Plasmon effects in a graphene nanostructure

Abstract

Plasmons are collective excitations of electrons in solids. The ability to change their properties by an electric field in low-dimensional materials and structures, such as graphene, which makes them promising for the use in a variety of optoelectronic devices, such as sensors, detectors, radiation sources, etc. The interaction between plasmonic oscillations in graphene leads to a strong shift in the absorption spectrum of light in the far- infrared range. Thus, it was experimentally found that the interaction of plasmons in graphene on a dielectric substrate leads to a strong redshift of the absorption spectrum in comparison to the plasmon spectrum in isolated graphene. The absorption spectra of graphene due to the interaction of plasmons cover the far IR range (photon energies from 10 meV to 200 meV), which, in turn, coincides with the vibrational spectra of most biological molecules. This provides the opportunities for the design and manufacture of graphene-based biosensors. In this regard, it’s important to simulate plasmon spectra for their use in optoelectronics and biosensorics. Even though plasmon spectra in isolated graphene have already been well studied, for the effective operation of real optoelectronic devices, it is relevant to study plasmon effects in graphene on various substrates, as well as in the composition of nanostructures.