Perovskite solar cells (PSCs) are increasingly being used as the foundation of the worldwide photovoltaic (PV) industry because of their cost-effective production and durable stability. Perovskite materials, both organic and inorganic, possess distinct optical, mechanical, and electrical properties, such as a high absorption coefficient, a customizable band gap, and a synthesis method based on solutions. This study employed numerical investigations to devise and propose innovative solar cell configurations utilizing the SCAPS-1D simulator. This research presents a Perovskite solar cell design comprising an ITO-C60-MASnI3-RbGeI3-Cu2O-Au solar cell configuration. The unique arrangement of this setup incorporates the use of Indium Tin-oxide (ITO) as the upper contact layer, which is directly exposed to light. The electron transport layer (ETL) is composed of a 0.030 μm thick layer of C60, while the light-harvesting/absorber layers are made up of MASnI3 and RbGeI3, each with a thickness of 0.4 µm. A layer of Cu2O with a thickness of 0.12 μm is employed as the hole transport layer (HTL), whereas the back-contact layer consists of Au. A comparison research was conducted to examine the optimal device configuration. Comprehensive studies are performed to assess the effects of different variables on optimized device performance and power conversion efficiency (PCE). These factors include interface defect densities, thicknesses of different structural layers, band gaps, series and shunt resistance, and operational temperature. The current density (Jsc) is calculated as 32.7 mA/cm2 at an open circuit voltage (Voc) of 0.914 V. Additionally, we observed a power conservation efficiency (PCE) of 20.19 % and an improved fill factor (FF) value of 65.49 %. The ongoing investigations are likely to be valuable for the development and production of cost-effective and high-performance PSCs.