Structural, electronic and optical properties of Cu-doped ZnS thin films deposited by the ultrasonic spray method- DFT study


Herein, the modifications on the properties of the ZnS thin films by copper doping with various concentrations Zn1−xCuxS (x = 0, 1, 3, and 5 at %) have been studied. The properties of pure ZnS have been provided for the purpose of comparing different thin films. All samples have been synthesized using the simple ultrasonic spray method on glass substrates at 200 °C and characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and ultraviolet–visible (UV-Vis) spectroscopy. Structural analysis revealed that the films are polycrystalline fitting well with the ZnS hexagonal wurtzite structure with the (002) direction as a preferential orientation for all the films except for the (5 at%) concentration that preferred (100) orientation. An increase in the grain size was observed through surface scanning as the dopant percentage increased. The deposited films possessed an average optical transmittance in the range of 86% at the visible region combined with a high absorption coefficient (~ 105 cm−1), while a slight decrement was observed on the optical band gaps of Zn1−xCuxS films passing from 3.93 eV to 3.64 eV as dopant content increased. The ab initio calculations revealed a major enhancement in the properties of ZnS as the Cu content increased. The findings obtained in the current study display that when the copper percentage is highest, the Zn1−xCuxS thin film can be a suitable candidate as an absorber layer in thin film solar cells.

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Author information




Hamza Shaili: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Data curation, Writing—original draft, Writing—review & editing, Visualization. El mehdi Salmani: Methodology, Software, Validation, Formal analysis, Investigation. Rida Essajai: Methodology, Software, Validation, Formal analysis, Investigation. Mustapha Beraich: Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation. Wafaa Battal: Methodology, Validation, Formal analysis, Investigation. Mouad Ouafi: Methodology, Validation, Formal analysis, Investigation. Abderrahim El hat: Methodology, Validation, Formal analysis, Investigation. Mustapha Rouchdi: Methodology, Validation, Visualization, Supervision, Formal analysis, Investigation. Hamid Ez-Zahraouy: Methodology, Validation, Formal analysis, Investigation, Supervision, Project administration. Najem Hassanain: Methodology, Software, Validation, Formal analysis, Investigation, Supervision, Project administration, Funding acquisition. Ahmed Mzerd: Methodology, Validation, Formal analysis, Data curation, Writing—original draft, Writing—review & editing, Visualization, Supervision, Project administration, Funding acquisition.

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Shaili, H., Salmani, E., Essajai, R. et al. Structural, electronic and optical properties of Cu-doped ZnS thin films deposited by the ultrasonic spray method- DFT study. Opt Quant Electron 53, 300 (2021).

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  • Thin films
  • Zinc sulfide
  • Ultrasonic spray
  • DFT
  • Optical properties
  • Band gap