Structural Comparison of CIGSS Thin Film Absorber Layer Fabricated on SS and Ti Substrates

Copper indium gallium selenide sulfide, CuIn_1−xGa_xSe_2−yS_y (CIGSS) absorber layer was prepared on stainless steel (SS) and SiO₂-coated titanium substrates. Comparative study was carried out to analyze the variation in the crystal quality depending on the substrate. Identical parameters were used for deposition and selenization/sulfurization of metallic precursors. This paper presents the observations made on the basis of surface morphology using scanning electron microscopy, crystal quality by x-ray diffraction and chemical composition and concentration-depth profiles by x-ray energy dispersive spectroscopy and Auger electron spectroscopy respectively. Film fabricated on both the substrate had chalcopyrite structure with variation of stoichiometry as well as morphology. Selenization/sulfurization cycle must be modified depending upon the substrate to obtain high quality CIGSS film.