Organic mixed conductors find use in batteries, bioelectronics technologies, neuromorphic computing, and sensing. While great progress has been achieved, polymer-based mixed conductors frequently experience significant volumetric changes during ion uptake/rejection, i.e., during doping/de-doping and charging/discharging. Although ion dynamics may be enhanced in expanded networks, these volumetric changes can have undesirable consequences, e.g., negatively affecting hole/electron conduction and severely shortening device lifetime. Here, the authors present a new material poly[3-(6-hydroxy)hexylthiophene] (P3HHT) that is able to transport ions and electrons/holes, as tested in electrochemical absorption spectroscopy and organic electrochemical transistors, and that exhibits low swelling, attributed to the hydroxylated alkyl side-chain functionalization. P3HHT displays a thickness change upon passive swelling of only +2.5%, compared to +90% observed for the ubiquitous poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, and +10 to +15% for polymers such as poly(2-(3,3'-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-[2,2'-bithiophen]-5-yl)thieno[3,2-b]thiophene) (p[g2T-TT]). Applying a bias pulse during swelling, this discrepancy becomes even more pronounced, with the thickness of P3HHT films changing by
|Original language||English (US)|
|Journal||Advanced materials (Deerfield Beach, Fla.)|
|State||Published - Nov 30 2020|
Bibliographical noteKAUST Repository Item: Exported on 2020-12-03
Acknowledgements: The authors thank Jonathan Rivnay and Sahika Inal for highly fruitful discussion and preliminary OECT measurements. T.N., G.H., and N.S. are grateful for the financial support provided by the IONBIKE RISE project, which has received funding from the European Union's Horizon 2020 research and innovation programme under the Horizon 2020 RISE Marie Skłodowska-Curie grant agreement No. 823989. T.N., G.H., and N.S. also acknowledge funding from the MARBLE project (IdEX). O.D. acknowledges funding from the MAPLE project (Institut Carnot Chimie Balard Cirimat). L.J.R. and T.N. thank NSLS-II for the access to the CMS 11-BM beamline of the Brookhaven National Laboratory, NY, USA which is a U.S. DOE Office of Science Facilities, at Brookhaven National Laboratory under Contract No. DE-SC0012704. This work was performed within the framework of the Equipex ELORPrintTec ANR-10-EQPX-28-01 with the help of the French state's Initiative d'Excellence IdEx ANR-10-IDEX-003-02.