Researchers

Raghad Zein and Dr. Ibrahim Alghoraibi

Published in

Journal of Nanomaterials, Volume 2019, Article ID 7541863, 13 pages, 2019. 

Abstract

In this paper Zinc sulfide nanoparticles (ZnS- NPs) thin films were deposited onto glass substrates by chemical bath deposition using zinc sulfate as cation precursor and thiourea as the anionic precursor. Different bath temperatures (65, 70, 75 and 80 ^oC) and different deposition times (20, 30, 40 and 50 min) were selected to study the performance of ZnS thin films. Topographical and optical characterizations of the films were studied using the atomic force microscopy AFM and UV-Vis spectroscopy. The best ZnS thin films were deposited at a bath temperature (70 ^oC) and a deposition time (30 min) with homogeneous distribution, high density and small average diameter (106 nm). The energy gap (E_g) was found to be in the range of 4.05- 3.97 eV for the ZnS films. Optical constants (refractive index, n, extinction coefficient, k, dielectric constant, ɛ) of the films were obtained in the wavelength range 300-500 nm by using spectrophotometric measurement. The dispersion of the refractive index is analyzed by using a single oscillator model. The oscillator energy E₀ and dispersion energy E_d were determined using the Wemple DiDomenico single oscillator model. Urbach's energy increases from 0.907 eV to 2.422 eV with increasing of deposition time. The calculated radius of nanoparticles using Brus equation were 1.9, 2.3, 2.45 and 2.51 nm at deposition times 20, 30, 40and 50 min respectively.

Key words: Zinc sulfide Nanoparticles (ZnS-NPs), ZnS thin films, Chemical Bath Deposition (CBD), Atomic Force Microscopy (AFM), Surface topography, energy gap, Urbach's energy.

Link to read full paper

https://doi.org/10.1155/2019/7541863