Comparative Study on the Performance of Different Lead‐Based and Lead‐Free Perovskite Solar Cells

A comparative theoretical study on the performance of perovskite solar cells (PSCs) with methyl ammonium lead iodide (MAPbI 3 ) and methyl ammonium germanium iodide (MAGeI 3 ) as absorber layers is reported by modeling the solar cells for a number of electron transport materials (ETMs), hole transport materials, and back‐contact metals using solar cell capacitance simulator 1D tool. For MAPbI 3 as the absorber layer, the best photovoltaic performance is observed for the configuration glass/fluorine‐doped tin oxide (FTO)/SnO 2 /MAPbI 3 /NiO/Au with a power conversion efficiency (PCE) of 20.58% and a fill factor (FF) of 68.34% and for MAGeI 3 , the configuration glass/FTO/SnO 2 /MAGeI 3 /CuO/Pd exhibits the best performance with a PCE of 13.12% and a FF of 68.29%. This study indicates that the low‐cost metal oxide SnO 2 is a better substitute for the commonly used TiO 2 as ETM, and the metal oxides like NiO and CuO provide a higher PCE for device configurations with MAPbI 3 and MAGeI 3 , respectively, as the absorber layer. The low‐cost back‐contact metal Pd provides a better performance for MAGeI 3 ‐based PSCs. This study also indicates that the nontoxic MAGeI 3 ‐based PSCs can be used for commercial applications as they are more thermally stable than the MAPbI 3 ‐based PSCs and provide an equally good quantum efficiency curve as that of MAPbI 3 ‐based PSCs.