In this research, we report the synthesis of ZnS nanocrystals with a size range of 1-10 nm in diameter with varying manganese (Mn) concentrations. Various samples of Zn1-x MnxS, with x = 0.0001, 0.007, 0.02, 0.03, 0.055, 0.09 and 0.13, have been prepared from a quaternary W/O microemulsion system. It is observed that by adding Mn to ZnS nanoparticles, the emission intensity changed and by using 5.5% magnesium for total Zn+2, a maximum emission were achieved. A photoluminescence (PL) study was carried out by band-to-band excitation (lambda(ex) = 293 nm and 321 nm) upon ZnS : Mn, which results in two emission peaks corresponding to surface states and Mn+2 emission. Also, we observe orange emission from Mn2+ ions in the doped ZnS nanocrystals, apart from the blue emission characteristic of the ZnS defect states. The relative intensity of the orange emission compared with the blue varies with the manganese concentration in a nonmonotonic way. For analyses of the quality and quantity of this product, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), inductive coupled plasma (ICP), and spectrograph techniques were used.

Keywords: Nanocrystal; Zinc sulfide; Manganese; Microemulsion