Voltage-induced Modulation of Optical Properties in Multilayer Graphene with Ionic Liquid Intercalation

We report a significant modulation of the optical properties of multilayer graphene using a simple device consisting of a multi-layer graphene/ porous membrane/ gold film stack. Applying a voltage of 3-4V drives the intercalation of anion [TFSI]^- resulting in the reversible modulation of the properties of this optically dense material. The intercalation of [TFSI]^- ions and the associated change in free carrier density leads to abrupt changes in the optical properties of this material. Raman spectra and IR imaging collected during the intercalation/deintercalation half-cycles show the emergence and disappearance of the intercalated G band mode around 1610 cm^-1. The intercalation/deintercalation is also monitored with thermal imaging via voltage-induced changes in the carrier density, complex dielectric function ε(ω), and thermal emissivity of the device.



1. “Dynamic Study of Intercalation/Deintercalation of Ionic Liquids in Multilayer Graphene Using an Alternating Current Raman Spectroscopy Technique” Zhi Cai, Haley Weinstein, Indu Aravind, Ruoxi Li, Sizhe Weng, Boxin Zhang, Jonathan L. Habif, and Stephen B. Cronin. The Journal of Physical Chemistry Letters 0, 14 DOI: 10.1021/acs.jpclett.3c01686. https://pubs.acs.org/doi/epdf/10.1021/acs.jpclett.3c01686



2. “Harvesting Planck radiation for free-space optical communications in the long-wave infrared band”[

Haley A. Weinstein, Zhi Cai, Stephen B. Cronin, and Jonathan L. Habif, Opt. Lett. 47, 6225-6228 (2022). https://opg.optica.org/ol/fulltext.cfm?uri=ol-47-23-6225&id=522051



3. “Gate-tunable modulation of the optical properties of multilayer graphene by the reversible intercalation of ionic liquid anions”

Zhi Cai, Indu Aravind, Haley Weinstein, Ruoxi Li, Jiangbin Wu, Han Wang, Jonathan Habif, and Stephen Cronin. Journal of Applied Physics. Volume 132, 095102 (2022). https://doi.org/10.1063/5.0093651