For commercial purposes in the solar cell field which toxicity and stability of lead-based perovskite solar cells (PSC) are important challenges, the presence of lead-free alternatives like Cs2TiBr6, Cs2AgBiBr6 and Cs2PtI6 double perovskites seems important. The aim of this study is to numerical evaluation of three double perovskite layers as potential photo- voltaic (PV) materials in solar cells with fluorine-doped tin oxide (FTO)/TiO2/perovskite/Cu2O/Au structures by using SCAPS-1D software. Different composite layers were optimized and analyzed to enable enhanced performance. Numerical results showed maximum power-conversion efficiency of 18.86%, 18.54%, and 26.50% for the suggested PSCs with Cs2TiBr6, Cs2AgBiBr6, and Cs2PtI6 absorbers. The achieved outcomes confirmed that Cs2PtI6 can contribute significantly to the development of highly efficient lead-free double-perovskite solar cell technology.
