Effect of complexing agents: investigations on structural, morphological, topographical and optical analysis of copper iron sulphide thin films deposited by chemical bath deposition method

Copper iron sulphide (FeCuS₂) thin films deposited by chemical bath deposition method using ferrous sulphate and copper sulphate as cationic sources and sodium sulphide as anionic source with complexing agents, EDTA and Leishman stain were reported. The structural, optical and morphological studies were carried out using X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV–Visible spectroscopy techniques. The X-ray spectrum reveals that the films are polycrystalline nature and also showed the deposition of cubic phases at room temperature. The SEM images for prepared films have clear morphology influenced by the complexing agents used in deposition process. The result of AFM studies shown that the particles in the film have grain size around ~ 60–70 nm and also have almost similar thickness. Based on the optical absorbance spectra the FeCuS₂ film exhibited a high absorbance in the visible region. The absorption edge shifted toward lower wavelength with varying complexing agents. The band gap value obtained was found to be 3.57–3.85 eV. From these results, it is indicated that the prepared films are suitable candidate for solar cell applications.