An easy to implement strategy for improving operational stability and controlling threshold voltage in organic electrochemical transistors: Combining chemical p-doping with degassed solvents

Published

November 4, 2024

Author(s)

Vianna N. Le, Kyle N. Baustert, Megan Brown, Joel H. Bombile, Lucas Flagg, Karl Thorley, Alyssa Stubbers, Christina J. Kousseff, Olga Solomeshch, T. John Balk, Iain McCulloch, Nir Tessler, Chad Risko, Kenneth R. Graham, Alexandra F. Paterson

Abstract

Although p-type organic mixed ionic electronic conductors (OMIECs) are susceptible to oxidation, it has not yet been considered as to whether oxygen, solvent degradation products, or degradation products formed in the solvent in the presence of oxygen, could behave as uncontrolled p-dopants. Here, dissolved oxygen in the widely used solvent chloroform is shown to be behave as a p-dopant, that fills traps to enable more effective electrochemical doping in OMIECs and organic electrochemical transistors (OECTs). Yet the presence of dissolved gasses in solvents also jeopardizes essential OMIEC and OECT requirements: stability, biocompatibility, device-to-device variation, and threshold voltage control. This contradictory problem is solved by introducing a two-step strategy where first the solvents are degassed, and second the OMIEC is doped in a controllable manner using a chemical p-dopant. This strategy improves operational stability, on-off ratio, and tunes the threshold voltage in OECTs, while enhancing the transconductance, volumetric capacitance, and mobility. This simple, solution-processing compatible technique is easily implemented, low-cost, and highly effective in air and water. Overall, the data herein suggests that combining chemical doping with solvent degassing could be a broadly applicable technique to improve essential criteria needed to realize organic bioelectronics and more complex OMIEC circuitry.

Citation

Advanced Materials

Pub Type

Journals

Download Paper

https://doi.org/10.1038/s41928-024-01297-8

Local Download

Keywords

OECT

Citation

Le, V. , Baustert, K. , Brown, M. , Bombile, J. , Flagg, L. , Thorley, K. , Stubbers, A. , Kousseff, C. , Solomeshch, O. , Balk, T. , McCulloch, I. , Tessler, N. , Risko, C. , Graham, K. and Paterson, A. (2024), An easy to implement strategy for improving operational stability and controlling threshold voltage in organic electrochemical transistors: Combining chemical p-doping with degassed solvents, Advanced Materials, [online], https://doi.org/10.1038/s41928-024-01297-8, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957362 (Accessed December 12, 2025)