Low cost sprayed CuIn(S^sub x^Se^sub 1-x^)^sub 2^ thin films for photovoltaic applications

In this paper, we report the single step fabrication of nanostructured CuIn(SxSe1−x)2 (CISSe) thin films employing the spray pyrolysis method, using low cost precursors. To the best of our knowledge, we are the first to report the use of selenium dioxide as the source for selenium in the spray synthesis of CISSe thin films. The use of SeO2 as the Se source makes the whole process of spray synthesis of such compounds eco-friendly and economical. X-ray diffraction (XRD) and optical transmission spectra confirm that the sprayed material is single phase CISSe with an optical band gap ∼1.25 eV. Solar cells of the type glass/FTO/ZnO/CdS/CISSe/Ag were fabricated and the best cell exhibits an AM 1.5 conversion efficiency of 4.9%.