ELECTRONICS OF COLLOIDAL NANOMETER PARTICLES

Small colloidal particles*) and clusters*) of semiconductors and metals exhibit unusual properties and may be considered as a new physico-chemical dimension between the molecules and the bulk materials. The surface to volume ratio is extremely large; small-particle research therefore constitutes a combination of solid state and surface science. The electronic properties of the particles (light absorption, colour, fluorescence, catalytic and photocatalytic activity, electrochemistry etc.) depend on particle size. Chemical surface modification affects these properties and allows one to prepare new nano-structures in solution, in layers, and in the crystalline state. No attempt is made in the present article to review the whole field, but to describe this new branch of colloid chemistry by focussing on a few selected topics.