Acquiring a Newly Tailored 2D Dion–Jacobson Hybrid Perovskite with Large Structural Distortion for Efficient Crystal Array Photodetector

Abstract Dion–Jacobson (DJ) phase of 2D hybrid perovskites has recently attracted intensive attention owing to their remarkable optoelectronic properties and superior structural stability. In spite of great endeavors, only a few DJ‐type multilayered hybrid perovskites are obtained and most of them are constructed by very small organic spacer cations (e.g., Cs + and CH 3 NH 3 + ). It is still challenging to incorporate larger spacing moieties inside the perovskite cages for accomplishing excellent photoelectric properties. Herein, a newly tailored member of DJ‐type 2D perovskites, (HIS)(DMA)Pb 2 Br 7 ( 1 , where HIS 2+ is histammonium and DMA + is dimethylammonium), of which the perovskite cavities display a remarkable structural distortion to accommodate relatively larger secondary DMA + cation as the “perovskitizer” is acquired. The monolayers of divalent HIS 2+ organic cations directly link to inorganic sheets through NH∙∙∙Br hydrogen bonds, thus eliminating the van der Waals gap in 2D Ruddlesden–Popper counterparts and enabling superior phase stability. As a result, crystal‐based array photodetector of 1 shows fascinating photoactive activities of high detectivity (1.2 × 10 13 Jones), large responsivity (18.1 A W −1 ), and antifatigue behavior, along with polarization‐sensitive detection based on the intrinsic anisotropy. Such findings disclose the potential of 1 for efficient photodetection, and definitely enrich the booming family of 2D hybrid perovskites.