Light Stability Enhancement of Perovskite Solar Cells Using 1H,1H,2H,2H‐Perfluorooctyltriethoxysilane Passivation

Passivation approaches of perovskite surface are key to improve the light stability of perovskite solar cells. However, a passivation strategy is still required to enhance the durability of the perovskite layer. Here, a promising passivation concept is demonstrated by applying a fluorinated agent on the perovskite layer for light stability improvement. Such fluorinated passivation agents can prevent the formation of Pb 0 at the perovskite surface resulting in suppressing a defect‐induced recombination and improving the durability of the perovskite solar cells. As an additional benefit, the fluorinated passivation agent increases the V OC which improves the photovoltaic performance of the perovskite solar cells. Consequently, with a fluorinated passivation agent, the perovskite maintains a power conversion efficiency of 95% after 300 h of light illumination. It is found that the fluorinated passivation material of 1H,1H,2H,2H ‐perfluorooctyltriethoxysilane (PFOTES) can improve the stability of the perovskite solar cells.