Visible Light‐Triggered Self‐Welding Perovskite Solar Cells and Modules

Abstract Flexible perovskite solar cells (F‐PSCs) are highly promising for both stationary and mobile applications because of their advantageous features, including mechanical flexibility, their lightweight and thin nature, and cost‐effectiveness. However, a number of drawbacks, such as mechanical instability, make their practical application difficult. Here, self‐welding dynamic diselenide that is triggered by visible light into the structure of F‐PSCs to improve their long‐term stability by repairing cracks and defects in the absorber layer is incorporated. The diselenide confers the flexibility and self‐welding properties to the Cs 0.05 MA 0.05 FA 0.9 PbI 3 perovskite layer, enabling optimized F‐PSC devices to achieve a power conversion efficiency of 24.85% while retaining ca. 92% of their initial efficiency after undergoing 15 000 bending cycles at a curvature radius of 3 mm. The corresponding flexible large‐scale module with an active area of 15.82 cm 2 achieved a record PCE of 21.65%.