Surfaces (Nov 2023)

Understanding the Effects of Post-Deposition Sequential Annealing on the Physical and Chemical Properties of Cu<sub>2</sub>ZnSnSe<sub>4</sub> Thin Films

  • Diana-Stefania Catana,
  • Mohamed Yassine Zaki,
  • Iosif-Daniel Simandan,
  • Angel-Theodor Buruiana,
  • Florinel Sava,
  • Alin Velea

DOI
https://doi.org/10.3390/surfaces6040031
Journal volume & issue
Vol. 6, no. 4
pp. 466 – 479

Abstract

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Cu2ZnSnSe4 thin films have been synthesized by employing two magnetron-sputtering depositions, interlaced with two sequential post-deposition heat treatments in low vacuum, Sn+Se and Se–rich atmospheres at 550 °C. By employing successive structural analysis methods, namely Grazing Incidence X–Ray Diffraction (GIXRD) and Raman Spectroscopy, secondary phases such as ZnSe coexisting with the main kesterite phase have been identified. SEM peered into the surface morphology of the samples, detecting structural defects and grain profiles, while EDS experiments showed off–stoichiometric elemental composition. The optical bandgaps in our samples were calculated by a widely used extrapolation method from recorded transmission spectra, holding values from 1.42 to 2.01 eV. Understanding the processes behind the appearance of secondary phases and occurring structural defects accompanied by finding ways to mitigate their impact on the solar cells’ properties is the prime goal of the research beforehand.

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