ZnS and ZnS/CdS core-shell Nano particles: Synthesis, properties and Perspectives

Abstract

ABSTRACT From ancient times, nanoparticles with the diameter in the scope of 1-20nm become a foremost interdisciplinary area of research. Now a day's in technology, II-VI Semiconductors perform a key role. By chemical precipitation technique, ZnS and ZnS/CdS core-shell nanoparticles are arranged with suitable thickness. Core particles are prepared first and then the amalgamation process of shells is performed by selecting ethanol as solvent at ordinary temperature. The structural and chemical characterizations were performed by utilizing X-ray diffraction (XRD), Scanning electron microscopy (SEM-EDAX) with energy dispersive, transmission electron microscopy (TEM), Fourier Transforms Infrared Spectroscopy (FTIR), Optical Absorption Spectroscopy (UV visible), Photoluminescence (PL) and Vibrating Sample Magnetometer (VSM). Shell growth is identified from XRD, SEM with EDAX, TEM. Using UV-Visible Spectroscopy optical properties were characterized. Powder XRD pattern exhibits peaks correspond to cubic phase of ZnS and ZnS/CdS core-shell nano particles and estimated the average particle size from Debye's Scherer's method is approximately equals to the individual methods of Williamson-Hall methods and are in the order of nm and also hold good with theoretical values from UV-Vis. It is practical that the inclusion perimeter was sort at 200–260 nm and corresponding energy gaps is 1.22eV and 3.02eV respectively, which is red-shifted compared to bulk ZnS (345nm) and the excitonic wavelength at 310 nm (3.99 eV). The cubic formation of bulk ZnS show the apparent red-shift, then the energy gap of the major portion of ZnS is 3.68 eV (345 nm). By stiffness effects, the radiant intensity gap is acquired with Brus equality. Luminescence is acquired to the recombination during the sulfur vacancy associated electron capture donor under the CB and ZnS correlated hole trap acceptor beyond the VB as report prior. The calculated coordinates of prepared sample and the theoretical values of chromaticity epicentre is (Xe, Ye) are at Xe = 0.3320 andYe = 0.1858. The M-H loop of the as-synthesized core-shell nanoparticles showed intrinsic ferromagnetic behaviour.