Tunnel oxide passivated contact (TOPCon) solar cells are key emerging devices in the commercial silicon-solar-cell sector. It is essential to have a suitable bottom cell in perovskite/silicon tandem solar cells for commercial use, given that good candidates boost efficiency through increased voltage. This is due to low recombination loss through the use of polysilicon and tunneling oxides. Here, a thin amorphous silicon layer is proposed to reduce parasitic absorption in the near-infrared region (NIR) in TOPCon solar cells, when used as the bottom cell of a tandem solar-cell system. Lifetime measurements and optical microscopy (OM) revealed that modifying both the timing and temperature of the annealing step to crystalize amorphous silicon to polysilicon can improve solar cell performance. For tandem cell applications, absorption in the NIR was compared using a semitransparent perovskite cell as a filter. Taken together, we confirmed the positive results of thin poly-Si, and expect that this will improve the application of perovskite/silicon tandem solar cells.

This study investigated the integration of perovskite solar cells (PSCs) on stainless steel (SS) substrates for application in building-integrated photovoltaics (BIPV). Using advanced atomic force microscopy measurements, we confirmed that enhanced substrate roughness increased the reflectance along an interface. Consequently, a remarkable final efficiency of 11.9% was achieved. Notably, PSCs, known for their exceptional efficiency of 26.1%, can overcome the inherent efficiency limitations of SS-based thin-film solar cells. In this study, a PSC with an efficiency of 14% was fabricated on a flexible SS substrate. This study is a significant step towards advancing sustainable energy solutions for BIPV applications. The global shift towards renewable energy sources has catalyzed intensive research and development efforts, rendering the exploration of alternative materials and manufacturing processes a priority. The success of PSCs on SS substrates underscores their promise to achieve a balance between efficiency and versatility in BIPV solutions. Moreover, our findings reveal that controlling the substrate surface characteristics can significantly enhance the performance of PSCs, offering a pathway toward greater energy efficiency and sustainability in the construction industry.