Non‐artificial Layered Heterostructure as Inch‐size Single Crystal for Shortwave Polarized‐Light Array Detector

Abstract Layered heterostructures of different 2D building blocks have invigorated the booming of 2D materials toward high‐performance optoelectronic devices. However, contrary to the typical artificial multi‐component form, the engineering of non‐artificial layered heterostructure into single‐phase crystals and resultant properties are largely overlooked. Here, for the first time, an inch‐sized single crystal of a non‐artificial layered heterostructure is exploited, (PbBr 2 ) 2 (AMTP) 2 PbBr 4 ( 1 , AMTP is 4‐ammoniomethyltetrahydropyran), serving as polarization‐sensitive candidate. Notably, it adopts an interleaved architecture of 2D perovskite slabs with the distinct non‐perovskite lattice, thus forming a self‐assembled perovskite‐intergrowth layered heterostructure. This motif leads to new electronic transitions distributed across two sublattices and affords an inherent in‐plane anisotropy ratio of ≈1.6, beyond some known inorganic materials (e.g., GeSe: 1.44; GeAs: 1.49). Combining this in‐plane anisotropy and wide bandgap (≈2.9 eV), lateral crystal array of 1 enables shortwave polarized‐light detection with ultrahigh responsivity and detectivity under weak illumination compared to some inorganic polarized detectors. As the first demonstration of inch‐sized single crystals of non‐artificial layered heterostructure, this study affords a new platform to explore candidates toward high‐performance optoelectronic devices.