Facile synthesis and characterization of highly luminescent UV-blue-emitting ZnSe/ZnS quantum dots via a one-step hydrothermal method

The synthesis of water-soluble blue-emitting quantum dots (QDs) in aqueous solutions has attracted much attention recently, and here we report the synthesis of high-quality core/shell ZnSe/ZnS QDs through a one-step hydrothermal route with thiol ligand N-acetyl-l-cysteine (NAC) as the stabilizer. The impacts of various synthesis factors on the fluorescence properties of the prepared QDs have been systematically investigated. Under optimal conditions, the as-prepared QDs exhibit high photoluminescence quantum yield (∼39%), narrow full-width at half-maximum, and high photostability, due to the formation of a protective ZnS shell on the ZnSe core through the decomposition of NAC under high temperature. The core/shell structure of the ZnSe/ZnS QDs was verified by UV irradiation experiment, X-ray powder diffraction, and electron diffraction spectroscopy.