Impact on generation and recombination rate in Cu2ZnSnS4 (CZTS) solar cell for Ag2S and In2Se3 buffer layers with CuSbS2 back surface field layer

For photovoltaic (PV) applications, the earth-abundant and non-hazardous Kesterite Cu₂ZnSnS₄ (CZTS) is a possible substitute for chalcopyrite copper indium gallium selenide (CIGS). This research offers insight into the most innovative method for improving the performance of Kesterite solar cells (SCs) by using CuSbS₂ back surface field (BSF) and Ag₂S and In₂Se₃ as buffer layers, focuses on aligning energy bands, reducing non-radiative recombination, and improving open-circuit voltage (V_oc). The proposed cells are Ni/CuSbS₂/CZTS/In₂Se₃/ITO/Al and Ni/CuSbS₂/CZTS/Ag₂S/ITO/Al by adding interfaces. The optimized CZTS SCs with In₂Se₃ achieve a short-circuit current density (J_sc) of 30.274 mA/cm², fill factor (FF) of 89.15%, power conversion efficiency (PCE) of 31.67%, and V_oc of 1.173 V. With the Ag₂S buffer layer, PCE is 31.02%, FF is 88.61%, J_sc is 30.245 mA/cm², and V_oc is 1.157 V. These results depict the potential of CZTS-based SCs with improved performance compared with conventional structures.