Synthesis of II-VI semiconductor nanoparticles by mechanochemical processing

The synthesis of II-VI semiconductor nanoparticles by mechanochemical reaction has been reviewed. Solid-state displacement reactions between ZnCl/sub 2/ or CdCl/sub 2/ and alkali or alkaline earth chalcogenides were induced during mechanical milling in a steady-state manner, leading to the formation of II-VI semiconductor nanoparticles in a chloride salt matrix. A simple washing process employed to remove the chloride byproduct resulted in separated particles of less than 10 nm. The resulting particles and crystallite sizes were controlled by changing the milling conditions, starting materials, annealing temperature and the presence of a diluent. With decreasing particle size, the band-gap energy and plasmon peak energy of CdS increased due to the quantum confinement effect.