Optical modelling and performance assessment of thin-film silicon/perovskite tandem solar cells (Invited Paper)

Dedicated optical models are crucial for advancing the modelling of next-generation solar cells. Incorporating various textures of different shapes and sizes into solar cells significantly improves light management. This study optimizes the optical design and predicts the performance of a novel thin-film tandem solar cell device. The top cell features a hydrogenated amorphous silicon (a-Si:H) absorber layer, while the bottom cell incorporates a low-bandgap tin-lead-based perovskite (Sn-Pb PVK) absorber layer, all supported on a flexible aluminum substrate Optical simulations exhibit 24 mA/cm² as total implied photo-current density when the absorber layer thicknesses are current-matched. The maximum absorptance reaches 80% at 500 nm for a-Si:H and only 62% at 800 nm for Sn-Pb PVK sub-cells. Experimental results show open-circuit voltages of 0.9 V for a-Si:H and 0.85 V for Sn-Pb PVK solar cells. Based on the highest achieved fill factor of 0.77, the researchers estimated a power conversion efficiency exceeding 16%.