Thin Films of CuFeS2 Prepared by Flash Evaporation Technique and Their Structural Properties

Thin films of chalcopyrite CuFeS2 were deposited on glass substrates by flash evaporation. The resulting film structure was analyzed by scanning electron microscopy (SEM) combined with energy dispersive x-ray spectroscopy (EDS). It was detected that the thin films consist of separate grains of almost equal areas of about (200–400) μm2. The thin films of chalcopyrite CuFeS2 have chemical composition with an atomic content of Cu, Fe, and S of 25.22 at.%, 23.38 at.%, and 51.40 at.% and atomic ratios of Cu/Fe and S/(Cu + Fe) equal to 1.08 and 1.06, respectively, which slightly differ from the theoretical values equal to 1 for both atomic ratios. A small inclusion of the second phase with chemical composition with the atomic content of Cu, Fe, and S of 29.24 at.%, 25.24 at.%, and 45.52 at.% was detected and can be attributed to talnakhite Cu9Fe8S16. The observed cracking of the thin films is explained by the separation of the additional phase with the structure of chalcocite Cu2S, which occurs during cooling of the thin films.