Investigate the growth mechanism of Cu₂FeSnS₄ thin films by sulfurization of metallic precursor

Cu₂FeSnS₄ (CFTS) thin films have been prepared on glass substrates by a process of sputtering metallic precursor with post-sulfurization. By means of various holding times, the growth mechanism of CFTS has been determined by X-ray diffraction and Raman patterns. Three steps have been involved, the binary-phases CuS_x, FeS_x and SnS_x are synthesized in the preliminary stage, and afterwards, CuS_x reacts with FeS_x to generate ternary-compound CuFeS₂. At last, the target product CFTS is obtained with the increasing holding time of sulfurization. All the thin films have smooth and closely packed surface, and longer holding time is in favor of the grain growth. The thickness of these thin films is around 1 µm.