Preparation and photoluminescence properties of Mn~(2+)-doped water-soluble ZnS quantum dots

Using 3-mercaptopropionic acid(MPA)as surface coated agent,Mn2+-doped water-soluble quantum dots of ZnS were synthesized by co-precipitation method.The effects of Mn2+dopant and doping amount on microstructure,morphology and photoluminescence properties of the as-products were researched by X-ray diffraction,transmission electron microscopy,UV-visible absorption spectrometer,and fluorescence spectrophotometer.The results show that the products were irregular spherical cubic zinc blender ZnS with sizes around9.7nm.Photoluminescence spectra analysis show that Mn2+-doped ZnS quantum dots appeared two emission peaks located at 587and 637nm which indicated ZnS surface emitting and Mn2+∶4 T1-6 A1level characteristic luminescence respectively.The synthesis mechanism of Mn2+-doped ZnS quantum dots was studied by infrared spectroscopy.