Advanced Tuning of Optoelectronic and Structural Parameters in Cs 2 AgBiI 6 ‐Based Lead‐Free Perovskite Solar Cells: Toward 28.95% Efficiency

ABSTRACT Lead‐free perovskite solar cells (PSCs) have engrossed substantial consideration from certain years for its promising photovoltaic (PV) outputs. This work includes a detailed discussion of the relative parameters of the PSC configurations, that is, ITO/ZnO/Cs 2 AgBiI 6 / Spiro‐OMeTAD/Ag, composed of a lead‐free, cesium‐based PSC. The Cs 2 AgBiI 6 ‐based PSCs offer high output parameters as compared to the outputs of methyl ammonium (MA)—based PSCs. Optimizing the bulk defect density (BDD) of perovskite materials is one of the best methods for reaching high efficiency, aside from physical factors like thickness. Additionally, SCAPS‐1D software is used to tune optoelectronic parameters J – V and QE in order to achieve high efficiency. The optimum PV parameters attained the output of J SC nearly 22.07 mA/cm 2 , V OC of 1.48 V, FF about 87.56%, and power conversion efficiency (PCE) of 28.95%, respectively.