Greener synthesis and optimization of highly photoluminescence Mn²⁺-doped ZnS quantum dots

In this study, ZnS quantum dots (QDs) and strong yellow light-emitting Mn²⁺-doped ZnS QDs are synthesized using 3-mercaptopropionic acid (MPA) as a stabilizer by a promising preparation method in an aqueous solution. Further, the photoluminescence (PL) properties of the ZnS QDs under different conditions are thoroughly investigated. Under optimized experimental conditions, the structure of the obtained ZnS:Mn²⁺ nanocrystals is consistent with that of the cubic zinc blende crystal, with a nearly spherical shape of approximately 5 nm average diameter. The emission peak varies from 450 nm to 575 nm with Mn²⁺ doping, which suggests effective energy transfer from the host ZnS QDs to the dopant Mn²⁺ ions. The results indicate that ZnS:Mn²⁺ QDs can potentially be used in light-emitting diodes (LEDs). - Highlights: • 3-mercaptopropionic acid was used as stabilizer in the synthesis of ZnS:Mn²⁺ QDs. • The average diameter of ZnS:Mn²⁺ nanocrystals is about 5 nm. • Effective energy transfer from the host ZnS QDs to dopant Mn²⁺ ions occurred