One-pot synthesis of highly luminescent CdTe/CdS core/shell nanocrystals in aqueous phase.

Surface passivation of nanocrystals with suitable organic or inorganic materials is key to improving the photoluminescence (PL) efficiency and stability of nanocrystals. Although the hot-injection organometallic approach is a powerful tool to achieve different kinds of core/shell structures, direct synthesis of such structures in aqueous phase, which bears many advantages such as biocompatibility, water-solubility, environment-friendliness, and cheapness, is less often reported. Herein we present a facile approach for the one-pot preparation of a water-soluble core/shell structure with CdTe cores packed in a CdS shell in aqueous phase. In comparison with plain CdTe nanocrystals, the PL efficiency of the obtained CdTe/CdS core/shell structure can approach about 75%. The stability of the core/shell structure to UV irradiation and oxidation is also improved.