Lead-free MAGeI₃ as a suitable alternative for MAPbI₃ in nanostructured perovskite solar cells: a simulation study

The lead is a heavy metal with hazardous impacts on environment and human life. Lead-free perovskite solar cells have attracted much attention in recent years, due to eco-friendly characteristics. Meanwhile, Pb-containing cells showed the highest efficiencies among the various types of cells. Hence, designing novel Pb-free solar cells with comparable or better performance than the Pb-containing ones is highly required. In this work, a lead-free methyl-ammonium-germanium-iodide (MAGeI₃)-based perovskite solar cell with ITO/TiO₂/MAGeI₃/Spiro-OMeTAD/Ag multilayer nanostructure has been proposed and its main characteristics including open-circuit voltage (V_OC) and power conversion efficiency (η) have been evaluated and compared with those of MAPbI₃-based cell, in simulation study. The V_OC and η of the MAGeI₃-based cell (1.18 V and 11.9%) have been found comparable with those of the MAPbI₃ one (1.10 V and 14.6%). These results can excite more attention to Ge as a more environment-friendly element than Pb, in highly efficient upcoming perovskite solar cells.