Nanoscale Operando Characterization of Electrolyte-Gated Organic Field-Effect Transistors Reveals Charge Transport Bottlenecks

Charge transport in electrolyte-gated organic field-effect transistors (EGOFETs) is governed by the microstructural property of the semiconducting thin film that is in direct contact with the electrolyte. Therefore, a comprehensive nanoscale operando characterization of the active channel is crucial...

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Bibliographic Details
Authors: Tanwar, Shubham, Millan Solsona, Ruben, Ruiz Molina, Sara, Mas Torrent, Marta, Kyndiah, Adrica, Gomila, Gabriel
Format: article
Status:Published version
Publication Date:2023
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/343609
Online Access:http://hdl.handle.net/10261/343609
https://api.elsevier.com/content/abstract/scopus_id/85180473590
Access Level:Open access
Keyword:Conduction anisotropy
Conductivity maps
Electrolyte-gated organic field-effect transistors
Nanoscale
Operando
Operation regimes
Potential maps
Scanning dielectric microscopy
Description
Summary:Charge transport in electrolyte-gated organic field-effect transistors (EGOFETs) is governed by the microstructural property of the semiconducting thin film that is in direct contact with the electrolyte. Therefore, a comprehensive nanoscale operando characterization of the active channel is crucial to pinpoint various charge transport bottlenecks for rational and targeted optimization of the devices. Here, the local electrical properties of EGOFETs are systematically probed by in-liquid scanning dielectric microscopy (in-liquid SDM) and a direct picture of their functional mechanism at the nanoscale is provided across all operational regimes, starting from subthreshold, linear to saturation, until the onset of pinch-off. To this end, a robust interpretation framework of in-liquid SDM is introduced that enables quantitative local electric potential mapping directly from raw experimental data without requiring calibration or numerical simulations. Based on this development, a straightforward nanoscale assessment of various charge transport bottlenecks is performed, like contact access resistances, inter- and intradomain charge transport, microstructural inhomogeneities, and conduction anisotropy, which have been inaccessible earlier. Present results contribute to the fundamental understanding of charge transport in electrolyte-gated transistors and promote the development of direct structure-property-function relationships to guide future design rules.