Growth and Characterization of Chalcopyrite CuFeS ₂ Thin Films Synthesized Through the Chemical Spray Technique

This study presents copper iron sulphide films, CuFeS2, deposited on glass substrates with various precursors’ volumes (10, 20, 30 and 40 mL) at 300°C, using a simple and low-cost chemical spray pyrolysis technique. A rhombohedral phase of chalcopyrite CuFeS2 is revealed by X-ray diffraction (XRD) analysis. Furthermore, the XRD spectra show that crystallinity becomes amorphous over a volume of precursor equal to 40 mL. In contrast, the surface of the obtained thin films shown by scanning electron microscopy (SEM) is adherent, compact and free of cracks, which reveals that the product consists of a uniform deposited film. On the other hand, with the increase in the volume of precursors (30 and 40 mL) the surface morphology presents a massive, dense structure of ice rock that is fractured irregularly, resembling crumb. The optical study proves that the Urbach energy increases as the amount of sprayed solution increases. M oreover, fault states that trap charge carriers may be promoted by increased sprayed solution volume. These localiz ed charge carriers can switch between these defective states. Consequently, we see that the gap energy values of CuFeS2 thin films decrease. Finally, after comparing all of the structural and morphological characteristics with the results of the photocatalytic process, we conclude that thin films with a dense layer of nanowires on the surface and superior crystallinity have higher photocatalytic efficiency.