Synthesis and spectroscopy of nanoparticles

Abstract

A lattice period of crystalline inorganic solids lies typically in the range 0.5-1.0 nm. The processes involved in the electron subsystem of solids determine their optical and other characteristics. The quantum dimensional effects are caused, when even one of the geometrical sizes of solids becomes commensurable with the de Broglie wavelength of an electron, a hole or an exciton. In this case the spatial confinement of these waves in solids takes place. For instance, in CdSe crystal at room temperature, de Broglie wavelengths are equal 5.3, 4.35 and 1.25 nm for an exciton, an electron and a hole accordingly. As we see, the lengths of de Broglie waves for particles in crystals lay in a nanometers range. Therefore, the objects, for which quantum dimensional effects are typical, should have sizes of the nanometers order. In this connection, about such objects they usually speak as about nanostructures or nanomaterials. The electron confinement results in size-dependent absorption spectra, emission spectra and transition probabilities in solids. In recent years, in view of the prospects of practical applications, increasing attention is paid to the development of methods for synthesizing nanostructures and studying their physicochemical properties. © 2013 Springer Science+Business Media Dordrecht.