Ionic-to-electronic coupling efficiency in PEDOT:PSS films operated in aqueous electrolytes

Achilleas Savva,Shofarul Wustoni,Sahika Inal

doi:10.1039/c8tc02195c

Achilleas Savva, Shofarul Wustoni + Show 1 more

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https://doi.org/10.1039/c8tc02195c

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Abstract

This work highlights the role of PEDOT:PSS composition in determining the efficiency of coupling between ionic and electronic charges.

Highlights

Organic mixed conductors are often soft, conjugated polymers that have garnered attention due to their ability to conduct ionic and electronic current simultaneously.[1,2,3] When interfacing with an electrolyte, the electrical and optical properties of a conjugated polymer film can be modulated dramatically if the ions penetrate into the bulk of the film.[4,5] These ions compensate for electronic charges injected from/extracted to an electrode, i.e., electrochemical doping or de-doping.[6]
We find that not all the injected cations are used for reducing PEDOT oligomers in thick films and some of these ions remain in the film upon de-doping
The efficiency of ion-to-electron transduction varies with thickness, a parameter which critically affects the distribution of PEDOT and PSS in the bulk as revealed by Raman spectroscopy, X-ray photoelectron spectroscopy and scanning transmission electron microscopy studies

Summary

Introduction

Organic mixed conductors are often soft, conjugated polymers that have garnered attention due to their ability to conduct ionic and electronic current simultaneously.[1,2,3] When interfacing with an electrolyte, the electrical and optical properties of a conjugated polymer film can be modulated dramatically if the ions penetrate into the bulk of the film.[4,5] These ions compensate for electronic charges injected from/extracted to an electrode, i.e., electrochemical doping or de-doping.[6]. We quantify the efficiency of ion-to-electron coupling in PEDOT:PSS films by measuring the number of cations taken up by the film as well as the in situ current generated as a result of their interactions with the electrically active sites. We investigate the efficiency of ion-to-electron coupling for PEDOT:PSS films of different thicknesses.

Results

Conclusion