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The development of high‐performance X‐ray detectors requires scintillators with fast decay time, high light yield, stability, and X‐ray absorption capacity, which are difficult to achieve in a single material. Here, we present the first example of a lanthanide chalcogenide of LaCsSiS4 : 1 % Ce3+ that simultaneously integrates multiple desirable properties for an ideal scintillator. LaCsSiS4 : 1 % Ce3+ demonstrates a remarkably low detection limit of 43.13 nGyair s−1 and a high photoluminescence quantum yield of 98.24 %, resulting in a high light yield of 50480±1441 photons/MeV. Notably, LaCsSiS4 : 1 % Ce3+ exhibits a fast decay time of only 29.35±0.16 ns, making it one of the fastest scintillators among all lanthanide‐based inorganic scintillators. Furthermore, this material shows robust radiation and moisture resistance, endowing it with suitability for chemical processing under solution conditions. To demonstrate the X‐ray imaging capacity of LaCsSiS4 : 1 % Ce3+, we fabricated a flexible X‐ray detector that achieved a high spatial resolution of 8.2 lp mm−1. This work highlights the potential of lanthanide chalcogenide as a promising candidate for high‐performance scintillators. [ABSTRACT FROM AUTHOR]

Luminescent covalent organic frameworks (COFs) find promising applications in chemical sensing, photocatalysis, and optoelectronic devices, however, the majority of COFs are non or weakly emissive owing to the aggregation‐caused quenching (ACQ) or the molecular thermal motion‐based energy dissipation. Here, we report a previously unperceived approach to improve luminescence performance of COFs by introducing isotope effect, which is achieved through substitution of hydrogen from high‐frequency oscillators X‐H (X=O, N, C) by heavier isotope deuterium. Combining the "bottom‐up" and in situ deuteration methods generates the first deuterated COF, which exhibits an impressively 19‐fold enhancement in quantum yield over that of the non‐deuterated counterpart. These results are interpreted by theoretical calculations as the consequence of slower C/N‐D and OD⋅⋅⋅O vibrations that impede the nonradiative deactivation process. The proposed strategy is proved applicable to many other types of emissive COFs. [ABSTRACT FROM AUTHOR]

Herein we report the first example of an actinide polyiodate compound, namely K4[(UO2)2(IO3)6(I4O11)]·(HIO3)4(H2O)6 (UPI-1), which was obtained from slow evaporation of nitric acid with a high I/U ratio. Spectroscopic measurements indicate that UPI-1 possesses X-ray luminescence properties applicable for X-ray scintillation and also exhibits modest protonic conduction. [ABSTRACT FROM AUTHOR]

Scintillators are a unique class of luminescent materials with specific applications towards radiation detection. The emitters within state‐of‐the‐art scintillators are mostly limited to bismuth, cerium, europium, thallium, lead, tungsten, etc. A shared feature of these elements is the relatively high atomic number, which is responsible for high radiation stopping power and radiation‐induced luminescence. Searching for new scintillating materials is an essential target aiming at specific applications. In this Concept article, we will discuss our recent works on the topic of "uranyl‐bearing scintillators". As a virgin territory in this field, uranyl‐bearing scintillators show intrinsic merits for designing new materials with X‐ray detection capability, that is, the large photoelectric cross‐section, high X‐ray attenuation efficiency, and high crystal density. In addition, we also present challenges in the further development of the uranyl‐bearing scintillators. [ABSTRACT FROM AUTHOR]

For the first time, we report intense X-ray scintillation enabled by a series of isotypic lanthanide (Eu and Tb) based metal–organic frameworks, initially showing a very efficient X-ray to visible light luminescence conversion. By systematic adjusting of the molar ratio of Eu3+ and Tb3+ in the same MOF structure as a traditional strategy for color-tuning in lanthanide-based photoluminescent materials, linear multicolor visualization of X-ray radiation from red to green can be facilely achieved, providing a new class of scintillating materials with continuous color tunability that can be customized for desired purposes. Moreover, these lanthanide–organic framework based scintillators exhibit excellent radiation resistance and humidity stability, in comparison with the state of the art and commercially-available X-ray scintillator, CsI:Tl. [ABSTRACT FROM AUTHOR]

Flexible X-Ray Detector, Lanthanide Chalcogenide Scintillator, Luminescence, X-Ray Imaging Keywords: Flexible X-Ray Detector; Lanthanide Chalcogenide Scintillator; Luminescence; X-Ray Imaging EN Flexible X-Ray Detector Lanthanide Chalcogenide Scintillator Luminescence X-Ray Imaging 1 1 1 08/10/23 20230814 NES 230814 B Scintillators b . Frontispiece: Emergence of a Lanthanide Chalcogenide as an Ideal Scintillator for a Flexible X-ray Detector. [Extracted from the article]

Cooperative performance of mixed-valent Eu2+/Eu3+ in single-compound phosphors offers significant advantages in color rendering and luminescence efficiency, but their synthesis is challenging because of Eu2+ oxidation. Using the tunable nature of the metal-ion nodes in metal-organic frameworks (MOFs), we present an in situ reduction and crystallization route for preparing MOFs and doping Eu2+/Eu3+ with a controlled ratio. These materials exhibit rich photoluminescence, including intrinsic- and sensitized-emissions of Eu2+ and Eu3+, and long-lived luminescence from charge transfer. Color rendering can be easily achieved by fine-tuning the valence states of Eu. A linear relation between temperature and the intensity ratio of Eu2+/Eu3+ emissions provides outstanding properties for applications as self-calibrated luminescent thermometers with a wide working temperature range. Further incorporation of Tb3+ into the MOFs results in white light, utilizing all Eu2+,Tb3+, and Eu3+ emissions in a single crystalline lattice. [ABSTRACT FROM AUTHOR]

Keywords: luminescence; radiation detection; scintillators; uranium As a new area in this field, uranyl-bearing scintillators show intrinsic merits for designing new materials with X-ray detection capability, that is, a large photoelectric cross-section, high X-ray attenuation efficiency, and high crystal density. Luminescence, radiation detection, scintillators, uranium. [Extracted from the article]

Abstract We report here the investigation of using a luminescent europium organic framework, [Eu 2 (MTBC)(OH) 2 (DMF) 3 (H 2 O) 4 ]·2DMF·7H 2 O (denoted as compound 1), for detecting of both Cu2+ and UO 2 2+ with high sensitivity. Based on the spectroscopy analysis, compound 1 could selectively respond to Cu2+ and UO 2 2+ ions among other selected monovalent, divalent, trivalent metal cations based on a turn-off mechanism. The detection limit of compound 1 towards Cu2+ ion was as low as 17.2 μg/L, which is much lower than the maximum tolerable concentration of Cu2+ in drinking water (2 mg/L) defined by United States Environmental Protection Agency. On the other hand, the detection limit towards UO 2 2+ ions is 309.2 μg/L, which could be used for detecting uranium in relative severely contaminated areas. The concentration-dependent luminescence intensity evolution process could be fully understood by the absorption kinetics and isotherm investigations. Furthermore, the quenching mechanism was elucidated by the UV-vis, excitation, luminescence, and lifetime studies. Compound 1 , as the first MOF based luminescence probe for both Cu2+ and UO 2 2+ ions, provides insight into developing MOF-based multifunctional sensors for both nonradioactive and radioactive elements. Graphical abstract fx1 Highlights • A new lanthanide metal organic framework was used for both radioactive UO 2 2+ and nonradioactive Cu2+ detection. • The detection limits toward UO 2 2+ and Cu2+ are 17.2 ppb and 309.2 ppb respectively. • The material could be used for directly detecting UO 2 2+ and Cu2+ contamination in a wide concentration range. • The detection mechanism was systematically investigated by bath experiments, spectroscopy and lifetime studies. [ABSTRACT FROM AUTHOR]