Numerical Investigation of a Novel Lead-Free Perovskite Solar Cell with FTO/WS₂/CsSnI₃/NiO Architecture For High-Efficiency Photovoltaic Applications

Perovskite-based solar cells (PSCs) are revolutionizing photovoltaics with elevated power conversion efficiencies (PCEs) and cost-effective manufacturing. However, lead-based PSCs pose environmental and health risks, emphasizing the need for lead-free alternatives. This study proposes a novel lead-free PSC architecture with Glass/FTO/WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/CsSnI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>/NiO layers. At the core of this design is CsSnI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>, a non-toxic perovskite with excellent optical properties, making it an ideal replacement for lead-based materials. In this design, WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, as the electron transport layer (ETL), provides enhanced mobility of electrons and a wide bandgap to improve charge transport, and NiO, as the hole transport layer (HTL), ensures efficient hole extraction. SCAPS-1D was applied to model and analyze the device’s performance. The thickness and defect density parameters of the ETL, HTL, and absorber layers, together with interface defects, were optimized to assess their influence on the solar device’s performance. The simulation results demonstrate the highest PCE of 31.42%, with a fill factor (FF) of 87.90%, an open-circuit voltage (V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</inf>) of 1.0253 V, and a short-circuit current density (J<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</inf>) of 34.859 mA/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. These findings suggest the potential to create efficient, sustainable, and affordable solar cells that contribute to a greener future.