Scintillators, one of the essential components in medical imaging and security checking devices, rely heavily on rare‐earth‐containing inorganic materials. Here, a new type of organic‐inorganic hybrid scintillators containing earth abundant elements that can be prepared via low‐temperature processes is reported. With room temperature co‐crystallization of an aggregation‐induced emission (AIE) organic halide, 4‐(4‐(diphenylamino) phenyl)‐1‐(propyl)‐pyrindin‐1ium bromide (TPA‐PBr), and a metal halide, zinc bromide (ZnBr2), a zero‐dimensional (0D) organic metal halide hybrid (TPA‐P)2ZnBr4with a yellowish‐green emission peaked at 550 nm has been developed. In this hybrid material, dramatically enhanced X‐ray scintillation of TPA‐P+is achieved via the sensitization by ZnBr42−. The absolute light yield (14,700 ± 800 Photons/MeV) of (TPA‐P)2ZnBr4is found to be higher than that of anthracene (≈13,500 Photons/MeV), a well‐known organic scintillator, while its X‐ray absorption is comparable to those of inorganic scintillators. With TPA‐P+as an emitting center, short photoluminescence and radioluminescence decay lifetimes of 3.56 and 9.96 ns have been achieved. Taking the advantages of high X‐ray absorption of metal halides and efficient radioluminescence with short decay lifetimes of organic cations, the material design paves a new pathway to address the issues of low X‐ray absorption of organic scintillators and long decay lifetimes of inorganic scintillators simultaneously.
Scintillators for radiation detection are of great significance in medical imaging, security, and nondestructive inspection. The current challenge for scintillators is to simultaneously achieve high scintillation light yield, fast radioluminescence, simple film fabrication, large X‐ray attenuation efficiency as well as stable and nontoxic compositions; no previous scintillators fulfill all the above requirements. Here, metal halide Rb2AgBr3, possessing defect‐bound excitonic radioluminescence, is shown as efficient and fast scintillators. This nontoxic and stable scintillator emits from excitons bound to neutral bromine vacancies, enjoying an efficient and spin‐allowed fast emission with minimized self‐absorption. Rb2AgBr3thus has a high light yield (25 600 photons MeV−1), fast scintillation decay time (5.31 ns), and a record value of light yield versus decay time (4821 photons MeV−1ns−1). The close‐space sublimation method is developed for fast and scalable fabrication of oriented Rb2AgBr3films. The scintillator film is further integrated with commercial flat‐panel imagers, and the spatial resolution reaches 10.2 line pairs per millimeter at the modulation transfer function of 0.2, doubling the resolution of conventional CsI:Tl flat‐panel detectors. The dynamic X‐ray imaging and its use to real‐time monitoring of bone movement without ghosting effect is also demonstrated.more » « less
- NSF-PAR ID:
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Medium: X
- Sponsoring Org:
- National Science Foundation
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