Influence of Different Precursors on CZTS Thin Films Deposition through the Sol-Gel Method

Kesterite (Cu 2 ZnSnS 4 ) thin films were deposited using the solgel, spin-coating technique with different precursor systems to understand the effect of precursor chemistry on film formation. It was observed that stable solutions could be obtained using chloride and acetate-based precursors, whereas the sulphate-based system showed poor stability and led to precipitation. The deposited Cu 2 ZnSnS 4 (CZTS) films were annealed at 500 ° C in a nitrogen atmosphere. X-ray diffraction (XRD) showed the formation of the kesterite phase with a dominant (112) peak, and Raman spectroscopy further supported this. Field-emission scanning electron microscopy (FESEM) revealed that the acetate-derived films have a more uniform surface, while the chloride-derived films exhibited relatively larger grains with slight agglomeration. Energy-dispersive X-ray spectroscopy (EDX) revealed differences in the elemental composition of the chloride- and acetate-derived films. Optical studies showed strong absorption in the visible region, with band gap values of 1.58-1.60 eV. The results indicate that precursor chemistry plays an important role in determining the properties of CZTS thin films.