Controlled synthesis, growth mechanism, and properties of monodisperse CdS colloidal spheres

Highly monodisperse submicrometer US colloidal spheres (CSCS) with a controllable and tunable size (between 80 and 500 nm) have been synthesized through a facile solvothermal technique. Owing to the controllability of the reaction process, the growth mechanism of the colloidal spheres has been elucidated in detail. The whole growth process can be summarized as homogenous and slow nucleation of nanocrystals, formation of"cores" through ment Of nanocr face-induced or colloidal spheres tion and random 3D-oriented attachment nanaocrystals, and further surowth to monodisperse through in situ formation attachment of addi-tional nanocrystals. It has been demonstrated that the obtained CSCS colloidal particles are able to be assembled into films which show characteristic stop band gaps of photonic crystals. By using the CSCS as a template, A92S, Bi2S3, Cu2S, HgS, and Sb2S3 colloidal spheres, which are difficult to obtain directly, have also been prepared successfully through ion exchange.