Modeling and experimental investigation of perovskite/black silicon/silicon tandem solar cells

The use of a nanotextured black silicon (b-Si) interlayer is a promising solution for improving the optical properties of perovskite/silicon two-terminal monolithic tandem solar cells. This work combines SCAPS-1D numerical simulations with experimental device fabrication to comprehensively evaluate the impact of the b-Si interlayer on the photovoltaic performance of tandem devices. Simulated (experimental) power conversion efficiencies increased from 27.17% (26.31%) for planar tandem solar cells to 28.97% (27.84%) for nanotextured tandem solar cells. This enhancement is predominantly attributed to a significant increase in short-circuit current resulting from improved light trapping and reduced reflectance in the bottom silicon subcell with a frontal b-Si layer. A parametric analysis reveals that the tandem device efficiency is maximized at an optimal b-Si thickness of ∼530 nm, which ensures current matching between the subcells. Furthermore, the study highlights the importance of minimizing defect density within the b-Si layer, as it directly impacts the open-circuit voltage of the bottom silicon subcell and the overall tandem device PCE. The good agreement between simulation results and experimental data validates the model and underscores the potential of the b-Si interlayer to enhance the photovoltaic performance of perovskite/silicon tandem solar cells.