Synthesis and luminescence properties of water-dispersible ZnSe nanocrystals

Water-dispersible ZnSe nanocrystals were synthesized by a green and simple route. Growth of the nanocrystals was performed under water-bath temperature, using selenium powder and zinc acetate as precursors, upon addition of mercaptoacetic acid as a stabilizer. Products were characterized by X-ray photoelectron spectra (XPS), X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), absorption and fluorescence spectra. Photoluminescence (PL) properties of ZnSe nanocrystals in evolution are discussed. PL is the contribution of both excitonic and defect emission. The excitonic emission peak can be tuned by changing the refluxing time and pH value. Mercaptoacetic acid is available in controlling the ratio of excitonic emission to defect emission. All desired properties of nanocrystals prepared here imply the possibility of high quality ZnSe nanocrystals developed under a mild condition.