Bottom-up fabrication of nanostructured silicon-based materials with unprecedented optical properties

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Controlling the crystallinity, form, dimensions and porosity of nano-objects produces remarkable and unique physical properties. Silica (SiO2) is among the most studied nanomaterial, where its morphology can be controlled precisely. The reduced form, silicon (Si), has exceptional properties of interest to batteries, semi-conductors, electronics and optics. If it were possible to control the physical characteristics of silicon nano-objects, a host of applications would become possible in new domains of optics. Hence a major current challenge is the creation of synthetic routes to Mie-resonant silicon particles and their assembly into metamaterials. The aim of Scatter is to revolutionize silicon synthesis, producing nano-objects that are currently inaccessible, and achieving silicon-based materials with fantastic light manipulation. To obtain an efficient metamaterial with a broad response, the intensity and frequency of dipole resonances should overlap. Creating materials with electric and magnetic resonances at the same frequency requires the development of novel synthesis techniques for silicon nano-objects. Four strategies, guided by optical models, will be pursued to coalesce the electric and magnetic resonance in silicon objects: controlled porosity in spheres, synthesis of anisotropic objects, fabrication of clusters of 13 kissing spheres, and the assembly of spheres with two differing diameters. The silicon nano-objects will be self-assembled into diverse materials and their optical properties assessed using advanced optical measurements. Properties that may result from the realization of silicon-based materials include zero and negative refractive index, total light transmission or total absorption, and low-loss light confinement below the diffraction limit. Mastering the fabrication of silicon building blocks will enable many new systems, including real examples of metamaterials in the form of planar lenses, monoliths, fibers, inks, films and surfaces.