Inorganic‐Derived 0D Perovskite Induced Surface Lattice Arrangement for Efficient and Stable All‐Inorganic Perovskite Solar Cells

The inverted inorganic CsPbI3 perovskite solar cells (PSCs) are prospective candidates for next‐generation photovoltaics owing to inherent robust thermal/photo‐stability and compatibility for tandems. However, the performance and stability of the inverted CsPbI3 PSCs fall behind the n‐i‐p counterparts due to poor energetic alignment and abundant interfacial defect states. Here, an inorganic 0D Cs4PbBr6 with a good lattice strain arrangement is implemented as the surface anchoring capping layer on CsPbI3. The Cs4PbBr6 perovskite induces enhanced electron‐selective junction and thus facilitates efficient charge extraction and effectively inhibits non‐radiative recombination. Consequently, the CsPbI3 PSCs with Cs4PbBr6 demonstrate the highest power conversion efficiency (PCE) of CsPbI3‐based inverted PSCs, reaching 21.03% PCE from a unit cell and 17.39% PCE from a module with a 64 cm2 aperture area. Furthermore, the resulting devices retain 92.48% after 1000 h under simultaneous 1‐sun and damp heat (85 °C / 85% relative humidity) environment. Inverted CsPbI3 PSCs treated with inorganic‐derived 0D Cs4PbBr6 perovskite nanocrystals show improved surface lattice arrangement, achieving a PCE of 21.03% and maintaining 92.48% stability after 1000 h under 1‐sun and damp heat conditions. Additionally, a module with a 64 cm2 aperture area demonstrates a PCE of 17.39%.