Physical investigations: structural, morphological, optical and electrical properties of CoFeS₂ thin films prepared using a chemical spray technique

In this work, Cobalt-iron sulfide (CoFeS₂) thin film was deposited on glass substrate at 300 °C using a chemical spray pyrolysis technique. The X-ray diffraction (XRD) investigation reveals that this film is polycrystalline, with a crystallite sizes equal to 86 nm. In addition, the XRD spectra and Energy-Dispersive X-ray analysis (EDXA) illustrate the appearance of CoFeS_2, while scanning electron microscopy (SEM) exhibits a surface shape that is largely flat. The optical characteristics of thin films are investigated using ultraviolet–visible (UV–vis) spectroscopy. As demonstrated by the results, CoFeS₂ thin films exhibit a high absorption coefficient α in the visible wavelength (α ≥ 10⁶ cm^− 1). The gap energy Eg of the film is equal to 2.49 eV. Finally, a Hall measurement device using the Vander Pauw method was used to measure electrical resistivity, Hall mobility, and carrier concentration at room temperature.