時間：2026-07-08(三) 10:30 am

講題：Understanding the Doping of Organic Mixed Ionic-Electronic Conductors for the Rational Design of High-Performance

講者 :  Prof. Olivier Bardagot

服務單位：CNRS Strasbourg, France  

地點：4樓創意講堂

主持人：林彥丞 教授

摘要：

Organic mixed ionic-electronic conductors (OMIECs) are π-conjugated materials designed for reversible electrochemical (de)doping. Processed as thin films, they serve as the active channel in organic electrochemical transistors (OECTs)—the core of bioelectronic devices such as biosensors and neuromorphic systems. Understanding the fundamental processes governing OMIEC doping is therefore crucial to guide molecular engineering and advance the OECT technology.

First, we present strategies for designing efficient OMIECs, focusing on five novel copolymers composed of two EDOT units (without side chains) and one ProDOT unit substituted with linear or branched oligo(ethylene oxy) (OE) side chains (coll: J. Reynolds).^[1]  Our key findings include:

• ProDOT-based copolymers yield a solution-processable polymer that outperforms polythiophenes and PEDOT:PSS as an OECT channel material.
• Reducing OE side-chain mass enhances OECT signal amplification, achieving a normalized transconductance of 453 ± 70 S cm⁻¹ in saline aqueous electrolyte.
• Reducing OE side-chain mass also improves OECT operational stability.
• A custom-built instrument reveals that the OECT stability (I_DS retention) correlates with reduced doping extent and slower ON/OFF switching.
• We introduce the concept of “electroactive polymer content” as a simple yet powerful tool for guiding OMIEC design.

In 2023, we demonstrated how the ratio of ordered to disordered domains in thin films directly influences both the extent and kinetics of OMIEC doping (coll: N. Banerji).^[2] Specifically, we find that (i) more ordered domains undergo faster doping, and (ii) more disordered domains promote ion uptake and the formation of more delocalized doped states. Building on these insights, we introduce in this oral contribution: PBTTT-⁸O - a novel PBTTT derivative featuring single-ether side chains with a single oxygen atom in the 8^th position (coll: N. Leclerc). We showcase the potential of single-ether side chains as a promising alternative to conventional alkyl chains and oligo(ethylene glycol) side chains for high-performance OMIECs. These single-ether side chains are not only simple to synthesize but also offer a trade-off between crystallinity and polarity to promote dopant insertion while preserving molecular order. Notably, by combining single-ether side chain engineering with uniaxial polymer chain alignment, we present an effective strategy to precisely control the channel morphology, resulting in unprecedented signal amplification performance in p-type accumulation-mode OECTs (geometry-normalized g_m over 2500 S cm^-1), coll: M. Brinkmann).^[3] To further rationalize these enhancements, we systematically investigated five PBTTT-xO polymers with single-ether side chains, varying the oxygen position (x = 3, 5, 8, 11), and compared them to the benchmark PBTTT-C₁₂.^[4] Our findings reveal a clear dependence of ether position on the thermo-structural behavior and crystallinity index of PBTTT-xO, highlighting how fine-tuning side chain polarity and polymer organization can optimize OMIEC doping properties and OECT performance. Preliminary results achieved on OECTs made of the next generation of PBTTT polymers may be presented.

學經歷：

詳情請參見附檔