Spectroscopic studies on Fe3+ doped CdS nanopowders prepared by simple coprecipitation method

Abstract

Nanopowders of PVP capped undoped, and Fe doped cadmium sulfide (CdS:Fe) were prepared by a simple co-precipitation method at room temperature, mixing the stoichiometric amount of reactants in a Milli Q water solvent. Spectral characteristics of as prepared nanopowders were investigated by using XRD, FTIR, Raman, UV-Vis absorption, FE-SEM-EDAX, Photoluminescence and ESR at room temperature. Extremely broad reflections of XRD peaks of as prepared powders are in nanometer size and cubic structure. Doping with Fe in CdS does not lead to any structural phase transformation but introduces a slight decrease in the lattice constants. Raman spectrum of pure and Fe doped CdS nanopowders has two characteristic LO phonon peaks. Raman spectrum of Fe doped CdS nanopowders shifts slightly towards higher energy side compared to their pure CdS nanopowders. Electron phonon confinement factor (S) varies in between 0.2 and 0.4. Photoluminescence emission spectrum shows a peak at 404nm which is attributed to localized band edge emission. At lower doping of Fe (5%, 10%) the emission intensity increases and for higher doping (20%) the emission intensity gets quenched. The electron spin resonance spectra of Fe doped CdS exhibit two distinct signals at g∼4.3 and g∼2 characteristic of Fe3+ ions.