Vol. 1, Issue 13, Part J (2015)

Abstract
The present study is focused on the synthesis and characterization of optical and structural properties of nanocrystalline copper doped ZnS particles with mercaptoethanol as a capping agent synthesized by co-precipitation method. The prepared nanoparticles were characterized optically by UV –Visible spectra and structurally by X- ray diffraction (XRD), Energy dispersive X-ray analysis (EDAX). The optical band gap energy (Eg) for all Cu doped ZnS and ZnS nanoparticles were evaluated by using UV-Visible optical absorption spectral data. The band gap energy values for all the nanoparticles are in the range of 3.60 to 3.0 eV. The results show that the optical band gap energies decrease with the increase in molar concentration of doping agent which is attributed to size quantization effect due to electron-electron and electron-impurity scattering effect. The XRD pattern show cubic zinc blende structure with the lattice parameter of 5.31-5.34 Å. The average crystallite sizes are in the range of 1.64-2.24 nm and also the crystallite size depends linearly on the molar concentration of doping agent. The calculated values of average strain and dislocation density from the XRD data indicate that the nanoparticles formed were less strained. EDAX analysis confirms that all the nanoparticles contain corresponding elements in the samples.