Spectrally Selective Thermal Emission from Graphene Decorated with Metallic Nanoparticles

Abstract

We showed in past work that nanopatterned monolayer graphene (NPG) enables spectrally selective thermal emission in the mid-infrared (mid-IR) from 3 to 12 μm. In that case, the spectral selection is realized by means of the localized surface plasmon (LSP) resonances inside graphene. Here, we show that graphene decorated with metallic nanoparticles, such as Ag nanocubes or nanospheres, also realizes spectrally selective thermal emission but, in this case, by means of acoustic graphene plasmons (AGPs) localized between graphene and the Ag nanoparticle inside a dielectric material. Our finite-difference time-domain (FDTD) calculations show that the spectrally selective thermal radiation emission can be tuned by means of a gate voltage into two different wavelength regimes, namely, the atmospherically opaque regime between λ = 5 and 8 μm or the atmospherically transparent regime between λ = 8 and 12 μm. This allows for electrical switching between a radiative heat trapping mode for the former regime and a radiative cooling mode for the latter regime. Our theoretical results can be used to develop graphene-based thermal management systems for smart fabrics.