| Abstract
| - The distribution of properties within ensembles of colloidally grown II−VI and III−V semiconductornanocrystals was studied. A drastic difference in the photoluminescence efficiencies of size-selected fractionswas observed for both organometallically prepared CdSe and InAs colloids and for CdTe nanocrystalssynthesized in aqueous medium, indicating a general character of the phenomenon observed. The differencein the photoluminescence efficiencies is attributed to different averaged surface disorder of the nanocrystalsoriginating from the Ostwald ripening growth mechanism when larger particles in the ensemble grow at theexpense of dissolving smaller particles. At any stage of growth, only a fraction of particles within the ensembleof growing colloidal nanocrystals has the most perfect surface and, thus, shows the most efficientphotoluminescence. This is explained by a theoretical model describing the evolution of an ensemble ofnanocrystals in a colloidal solution. In an ensemble of growing nanocrystals, the fraction of particles withthe highest photoluminescence corresponds to the particle size having nearly zero average growth rate.The small average growth rate leads to the lowest possible degree of surface disorder at any given reactionconditions.
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