Effect of Mn 2+ Doping on Structural, Morphological and Optical Properties of ZnS Nanoparticles by Chemical Co-Precipitation Method

Zinc Sulphide (ZnS) nanoparticles doped with different concentrations of Mn 2+ (0%, 2%, 4%, 6%, 8%, 10%) have been synthesized by chemical co-precipitation method using polyvinyl alcohol (PVA) as a capping agent to control the particle growth. The structural characterizations of as synthesized nanoparticles are determined by X-ray diffraction (XRD) which showed cubic zinc blende structures with average crystallite sizes of the range 2.3 nm - 2.1 nm. There is no phase transformation due to Mn 2+ doping and this characteristic has been observed in all the synthesized powder. Scanning electron microscopy (SEM) and energy dispersive X- ray (EDX) analysis show the morphology and elemental analysis of as synthesized nanoparticles.TEM images confirms the spherical shape of the nanoparticles. HRTEM and SAED images show the crystalline nature and confirm the cubic nature of ZnS nanoparticles. Absorption study has been carried out by using UV-Vis spectrophotometer to determine the band gap of ZnS:Mn nanoparticles and they showed a blue shift with respect to the bulk. The effect of Mn 2+ substitution on the photoluminescence properties of doped samples is also studied and doped ZnS:Mn showed enhanced luminescence property compared with that of the undoped ZnS nanoparticles. Radius of the synthesized nanoparticles has been evaluated from the absorption spectrum by using the Effective Mass Approximation (EMA) formula. Fourier Transform Infrared Spectra (FTIR) is recorded in an FTIR spectrometer to verify the presence and effect of capping agent.