Synthesis and Characterization of Chromium Doped Zinc Sulfide Nanoparticles

Nanoparticles of pure and Zn_1-xCr_xS with concentrations (x = 0.00, 0.02, 0.08 and 0.10) were prepared successfully by co-precipitation technique. Crystallographic study was intervened by X-ray diffraction spectroscopy. There were no extra peaks observed in the XRD pattern. From XRD peaks it is confirmed that the samples prepared were highly pure and cubic in structure. The particle size calculated from XRD data was around 3 nm. It confirms that the quantum dots were formed. Surface morphology and crystal size were verified by scanning electron microscopic (SEM) and transmission electron microscopic (TEM) studies. The aggregation of the nanoparticles was observed, which is due to the quantum dots. Chemical species present in the prepared samples were identified by FTIR study. Using UV-Vis spectrometer (Ultra Violet Visible), absorption spectra were obtained for x = 0.00, 0.02, 0.08 and 0.1. It is confirmed from UV-Vis that the detected absorption peaks were shifted towards higher wavelengths. The energy band gap values were estimated using UV-Vis spectrometer and found lying in the range of 3.33 eV - 3.02 eV. The energy band gap decreases with increasing Cr concentrations i.e. the red shift was observed.