Preparation and Luminescent Properties of CdSe and Core-Shell CdSe/CdS Quantum Dots in Aqueous Solution

CdSe and core/shell CdSe/CdS quantum dots (QDs) were prepared in aqueous solution by using mercapto-acetate acid as stabilizer.Their luminescence characterization was studied by UV-Vis absorption and emission spectra. The nanocrystals were characterized by X-ray powder diffraction (XRD),transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS), which were used to characterized their structure, shape and composition. The results indicated that the quantum dots synthesized with this method possessed better dispersibility, as well as the intensity of luminescence of the quantum dots modified the surface was enhanced greatly and the red shift was shown in the emission and absorption spectra. The position of absorption peak was different with the different quantum dots' sizes.