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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 Xray (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.

Nanocrystalline CdS thin films were deposited on glass substrate by chemical bath deposition method using Cadmium Sulphate and Thiourea as Cd+2and S-2ion sources for different molarities i.e. 0.1 M, 0.2 M and 0.3 M. The crystallite size and lattice parameters for each sample were determined from X-Ray diffraction data using Scherrers formula. The value of the crystallite size was found to be within the range 14.7 nm-11.4 nm. The optical characterization was done by UV-Visible and photoluminescence spectroscopy. The optical band gap of the films was determined from the transmittance spectra. It was observed that when the molarity increases, the average crystallite size decreases and the band gap energy of the prepared films increases. Photoluminescence studies showed a prominent peak at around 530 nm. The radius of the nanocrystalline films had been evaluated from the absorption spectrum by using effective mass approximation formula.