Intermediate matching layer for light-induced performance and removable clip-on applications of four-terminal perovskite/silicon heterojunction tandem solar cells

Perovskite/silicon tandem solar cells are one of the most efficient ways to improve the performance of the photovoltaic industry and should be viewed as a promising path in the photovoltaic field. The silicon photovoltaic modules have a lifespan of over 20 years, while the low device stability of perovskite solar cells (PSCs) remains a significant commercialization barrier. An air gap acts as an optical spacer layer for four terminal (4T) perovskite/silicon tandem cells, resulting in a loss of efficiency. Using polydimethylsiloxane (PDMS) as an intermediate matching layer (IML) and a clip-on design made of a PDMS-based material sandwiched between polyvinyl chloride (PVC) layers with the configuration of PVC/IML/PVC, this research not only achieved efficiency improvement of four-contact tandem solar cells but also greatly simplified disassembly of individual cells. The 4T perovskite/silicon heterojunction tandem cells with a clip-on design achieved the highest efficiency of 23.49% for the active area of 1 cm², while the fully tandem configuration without a clip-on layer only exhibited a PCE of 22.83%. The clip-on technology has the potential to boost the current density of silicon heterojunction solar cells from 15.01 mA/cm² (for the filtered bottom cell with an air gap) up to 16.51 mA/cm² (for the filtered bottom cell with a clip-on). Therefore, this state-of-the-art allows for the removal of PSCs with a shorter lifespan while adhering two photovoltaic cells together securely and effectively.