Enhanced Stability of MAPbI ₃ Perovskite Films with Zirconium Phosphate‐Phosphonomethylglycine Nanosheets as Additive

Abstract Methylammonium lead iodide perovskite (MAPbI ₃ ) is today considered the most promising component for highly efficient third generation solar cells. However, the lifetime of the solar devices is strongly affected by the stability of the MAPbI ₃ films toward humidity, UV irradiation, and temperature. The search for efficient protective additives to be used for building up composite perovskite films with enhanced stability is a topic of great interest in the scientific community. In the present paper, a layered zirconium phosphate‐phosphonate based on N , N ‐phosphonomethylglycine, exfoliated in thin nanosheets (NS), as additive for the stabilization of MAPbI ₃ crystalline films toward humidity, UV‐irradiation, and temperature changes is applied. Notably, the additive is extremely efficient in preventing degradation of the perovskite film, preserving the optical and structural properties, and avoiding the phase transitions normally observed due to temperature increase.