Thiol-stabilized CdSe and CdTe nanocrystals in the size quantization regime: Synthesis, optical and structural properties

We report on the recently developed method for the synthesis, optical and s tructural properties of CdSe and CdTe nanocrystals. They. were formed in aq ueous solutions at moderate temperatures by a wet chemical route in the pre sence of thiol molecules as effective stabilizing agents. The size-selectiv e precipitation technique was applied for the post-preparative nanoparticle fractionation into a series of CdSe and CdTe nanocrystals with extremely n arrow size distributions exhibiting mean cluster sizes in the range of 2 to 4 mn. The nature of stabilizing agent (mercaptoalcohols and mercaptoacids) had an important influence on the particle size and determines largely the photoluminescence properties. The nanocrystals were characterized by means of UV-vis absorption and photoluminescence spectroscopy, X-ray diffraction , and high resolution transmission electron microscopy (HRTEM).