Synthesis of InP/ZnS Nanocrystals and Phase Transfer by Hydrolysis of Ester

Abstract

The synthesis of highly luminescent non-toxic nanocrystals (NCs) and the subsequent phase transfer to aqueous solution by hydrolysis of the crystal-bound ester are presented. Therefore, the synthesis of the spherical semiconductor system InP/ZnS was modified by changing the sulfur precursor in the synthesis from 1-dodecanethiol to dodecyl 3-mercaptopropionate (D3MP). By employing D3MP both as sulfur precursor for the ZnS shell growth and as stabilizing ligand, the phase transfer from organic to aqueous solution can be performed easily. Instead of the usually employed ligand exchange with mercaptopropionic acid, the NCs are only shaken with a sodium borate buffer in order to obtain aqueous soluble NCs by hydrolysis of the ester. In future work, the NCs must be protected against aggregation and the long term stability has to be increased. The optical properties of the samples are investigated by UV/Vis and photoluminescence spectroscopy, and the morphology of the nanoparticles (NPs) before and after phase transfer is determined by transmission electron microscopy.