Highly photoluminescent water-soluble ZnSe/ZnS/ZnS quantum dots via successive shell growth approach

ZnSe quantum dots (QDs) are considered to be the most promising alternative to Cd-based QD owing to their distinct optical properties and low toxicity. In this paper, we develop an efficient and simple method to prepare a water-soluble ZnSe/ZnS/ZnS core/shell/shell heterostructure QDs for the first time. In this strategy, the ZnSe core is first coated with ZnS, then the second ZnS shell is loaded on ZnSe/ZnS by growing successively. The prepared ZnSe/ZnS/ZnS QDs with the merit of environmentally friendly show a uniformly dispersed spherical structure, and the photoluminescence (PL) intensity of ZnSe/ZnS/ZnS is 3.1 and 1.3 times as large as that of ZnSe and ZnSe/ZnS. In addition, the prepared QDs have good dispersion in water and remain the stability for at least 30 days without sedimentation. The excellent performance of ZnSe/ZnS/ZnS is ascribed to the mercaptopropionic (MPA) is used as an effective stabilizer for the QDs and the second ZnS shell that effectively inhibits the exciton leakage.