Performance Investigation of Lead-Free Cs_₂AgBiBr_₆ Perovskite Solar Cells by Optimizing Layer Thickness

Perovskite solar cells (PSCs) are changing the game in the photovoltaic sector because of their highly efficient and flexible manufacturing processes. The certified efficiency of hybrid halide perovskites is 26.1%, but their commercial feasibility is severely limited since many of their formulations include harmful lead. This poses substantial dangers to human and environmental health. The numerous beneficial characteristics of lead-free alternatives like Cesium Silver Bismuth Bromide (Cs<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₂</inf>AgBiBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₆</inf> or CABB) have attracted a lot of interest. These characteristics include suitable bandgaps, thermodynamic stability, and low exciton binding energies. To accomplish photon absorption with the lowest possible recombination, the ideal thickness of the CABB absorber layer, according to the calculations, is 0.32µm. When tested as HTLs, Spiro-OMeTAD performed better than Cu<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₂</inf>O with 0.05µm layers, but Cu<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">₂</inf>O needed 0.12µm layers to reach its full potential. This study demonstrates that solar cells made of CABBs are a promising new ecologically friendly and efficient energy source.