ISJ Theoretical & Applied Science 11(91) 2020

Philadelphia, USA

Alkhayatt, A. H. O., & Ahmed, M. R.

Reaction temperature effect on the structural, surface texture and optical properties of CdS nanostructure thin films deposited by hydrothermal method.

Full Article: PDF

Scientific Object Identifier: http://s-o-i.org/1.1/TAS-11-91-65

DOI: https://dx.doi.org/10.15863/TAS.2020.11.91.65

Language: English

Citation: Alkhayatt, A. H. O., & Ahmed, M. R. (2020). Reaction temperature effect on the structural, surface texture and optical properties of CdS nanostructure thin films deposited by hydrothermal method. ISJ Theoretical & Applied Science, 11 (91), 401-409. Soi: http://s-o-i.org/1.1/TAS-11-91-65 Doi: https://dx.doi.org/10.15863/TAS.2020.11.91.65

Pages: 401-409

Published: 30.11.2020

Abstract: Cadmium Sulfide (CdS) nanostructure thin films were deposited on conductive glass (FTO) substrates by hydrothermal method at different reaction temperatures (140, 160 and 200 °C) for 4 hours. The structure, surface texture and optical characteristics were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-Vis spectrophotometer. The XRD results of CdS nanostructure thin films deposited on FTO substrate showed that the films have a polycrystalline structure nature and hexagonal wurtzite phase. The preferential orientation was along (002) and (112) planes. A strong peak with a high intensity related to the FTO substrate appeared in all samples. The crystallite size of the nanostructure films was increased with the increase of reaction temperature which about (21-29) nm. Structure parameters such as lattice constants, dislocation density, the number of crystallites, and microstrain have been determined. The surface texture of nanostructure CdS thin film includes dense uniform and homogenous surface without pinholes or cracks with fine grain size. The nanostructure CdS thin films with small nanosized grains (37-203) nm were successfully obtained on FTO substrates. The optical properties of the prepared CdS nanostructure thin films were investigated in the wavelength region (400-800) nm. The transmittance spectra exhibit a high transmittance value of about 88% in the visible and near infrared regions. The results demonstrated a red shift in the fundamental absorption edge towards the lower energies long wavelengths. The optical energy gap for the permissible direct transmission decreases from (2.435 to 2.389) eV with increasing the reaction temperature from (140 to 200) oC, respectively.

Key words: CdS nanostructure; Hydrothermal method; structure parameters: Surface morphology; Optical band gap.