Preparation of CdSe/ZnSe core-shell nanocrystal in one-step reaction

High-quality Zn-doped CdSe core-shell nanocrystals were successfully prepared by incorporating a stoichiometric amount of Zn precursor into the CdSe reaction system, in which the Se precursor was excess and an Se-rich surface was formed. By injecting different amounts of Zn precursor, the core-shell nanocrystals demonstrated by the emission spectra were formed. The obtained Zn-doped CdSe nanocrystals exhibit a photoluminescence efficiency from 30% to 85%, which is comparable to those for the reported CdSe-/ZnS, CdSe/CdS in the literature. In particular, a shell ZnSe layer with different thicknesses of ZnSe can be formed in this experiment by only changing the amount of Zn precursor added, which is simple and effective.