Preparation and Optical Properties of CdS u/CdS Nanocrystals

CdS cores were successfully synthesized in noncoordinating solvents. The composite structure of core/shell CdS u/CdS nanocrystals was obtained through the modification of as-prepared Cu2+ ions doped CdS cores using successive ion layer adsorption and reaction (SILAR) technique. The crystal structures, shapes and optical properties of as-synthesized nanocrystals were characterized by X-ray diffraction, transmission electron microscope, UV-Vis absorption and photoluminescence spectroscope. The results show that the crystal structure of asa2prepared CdS u/CdS nanocrystal is zinc blende. Compared with pure CdS nanocrystals, the Cu2+ dopant in CdS leads the surfacea2state related emission peak shifting to longer wavelength. The surfacea2state related emission of CdS u nanocrystal can also be adjusted consecutively from 570nm to 620nm by tuning the doping concentration of Cu2+ ions from 2% to 6%. The overcoating of CdS shell can increase the stability of surfacea2state related emission of CdS u nanocrystals.