Defect Suppression via Tailoring Functionalized Additives for Efficient and Stable CsPbI₃ Perovskite Solar Cells

Abstract

Cesium lead iodide perovskites offer promising stability and a bandgap near 1.7 eV, making them suitable as the top cell in tandem solar cells. However, the inorganic perovskite films suffer from a high defect density and substantial recombination losses, undermining their optoelectronic performances. Here, by activating the aromatic system, we develop 4-methoxybenzoylhydrazine (MeOBH)-modified CsPbI₃ film with regulated crystallinity, suppressed non-radiative recombination, and improved interfacial energetic alignment. The resultant inorganic perovskite solar cells achieved a power conversion efficiency of 20.95%, along with enhanced phase stability owing to the strong coordination interaction between the lead cation and the hydrazide group. Encapsulated devices retain 90.4% of the initial performance after 624 h of maximum power point operation under the ISOS-L-1I protocol.

Keywords

benzohydrazide-based additives / defect passivation / inverted perovskite solar cells / structural regulation

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