Synthesis of High-Performance Aqueous CdSe Quantum Dots Based on Combination of Se Source as Vapor-Phase and Hydrothermal Method
High performance aqueous CdSe quantum dots (QDs) have been prepared by combination of Se source as vapor-phase and hydrothermal method. The main advantages of this approach included: one is to utilize H2Se vapor as a higher pure selenium source to make the prepared QDs have little other impurities, another is to obtain the QDs with characteristics of more rapid growth in the hydrothermal reaction. The as-prepared products have been characterized by ultraviolet-visible absorption spectra, photoluminescence spectroscopy (PL), X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive spectroscopy (EDS) analysis etc. The results show the as-synthesized water-soluble CdSe nanoparticles possess higher purity and quantum yields (QY), favorable narrow photoluminescence band with full width of half-maximum (FWHM) down to 40 nm, better photo-stability, and less synthetic time as compared with aqueous CdSe QDs obtained by other methods.