Synthesis of water-soluble ZnS : Mn2+ nanocrystals by using mercaptopropionic acid as stabilizer

The synthesis of water-soluble Mn doped ZnS nanocrystals with MPA (3-mercaptopropionic acid) as stabilizer is described. The coordination of Zn ion with MPA helps efficient doping of Mn and thus makes the process reproducible as compared to the common co-precipitation method. To obtain a high luminescent intensity, post-preparative treatments are performed. It is found that the surface states of the nanocrystals, such as the adsorption of oxygen and the coordination of MPA, play important roles in the enhancement of the luminescent intensity.