Chelating agent effect on optical properties of SnS films and an output characteristics simulation of based solar cells

SnS thin films were electrodeposited on glass substrates coated with indium tin oxide (ITO) from an aqueous solution of tin chloride (SnCl2) and sodium thiosulfate (Na2S2O3) as precursors. In order to obtain stoichiometric layers, ethylenediamine tetraacetic acid (C10H16N2O8, EDTA) or triethanolamine (C6H15NO3, TEA) were added to the solution as chelating agents. The X-ray diffraction pattern (XRD) confirms the nature of the polycrystalline samples as the α-SnS orthorhombic structure. The optical characterization shows, on the one hand, the direct band gap’s nature and on the other hand, its shift dependence on the chelator’s kind. Strong absorption with a coefficient greater than 104 cm−1 was observed. This makes electrodeposited SnS, a material with very interesting characteristics that allows it to be used as the absorber layer in solar cells. Hence, we were interested in the simulation of based solar cells output characteristics. Numerical simulation, using 1D-SCAPS software, of the photocurrent provides power conversion efficiency (PCE) approaching 27% when adding EDTA.