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The two‐step sequentially deposition strategy has been widely used to produce high‐performance FAPbI3‐based solar cells. However, due to the rapid reaction between PbI2 and FAI, a dense perovskite film forms on top of the PbI2 layer immediately and blocks the FAI diffusion into the bottom of the PbI2 film for a complete reaction, which results in a low‐efficiency and limited reproducibility of perovskite solar cells (PSCs). Here, high‐quality α‐FAPbI3 perovskite films by crystal growth regulation with 4‐fluorobenzamide additives is fabricated. The additives can interact with FAI to suppress the fast reaction between the FAI and PbI2 and effectively passivate the under‐coordinated Pb2+ or I‐ defects. As a result, α‐FAPbI3 perovskite films with low trap density and large grain size are prepared. The modified PSCs present a high‐power conversion efficiency of 24.08%, maintaining 90% of their initial efficiency after 1400 h in high humidity. This study provides an efficient strategy of synergistic crystallization and passivation to form high‐quality α‐FAPbI3 films for high‐performance PSCs. [ABSTRACT FROM AUTHOR]

A systematic understanding of perovskite single crystal is critical for the development of high-performance functional devices. We outline the synthesis strategies, unique characteristics, and optoelectronic applications of perovskite single crystals with diverse dimensions, including 0D perovskite QDs, 1D micro/nanowires arrays, 2D micro/nanoplates arrays and single-crystal films, and 3D micro/nanoscale single-crystal structures, providing guidelines for the application of integrated devices. [Display omitted] Lead halide perovskite single crystals have emerged as promising candidates for high-performance optoelectronic devices because of their superior optoelectronic properties. To date, much literature has reported the fabrication of various perovskite single-crystal structures. However, it still lacks effective rationalization and a comprehensive understanding of the relationship between the structural characteristics and functional properties of the perovskite single crystals, which is of great significance for fabricating perovskite single crystals-based high-performance optoelectronic devices. In this review, we give a comprehensive overview of the synthesis of perovskite single crystals with diverse dimensions, including 0D perovskite quantum dots (QDs), 1D micro/nanowires, 2D micro/nanoplates and single-crystal thin films (SCTFs), and 3D micro/nanoscale single-crystal structures. The relationship between the dimensional structure and properties of the perovskite single crystals is discussed in detail. Dimensional requirements for different optoelectronic applications are systematically summarized. Finally, perspectives on remaining challenges and future opportunities are highlighted. [ABSTRACT FROM AUTHOR]