Dual passivation and UV shielding by bifunctional UV0 Molecule for high-performance and stable perovskite solar cells

Abstract

To mitigate UV irradiation-induced lattice damage and ion migration in perovskite solar cells, we introduce an ultraviolet (UV)-resistant molecule, 2,4-dihydroxybenzophenone (UV0), into perovskite films via additive engineering. The unique self-assembled intramolecular hydrogen bonds of UV0 enable a dual-dissipation mechanism: UV energy is consumed and converted into thermal energy for dissipation during the process of hydrogen bond breaking and regeneration. The testing results demonstrate that UV0 not only suppresses the degradation of formamidinium iodide (FAI) but also significantly inhibits iodide ion migration. Simultaneously, its functional groups passivate perovskite defects and synergistically optimize film crystallinity, as evidenced by reduced trap density and enlarged grain size. Consequently, the champion device achieves a power conversion efficiency (PCE) of 24% and exhibits enhanced stability under continuous illumination. This multifaceted modulation strategy effectively enhances UV stability, optimizes energy band alignment, and promotes carrier transport, offering a novel approach for developing UV-resistant perovskite optoelectronic devices.