Study of the Effect of Film Thickness on Structure and Optical Properties of Nanostructured ZnS Thin Films Deposited by Spray Technique

Authors M. Ayadi1,2, M. Sebais1, S. Benramache2,3, A. Benhaoua2, B. Benhaoua2, O. Halimi1, B. Boudine1, A. Bensouici4

1Laboratory of Crystallography, Department of Physics, Mentouri-Constantine University, Constantine 2500, Algeria

2VTRS Laboratory, Institute of Technology, University of El-Oued, El-Oued 39000, Algeria

3Material Sciences Department, Faculty of Science, University of Biskra, 07000, Algeria

4Ceramics Laboratory, Department of Physics, Mentouri-Constantine University, Constantine 2500, Algeria

Issue Volume 11, Year 2019, Number 6
Dates Received 01 August 2019; revised manuscript received 06 December 2019; published online 13 December 2019
Citation M. Ayadi, M. Sebais, S. Benramache, et al., J. Nano- Electron. Phys. 11 No 6, 06013 (2019)
PACS Number(s) 68.18.Jk, 73.20.At, 78.20.– e
Keywords ZnS (23) , Thin films (60) , Film thickness, Ultrasonic spray method.

The sprayed ZnS thin films were deposited on a glass substrate at 400 °C using ultrasonic spray che-mical technique (SPC). In this work, we have studied the effect of film thickness on structure and optical properties of nanostructured ZnS thin films. XRD analysis of ZnS thin films, which confirmed a hexagonal structure of ZnS with good crystallinity, has revealed that the crystallite size maximum of 45.3 nm was obtained with 577 nm. This is confirmed by the polycrystalline films at high film thickness. As for the optical properties, ZnS thin films have a good transparency in the visible region; the band gap energy of all depo-sited films was varied from 3.9 to 4.1 eV. At lower film thickness, the ZnS thin films become less disorder and fewer defects that are related to the Urbach energy, which was obtained of the order of 0.19 eV at 360 nm. However, it is noted that the variation of the extinction coefficient k follows the same trend, which indicates that the minimum value was obtained for ZnS film deposited with 360 nm. The best variation of refractive index was also obtained for 360 nm.

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