Lead-free halide double perovskites (HDPs) have sparked broad interest in developing “green” photodetectors; however, self-powered X-ray detectors in this family remain elusive. Here, by exploiting the chirality-induced polar photovoltaic effect in a chiral-polar 2D HDP, (R-MPA)4AgBiI8 (1, R-MPA = R-β-methylphenethylammonium), we successfully realized self-powered X-ray detection. The significant spontaneous electric polarization in 1 gives it a large polar photovoltage of 0.36 V, which drives the separation and transport of X-ray-generated carriers, thus acquiring the capability of self-powered detection. Consequently, X-ray detectors based on high-quality single crystals of 1 exhibit a high sensitivity of 46.3 μC Gy–1 cm–2 and an ultralow detection limit of 85 nGy s–1 at zero bias. The sensitivity can be further increased to 949.6 μC Gy–1 cm–2 at 50 V bias, outperforming all current 2D HDP detectors. Our work is the first to demonstrate self-powered X-ray detection in single-phase lead-free HDPs, enlightening future design of “green” self-powered radiation detectors.
The exceptional photophysical properties of 3D organic–inorganic lead halide hybrids (OILHs) endow their significant potential for usage in optoelectronics, which has sparked intense research on novel 3D OILHs and associated applications. However, constructing new 3D OILHs based on large organic cations suffers from tough challenges due to the limitation of the Goldschmidt tolerance factor rule, let alone further explorations of their practical applications. Herein, a brand‐new 3D lead chloride hybrid, (1MPZ)Pb4Cl10·H2O (1, 1MPZ = 1‐methylpiperazine) is reported, featuring a dense 3D lead chloride framework made of the corner‐, edge‐, and face‐shared lead chloride polyhedra. 1 presents a broadband white light emission with a large Stokes shift and a nanosecond photoluminescence lifetime, which originates from radiative recombination of self‐trapped excitons (STEs) induced by the highly distorted structure. Such a reabsorption‐free and fast‐decayed STEs emission coupling with the dense 3D architecture further enables 1 with effective X‐ray scintillation with good sensitivity. Impressively, 1 also shows superior environmental and radiation stability. This study provides a new 3D OILH with appealing luminescence, not only expanding the 3D OILH family but also inspiring the exploitation of their optoelectronic applications.
Lead halide perovskites have made great advance in direct X‐ray detection, however the presence of toxic lead and the requirement of high working voltages severely limit their applicability and operational stability. Thus, exploring “green” lead‐free hybrid perovskites capable of detecting X‐rays at zero bias is crucial but remains toughly challenging. Here, utilizing chiral R/S‐1‐phenylpropylamine (R/S‐PPA) cations, a pair of 0D chiral‐polar perovskites, (R/S‐PPA)2BiI5 (1R/1S) are constructed. Their intrinsic spontaneous electric polarization induces a large bulk photovoltage of 0.63 V, which acts as a driving force to separate and transport photogenerated carriers, thus endowing them with the capability of self‐driven detection. Consequently, self‐driven X‐ray detectors with a low detection limit of 270 nGy s−1 are successfully constructed based on high‐quality, inch‐sized single crystals of 1R. Notably, they show suppressed baseline drift under the self‐driven mode, exhibiting superior operational stability. This study realizes self‐driven X‐ray detection in a single‐phase lead‐free hybrid perovskite by exploiting the intrinsic bulk photovoltaic effect, which sheds light on future explorations of lead‐free hybrid perovskites toward “green” self‐driven radiation detectors with high performance.
2D chiral hybrid perovskites have recently emerged as outstanding semiconductor materials. However, most of the reported 2D chiral perovskites have limited structural types and contain high levels of toxic lead, which severely hinders their further applications. Herein, by using a mixed-cation strategy, an unprecedented type of lead-free cluster-based 2D chiral hybrid double perovskite derivatives are successfully obtained, [(R/S-PPA) 4 (IPA) 6 Ag 2 Bi 4 I 24 ]• 2H 2 O (1-R and 1-S), and [(R/S-PPA) 4 (n-BA) 6 Ag 2 Bi 4 I 24 ]•2H 2 O (2-R and 2-S) (R/S-PPA=R/S-1-phenylpropylamine; IPA=isopentylamine; n-BA=n-butylamine).Their inorganic skeletons are linked by binuclear {Bi 2 I 10 } and infinite chain {Ag 2 Bi 2 I 14 } ∞ , in which bismuth clusters and multiple coordination modes (e.g., tetrahedral AgI 4 and octahedral AgI 6 ) are introduced into the double perovskite system for the first time. This introduction induces distortion of the inorganic layer, which may facilitate the transfer of chirality from the chiral cations into achiral double perovskite skeletons. Further, circular dichroism measurements and circularly polarized light detection confirm their inherent chiral optical activities. In addition, 1-S exhibits an ultralow X-ray detection limit of 129.5 nGy s −1 , which is 42-fold lower than that of demands in regular medical diagnosis (5.5 µGy s −1 ). This study provides a pathway to construct novel type of lead-free cluster-based double perovskite derivatives.
Broadband photodetectors (PDs) with low detection limits hold significant importance to next-generation optoelectronic devices. However, simultaneously detecting broadband (i.e., X-ray to visible regimes) and weak lights in a single semiconducting material remains highly challenging. Here, by alloying iodine-substituted short-chain cations into the 3D FAPbI 3 (FA = formamidine), a new 2D bilayered lead iodide hybrid perovskite, (2IPA) 2 FAPb 2 I 7 (1, 2IPA = 2-iodopropylammonium), that enables addressing this challenge is reported. Such a 2D multilayered structure and lead iodide composition jointly endow 1 with a minimized dark current (6.04 pA), excellent electrical property, and narrow bandgap (2.03 eV), which further gives it great potential for detecting broadband weak lights. Consequently, its high-quality single crystal PDs exhibit remarkable photoresponses to weak ultraviolet-visible lights (377-637 nm) at several tens of nW cm −2 with high responsivities (>10 2 mA W −1 ) and significant detectivities (>10 12 Jones). Moreover, 1 has an excellent X-ray detection performance with a high sensitivity of 438 μC Gy −1 cm −2 and an ultralow detection limit of 20 nGy s −1 . These exceptional attributes make 1 a promising material for broadband weak lights detection, which also sheds light on future explorations of high-performance PDs based on 2D hybrid perovskites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.