Perovskites offer many advantages like high efficiency, cost-effective, and easy fabrication of malleable solar cells. Nonetheless, enduring stability and eco-friendly lead (Pb)-free applications pose obstacles for commercialization. Mostly, the most efficient perovskite solar cells (PSC’s) reported use toxic lead (Pb) and volatile polymers as absorption and hole/electron transport layers. So, in this research, we introduced and simulated the photovoltaic (PV) response of Pb-free methylammonium germanium iodide (MAGeI3) with a wide bandgap (1.9 eV) as an absorption layer. Different hole transport layers (HTLs), such as copper oxide (Cu₂O), copper iodide (CuI), and copper thiocyanate (CuSCN), utilized to investigate the impact of HTL improved charge extraction and transfer properties, increasing the efficiency (η) of CuI-based perovskite solar cells to 23.9%.