In this work, the SCAPS-1D solar cell simulation software was used to model, simulate and track perovskite solar cells (PSCs) with planar structure, in a confined mode arrangement (FTO/TiO/CH₃NH₃PbI₃/CH₃NH₃GeI₃/CH₃NH₃SnI₃/CuO₂). Different compositions, absorber thickness, electron affinity, and absorber doping concentration were investigated. Different hole transport materials (CuO₂, CuI, NiO, PEDOT: PSS) were used. The best result for CH₃NH₃PbI₃ with CuO₂ hole transport material (HTM) showed an overall efficiency of 18.28%, FF of 62.71%, Jsc of 25 mA/cm², and Voc of 1.1 V. For tin lead-free halide CH₃NH₃SnI₃, the best results showed an overall efficiency of 24.54%, FF of 71.30%, Jsc of 34 mA/cm², and Voc of 0.99 V. Lead-free PSC has an advantage over lead PSC due to lead toxicity. However, a tin-based cell is unstable, hence, the p-type carrier doping concentration of tin-based perovskite PCE of the device can be improved due to the better and stronger combined electric field.