Numerical Design and Performance Optimization of Lead‐Free CsSnGeI 3 Perovskite Solar Cells Using Cu 2 O Hole Transport Layer via SCAPS‐1D

ABSTRACT Perovskite solar cells represent an innovative photovoltaic technology, surpassing traditional silicon solar cells in efficiency, production cost, and versatility. In this study, we present silicon‐based traditional perovskite solar cells that are more flexible, more economical, and more efficient using SCAPS‐1D software. The primary objective of this research was to create environmentally benign and highly efficient perovskite solar cells. The optimal device structure, FTO/ZnS/CsSnGeI 3 /Cu 2 O/Au, consists of a CsSnGeI 3 absorber layer and ZnS as the buffer layer, electron transport layer (ETL), and Cu 2 O as the hole transport layer (HTL). For the back contact, gold is utilized. The effects of absorber layer thickness, buffer layer thickness, absorber layer defect density, series resistance, generation effect, recombination, and operating temperature have all been examined for the proposed solar cell construction. When the buffer layer was 0.05 μm thick and the absorber layer was 1.5 μm thick, the efficient perovskite solar cell achieved an exceptionally high efficiency of 32.35%, an open‐circuit voltage of 1.26 V, a short‐circuit current of 28.34 mA/cm 2 , and a fill factor of 90.16%.