PROCEEDINGS ARTICLE | April 29, 2010
Proc. SPIE. 7711, Metamaterials V
KEYWORDS: Metamaterials, Nanoparticles, Particles, Crystals, Chemistry, Transmission electron microscopy, Solids, Superlattices, Nanolithography, Lead
Colloidal chemistry strategies are mature techniques, now able to provide highly processable nanocrystals (NCs)
soluble in a variety solvents, possessing an adjustable organic interface, for obtaining assembled structures. Indeed the
NCs can be organized in superstructures by means of spontaneous assembly, in order to bridge the gap between nanoand
mesoscale. In self assembly procedures, the organization is driven by the intrinsic information coded into the
building blocks, namely size, shape and surface chemistry. The distinct properties of the nanometer-scale "buildingblocks"
can be thus harnessed in assemblies presenting new collective properties, which can be further engineered by
controlling inter-particle spacing and by material processing. Self assembly approaches of colloidal NCs can effectively
exploit the solvent evaporation to form closely packed superlattices, since collective interaction energy can overcome the
entropy loss due to ordering. The control on the NC characteristics is then crucial for the achievement of well controlled
superstructures, with long range order and stability, being the individual NCs considered as "artificial atoms" in such
superlattice structures. In this perspective the emerging concept of NC based metamaterials, that is a material with
properties occurring from the controlled positioning of the different interacting NCs in an assembly, arise.
