Abstract

The discovery of size-dependent physical properties of solids at the nanometer scale has recently triggered an intense research on the fabrication of nanostructures by a variety of approaches. Among the various nanostructures that are studied, inorganic nanocrystals are clusters composed of a number of atoms that can range from a few tens up to several tens of thousands and can be thought of as solids whose sizes along the three dimensions have been reduced down to a few nanometers or less. The properties of nanocrystals and their mutual interactions can be controlled finely by tailoring their size, composition, and surface functionalization. Nanocrystals have been investigated in a variety of applications in many fields, among them biology and biomedicine, optics and photonics, catalysis, sensing, and high-density memory storage. Also, many strategies for assembly of nanocrystals have been proposed, with the final aims to fabricate new materials in which the single-particle properties are amplified and/or in which chemical and physical interactions among nanocrystals can give rise to novel phenomena, or to develop nanoscale devices whose behavior is dictated by the properties of individual nanocrystals. In this chapter, we will first highlight briefly the most relevant physical properties of nanocrystals, then we will describe the most popular methods for the synthesis of nanocrystals in the liquid phase, and finally we will highlight the various strategies developed so far for their assembly.