Homogeneous Charge Relaxation in Organic Mixed Ionic-Electronic Conductors
Abstract
Organic mixed ionic-electronic conductors (OMIECs) couple ionic and electronic signals, enabling energy storage, neuromorphic computing, and bioelectronics. However, how charge relaxes in water once the bias is removed, which determines how long stored states persist, remains unclear. Using operando charge photometry, we tracked charge in OMIEC films during biasing and open-circuit relaxation. Under bias, charges moved as redox fronts. After bias removal, charge instead relaxed uniformly across the channel. Modeling and cryo-electron microscopy indicate that swelling creates connected water-rich pathways through the bulk. These pathways speed ion motion but also let stored charge leak away. Tuning the terminal side chain of a polythiophene controls water uptake and ion trapping. Bulky hydrophobic side chains enable stable programmable states, whereas hydrophilic side chains support fast electrophysiology sensing.
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BibTeX
@misc{zhang2026homogeneous,
title = {{Homogeneous Charge Relaxation in Organic Mixed Ionic-Electronic Conductors}},
author = {Silan Zhang and Scott T. Keene and Junfu Tian and Georgina E. Lindop and Simon M. Fairclough and Zhengkang Qu and Xian Wei Chua and Christopher Slaughter and Christina J. Kousseff and Caterina Ducati and Iain McCulloch and Henning Sirringhaus and Akshay Rao and George G. Malliaras},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.11977},
eprint = {2610.11977},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.11977},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Homogeneous Charge Relaxation in Organic Mixed Ionic-Electronic Conductors
AU - Silan Zhang
AU - Scott T. Keene
AU - Junfu Tian
AU - Georgina E. Lindop
AU - Simon M. Fairclough
AU - Zhengkang Qu
AU - Xian Wei Chua
AU - Christopher Slaughter
AU - Christina J. Kousseff
AU - Caterina Ducati
AU - Iain McCulloch
AU - Henning Sirringhaus
AU - Akshay Rao
AU - George G. Malliaras
PY - 2026
DA - 2026/10/08
PB - arXiv
DO - 10.48550/arxiv.2610.11977
UR - https://arxiv.org/abs/2610.11977
AB - Organic mixed ionic-electronic conductors (OMIECs) couple ionic and electronic signals, enabling energy storage, neuromorphic computing, and bioelectronics. However, how charge relaxes in water once the bias is removed, which determines how long stored states persist, remains unclear. Using operando charge photometry, we tracked charge in OMIEC films during biasing and open-circuit relaxation. Under bias, charges moved as redox fronts. After bias removal, charge instead relaxed uniformly across the channel. Modeling and cryo-electron microscopy indicate that swelling creates connected water-rich pathways through the bulk. These pathways speed ion motion but also let stored charge leak away. Tuning the terminal side chain of a polythiophene controls water uptake and ion trapping. Bulky hydrophobic side chains enable stable programmable states, whereas hydrophilic side chains support fast electrophysiology sensing.
ER -