Super-spherical core-shell nanoparticles: Nanostructured materials enabling applications in the visible regime

In this contribution, we present a non-conventional core-shell nanoparticle, named supersphere, for implementing optical devices whose performances cannot be easily achieved with conventional nanoparticles. Superspheres are solids with intermediate shape between a sphere and a cube, whose external boundaries are described by Lamè surface equation. Thanks to its particular shape, a core-shell supersphere resonates at a lower resonant frequency with respect to a conventional core-shell spherical nanoparticle with same electrical dimensions. Such a characteristic allows relaxing the fabrication constrains, i.e. extremely thin shells, typically required for making the conventional spherical core-shell nanoparticles to operate in the lowest region of the visible spectrum. Here, after having discussed the geometry and electrical response of a core-shell supersphere, we report some preliminary results on their successful employment in the implementation of three optical devices: a trasparent screen, a biosensor and a mantle cloak.