Perovskite Dimensional Evolution Through Cations Engineering to Tailor the Detection Limit in Hard X‐ray Response. Issue 42 (18th September 2022)

• Record Type: Journal Article
• Authors: Li, Huayang; He, Yuhong; Li, Weijun; Lu, Tong; Tan, Mingrui; Wei, Wei; Yang, Bai; Wei, Haotong
• Is Part Of: Small. Volume 18:Issue 42(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-18
• Subjects: detection limit coefficient -- dimensional evolution -- lead‐free -- perovskite single crystals -- X‐ray detectors; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202203884
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Halide perovskites with various compositions are potential candidates in low‐dosage X‐ray detection due to their large sensitivity and tunable optoelectronic properties. Here, cations engineering induced dimensional evolution of halide perovskites between 0D, 2D, and 3D is reported. Centimeter‐sized 2D lead‐free perovskite single‐crystal of 4‐fluorophenethylammonium antimony iodide (FPEA3 SbI6 ) is synthesized. In contrast to the 0D phenethylammonium antimony iodide (PEA3 Sb2 I9 ), face‐shared [Sb2 I9 ] 3– of the bi‐octahedral structure of PEA3 Sb2 I9 is split into corner‐shared [SbI6 ] 3– by intermolecular interactions and steric hindrance of FPEA + ions in 2D FPEA3 SbI6 . Two Sb 3+ ions share three octahedral [SbI6 ] 3–, leaving one‐third of Sb 3+ vacancies in the framework of FPEA3 SbI6 . Furthermore, Sn 2+ ions can be filled into the vacancies to form continuous 2D frameworks to tune the anisotropic conductivity and device sensitivity to hard X‐rays. The dimensional evolution of perovskite single‐crystals from 3D to 2D or 0D to 2D maximizes the signal/noise ratio to facilize the adjustability of detection limit in hard X‐ray detection, which is determined by both device sensitivity and device noise current. A record low detection limit coefficient of 0.65 is achieved in the 2D FPEA3 SbSn0.5 I7 single‐crystal sample, which results from selective charges collection over mobile ions/noise current in the 2D perovskite structure. Abstract : 0D PEA3 Sb2 I9 can evolve to 2D FPEA3 SbI6, ascribed to the intermolecular interactions and steric hindrance of FPEA + in FPEA3 SbI6 . Two Sb 3+ ions share three octahedral [SbI6 ] 3–, leaving one‐third of Sb 3+ vacancies in the framework of FPEA3 SbI6 . Introducing Sn 2+ can effectively fill the vacancies, reduce the trap density, and tune the anisotropic electrical conductivity and sensitivity of FPEA3 SbSnx I6+2x to hard X‐rays.