A Universal Assembly Strategy of All‐Inorganic Non‐Layered Perovskite Single Crystals for High‐Responsivity Photodetectors

Abstract Non‐layered all‐inorganic perovskite single crystals (AIPSCs) have ultralow trap density and exceptional optoelectronic properties, which can be used for developing high‐performance perovskite optoelectronic devices with high efficiency and stability. However, there is a lack of comprehensive insight and universal principles to guide the preparation of high‐quality AIPSCs. Herein, a universal liquid–air interfacial assembly strategy is proposed for synthesizing non‐layered AIPSCs, in virtue of which a series of AIPSCs including whole structural dimensions from 0D to 3D are acquired. Specially, the CsPbI₃ AIPSCs exhibit an ultrathin thickness of 40 nm, and the CsPbBr₃ AIPSCs show ultra‐narrow PL FWHM of 11 nm. Photodetectors (PDs) based on CsPbBr₃ show excellent performance with responsivity up to 120 A W⁻¹ and detectivity exceeding 2 × 10¹³ Jones. Moreover, vertically integrated heterojunctions of mixed‐dimensions are fabricated, and the 2D/3D heterostructure PDs further display enhanced self‐powered characteristics. This work provides general synthetic guidance toward the synthesis of non‐layered AIPSCs and promotes their application in AIPSCs‐based optoelectronics.