ERC Starting grant “SCATTER”

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

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 optical properties thanks to its high refractive index. Currently, it is not possible to control the physical characteristics of silicon nano-objects. Hence a major current challenge is to create synthetic routes to silicon particles having controlled shape and dimensions.

The aim of Scatter is to revolutionize silicon synthesis, producing nano-objects that are currently inaccessible, and achieving silicon-based materials with fantastic optical properties.

Four strategies, guided by optical models, will be pursued to modulate light propagation by silicon objects: controlled porosity in spheres, synthesis of anisotropic objects, fabrication of clusters of 13 kissing spheres, and the assembly of spheres of differing diameter. The silicon nano-objects will be self-assembled into diverse materials and their optical properties assessed using advanced characterization techniques.

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.