Growth and characterization of CuFeS2 thin films

The chalcopyrite copper iron sulphide films, CuFeS2, have been grown in thin films’ form by sulphurization of CuFe alloy precursor. Cu/Fe…/Cu thin layers have been sequentially deposited by vacuum evaporation on a substrate heated at a temperature Ts=723 K. After deposition of the metal alloy precursor, there is an interdiffusion of the metals all along the thickness. The relative thicknesses of the layers deposited were calculated to achieve the desired atomic ratio Cu/Fe: 2.5.These precursors are sulphured in a vacuum chamber using an S source. The sulphurization duration is 20 min. At the end of the process, the film exhibits a (1 1 2) preferential orientation. Thus, the structure of the film is the expected tetragonal structure of CuFeS2.The XPS study shows that there is no oxygen contamination of the film, except the surface because it has been exposed to air. The composition measured is in good agreement with that measured by electron microprobe analysis.