Nanoparticles of ZnS and Mn-doped ZnS capped with TOPO (tri-n-octylphosphine oxide) and close to mono-dispersed have been prepared by a single source route using bis(diethyldithiocarbamato) zinc(II) as a precursor. The nanoparticles obtained show quantum size effects in their optical spectra and ZnS nanoparticles exhibit near band-edge luminescence. Clear difference in photoluminescence results between ZnS and ZnS:Mn samples. Changes in Mn-doping levels are shown by the changes in photoluminescence intensity. The most intense photoluminescence was observed for 1% and the least intense for 5% doping level. ESR spectra and ICP results confirm the presence of Mn in ZnS quantum dots and also correspond to the amount of Mn in each ZnS:Mn sample.
The Selected Area Electron Diffraction (SAED), X-ray diffraction (XRD) pattern and Transmission Electron Microscopy (TEM) show the material to be of the hexagonal phase. The crystallinity of the material was also evident from High Resolution Transmission Electron Microscopy (HRTEM) which gave well-defined images of nanosize particles with clear lattice fringes.