Electro-Ionic Control of Surface Plasmons in Graphene-Layered Heterostructures

Abstract

Precise control of light is indispensable to modern optical communication devices especially as the size of such devices approaches the subwavelength scale. Plasmonic devices are suitable for the development of these optical devices due to the extreme field confinement and its ability to be controlled by tuning the carrier density at the metal/dielectric interface. Here, an electro-ionic controlled plasmonic device consisting of Au/graphene/ion-gel is demonstrated as an optical switch, where an external electric field modulates the real part of the electrical conductivity. The graphene layer enhances charge penetration and charge separation at the Au/graphene interface resulting in an increased photoinduced voltage. The ion-gel immobilized on the Au/graphene further enables the electrical tunability of plasmons which modulates the intensity of the reflected laser light. This work paves the way for developing novel plasmonic electro-optic switches for potential applications such as integrated optical devices.

Nanoimpedimetry with plasmonic nanoparticles

“…This nonlinearity is due to the effect of the double-layer capacitor of the interface that varies with the applied voltage as reported previously in ref. 11,31 Since the underlying sensing concept is governed by charging the interfacial nanoscale double-layer capacitor, the charge density at the metal-electrolyte interface (∆σ) can be found from knowledge of the voltage applied (∆V) and the interface capacitance (C) from: shows that applying a negative potential to the electrode results in increased accumulation of sodium that decays to the bulk concentration within the Debye layer, and vice versa for the chloride ions. It is worthy of mention that there is an important advantage when employing the electrostatics-electrodiffusion approach in comparison to solving SGC equations.…”

Nanoimpedimetry with plasmonic nanoparticles

“…This nonlinearity is due to the effect of the double-layer capacitor of the interface that varies with the applied voltage as reported previously in ref. 11,31 Since the underlying sensing concept is governed by charging the interfacial nanoscale double-layer capacitor, the charge density at the metal-electrolyte interface (∆σ) can be found from knowledge of the voltage applied (∆V) and the interface capacitance (C) from: shows that applying a negative potential to the electrode results in increased accumulation of sodium that decays to the bulk concentration within the Debye layer, and vice versa for the chloride ions. It is worthy of mention that there is an important advantage when employing the electrostatics-electrodiffusion approach in comparison to solving SGC equations.…”

Engineering Surface Plasmons in Metal/Nonmetal Structures for Highly Desirable Plasmonic Photodetectors

“…Furthermore, doped semiconductors can also generate surface plasmons within a broad range from the visible region to the mid-infrared (MIR) region . Graphene plasmons can be actively tuned by a gate voltage, − showing a plasmon frequency at the MIR and terahertz (THz) regions. These excellent properties make plasmonic photodetectors promising candidates for developing superintegrated circuits.…”