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Organic scintillators have recently gained considerable attentions in X‐ray detection for their potential applications in biomedical radiograph and security inspection. However, the weak X‐ray absorption and/or inefficient exciton utilization have limited the development and commercialization of organic scintillators. Currently, high‐performance X‐ray organic scintillators are scarce and organic scintillators with dual triplet‐harvesting channels have not been explored before. Here, we develop several proof‐of‐concept sulfone‐based organic molecules, C1–C7, using different alkoxy chains to manipulate molecular packing mode. These materials exhibit dual triplet‐harvesting channels of thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) in aggregated state. Inspiringly, these molecules display distinct radioluminescence under the X‐ray stimulation. Among them, C6 behaves the highest light yield of 16,558 photons MeV−1. Moreover, clear X‐ray images are demonstrated in both aggregated state and single‐molecule level. High spatial resolutions of 15.0 and 10.6 line pairs per millimeter (lp mm−1) are achieved for rigid and flexible scintillator screens, exceeding most reported organic and conventional inorganic scintillators. These results highlight the great potential of organic molecules with TADF and RTP nature for efficient X‐ray scintillation and imaging. [ABSTRACT FROM AUTHOR]

Quasi-zero-dimensional quantum dots (QDs) have garnered significant attention owing to their distinct structural attributes, quantum confinement behaviors, optoelectronic characteristics, etc. Regrettably, their susceptibility to stability poses a challenge. In this context, leveraging rational component regulation and crystallization process optimization strategies, we presented the successful preparation of CdS QDs silicate glass through the amalgamation of melt-quenching and controlled crystallization. The optical and morphological analysis substantiated the accomplishment of in-situ precipitation of CdS QDs within the glass matrix, with grain sizes <20 nm. Integrating CdS QDs into an inorganic glass matrix remarkably augmented its fluorescence thermal stability, enabling the preservation of 85.1 % of the room-temperature luminescent intensity even at an elevated temperature of 150 °C. Moreover, the encapsulated W-LED device by near-UV LED chip, CdS QDs glass, and BaMgAl 10 O 17 :Eu2+ phosphor exhibited a warm white-light emission characterized by suitable chromaticity coordinates (0.3741, 0.3452) and a notably high color rendering index (CRI = 93). Ultimately, the radioluminescence behavior of CdS QDs glass was unveiled by utilizing it as the scintillator wafer in an X-ray imaging system, which clearly demonstrated the structure of spring encapsulated within an opaque capsule. In a nutshell, these demonstrations unequivocally emphasize the substantial potential merits of CdS QDs glass, particularly in the domains of long-term W-LED lighting and X-ray imaging applications. [ABSTRACT FROM AUTHOR]

Scintillating materials that convert ionizing radiation into low‐energy photons hold great potential for radiation detection, nondestructive inspection, medical radiography, and space exploration. However, organic scintillators are characterized by low radioluminescence, while bulky inorganic scintillators are not suitable for the development of flexible detectors. Here, high‐resolution X‐ray imaging using solution‐processable lanthanide‐based metal–organic frameworks as microscale scintillators is demonstrated. Mechanistic studies suggest that lanthanide ions absorb X‐rays to generate high‐density molecular triplet excitons, and excited linkers subsequently sensitize lanthanide ions via nonradiative resonance energy transfer. Furthermore, the crystalline nature offers a delocalized electronic feature rather than isolated subunits, which enables direct trapping of charge carriers by lanthanide emitters. By controlling the concentration ratio between Tb3+ and Eu3+ ions, efficient and color‐tunable radioluminescence of lanthanide ions can be achieved. When coupled with elastic, transparent polymer matrices, these metal–organic framework‐based microscintillators allow the fabrication of flexible X‐ray detectors. Such detectors feature a detection limit of 23 nGy s−1, which is 240 times lower than the typical radiation dose for medical diagnosis. X‐ray imaging with resolution higher than 16.6 line pairs per millimeter is further demonstrated. These findings provide insight into the future design of hybrid scintillators for optoelectronics and X‐ray sensing and imaging. [ABSTRACT FROM AUTHOR]

The search for color‐tunable, efficient, and robust scintillators plays a vital role in the development of modern X‐ray radiography. The radioluminescence tuning of copper iodide cluster scintillators in the entire visible region by bandgap engineering is herein reported. The bandgap engineering benefits from the fact that the conduction band minimum and valence band maximum of copper iodide cluster crystals are contributed by atomic orbitals from the inorganic core and organic ligand components, respectively. In addition to high scintillation performance, the as‐prepared crystalline copper iodide cluster solids exhibit remarkable resistance toward both moisture and X‐ray irradiation. These features allow copper iodide cluster scintillators to show particular attractiveness for low‐dose X‐ray radiography with a detection limit of 55 nGy s−1, a value ≈100 times lower than a standard dosage for X‐ray examinations. The results suggest that optimizing both inorganic core and organic ligand for the building blocks of metal halide cluster crystals may provide new opportunities for a new generation of high‐performance scintillation materials. [ABSTRACT FROM AUTHOR]

Scintillators are key components in high-energy x-ray detectors for x-ray computed tomography, which are applied in medical diagnosis, nondestructive testing, and security inspection. Scintillators in x-ray imaging are required to have both high spatial resolution and sensitivity; however, a trade-off between spatial resolution and sensitivity exists. To improve the sensitivity of a scintillator, its thickness must be increased; however, spatial resolution deteriorates with increasing thickness. Here, we developed a well-aligned Tb-doped GdAlO3-αAl2O3 phase-separated scintillator fiber (PSSF) with a diameter of 1.25-μm by a micro-pulling-down method. The luminescence, scintillation, and imaging performances of a grown PSSF sample were evaluated. X-ray-induced radioluminescence measurements of the sample showed Tb3+ 4f–4f emissions in the wavelength range of 470–700 nm, and the maximum emission peak was at 550 nm. The contrast transfer function at 10 lp/mm was 82% for both 270 and 500 μm-thick PSSF samples. We calculated the luminescence index, which is the product of the scintillator's light yield and sensitivity, of the samples and compared their values with commercially available conventional CsI:Tl columnar scintillators. The Tb-doped GdAlO3-αAl2O3 PSSF exhibits higher contrast transfer function and luminescence index values at above 60 keV x-ray region compared with the tested conventional scintillators. [ABSTRACT FROM AUTHOR]

Lead-free Cs 3 Cu 2 Cl 5 metal halide exhibits high photoluminescence quantum yield (PLQY), large Stokes shifts and small self-absorption due to self-trapped excitons (STE) emission, which undoubtedly is a potential scintillator material. However, Cs 3 Cu 2 Cl 5 nanocrystals (NCs) are susceptible to degradation by moisture at high humidity environment, which severely affects its long-term application in X-ray imaging. Herein, we prepared Cs 3 Cu 2 Cl 5 scintillator films with a PLQY of 72.4% and a high spatial resolution of 20 lp mm−1. Moreover, we firstly propose a self-healing strategy with facile microwave treatment to recover the crystal structure of Cs 3 Cu 2 Cl 5 film which damaged by moisture, while the photoluminescence (PL) and radioluminescence (RL) intensities of the damaged Cs 3 Cu 2 Cl 5 film are repaired to more than 95% and the spatial resolution can be restored to 20 lp mm−1. Furtherly, the imaging quality of the self-healing scintillator film can be maintained stably by cyclic microwave treatment. It found that microwave treatment provides a simultaneous and molecular level heating environment for the Cs 3 Cu 2 Cl 5 film, which drives the hydrolysates to re-crystallize along with the surface of the destroyed crystals. Therefore, microwave treatment opens a new avenue to recover Cs 3 Cu 2 Cl 5 films degraded by moisture, and provides a solution for long-term application of scintillator films at low cost. [ABSTRACT FROM AUTHOR]

Scintillators that exhibit X-ray-excited luminescence have great potential in radiation detection, X-ray imaging, radiotherapy, and non-destructive testing. However, most reported scintillators are limited to inorganic or organic crystal materials, which have some obstacles in repeatability and processability. Here we present a facile strategy to achieve the X-ray-excited organic phosphorescent scintillation from amorphous copolymers through the copolymerization of the bromine-substituted chromophores and acrylic acid. These polymeric scintillators exhibit efficient X-ray responsibility and decent phosphorescent quantum yield up to 51.4% under ambient conditions. The universality of the design principle was further confirmed by a series of copolymers with multi-color radioluminescence ranging from green to orange-red. Moreover, we demonstrated their potential application in X-ray radiography. This finding not only outlines a feasible principle to develop X-ray responsive phosphorescent polymers, but also expands the potential applications of polymer materials with phosphorescence features. The authors achieved the X-ray-excited organic phosphorescent scintillation from copolymers through copolymerization of bromine-substituted chromophores and acrylic acid and demonstrated their potential application in X-ray radiography. [ABSTRACT FROM AUTHOR]

Copper-based lead-free perovskite derivatives have recently drawn great attention for their excellent optoelectronic properties and potential applications in light-emitting diodes (LEDs) and photodetectors. Herein, facile synthesis methods of cooling crystallization and wet ball milling (WBM) are adopted to synthesize K2CuCl3, resulting in single crystals (SCs) and powder samples, respectively. The as-fabricated K2CuCl3 samples exhibit blue–violet emission, with the highest photoluminescence quantum yield (PL QY) of 70% (under 280 nm excitation), and the photoluminescence (PL) is attributed to the self-trap excitons (STEs) emission. We also test the scintillation properties of K2CuCl3 for X-ray detection and imaging applications. A down-conversion LED is finally made by using K2CuCl3 as phosphor. As-synthesized K2CuCl3 can be used for either photoluminescence under UV light or X-ray imaging under X-ray radiation. -- Present in ms [ABSTRACT FROM AUTHOR]

Glass scintillators have attracted increasing attention for X-ray imaging because of their low cost, easy manufacturing, superb transparency, and uniformity. In this paper, oxyfluoride glass scintillators doped with Ce3+ were developed through the utilization of carbon as a reducing agent. All oxyfluoride glasses exhibit exceptional transmittance (surpassing 90% @ 550 nm). The optimal glass prepared with carbon presents excellent integrated X-ray excited luminescence (XEL) intensity. It is about 86% of that of Bi 4 Ge 3 O 12 , which is 2.1 times of that of glass prepared without carbon. And the spatial resolution of optimal glass for X-ray imaging can reach 18 lp·mm−1. Notably, the integrated XEL intensity of optimal sample is comparable to the best Ce3+-doped glass materials and its spatial resolution exceeds that of Ce3+-doped glass ceramics. The aforementioned results demonstrate the possible utility of Ce3+-doped glass scintillators in the field of X-ray imaging applications. • Glass samples own high transmittance and high IQE. • Carbon is employed as reducing agent to improve the XEL intensity. • GCe8C9 glass presents relatively high integrated XEL intensity (86% of Bi 4 Ge 3 O 12). • GCe8C9 glass shows high spatial resolution (18 lp·mm−1) for X-ray imaging. [ABSTRACT FROM AUTHOR]

Gd3+-sensitized rare earth fluoride scintillators for high-resolution flexible X-ray imaging. [Display omitted] • Dumbbell-shaped YF 3 :Gd3+/Tb3+ NPs were prepared through ultra-fast chemical precipitation. • YF 3 :Gd3+/Tb3+ NPs show superb chemical stability and X-ray radioluminescence. • YF 3 :Gd3+/Tb3+@PDMS films have enough capacity for high-resolution flexible X-ray imaging. X-ray imaging technology is widely used in the medical, industrial, and scientific fields, where highly sensitive, flexible, and cost-effective scintillation screens are crucial prerequisites. In this work, YF 3 :Gd3+/Tb3+ microparticles (MPs) were prepared via an ultrafast chemical precipitation method and exhibited excellent luminescent properties under the excitation of ultraviolet light and X-ray. It was found that Gd3+ doping could effectively enhance the photoluminescence (PL) and X-ray activated radioluminescence (RL) of Tb3+ owing to an efficient energy transfer process from Gd3+ to Tb3+. The prepared YF 3 :30%Gd3+/10%Tb3+ MPs exhibited fine environmental stability and superb X-ray RL, which was stronger than that of commercial scintillators Bi 4 Ge 3 O 12 (BGO) and even comparable to that of CsI:TI single crystal. Highly flexible transparent YF 3 :Gd3+/Tb3+/PDMS scintillation screens were prepared to record high-resolution X-ray images of planar/nonplanar objects, where the imaging spatial resolution was 16.8 lp mm−1, which was far higher than the standard spatial resolutions required for medical computed tomography (CT) scan (2 lp mm−1) and X-ray imaging (3.5 lp mm−1). The excellent scintillation performance, superior flexibility and environmental stability of YF 3 :Gd3+/Tb3+/PDMS scintillation films endow them with the potential application in high-resolution industrial nondestructive inspection and biological imaging. [ABSTRACT FROM AUTHOR]

Radioluminescent materials (scintillators) are widely applied in medical imaging, nondestructive testing, security inspection, nuclear and radiation industries, and scientific research. Recently, all‐inorganic lead halide perovskite nanocrystal (NC) scintillators have attracted great attention due to their facile solution processability and ultrasensitive X‐ray detection, which allows for large area and flexible X‐ray imaging. However, the light yield of these perovskite NCs is relatively low because of the strong self‐absorption that reduces the light out‐coupling efficiency. Here, NCs with self‐trapped excitons emission are demonstrated to be sensitive, reabsorption‐free scintillators. Highly luminescent and stable Cs3Cu2I5 NCs with a photoluminescence quantum yields of 73.7%, which is a new record for blue emission lead‐free perovskite or perovskite‐like NCs, is produced with the assistance of InI3. The PL peak of the Cs3Cu2I5 NCs locates at 445 nm that matches with the response peak of a silicon photomultiplier. Thus, Cs3Cu2I5 NCs are demonstrated as efficient scintillators with zero self‐absorption and extremely high light yield (≈79 279 photons per MeV). Both Cs3Cu2I5 NC colloidal solution and film exhibit strong radioluminescence under X‐ray irradiation. The potential application of Cs3Cu2I5 NCs as reabsorption‐free, low cost, large area, and flexible scintillators is demonstrated by a prototype X‐ray imaging with a high spatial resolution. [ABSTRACT FROM AUTHOR]

Scintillators play a vital role in high-energy physics, medical imaging, security inspection, etc. Here, we designed and prepared a highly efficient scintillator of Ce,Tb-codoped LiLuF 4 , which was synthesized by a hydrothermal method using low-cost raw materials. The microcrystalline scintillator exhibits the strong luminescence of rare earth ion, which has a characteristic green fluorescence emission with a quantum yield of 71.59%. This material has a strong X-ray response, superior light output (16,509 ph/MeV), excellent ray cut-off capability and absolute stability. Based on micron-level powdered compounds, we used direct coating to manufacture a scintillation film with a size of 5.5 cm × 8.0 cm for X-ray imaging testing. The imaging test shows that the highly stable scintillation film not only has a spatial resolution capability of more than 10.0 LP/mm but also has great potential to be prepared as a flexible scintillator, which exhibited excellent performance as an potential scintillation detection material. Tetragonal LLF:Ce,Tb MCs exhibit bright and sensitive radioluminescence with the energy transfer process between rare earth ions, and its composite film can provide a decent spatial resolution for X-ray imaging applications. [Display omitted] • Lu element was used instead of Y element to improve the scintillation property of the material. • Ce ion sensitizing Tb ion strategy was adopted to improve the radiation light output of the material. • A large area scintillation film with transmittance of 79.92% was successfully prepared by direct coating method. • The spatial resolution of the scintillation film for radiation detection is more than 10.0 LP/mm. [ABSTRACT FROM AUTHOR]