Electrostatic Gating of Monolayer Graphene by Concentrated Aqueous Electrolytes

0572772 - ÚFCH JH 2024 RIV US eng J - Journal Article
Abbas, Ghulam - Farjana, Jaishmin Sonia - Jindra, Martin - Červenka, Jiří - Kalbáč, Martin - Frank, Otakar - Velický, Matěj
Electrostatic Gating of Monolayer Graphene by Concentrated Aqueous Electrolytes.
Journal of Physical Chemistry Letters. Roč. 14, č. 18 (2023), s. 4281-4288. ISSN 1948-7185
R&D Projects: GA ČR(CZ) GA23-05895S; GA MŠMT(CZ) LTAUSA19001; GA MŠMT EF16_026/0008382
Grant - others:Ministerstvo školství, mládeže a tělovýchovy - GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_026/0008382; AV ČR(CZ) LQ200402201
Program: Prémie Lumina quaeruntur
Institutional support: RVO:61388955 ; RVO:68378271
Keywords : CHARGED-IMPURITY SCATTERING * QUANTUM CAPACITANCE * RAMAN-SPECTROSCOPY
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) (FZU-D)
Impact factor: 5.7, year: 2022
Method of publishing: Open access

Electrostatic gating using electrolytes is a powerful approach for controlling the electronic properties of atomically thin two-dimensional materials such as graphene. However, the role of the ionic type, size, and concentration and the resulting gating efficiency is unclear due to the complex interplay of electrochemical processes and charge doping. Understanding these relationships facilitates the successful design of electrolyte gates and supercapacitors. To that end, we employ in situ Raman microspectroscopy combined with electrostatic gating using various concentrated aqueous electrolytes. We show that while the ionic type and concentration alter the initial doping state of graphene, they have no measurable influence over the rate of the doping of graphene with applied voltage in the high ionic strength limit of 3-15 M. Crucially, unlike for conventional dielectric gates, a large proportion of the applied voltage contributes to the Fermi level shift of graphene in concentrated electrolytes. We provide a practical overview of the doping efficiency for different gating systems.
Permanent Link: https://hdl.handle.net/11104/0343343