A Targeting Light-Management Strategy Affords Ultraviolet-Stable and Efficient Perovskite Solar Cells

Despite significant progress in the efficiency of inverted perovskite solar cells (PSCs), their poor long-term operational stability under complex environmental stressors remains a major challenge for their commercialization. Herein, a targeting light-management strategy with a down-conversion small molecule, Rhodamine B-acylhydrazine (RhBH), is innovatively demonstrated to enhance the ultraviolet (UV) resistance and optimize photon management. It reveals that the chelates formed by RhBH and uncoordinated Pb²⁺ can convert the harmful UV light into visible light that can be absorbed by perovskite, thereby enhancing both the UV stability of the device and the photon utilization efficiency. Furthermore, the strong interaction between RhBH and the perovskite components significantly reduces intrinsic defects in the perovskite, enhances crystallization quality, suppresses non-radiative recombination losses, and stabilizes the perovskite structure. As a result, the resultant non-encapsulated device delivers a champion power conversion efficiency (PCE) of 25.91%, accompanied by significantly enhanced stabilities against environments, with retaining over 80% of initial PCE for ≈780 and ≈1100 h aging under continuous UV radiation and high-humidity ambient air, respectively. This research offers a targeting light-management strategy for developing UV-stable and efficient PSCs.