Publication detail

Side charge propagation in simultaneous KPFM and transport measurement of humidity exposed graphene FET sensor

ŠVARC, V. BARTOŠÍK, M. KONEČNÝ, M. PIASTEK, J. NEZVAL, D. MACH, J. ŠIKOLA, T.

Original Title

Side charge propagation in simultaneous KPFM and transport measurement of humidity exposed graphene FET sensor

Type

journal article in Web of Science

Language

English

Original Abstract

The surface diffusion (dissipation) of charge carriers enhanced by water molecules in solution-based biosensors and ambient operating gas sensors strongly influence their resistance response, sensitivity, and stability in time. Therefore, the information on the charge distribution at interfaces of conductive and insulating parts is essential for the operating sensors. This work presents the simultaneous measurement of the longitudinal macroscopic resistance response and local surface potential (SP) mapping by Kelvin probe force microscopy (KPFM) on a graphene Hall bar sensor. The results show the propagation of an electric charge from the main graphene channel onto the neighboring SiO2 surface. The charge propagation strongly increases with the relative humidity and can be controlled by a bottom-gate voltage used in most sensors based on a field effect transistor (FET) architecture. As proved by the longitudinal resistance measurements, the resulting side charge accumulation has a very small impact on the 2D resistivity of the graphene channel. It has been explained by an application of the Thomas Fermi theory, proving an efficient screening of side accumulated charge potential caused by a redistribution of the charge inside the wide graphene channel. The combination of a transport resistance response and KPFM provides a deeper understanding of sensors/biosensors functionality and their design features than a simple resistance response usually observed.

Keywords

Graphene; Hall bar; Side charge; KPFM; FET

Authors

ŠVARC, V.; BARTOŠÍK, M.; KONEČNÝ, M.; PIASTEK, J.; NEZVAL, D.; MACH, J.; ŠIKOLA, T.

Released

24. 9. 2023

Publisher

PERGAMON-ELSEVIER SCIENCE LTD

Location

OXFORD

ISBN

1873-3891

Periodical

CARBON

Year of study

215

Number

1

State

United States of America

Pages from

118471

Pages to

118482

Pages count

12

URL

https://doi.org/10.1016/j.carbon.2023.118471

BibTex

@article{BUT187077,
  author="Vojtěch {Švarc} and Miroslav {Bartošík} and Martin {Konečný} and Jakub {Piastek} and David {Nezval} and Jindřich {Mach} and Tomáš {Šikola}",
  title="Side charge propagation in simultaneous KPFM and transport measurement of humidity exposed graphene FET sensor",
  journal="CARBON",
  year="2023",
  volume="215",
  number="1",
  pages="12",
  doi="10.1016/j.carbon.2023.118471",
  issn="1873-3891",
  url="https://doi.org/10.1016/j.carbon.2023.118471"
}