Lead-Free CS₂AgBiI₆ Perovskite Solar Cells for Eco-Friendly Energy Solutions: A Thickness-Dependent Performance Analysis

The introduction of lead-containing metal halide perovskite materials has had a profound impact on sustainable energies; nevertheless, the inclusion of lead in these compounds raises issues related to their toxicity and durability over time. Lead-free perovskite solar cells offer eco-friendly benefits by reducing hazardous waste, using natural materials, enhancing recyclability, and promoting ecological sustainability. This research investigates a perovskite solar cell without Pb that utilizes a Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>AgBiI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> absorber layer, employing SCAPS-1D software as the analytical tool. The study emphasizes the effect of the perovskite layer's thickness on critical efficiency indicators. The findings indicate that the application of thicker layers enhances light absorption and current density; while a thicker absorber layer may result in recombination losses, which subsequently diminish the power conversion efficiency (PCE), open circuit voltage (Voc), and the fill factor (FF). The optimized solar cell achieved a Jsc of 24.98 mA/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, Voc of 0.96 V, FF of 83.16%, and PCE of 19.94%. Improving efficiency and solving the toxicity problem is vital for advancing the progress of perovskite solar cells and steering them toward a hopeful future.