Flexible solar cells beat 10,000 bending cycles with 96% efficiency

Researchers at the Korea Institute of Materials Science (KIMS) have developed a flexible perovskite solar cell that combines high efficiency with exceptional mechanical durability and environmental stability. By employing a "defect passivation strategy," they sandwiched the light-absorbing perovskite layer between two protective two-dimensional (2D) perovskite layers. This innovation shields the core material from moisture, enabling fabrication in ambient air conditions with up to 50% relative humidity—overcoming a major hurdle of perovskite’s traditional sensitivity to moisture and eliminating the need for costly controlled environments. The resulting solar cells demonstrate remarkable performance retention, maintaining over 85% of their initial efficiency after 2,800 hours of operation and 96% efficiency after 10,000 bending cycles, highlighting their mechanical resilience. Additionally, in more rigorous shear-sliding tests, the cells preserved 87% efficiency. This durability, combined with the ability to produce the cells in open air, significantly reduces