Plasmonic Core–Shell Silicon Carbide–Graphene\nNanoparticles

Abstract

We demonstrate the\nsynthesis of silicon carbide nanoparticles exhibiting\nmonolayer to few-layer graphene coatings and characterize their optical\nresponse to confirm their plasmonic behavior. A multistep, low-temperature\nplasma process is used to nucleate silicon particles, carbonize them\nin-flight to give small silicon carbide nanocrystals, and coat them\nin-flight with a graphene shell. These particles show surface plasmon\nresonance in the infrared region. Tuning of the plasma parameters\nallows control over the nanoparticle size and consequently over the\nabsorption peak position. A simplified equivalent dielectric permittivity\nmodel shows excellent agreement with the experimental data. In addition,\noptical characterization at high temperatures confirms the stability\nof their optical properties, making this material attractive for a\nbroad range of applications.