Nearly monodisperse 17-20 nm ZnS nanoparticles capped with the Poly vinyl pyrrolidone (PVP) and Thioglycolic acid (TGA) were prepared in aqueous solution. During hydrothermal coarsening of ZnS nanoparticles, the evolution of optical properties and growth kinetics were investigated. As the particle size increased, the absorbance spectrum continued a size dependent shift to long wavelength. A significant enhancement in photoluminescence was obtained during the growth, indicating the decrease of defects and the increase of ZnS crystallinity. Transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high resolution transmission electron microscopy (HRTEM) analytic techniques were applied to characterize the average particle size and size distributon, composition and morphology of the product. The thermal stability of the sample is analyzed with thermogravimetricdifferential thermal analysis (TG-DTA). The effect of reactant concentration, reaction temperatures and reaction times on crystal structures and shapes of ZnS have been investigated.
