Abstract

Changiz. Vatankhah¹, Mohammad Saki², Shapur. Jafargholinejad³

DOI : http://dx.doi.org/10.13005/ojc/310234

Nano particles of zinc sulfide (ZnS) of face centered cubic (fcc) structures were synthesized using sulphur source of soium sulphide and mercaptoethanol respectively via Chemical Bath Deposition method. The synthesized quantum dots were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible spectrophotometry. The average crystallite size calculated from TEM and XRD pattern has been found to in the range 4.6 – 1.9 nm, the pariticles size decreases with the increase of the capping agent concentrations from 0. 001 to 0.7 Mol. The absorption coefficient in the range 325 - 250 nm decreases with increasing capping agent and the particles. ZnS nanoparticles were also derived from time independent Schrodinger equations for ZnS system and calculated the coefficient absorption using the density functional theory (DFT) . It is shown that decreasing of ZnS nanosize lead to changes the optical properties and coefficient absorption in the visible region does not occur and the particles act like a transparent material. In this work, the blue shift was observed in absorption-wavelength both theoretical and experimental method due to the quantum confinement effects.

Density functional theory; Blue shift; Absorption coefficient; Dielectric properties; Quantum dots

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