• 文献标题:   Electrostatic Gating of Monolayer Graphene by Concentrated Aqueous Electrolytes
  • 文献类型:   Article
  • 作  者:   ABBAS G, SONIA FJ, JINDRA M, CERVENKA J, KALBAC M, FRANK O, VELICKY M
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICAL CHEMISTRY LETTERS
  • ISSN:   1948-7185
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1021/acs.jpclett.3c00814 EA MAY 2023
  • 出版年:   2023

▎ 摘  要

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.