Synthesis and Characterization of ZnS Nanoparticles and Effects of Nanoparticle Size on Optical Properties

Abstract

This research presents a methodology for obtaining ZnS nanoparticles (NZnS). Doped with transition metal ions (MnCl₂) and use of rare earth EuCl₃ to improve their photoluminescence properties. Semiconductor nanoparticles were synthesized using the nanoprecipitation technique. The characterization of the ZnS nanoparticles was carried out using Dynamic Light Scattering (DLS), Powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), and Luminescence Spectroscopy (PL) technique. A cubic zinc crystalline structure could be observed considering the position and intensity of the characteristic peaks in the XRD pattern.  Also, taking the width at half height of the main peak and using the Debye-Scherrer equation, it is possible to obtain the average size of the nanoparticles, which for the samples analyzed was between 2-4 nm. SEM micrograph revealed a morphology with aggregated nanoparticles. High-Resolution Transmission Electron Microscopy showed the crystalline structure of the doped nanomaterial. PL characterization showed an increase in the luminescent intensity of doped NZnS compared to NZnS doped with the lowest concentration of the coating agent. These results confirm the effectiveness of the methodology for possible application in bioimaging diagnosis of PL in nanomedicine.