Graphene induced tunability of the surface plasmon resonance

TL;DR

This paper demonstrates that the surface plasmon resonance wavelength can be tuned by adjusting the spacer layer thickness between graphene and nanoparticles, affecting electromagnetic coupling.

Contribution

It introduces a method to control plasmon resonance via spacer thickness in graphene-nanoparticle systems, showing tunability not observed without graphene.

Findings

Resonance wavelength shifts from 583 to 566 nm with spacer thickness increase

Shift caused by electromagnetic coupling change between plasmons and graphene

No shift observed without graphene layer

Abstract

Tunability of the surface plasmon resonance wavelength is demonstrated by varying the thickness of Al2O3 spacer layer inserted between the graphene and nanoparticles. By varying the spacer layer thickness from 0.3 to 1.8 nm, the resonance wavelength is shifted from 583 to 566 nm. The shift is due to a change in the electromagnetic field coupling strength between the localized surface plasmons excited in the gold nanoparticles and a single layer graphene film. In contrast, when the graphene film is absent from the system, no noticeable shift in the resonance wavelength is observed upon varying the spacer thickness.