IN OPERANDO PROBING OF DOPING LEVEL IN OECT CHANNELS VIA TRANSIENT ABSORPTION MEASUREMENTS

Florian Günther; German Dario Gomez Higuita; Henrique Frulani de Paula Barbosa; Paulo Miranda

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Submission

Paper Title

IN OPERANDO PROBING OF DOPING LEVEL IN OECT CHANNELS VIA TRANSIENT ABSORPTION MEASUREMENTS

Authors

Florian Günther
German Dario Gomez Higuita
Henrique Frulani de Paula Barbosa
Paulo Miranda

Modality

Pôster

Subject area

Dispositivos eletrônicos e ópticos (OLED/OFET/OPVs/etc.)

Publishing Date

12/12/2023

Country of Publishing

Brasil

Language of Publishing

Inglês

Paper Page

https://www.even3.com.br/anais/workshop-do-ineo-2023/613364-in-operando-probing-of-doping-level-in-oect-channels-via-transient-absorption-measurements

ISBN

978-65-272-0088-8

Keywords

Organic electrochemical transistors, transient absorption, PEDOT:PSS

Summary

Organic electrochemical devices form an emerging research topic in the field of organic electronics that is very promising for new applications, especially in biological systems. They operate by oxidizing or reducing polymer films, thereby annihilating or creating (bi)polaronic states within the active material, which results in variation in electrical properties. Out of the many available architectures, the device of choice that has been heavily investigated in recent years is the organic electrochemical transistor (OECT). An OECT consists of an organic semiconducting material that connects the source and drain electrodes. This channel is in contact with an electrolyte, where a gate electrode is immersed. Upon application of an electrical voltage difference between gate and drain, ions migrate from the electrolyte in the channel’s bulk, causing (de-)doping of the organic material and, consequently, modulation of the conductivity. This doping process comes with a change in absorption, typically in the infra-red region due to the formation/depletion of (bi-)polarons. In our work, we use this effect to probe the change in charge density, by following the transient of the absorption upon the application of a gate voltage. In this contribution, results obtained for depletion mode OECTs based on PEDOT:PSS will be presented. We observed that when the gate voltage is applied, the absorption in the bipolaron region decreases, which indicates the dedoping of PEDOT. Simultaneously, the absorption in the polaron region increases. This shows that bipolarons are transformed into polarons rather than directly into the neutral species. For stronger gate voltages, we observed that, after a certain time, the absorption in the polaron region decreases again meaning that they are transformed into the neutral species. We furthermore found that this effect also occurs for low gate voltages when the electrolyte composition is changed, for instance regarding salt concentration or electrolyte composition. Hence, the transient absorption yields new perspectives on the dynamics of ion migration from the electrolyte to the semiconductor.

Title of the Event: Workshop do INEO 2023
City of the Event: Nazaré Paulista
Title of the Proceedings of the event: Anais do Workshop INEO 2023
Name of the Publisher: Even3
Means of Dissemination: Meio Digital

How to cite

GÜNTHER, Florian et al.. IN OPERANDO PROBING OF DOPING LEVEL IN OECT CHANNELS VIA TRANSIENT ABSORPTION MEASUREMENTS.. In: Anais do workshop INEO 2023. Anais...Nazaré Paulista(SP) Hotel Estância Atibainha, 2023. Available in: https//www.even3.com.br/anais/workshop-do-ineo-2023/613364-IN-OPERANDO-PROBING-OF-DOPING-LEVEL-IN-OECT-CHANNELS-VIA-TRANSIENT-ABSORPTION-MEASUREMENTS. Access in: 01/07/2025