Structural and Optical Properties of Ca^{2 +} Doped ZnS Nanoparticles

In this work, we synthesized undoped ZnS and Ca²⁺ doped ZnS nanoparticles by chemical precipitation method. The structural and optical properties of the prepared nanoparticles have been analyzed using X-ray diffraction, Field emission scanning electron microscope, UV-vis-NIR spectrophotometer and Fluorescence spectroscopy. XRD patterns showed that the ZnS and ZnS:Ca nanoparticles have zinc blende structure with the crystallite sizes of about 7–8 nm range. The value of optical band gap has been found to be in the range 4.41–4.06 eV. Room temperature photoluminescence (PL) spectrum of the undoped sample exhibits emission in the blue region with multiple peaks under UV excitation. Ca²⁺ doped ZnS samples shows enhanced visible light emissions under the same UV excitation wavelength of 310 nm.