polymers Enable High‐Performance Electrochemical Transistors

“…[ 32,35,37,40–42 ] Furthermore, copolymerizing conjugated polymers with electrolyte polymers also increases ionic conductivity while preserving some electronic mobility. [ 43,44 ] Including additives/plasticizers such as ethylene glycol or ionic liquids into the active layer (e.g., poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)) also enhances transconductance via improved morphologies while maintaining comparable ion uptake. [ 45–49 ]…”

“…[32,35,37,[40][41][42] Furthermore, co polymerizing conjugated polymers with electrolyte polymers also increases ionic conductivity while preserving some electronic mobility. [43,44] Including additives/plasticizers such as ethylene glycol or ionic liquids into the active layer (e.g., poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)) also enhances transconductance via improved morphologies while maintaining comparable ion uptake. [45][46][47][48][49] The interfacial area between the electrolyte (typically liquid) and the active layer (solid) is a critical OECT component since it directly affects ion exchange between the two phases.…”

Polydiketopyrrolopyrroles Carrying Ethylene Glycol Substituents as Efficient Mixed Ion‐Electron Conductors for Biocompatible Organic Electrochemical Transistors

“…Other than the above‐mentioned classes of MIECs based on polythiophenes, there are only a very few reports of OECTs using the second‐generation conjugated polymers, based on donor–acceptor structures as p‐type MICEs. [ 20,21 ] Donor–acceptor copolymers, especially those incorporating diketopyrrolopyrrole (DPP) moieties as acceptor units can exhibit high charge carrier mobilities and their synthetic strategies to tune the chemical structures over a wide range are well established. [ 22,23 ] We as well as others have earlier shown that the flanking units, solubilizing side‐chains and comonomers can be adjusted deliberately to attain the desired type of charge transport and alignment.…”

Fused Bithiophene Imide Dimer‐Based n‐Type Polymers for High‐Performance Organic Electrochemical Transistors

“…Organic electrochemical transistors (OECTs) have attracted extensive attention recently due to their capability of transducing ionic signals into electronic ones at low electrochemical potentials (<1 V), which have greatly facilitated the advance of low‐voltage electronics, [1–5] including bioelectronics, [6–9] printed logic circuits, [10–12] and memory/neuromorphic devices [13–16] . Up to now, p‐type (hole‐transporting) polymer semiconductors have been intensively investigated as the channel materials in OECTs with the product ( μC *) of charge carrier mobility ( μ) and volumetric capacitance ( C *), the key Figure of merit determining the performance of OECTs, up to 522 F cm −1 V −1 s −1 achieved [17–21] . However, the development of n‐type (electron‐transporting) polymers lags greatly behind with the μC * values typically in the range of only 0.1–1 F cm −1 V −1 s −1 (Figure 1).…”