Performance-Oriented Design and Numerical Investigation of a 34% Efficient Two-Terminal Monolithic Perovskite/Silicon Tandem Solar Cell

Crystalline silicon solar cells have reached technological maturity, with efficiency gains slowing as performance approaches the intrinsic Auger recombination limit. The record efficiency of 26.7% highlights the inherent constraints of single-junction silicon devices and motivates the development of advanced architectures. Monolithic perovskite–silicon tandem solar cells offer a promising pathway for enhanced spectral utilization and higher conversion efficiency. Owing to their tunable band gap and strong optical absorption, metal-halide perovskites are well suited for integration with silicon bottom cells to reduce thermalization and transmission losses. In this work, a simulation-based optimization of a monolithic perovskite–silicon tandem solar cell is presented. The optimized structure employs a 1.68 eV perovskite top absorber integrated with a 1.12 eV crystalline silicon heterojunction (HIT) bottom cell. Interface engineering using Me-4PACz and an indium tin oxide (ITO)-based tunnel recombination junction enables improved hole extraction and efficient current matching while limiting parasitic optical losses. Systematic analysis of absorber thickness, interface defect density, spectral filtering, energy band alignment, operating temparature and illuminated J–V characteristics yields a power conversion efficiency of 34% and an open-circuit voltage of 2.02 V. These results provide practical design guidelines for high-efficiency perovskite–silicon tandem solar cells.