Initial study on performance enhancement of using FeS2 back surface field and antireflective layers in CZTS solar cells

Abstract This investigation advances kesterite photovoltaic technology through optimized Cu₂ZnSnS₄ (CZTS) absorber design, capitalizing on its earth-abundant and eco-friendly characteristics. Although CZTS devices with CdS buffers are currently limited to a certified efficiency of 13.44% (well below the standards of CIGS/CdTe), we demonstrate that integrating a FeS 2 back surface field offers a promising alternative pathway for enhancing efficiency. Our spray pyrolysis synthesis yields uniform CZTS nanostructures, with gamma irradiation studies revealing dose-dependent modifications. Numerical simulations using Silvaco TCAD confirmed notable performance improvements in the engineered Al/ARC/FTO/ZnO/CZTS/FeS₂/Mo architecture, achieving a short-circuit current density (J sc ) of 17.70 mA/cm², open-circuit voltage (V oc ) of 1.20 V, fill factor (FF) of 85.32%, and overall power conversion efficiency (PCE) of 18.06%. These findings establish a new paradigm for high-efficiency, sustainable thin-film photovoltaics.