Original Articles
K. Vijai Anand
Abstract
Transition metals (Cu, Co and Mn) doped ZnS nanoparticles have been prepared by surfactant-assisted controlled synthesis route using Hexamethylenetetramine (HMTA) as surfactant in aqueous solution. X-ray diffraction (XRD) studies show that the average grain size of the prepared ZnS nanoparticles is about 2 nm with cubic zinc blende structure and doping of transition metals has no effect on the structure. The ultraviolet-visible (UV-Vis) absorption spectra of the synthesized nanoparticles exhibit a blue shift in the absorption onset compared to the bulk ZnS, which is due to the quantum confinement of charge carriers in the nanoparticles. From the photoluminescence (PL) spectra, except for the HMTA stabilized ZnS nanoparticles doped with copper ((Cu2+) ion, the relative emission intensity of the ZnS samples doped with cobalt (Co2+) and manganese (Mn2+) ions are higher than that of pure ZnS. The PL spectra exhibit two emission peaks at around 420 and 442 nm attributed to deep-trap emission of ZnS and presence of various surface states.