POS5-0544
Elucidating Self-Doping in Donor–Acceptor Conjugated Polyelectrolytes: From Molecular Origin to Applications
Topic
S5. Polymers for Electronics and Photonics
When and Where
Oct 1, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Jinkee HONG
Ki Su KIM
Presenter(s)
Sangmin Chae (RIKEN)
Co-Author(s)
Abstract
Conjugated polyelectrolytes (CPEs) are promising mixed ionic–electronic conductors, yet the molecular origin of self-doping in donor–acceptor (D–A) CPEs remains unclear. Here, we establish design principles for self-doped D–A CPEs by systematically tuning the acceptor strength in CPDT-based polyelectrolytes.
Combining theoretical calculations, spectroelectrochemistry, structural analysis, and OECT characterization, we reveal that self-doping proceeds through water-assisted protonation followed by intermolecular electron transfer. Free-energy analysis identifies protonation as the thermodynamic bottleneck, whereas oxidation and polaron stabilization are strongly governed by acceptor strength. These results show that efficient self-doping requires not only favorable energy levels, but also low protonation barriers, mobile polarons, and ordered transport pathways.
Among the series, CPE-BT exhibits the optimal balance, showing strong polaron formation, high conductivity, low polaron binding energy, and ordered molecular packing. Spectroelectrochemical and capacitance measurements further confirm its efficient response to both anion-driven doping and cation-driven dedoping. As a result, CPE-BT-based OECTs deliver high drain current, large transconductance, near-zero threshold voltage, and unique dual-mode operation in both accumulation and depletion regimes.
These findings establish a molecular design route for D–A CPEs as a versatile materials platform, enabling diverse advanced applications from chemically programmable organic mixed conductors for bioelectronics to high-performance organic optoelectronics.
Combining theoretical calculations, spectroelectrochemistry, structural analysis, and OECT characterization, we reveal that self-doping proceeds through water-assisted protonation followed by intermolecular electron transfer. Free-energy analysis identifies protonation as the thermodynamic bottleneck, whereas oxidation and polaron stabilization are strongly governed by acceptor strength. These results show that efficient self-doping requires not only favorable energy levels, but also low protonation barriers, mobile polarons, and ordered transport pathways.
Among the series, CPE-BT exhibits the optimal balance, showing strong polaron formation, high conductivity, low polaron binding energy, and ordered molecular packing. Spectroelectrochemical and capacitance measurements further confirm its efficient response to both anion-driven doping and cation-driven dedoping. As a result, CPE-BT-based OECTs deliver high drain current, large transconductance, near-zero threshold voltage, and unique dual-mode operation in both accumulation and depletion regimes.
These findings establish a molecular design route for D–A CPEs as a versatile materials platform, enabling diverse advanced applications from chemically programmable organic mixed conductors for bioelectronics to high-performance organic optoelectronics.
