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The zero-dimensional copper halide perovskite Cs 3 Cu 2 I 5 displays extraordinary luminescence and scintillation characteristics, and high-quality crystals are extremely desirable for exploring the commercial applications. Currently, the most critical issue in the solution growth of Cs 3 Cu 2 I 5 crystals is the easy oxidation of halides, which significantly hinders the optimization of crystal qualities. The hypophosphorous acid (H 3 PO 2) has been applied to inhibit the oxidation, nevertheless, the related mechanism is elusive and has been largely ignored. Herein, Cs 3 Cu 2 I 5 crystals have been grown from N, N-Dimethylformamide (DMF) solvent by the antisolvent vapor-assisted crystallization (AVC) method. It is verified that H 3 PO 2 effectively prevents the oxidation of Cs 3 Cu 2 I 5 by rapidly reducing Cu2+ and I 3 −, maintaining the stability of the precursor solution and continuously suppressing oxidation during the whole growth process. Meanwhile, by increasing the acidity of the solution, H 3 PO 2 dissolve precursor colloids and efficiently enhance the solubility of halides. Thus, the addition of H 3 PO 2 favors the rapid growth of centimeter-sized Cs 3 Cu 2 I 5 crystals with well-defined crystallographic planes within several days. As excellent gamma ray scintillator, the crystal exhibits high light yield of 38000 photons/MeV, with energy resolution of 5.6 % under 662 keV radiation from a 137Cs source. This work deeply elucidates new insight into the critical effect of H 3 PO 2 in the DMF based solution crystal growth, facilitating the preparation of large-size and high-performance copper halide perovskite crystals. [ABSTRACT FROM AUTHOR]

Site‐selective occupation generated by ion doping into crystal lattices is an effective way to explore new matter and regulate luminescent properties. Herein, equiv. M2+ (Ca, Sr, Ba) is partially replaced each other to formulate multiple doped sites in Li2MSiO4: Eu2+ (LMSO: Eu2+). As the luminescence center, Eu2+ selectively occupies different sites to regulate luminescent color in the visible spectrum ranging from blue to orange, and ultimately functionality improvement. The Huang‐Rhys factor is quite small and the resulting phosphors display an ultrahigh thermal stability for optical thermometry. Besides, utilizing synthesized phosphors combined with the InGaN chip generates high‐quality full‐spectrum white light. Under X‐ray irradiation, LMSO: Eu2+ (M = Ca, Sr, Ba) exhibits great X‐ray imaging ability, the detection limit of X‐ray reaches 0.18, 0.075, and 0.12 µGy s−1. This work presents great potentiality of synthesized phosphors in the fields of solid‐state lighting and X‐ray imaging. [ABSTRACT FROM AUTHOR]

High-performance and low-cost metal halide perovskite scintillator materials have important applications in X-ray detection and imaging. However, large-sized perovskite scintillator panel with high transmittance, low toxicity and long-term stability is still lacking. Herein, Eu2+ doped cesium alkaline earth chloride nanocrystals (Eu2+: CsCaCl 3 , Eu2+: CsSrCl 3 , and Eu2+: Cs 2 BaCl 4 NCs) embedded in glasses through conventional melt-quenching and subsequent heat-treatment were developed. These NCs doped glasses exhibited highly efficient and narrowband photoluminescence in blue region. Benefitting from the large X-ray absorption coefficient and high photoluminescence quantum yied, these Eu2+: CsCaCl 3 NCs doped glass scintillator shows light yield of ∼9300 photons/MeV, detection limit of ∼213.8 μGy/s, and spatial resolution of 30.0 lp/mm. These results demonstrated that glasses containing Eu2+ doped cesium alkaline earth chloride nanocrystals are promising for X-ray detection and imaging. [ABSTRACT FROM AUTHOR]

The development of all‐inorganic lead‐free Cs3Cu2I5 perovskite materials has garnered significant attention due to their non‐toxic nature and unique optoelectronic properties, particularly in the field of X‐ray detection. However, the stability of perovskites remains a major concern for their optical applications. In this study, a highly stable Cs3Cu2I5‐in‐glass composite (Cs3Cu2I5@Borosilicate) is fabricated by spark plasma sintering (SPS), a rapid and low‐temperature sintering process. The Cs3Cu2I5@Borosilicate composite exhibits strong photoluminescence even after prolonged immersion in various polar solvents, whereas Cs3Cu2I5 perovskite loses its photoluminescence within seconds. Moreover, the Cs3Cu2I5@Borosilicate composite demonstrates robust radio‐luminescence under X‐ray irradiation, and its potential as a scintillator material is validated through prototype X‐ray imaging with a high spatial resolution (≈7 lp mm−1). This innovative composite material holds immense potential for scintillation applications and represents a promising approach for encapsulating perovskites in a transparent amorphous medium. [ABSTRACT FROM AUTHOR]

Gadolinium pyrosilicate (GPS, Gd2Si2O7) single crystals with different doping concentrations of Tb (0.1–2.0 mol%) are successfully fabricated using the floating-zone technique. In this work, the dependence of Tb-doping concentration on the photoluminescence (PL) and scintillation properties of Tb-doped GPS (Tb:GPS) has been investigated. The PL emission contour graph shows multiple emissions, with the strongest emissions at 378 nm for 0.1% and 0.5% Tb-doping and 544 nm for 1.0% and 2.0% Tb-doping, corresponding to Tb3+ 4f-4f transitions. The PL lifetimes of the specimens range from 4.89 to 5.22 ms. The scintillation spectra exhibit comparable wavelength and intensity trends to the PL emission. The scintillation lifetimes of the specimens range from 2.41 to 3.88 ms. The Tb:GPS specimens demonstrate a relatively excessive afterglow level, with Af20 values ranging from 1640 to 7250 ppm and Af40 values ranging from 136 to 362 ppm. Using recently developed pulse height measurement for millisecond decay scintillators, under excitation at 662 keV γ-rays, the 1.0% Tb:GPS specimen exhibits the highest scintillation light yield among all other specimens at 95,600 ph/MeV, making Tb:GPS one of the highest light yield oxide scintillators. [ABSTRACT FROM AUTHOR]

Thanks to advancements in silicon photomultiplier sensors (SiPMs) and system-on-chip (SoC) technology, our INFN Roma1 group developed ArduSiPM in 2012, the first all-in-one scintillator particle detector in the literature. It used a custom Arduino Due shield to process fast signals, utilizing the Microchip Sam3X8E SoC's internal peripherals to control and acquire SiPM signals. The availability of radiation-tolerant SoCs, combined with the goal of reducing system space and weight, led to the development of an innovative second-generation board, a better-performing device called Cosmo ArduSiPM, suitable for space missions. The architecture of the new detector is based on the Microchip SAMV71 300 MHz, 32-bit ARM® Cortex®-M7 (Microchip Technology Inc., Chandler, AZ, USA). While the analog front-end is essentially identical to the ArduSiPM, it utilizes components with the smallest possible package. The board fits in a CubeSat module. Thanks to the compact design, the board has two independent channels, with a total weight of only 40 grams within a CubeSat form factor. The ArduSiPM architecture is based on a single microcontroller and fast discrete analog electronics. It benefits from the continued development of SoCs related to the IoT (Internet of Things) market. Compared with a system with a custom ASIC, this architecture based on software and SoC capabilities offers considerable advantages in terms of cost and development time. The ability to incorporate new commercial SoCs, continuously emerging from advancements in the aerospace and automotive industries, provides the system with a robust foundation for sustained growth over the years. A detailed characterization of the hardware and the system's response to different photon fluxes is presented in this article. Additionally, coupling the device with a scintillator was tested at the end of this article as a preliminary trial for future measurements, showing potential for further enhancement of the detector's capabilities. [ABSTRACT FROM AUTHOR]

Luminescent metal halides, as a type of luminescent semiconductor material, offer advantages that fulfill the requirements of emerging light source devices, such as high luminescence efficiency, good thermal stability, and tunable colorful emission. Blue light being one of the three primary colors plays a crucial role in the field of lighting and colorful displays. However, the progress in device performance of blue‐light materials lags behind that of green and red‐light materials. Currently, there have been numerous reports on metal halide perovskite blue‐light materials, but a comprehensive review on the development and performance control of blue‐light metal halides is yet to be found. This paper provides a comprehensive summary of the design strategies and luminescence mechanisms of blue‐light perovskites with various luminescence centers, as well as their application progress in the fields of light‐emitting diodes (LEDs), X‐ray scintillators, information anti‐counterfeiting and encryption. It also explores possible directions for subsequent performance improvement. This work aims to offer valuable insights and recommendations for the future development of blue‐light metal halides, with significant implications for the fabrication of novel blue light devices and advancements in detection technology. [ABSTRACT FROM AUTHOR]

Background: Dosimetry in ultra‐high dose rate (UHDR) beamlines is significantly challenged by limitations in real‐time monitoring and accurate measurement of beam output, beam parameters, and delivered doses using conventional radiation detectors, which exhibit dependencies in ultra‐high dose‐rate (UHDR) and high dose‐per‐pulse (DPP) beamline conditions. Purpose: In this study, we characterized the response of the Exradin W2 plastic scintillator (Standard Imaging, Inc.), a water‐equivalent detector that provides measurements with a time resolution of 100 Hz, to determine its feasibility for use in UHDR electron beamlines. Methods: The W2 scintillator was exposed to an UHDR electron beam with different beam parameters by varying the pulse repetition frequency (PRF), pulse width (PW), and pulse amplitude settings of an electron UHDR linear accelerator system. The response of the W2 scintillator was evaluated as a function of the total integrated dose delivered, DPP, and mean and instantaneous dose rate. To account for detector radiation damage, the signal sensitivity (pC/Gy) of the W2 scintillator was measured and tracked as a function of dose history. Results: The W2 scintillator demonstrated mean dose rate independence and linearity as a function of integrated dose and DPP for DPP ≤ 1.5 Gy (R2 > 0.99) and PRF ≤ 90 Hz. At DPP > 1.5 Gy, nonlinear behavior and signal saturation in the blue and green signals as a function of DPP, PRF, and integrated dose became apparent. In the absence of Cerenkov correction, the W2 scintillator exhibited PW dependence, even at DPP values <1.5 Gy, with a difference of up to 31% and 54% in the measured blue and green signal for PWs ranging from 0.5 to 3.6 µs. The change in signal sensitivity of the W2 scintillator as a function of accumulated dose was approximately 4%/kGy and 0.3%/kGy for the measured blue and green signal responses, respectively, as a function of integrated dose history. Conclusion: The Exradin W2 scintillator can provide output measurements that are both dose rate independent and linear in response if the DPP is kept ≤1.5 Gy (corresponding to a mean dose rate up to 290 Gy/s in the used system), as long as proper calibration is performed to account for PW and changes in signal sensitivity as a function of accumulated dose. For DPP > 1.5 Gy, the W2 scintillator's response becomes nonlinear, likely due to limitations in the electrometer related to the high signal intensity. [ABSTRACT FROM AUTHOR]

X‐ray scintillators have gained significant attention in medical diagnostics and industrial applications. Despite their widespread utility, scintillator development faces a significant hurdle when exposed to elevated temperatures, as it usually results in reduced scintillation efficiency and diminished luminescence output. Here we report a molecular design strategy based on a hybrid perovskite (TpyBiCl5) that overcomes thermal quenching through multi‐excited state switching. The structure of perovskite provides a platform to modulate the luminescence centers. The rigid framework constructed by this perovskite structure stabilized its triplet states, resulting in TpyBiCl5 exhibiting an approximately 12 times higher (45 % vs. 3.8 %) photoluminescence quantum yield of room temperature phosphorescence than that of its organic ligand (Tpy). Most importantly, the interactions between the components of this perovskite enable the mixing of different excited states, which has been revealed by experimental and theoretical investigations. The TpyBiCl5 scintillator exhibits a detection limit of 38.92 nGy s−1 at 213 K and a detection limit of 196.31 nGy s−1 at 353 K through scintillation mode switching between thermally activated delayed fluorescence and phosphorescence. This work opens up the possibility of solving the thermal quenching in X‐ray scintillators by tuning different excited states. [ABSTRACT FROM AUTHOR]

The characteristics of neutron scintillation detectors built on monolithic and heterogeneous scintillators containing 6Li were studied. The detectors were tested on a thermal neutron beam and on a stand with a source of γ-quanta 60Co. To process the signals received from the detector with a monolithic scintillator, three different γ-radiation discrimination algorithms were used: registration of pulses at a constant threshold and selection according to the pulse shape using two digital signal separation methods: charge integration and pulse duration measurement. For a homogeneous scintillator, pulse shape selection methods work approximately the same when separating thermal neutrons and γ-quanta and are significantly inferior to the method of registration at a constant threshold. In this case, the quality of the n/γ separation is worse than the result obtained with a heterogeneous scintillator when recording at a constant threshold. The purpose of the work is to compare the results of using digital methods for discrimination of gamma-quanta with the results obtained using heterogeneous scintillators. [ABSTRACT FROM AUTHOR]

Scintillators, owing to their exceptional ability to convert high-energy ionizing radiation into visible light, are the core component of X-ray radiography. However, conventional single-crystal scintillators are inadequate to satisfy the modern social and scientific demands. So, the development of novel scintillator materials is imminent. Herein, a series of Na 5 Lu 9- x Gd x F 32 :Ce3+ glass-ceramics (GCs) scintillators were elaborated by an exercisable and low-cost method. Benefiting from the proper introduction of Al powder and Gd3+, as well as the crystallization of Na 5 Lu 9- x Gd x F 32 nanocrystal (NCs) after heat treatment, luminescence excited by ultraviolet and X-ray of the sample is enhanced significantly. The integrated X-ray excited luminescence intensity of the representative sample can reach up to 128% of that of Bi 4 Ge 3 O 12. More importantly, the sample has excellent irradiation stability that is almost undamaged even exposed to high-energy X-ray radiation. Finally, satisfactory X-ray imaging based on the resultant sample was realized. The spatial resolution is as high as 14 lp mm−1, which exceeds that of many novel perovskite scintillators. Thus, this investigation promotes the development of low-cost, stable and high-performing Ce3+-activated GCs scintillators. • Three effective ways were designed to improve the scintillating property of the sample. • The integrated X-ray excited luminescence reaches 128% of that of Bi 4 Ge 3 O 12. • The sample is undamaged even excited by high-power (12 W) X-ray, infering outstanding irradiation stability. • Satisfactory X-ray imaging based on the sample was achieved. • The spatial resolution reaches 14 lp mm−1, exceeding that of many perovskite scintillators. [ABSTRACT FROM AUTHOR]

Organic materials show good mechanical flexibility, easy processing, and large‐area manufacturing, while weak X‐ray absorption and low sensitivity for X‐ray scintillator media. As seen originally, this is a synergistic result of the lack of heavy elements in the molecule that can effectively truncate X‐rays and the massive dissipation of triplet excitons produced by molecular ionization. Herein, cocrystal with phosphorescence enhancement is found to be brilliant in addressing the shortcomings of organic scintillators. The results show that heavy atoms can be easily introduce into the donor unit of organic cocrystal to satisfy the X‐ray absorption and effectively activate the triplet excitons via promoting intersystem crossing (ISC). Moreover, the rational structural design of the acceptor molecule can achieve coupling with the donor for inhibiting the non‐radiative loss of the triplet exciton. Finally, the preferred PNPA (4,4′‐Dibromobiphenyl and N‐phenylnaphthalen‐2‐amine) cocrystals achieve record X‐ray‐induce exciton utilization and emit bright phosphorescent light. Meanwhile, the related device shows durable radiation stability, spatial resolution (>11 lp mm−1), low detection limit (<0.6 µGyair s−1), and effective dynamic imaging application. Hence, it is believed the organic cocrystal‐designed principle can provide guidance to develop advanced sensitive X‐ray scintillators in the future. [ABSTRACT FROM AUTHOR]

In this study, highly (Y 0.99−x Gd x Sm 0.01) 2 O 3 transparent ceramics with varying Gd3+ content (x = 0–0.1) was successfully fabricated by vacuum sintering. The effect of the Gd3+ content on the structural, mechanical and optical properties of the Y 2 O 3 ceramics were systematically investigated. The prepared transparent ceramics have high optical quality with an in-line transmittance of 75.16%− 81.44% at 610 nm (4G 5/2 →6H 9/2 transitions of Sm3+). Mechanical properties, including Vickers hardness (HV), are also evidently enhanced by solid solution strengthening. Photoluminescence properties of ceramics including excitation spectra, emission spectra and fluorescence lifetimes are systematically investigated. Notably, the photoluminescence properties of the ceramics, including excitation spectra, emission spectra and fluorescence lifetimes, confirm the existence of energy transfer (ET) from Gd3+ to Sm3+ ions and provide a qualitative understanding of the ET process. The efficiency of ET between Gd3+ and Sm3+ emission centers was found to increase with higher Gd3+ concentration. This work may provide guidance on the design, preparation and application of Gd-doped transparent ceramic scintillators. [ABSTRACT FROM AUTHOR]

The 3He gas is commonly used for the detection of thermal neutrons. However, with the depletion of 3He gas, there is a need to develop new solid scintillators for thermal neutron detection. Solid scintillators containing 6Li, which have large neutron capture cross-sections and a large amount of energy released by transmutation reactions, are commonly used as alternative candidates. However, only single-crystal scintillators are currently used, and their 6Li concentration is limited by their chemical composition. In this study, we designed, grew, and evaluated a new eutectic scintillator, Rb2CeCl5/LiCl, which can improve the 6Li concentration compared with single-crystal scintillators. Rb2CeCl5, which was selected as the scintillator phase, has excellent scintillator properties (light yield: 36,000 photons/MeV, decay time: mostly 24 ns, slightly 153 ns), and is less deliquescent than other halide scintillators. The crystal grown using the vertical Bridgman method exhibited a eutectic phase composed of Rb2CeCl5 and LiCl. The eutectic crystals exhibited Ce3+ 5d-4f emissions, with a peak between 360 and 370 nm. The Rb2CeCl5 phase was identified as the luminescent phase via cathodoluminescence mapping, and 16,000 photons/neutron of the light yield and 56.1 ns of the decay time were observed. This study indicates that the Rb2CeCl5/LiCl eutectic scintillator is a promising candidate for use in thermal neutron detectors. [ABSTRACT FROM AUTHOR]

The photoluminescence and scintillation properties of KI:Eu synthesized by the vertical Bridgman-Stockbarger method were investigated. All the samples showed a broad peak at 430-450 nm under UV and X-ray irradiations, and the origin of emission was ascribed to the 4f65d1-4f7 transition of Eu2+. Furthermore, a tail emission at 500 nm under X-ray irradiation was observed, the origin of which could be ascribed to color centers associated with oxygen impurities. According to the pulse height spectra, the highest light yield (LY) under 241Am ?-ray (60 keV) irradiation was 3400 photons/MeV among the prepared samples. In terms of LY and afterglow, the optimal concentration of Eu was found to be 0.3%. [ABSTRACT FROM AUTHOR]

Eu:CaHfO3 single crystals with various Eu concentrations were synthesized by the floating zone method, and their photoluminescence (PL) and scintillation properties were investigated. All the samples showed PL peaks at 590, 620, and 650 nm, which were due to the 4f-4f transitions of Eu3+. The PL quantum yield of 1.0% Eu:CaHfO3 was the highest at 42.2% among the samples. The X-ray-induced scintillation spectra showed several emission peaks in the range of 400-690 nm, and the emissions were attributed to the 4f-4f transitions of Eu3+. Among the samples, 0.05% Eu:CaHfO3 showed the highest intensity. In the afterglow curves, the levels were within the range of 1,000-10,000 ppm and those of previous studies. [ABSTRACT FROM AUTHOR]

Ce-doped 20CsCl-20SrCl2-60ZnCl2 glasses were investigated for their optical and scintillation properties. Under X-ray irradiation, a broad emission peak at approximately 350 nm with a shoulder peak at 375 nm was observed, and its origin was attributed to Ce3+. In the pulse height spectrum under 241Am a-ray, the glass doped with 0.05% Ce exhibited the highest light yield (LY) of 25 ph/MeV (138 ph/5.5MeV-a) among zinc-halide-based glasses. The afterglow levels of the samples were superior to that of commercial CsI:Tl. [ABSTRACT FROM AUTHOR]

Eu-doped SrF² transparent ceramics were synthesized by spark plasma sintering, and their optical and scintillation properties were studied. The Eu-doped SrF² transparent ceramics showed an emission peak at 410 nm with excitations of 250 and 350 nm, and the PL quantum yield of the 0.1% Eu-doped SrF² transparent ceramic was 8.1%. Moreover, the Eu-doped SrF² transparent ceramics showed scintillation with emission peaks at 300 and 410 nm under X-ray irradiation. Based on the measured scintillation decay times, the origins of the emissions at 300 and 410 nm were self-trapped excitation and 5d-4f transitions of Eu2+ ions, respectively. The scintillation light yield of the 0.1% Eu-doped SrF² transparent ceramic was evaluated to be about 6100 photons/MeV under 137Cs γ-rays. [ABSTRACT FROM AUTHOR]

We synthesized an undoped La2Be2O5 single crystal by the floating zone method and investigated its scintillation properties. The synthesized sample was confirmed to have a singlephase structure of La2Be2O5 as shown by the powder X-ray diffraction pattern. The diffuse transmittance spectrum of the synthesized sample had transmittance at 80% in the range of 250-850 nm. The scintillation spectrum had a broad emission band from 280 to 600 nm, which was derived from unidentified lattice defects. In the scintillation decay profile, the obtained decay time constants were 1.1, 6.2, and 386 ns. From pulse height spectra, the light yield of the La2Be2O5 single crystal was 1000 photons/MeV. In afterglow profiles, the afterglow level was 42.9 ppm. [ABSTRACT FROM AUTHOR]

Copper‐based halides have emerged as promising scintillator materials for X‐ray imaging due to their favorable photophysical characteristics, such as negligible self‐absorption, high light output, and fast decay. Among these materials, Cs3Cu2I5, a blue emitter, currently delivers the highest scintillation light output under steady‐state X‐rays. However, there is a significant spectral mismatch between its emission band and the spectral responsivity of regular flat‐panel photodiode arrays. In this study, a comprehensive analysis of the physical properties of the CsCu2I3 scintillator is conducted, and its perfect spectral compatibility is discovered, which results in a higher photodiode signal despite its relatively lower light output compared to typical Cs3Cu2I5 scintillators. Furthermore, CsCu2I3 exhibits faster light decay properties, making it especially suitable for Computed Tomography (CT) X‐ray imaging. High‐quality X‐ray cone beam computed tomography (CBCT) imaging is successfully demonstrated using the fast‐decaying CsCu2I3 scintillator screen. Additionally, the flexibility of the scintillator allows for non‐planar imaging, showcasing advantages not available with traditional rigid scintillators. These results not only highlight the significant promise of the CsCu2I3 scintillator but also emphasize the necessity of considering spectral compatibility when designing novel scintillator materials. [ABSTRACT FROM AUTHOR]

Scintillators are used not only as single crystals in radiation detection systems but also as arrays, columns, and fibers. In this study, a novel optical-guiding crystal scintillator (OCS) was fabricated using an Eu:SrI 2 crystal as the core and borosilicate glass as the cladding. The OCS has an elongated shape and can be flexibly processed like an optical fiber. Furthermore, because inorganic scintillator crystals are used as the core, the OCS has high sensitivity to high-energy radiation, such as γ- and X-ray radiation, unlike plastic scintillators. In this study, by observing the cross section of the fabricated OCS, identifying the crystal structure, and investigating the radioluminescence spectrum under X-ray irradiation, OCS fabrication in accordance with the OCS design specifications was confirmed, and the SrI 2 crystal structure and Eu2+ 5d–4f luminescence were maintained. The γ-ray responses, such as light yield and decay time, were also investigated. [ABSTRACT FROM AUTHOR]

Metal halide crystals are bright but hygroscopic scintillator materials that are widely used in X‐ray imaging and detectors. Precipitating them in situ in glass to form glass ceramics (GCs) scintillator offers an efficient avenue for large‐scale preparation, high spatial resolution, and excellent stability. However, precipitating a high fraction of metal halide nanocrystals in glass to maintain high light yield remains a challenge. Herein, an ionic‐covalent hybrid network strategy for constructing GCs scintillator with high crystallinity (up to ≈37%) of BaCl2: Eu2+ nanocrystals is presented. Experimental data and simulations of glass structure reveal that the Ba2+‐Cl− clustering promotes the high crystallization of BaCl2 nanocrystals. The ultralow phonon energy (≈200 cm−1) of BaCl2 nanocrystals and good Eu reduction effect enable high photoluminescence inter quantum efficiency (≈80.41%) in GC. GCs with varied crystallinity of BaCl2: Eu2+ nanocrystals demonstrate efficient radioluminescence and tunable scintillator performance. They either outperform Bi4Ge3O14 single crystal by over 132% steady‐state light yield or provide impressive X‐ray imaging resolutions of 20 lp mm−1. These findings provide a new design strategy for developing bright transparent GCs scintillators with a high fraction of metal halide nanocrystals for X‐ray high‐resolution imaging applications. [ABSTRACT FROM AUTHOR]

The paper presents the results of a comprehensive study of the structural-phase composition, morphology, optical, luminescent, and scintillation characteristics of thick ZnO films fabricated by magnetron sputtering. By using a hot ceramic target, extremely rapid growth (~50 µm/h) of ZnO microfilms more than 100 µm thick was performed, which is an advantage for the industrial production of scintillation detectors. The effects of post-growth treatment of the fabricated films in low-temperature plasma were studied and a significant improvement in their crystalline and optical quality was shown. As a result, the films exhibit intense near-band-edge luminescence in the near-UV region with a decay time of <1 ns. Plasma treatment also allowed to significantly weaken the visible defect luminescence excited in the near-surface regions of the films. A study of the luminescence mechanisms in the synthesized films revealed that their near-band-edge emission at room temperature is formed by phonon replicas of free exciton recombination emission. Particularly, the first phonon replica plays the main role in the case of optical excitation, while upon X-ray excitation, the second phonon replica dominates. It was also shown that the green band peaking at ~510 nm (2.43 eV) is due to surface emission centers, while longer wavelength (>550 nm) green-yellow emission originates mainly from bulk parts of the films. [ABSTRACT FROM AUTHOR]

Eco‐friendly lead‐free organic–inorganic manganese halides (OIMHs) have attracted considerable attention in various optoelectronic applications because of their superior optical properties and flexible solution processibility. Herein, we report a novel pseudo‐2D layered OIMH (MTP)2MnBr4 (MTP: methyltriphenylphosphonium), which exhibits intense green emission under UV/blue or X‐ray excitation, with a near‐unity photoluminescence quantum yield, high resistance to thermal quenching (I150 °C=84.1 %) and good photochemical stability. These features enable (MTP)2MnBr4 as an efficient green phosphor for blue‐converted white light‐emitting diodes, demonstrating a commercial‐level luminous efficiency of 101 lm W−1 and a wide color gamut of 116 % NTSC. Moreover, these (MTP)2MnBr4 crystals showcase outstanding X‐ray scintillation properties, delivering a light yield of 67000 photon MeV−1, a detection limit of 82.4 nGy s−1, and a competitive spatial resolution of 6.2 lp mm−1 for X‐ray imaging. This work presents a new avenue for the exploration of eco‐friendly luminescent OIMHs towards multifunctional light‐emitting applications. [ABSTRACT FROM AUTHOR]

Alkali metal halides have long been used as scintillators for applications as sensors and detectors. Usually, a small amount of impurities are added to these inorganic materials to improve their luminescence efficiencies. We investigate the structures and luminescent properties of un-doped sodium iodide (NaI) and cesium-doped NaI (NaI:Cs) films deposited by thermal vacuum evaporation. Instead of using the toxic element thallium (Tl), we introduced cesium dopant into NaI. This is the first study for the NaI:Cs film excited by UV LED's ultraviolet C (273 nm, 4.54 eV). The luminescence spectra show two main peaks at 3.05 and 4.32/3.955 eV (for fused silica/B270 substrate), originating from the intrinsic defects and/or activator excited states and the intrinsic self-trapped excitons (STEs), respectively. In general, both Cs-doping and post-annealing processes enhance the luminescence performance of NaI films. [ABSTRACT FROM AUTHOR]

X‐ray imaging technology has achieved important applications in many fields and has attracted extensive attentions. Dynamic X‐ray flexible imaging for the real‐time observation of the internal structure of complex materials is the most challenging type of X‐ray imaging technology, which requires high‐performance X‐ray scintillators with high X‐ray excited luminescence (XEL) efficiency as well as excellent processibility and stability. Here, a macrocyclic bridging ligand with aggregation‐induced emission (AIE) feature was introduced for constructing a copper iodide cluster‐based metal–organic framework (MOF) scintillator. This strategy endows the scintillator with high XEL efficiency and excellent chemical stability. Moreover, a regular rod‐like microcrystal was prepared through the addition of polyvinyl pyrrolidone during the in situ synthesis process, which further enhanced the XEL and processibility of the scintillator. The microcrystal was used for the preparation of a scintillator screen with excellent flexibility and stability, which can be used for high‐performance X‐ray imaging in extremely humid environments. Furthermore, dynamic X‐ray flexible imaging was realized for the first time. The internal structure of flexible objects was observed in real time with an ultrahigh resolution of 20 LP mm−1. [ABSTRACT FROM AUTHOR]

Fast neutron and X‐ray imaging are considered complementary nondestructive detection technologies. However, due to their opposite cross‐sections, development of a scintillator that is sensitive to both fast neutrons and X‐rays within a single‐material framework remains challenging. Herein, an organic–inorganic hybrid perovskite (C4H9NH3)2PbBr4 (BPB) is demonstrated as a scintillator that fully meets the requirements for both fast neutron and X‐ray detection. The hydrogen‐rich organic component acts as a fast neutron converter and produces detectable recoil protons. The heavy atom‐rich inorganic fraction efficiently deposits the energy of charged recoil protons and directly provides a large X‐ray cross‐section. Due to the synergy of these organic and inorganic components, the BPB scintillator exhibits high light yields (86% of the brightness of a commercial ZnS (Ag)/6LiF scintillator for fast neutrons; 22 000 photons per MeV for X‐rays) and fast response times (τdecay = 10.3 ns). More importantly, energy‐selective fast neutron and X‐ray imaging are also demonstrated, with high resolutions of ≈1 lp mm−1 for fast neutrons and 17.3 lp mm−1 for X‐rays; these are among the highest resolution levels for 2D perovskite scintillators. This study highlights the potential of 2D perovskite materials for use in combined fast neutron and X‐ray imaging applications. [ABSTRACT FROM AUTHOR]

The article presents the results of experiments on a detection system used for detecting signals from a miniature, low-energy micro-electro-mechanical system (MEMS) X-ray source. The authors propose to use a detection based on luminescence phenomena occurring in luminophore and scintillators to record the visual signal on a CMOS/CCD detector. The main part of the article is a review of various materials of scintillators and luminophores which would be adequate to convert low-energy X-ray radiation (E < 25 keV - it is a range not typical for conventional X-ray systems) to visible light. Measurements obtained for different energies, exposure times, and different targets have been presented and analysed. [ABSTRACT FROM AUTHOR]

The technological aspects of the light inorganic crystalline compounds suitable to create scintillation materials to detect charged particles and neutrons in a wide energy range have been examined. Among them, Li2CaSiO4:Eu was found to be a prospective candidate to control the valent state of the Rare Earth (RE) and to provide a high intensity of luminescence. It was demonstrated that the material has room for future improvement; however, this requires precise engineering of its composition—an experimental search of compositions or additives that will provide the maximum Eu2+/Eu3+ ratio to achieve a high scintillation light yield. The benefits of light inorganic materials are disclosed through the modeling of the linear density of nonequilibrium carriers along secondary particle tracks created in scintillators utilized for neutron detection. It is shown that oxide matrices have a larger linear density in comparison with halide crystalline compounds under alpha-particles and tritons, whereas light oxides can provide smaller numbers under protons. [ABSTRACT FROM AUTHOR]

This study aims to determine the optimum composition of the CeBr1−xIx compound to achieve the maximum light output. It is based on calculations of the band energy structure of crystals, specifically taking into account the characteristics of the mutual location of local and band 5d states of the Ce3+ ions. The band energy structures for CeBr2I and CeBrI2 crystals were calculated using the projector augmented wave method. The valence band was found to be formed by the hybridized states of 4p Br and 5p I. The 4f states of Ce3+ are located in the energy forbidden band gap. The conduction band is formed by the localized 5d1 states, which are created by the interaction between the 5d states of Ce3+ and the 4f0 hole of the cerium ion. The higher-lying delocalized 5d2 states of Ce3+ correspond to the energy levels of the 5d states of Ce3+ in the field of the halide Cl0 (Br0) hole. The relative location of 5d1 and 5d2 bands determines the intensity of 5d–4f luminescence. The bottom of the conduction band is formed by localized 5d1 states in the CeBr2I crystal. The local character of the bottom of the conduction band in the CeBr2I crystal favors the formation of self-trapped Frenkel excitons. Transitions between the 5d1 and 4f states are responsible for 5d–4f exciton luminescence. In the CeBrI2 crystal, the conduction band is formed by mixing the localized 5d1 and delocalized 5d2 states, which leads to quenching the 5d–4f luminescence and a decrease in the light output despite the decrease in the forbidden band gap. CsBr2I is the optimum composition of the system to achieve the maximum light output. [ABSTRACT FROM AUTHOR]

X-ray radiography and computed tomography have become well-established methods for investigation of internal structure of objects and for defectoscopy. Recently, the methods have even been used for in-situ analysis of materials under mechanical loading. Although the techniques would be very suitable for analysis during dynamic events, their application is constrained by typical achievable frame rates. Therefore, fast imaging is usually limited to facilities providing sufficient flux like particle accelerators. In this paper, we test imaging performance of a laboratory-based setup with a high-power X-ray tube, a scintillation panel, and an optical camera. Fast-rotating object and typical specimens for impact testing are irradiated with different power settings and quality of captured images is evaluated and analyzed. It is found out that the system can be successfully used for imaging at several hundred frames per second allowing for inspection of slow impact dynamics experiments. [ABSTRACT FROM AUTHOR]

Eulytite-type Ba3RE(PO4)3 (RE = Y, La, and Lu) single crystals were synthesized by the floating zone method, and their scintillation properties were investigated. The powder X-ray diffraction measurement revealed that the single phase of Ba3RE(PO4)3 samples were successfully synthesized. The samples exhibited a luminescence peak due to self-trapped exciton at around 400 nm under vacuum ultraviolet and X-ray irradiation. The X-ray-induced scintillation decay time constants of the samples were several microseconds at room temperature. In the 241Am α-ray irradiated pulse height spectra, all the samples showed a clear full energy peak, and the absolute light yields of the Ba3Y(PO4)3, Ba3La(PO4)3, and Ba3Lu(PO4)3 single crystals were estimated to be 960, 1160, and 1220 ph/5.5 MeV-α, with a typical error of ±10%, respectively. The scintillation light yields of the Ba3RE(PO4)3 have been quantitatively clarified for the first time. [ABSTRACT FROM AUTHOR]

NM (Nuclear medicine) uses radioisotopes to diagnose and treat biological functions. This paper outlines the history and principles of PET. Measurement of projection data by electron-positron annihilation, 3D scan that contributed to the advancement of PET performance, TOF and other representative technologies will be explained. [ABSTRACT FROM AUTHOR]

Mg4Ta2O9 single crystals doped with 0.01, 0.1, and 1% Er were grown using the floating zone method, and their photoluminescence and scintillation properties were studied. X-ray diffraction analysis confirmed that all samples had a hexagonal structure of Mg4Ta2O9. The samples showed that the emission peak at 1550 nm was due to 4f−4f transitions of Er3+ ions, with quantum yields of 32.9, 46.6, and 18.0% for 0.01, 0.1, and 1% doping concentrations, respectively. All samples showed scintillation with a broad emission band at 350 nm due to charge transfer from Ta5+ to O2− ions and emission peak at 1550 nm due to 4f−4f transition of Er3+ ions. The dose rate response functions showed that the detection limit for all samples was 0.06 Gy/h for scintillation detector applications. [ABSTRACT FROM AUTHOR]

β-Ga2O3 is a well-known semiconductor material for power devices and other applications. Recently, β-Ga2O3 has also been reported as a scintillator material with a light yield of approximately 8400 ph./MeV, scintillation decay time of <1 μs, and density of 6.44 g/cm3. In this study, 45 cm diameter β-Ga2O3 single crystals were prepared via oxide crystal growth using the cold crucible (OCCC) method under various oxygen partial pressures. In the OCCC method, as in the cold crucible method, a high frequency is applied directly to the oxide materials, which are heated and melted, and the melt is held by the outermost solid material itself that is cooled by water using a copper hearth. In the OCCC method, crystal growth is performed while rotating the seed crystal, as in the Czochralski method, to increase the crystal diameter. The optical properties and radiation responses of the crystals grown under various oxygen partial pressures were evaluated. [ABSTRACT FROM AUTHOR]

Objective. Together with novel photodetector technologies and emerging electronic front-end designs, scintillator material research is one of the key aspects to obtain ultra-fast timing in time-of-flight positron emission tomography (TOF-PET). In the late 1990s, Cerium-doped lutetium–yttrium oxyorthosilicate (LYSO:Ce) has been established as the state-of-the-art PET scintillator due to its fast decay time, high light yield and high stopping power. It has been shown that co-doping with divalent ions, such as Ca 2+ and Mg 2+, is beneficial for its scintillation characteristics and timing performance. Therefore, this work aims to identify a fast scintillation material to combine it with novel photosensor technologies to push the state of the art in TOF-PET. Approach. This study evaluates commercially available LYSO:Ce,Ca and LYSO:Ce,Mg samples manufactured by Taiwan Applied Crystal Co., LTD regarding their rise and decay times as well as their coincidence time resolution (CTR) with both ultra-fast high-frequency (HF) readout and commercially available readout electronics, i.e. the TOFPET2 ASIC. Main results. The co-doped samples exhibit state-of-the-art rise times of on average 60 ps and effective decay times of on average 35 ns. Using the latest technological improvements made on NUV-MT SiPMs by Fondazione Bruno Kessler and Broadcom Inc., a 3 × 3 × 19 mm3 LYSO:Ce,Ca crystal achieves a CTR of 95 ps (FWHM) with ultra-fast HF readout and 157 ps (FWHM) with the system-applicable TOFPET2 ASIC. Evaluating the timing limits of the scintillation material, we even show a CTR of 56 ps (FWHM) for small 2 × 2 × 3 mm3 pixels. A complete overview of the timing performance obtained with different coatings (Teflon, BaSO4) and different crystal sizes coupled to standard Broadcom AFBR-S4N33C013 SiPMs will be presented and discussed. Significance. This work thoroughly evaluates commercially available co-doped LYSO:Ce crystals and, in combination with novel NUV-MT SiPMs, shows a TOF performance that significantly exceeds the current state of the art. [ABSTRACT FROM AUTHOR]

Sesquioxides of lanthanides, yttrium, and scandium are promising hosts for laser and scintillation materials; however, the crystallization of such compounds is complicated by very high melting temperatures, as well as polymorph transitions. This work reports for the first time the growth of Y2O3 and Y2−xScxO3 crystals by the Vertical Gradient Freezing method from tungsten crucibles, proposing an alternative to extremely expensive rhenium and iridium crucibles. Translucent Y2O3 samples are obtained, and their luminescent and scintillation parameters are evaluated. The main issues of Y2O3 crystallization under the proposed conditions are discussed, as well as ways of enhancing the crystal quality. Finally, polymorph transitions are avoided by decreasing the average radius of the rare earth cation by Y3+/Sc3+ substitution, providing transparent Y2−xScxO3 crystals with a cubic structure. [ABSTRACT FROM AUTHOR]

As a promising material for dual γ-ray and neutron detection, Cs2LiYCl6:Ce (CLYC:Ce) has been increasingly studied and developed. In this work, CLYC:Ce is grown by two different growth methods, edge-defined film-fed growth (EFG) and the vertical Bridgman method. The phase segregation, macroscopic morphology, microscopic defects, trap-state density and radioluminescence spectra of CLYC:Ce are recorded and analyzed in detail. Because of the different raw material ratios, different second phases appear in the crystal growth process, which shows the phase segregation in the crystal. In the process of crystal growth, there are obvious cracks, bubbles, and inclusion and agglomeration phenomena in the crystal. We speculate that the reasons for these issues include inadequate mixing of the melt, the mismatch of temperature field and the excessive growth rate or excessive cooling rate. The high-quality CLYC:Ce has high carrier mobility (21.3390 cm2V−1 s−1) and ultra-low trap-state density (4.0681 × 108 cm−3). According to the radioluminescence spectra, only peaks in the range of 330–450 nm exist in the whole temperature range, corresponding to Ce3+ component luminescence. With the increase in temperature, the emission peaks show a slight red-shift and the full width at half maximum (FWHM) generally shows an increasing trend. In the high-temperature region, the intensity of the main peak at 360 nm gradually decreases, while the intensity of the weak peak at 435 nm gradually increases. [ABSTRACT FROM AUTHOR]

High-resolution neutron radiography provides novel and stirring opportunities to investigate the structures of light elements encased by heavy elements. For this study, a series of Gd2O2S:Tb, F particles were prepared using a high-temperature solid phase method and then used as a scintillation screen. Upon reaching 293 nm excitation, a bright green emission originated from the Tb3+ luminescence center. The level of F doping affected the fluorescence intensity. When the F doping level was 8 mol%, the fluorescence intensity was at its highest. The absolute quantum yield of the synthesized particles reached as high as 77.21%. Gd2O2S:Tb, F particles were applied to the scintillation screen, showing a resolution on the neutron radiograph as high as 12 μm. These results suggest that the highly efficient Gd2O2S:Tb, F particles are promising scintillators for the purposes of cold neutron radiography. [ABSTRACT FROM AUTHOR]

We synthesized Ce-doped Gd3Al5-yGayO12 (GAGG) nanoparticle scintillators for obtaining efficient emission in living bodies upon X-ray irradiation from outside. To obtain a high photoluminescence quantum yield (QY), the chemical composition and synthesis conditions were optimized. The highest QY of 90%, which is higher than that of a commercially available Ce-doped GAGG single-crystal scintillator (87%), was achieved with the composition for Gd:Al:Ga = 3:3:2, a Ce concentration of 0.1 mol% relative to (Gd + Ce), aging at room temperature for 1 d, and a calcination temperature of 1300 °C. The size of the particles was 200-300 nm. A dominant emission band at around 550 nm was observed in the photoluminescence and X-ray-induced radioluminescence spectra and attributed to the 5d-4f transition of Ce3+. The high photoluminescence QY and appropriate size for applications in living bodies indicated that nanoparticle scintillators based on Ce-doped GAGG were successfully developed. [ABSTRACT FROM AUTHOR]

We synthesized 20Lu2O3-30Ga2O3-50SiO2 glasses doped with various concentrations of Sn using a floating zone furnace equipped with Xe arc lamps. The samples showed a luminescence band around 450 nm in both photoluminescence (PL) and scintillation spectra. The origin of the luminescence was ascribed to the T1-S0 transition of Sn2+ on the basis of the luminescence wavelength and PL decay time constant. The highest scintillation intensity and PL quantum yield were observed from the 1% Sn-doped sample. The afterglow level tended to decrease with increasing Sn doping, and the afterglow levels of the 1 and 3% Sn-doped samples were comparable to that of the conventional Tl-doped CsI scintillator. The optimal concentration of Sn for the glass was estimated to be 1%. [ABSTRACT FROM AUTHOR]

We investigated the scintillation light yields of Tb-doped SiO2 glasses. We prepared 0.05, 0.1, and 0.5% Tb-doped SiO2 glasses by melting and solidifying sintered ceramic rods using an oxygen burner. The obtained samples showed no crystalline phases in X-ray diffraction measurements. Pulse height spectra of the Tb-doped SiO2 samples were measured under γ-ray excitation using a measurement system for slow decay pulses. The number of channels at the Compton edge of the 0.5% Tb-doped sample was the highest and was approximately 50% of that of a commercial lithium glass scintillator (GS20). By considering the light yield of GS20 and the wavelength dependence of the quantum efficiency of the photomultiplier tube, the light yield of the 0.5% Tb-doped SiO2 sample was estimated as 3800 photons/MeV. [ABSTRACT FROM AUTHOR]

A comparative study on the radioluminescence properties of Ce-doped SrAl2O4 single crystal and translucent ceramic was performed. The transmittance of the synthesized ceramic is 20-30% in the visible region. Both samples exhibit photo- and radioluminescence with a broad emission peaking at 380 nm. The decay curves are fitted by a single exponential decay function with decay time constants of 30-50 ns, consistent with the typical value of the emission for the 5d-4f transitions of Ce3+. From the pulse height spectra measured under 241Am γ-ray (59.5 keV) irradiation, the scintillation light yields are 17000 ph/MeV for the single crystal and 6100 ph/MeV for the synthesized ceramic. The scintillation light yield and afterglow of the present samples show a negative correlation. [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]

Glass is a group of materials with appealing qualities, including simplicity in fabrication, durability, and high transparency, and they play a crucial role in the optics field. In this paper, a new organic–inorganic metal halide luminescent glass exhibiting >78 % transmittance at 506–800 nm range together with a high photoluminescence quantum yield (PLQY) of 28.5 % is reported through a low‐temperature melt‐quenching approach of pre‐synthesized (HTPP)2MnBr4 (HTPP=hexyltriphenylphosphonium) single crystal. Temperature‐dependent X‐ray diffraction, polarizing microscopy, and molecular dynamics simulations were combined to investigate the glass‐crystal interconversion process, revealing the disordered nature of the glassy state. Benefiting from the transparent nature, (HTPP)2MnBr4 glass yields an outstanding spatial resolution of 10 lp mm−1 for X‐ray imaging. The superb optical properties and facility of large‐scale fabrication distinguish the organic–inorganic metal halide glass as a highly promising class of materials for optical devices. [ABSTRACT FROM AUTHOR]

Luminescent metal halide perovskites (MHPs) open new avenues for highly efficient radiation detection. To challenge the state‐of‐art technology, fundamental understanding of factors controlling radiation light yield of MHP scintillators is urgent. Herein, a design method is established by simultaneously considering charge‐transfer and recombination efficiencies via band alignment engineering in doped MHPs materials, and this strategy is corroborated experimentally and computationally by applying it to the luminescence of ns2 electron (Sb3+, Bi3+, and Te4+) doped vacancy‐ordered double perovskite Cs2ZrCl6. Alloying Te4+ into Cs2ZrCl6 is optimized and significantly improves the scintillation performance, including a twofold increase in light yield and a threefold increase in detection limit over pristine Cs2ZrCl6, and high‐resolution X‐ray imaging with 20 μm for 2D and 0.2 mm for 3D imaging. It is believed that doping engineering in MHPs enabling band alignment method holds great potential for the development of next‐generation MHP scintillators. [ABSTRACT FROM AUTHOR]

BACKGROUND: X-ray micro-tomography (μCT) is a powerful non-destructive 3D imaging method applied in many scientific fields. In combination with propagation-based phase-contrast, the method is suitable for samples with low absorption contrast. Phase contrast tomography has become available in the lab with the ongoing development of micro-focused tube sources, but it requires sensitive and high-resolution X-ray detectors. The development of novel scintillation detectors, particularly for microscopy, requires more flexibility than available in commercial tomography systems. OBJECTIVE: We aim to develop a compact, flexible, and versatile μCT laboratory setup that combines absorption and phase contrast imaging as well as the option to use it for scintillator characterization. Here, we present details on the design and implementation of the setup. METHODS: We used the setup for μCT in absorption and propagation-based phase-contrast mode, as well as to study a perovskite scintillator. RESULTS: We show the 2D and 3D performance in absorption and phase contrast mode, as well as how the setup can be used for testing new scintillator materials in a realistic imaging environment. A spatial resolution of around 1.3μm is measured in 2D and 3D. CONCLUSIONS: The setup meets the needs for common absorption μCT applications and offers increased contrast in phase contrast mode. The availability of a versatile laboratory μCT setup allows not only for easy access to tomographic measurements, but also enables a prompt monitoring and feedback beneficial for advances in scintillator fabrication. [ABSTRACT FROM AUTHOR]

Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Here, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillator (ScNPs@RB/Ab) for efficient deep-brain phototherapy. We demonstrate that the as-synthesized ScNPs@RB/Ab is capable of converting X-rays into visible light to activate the photosensitizers of rose bengal (RB) for Aβ oxygenation through the scalp and skull. We show that the ScNPs@RB/Ab persistently emitting visible luminescence can substantially minimize the risk of excessive X-ray exposure dosage. Importantly, peptide KLVFFAED-functionalized ScNPs@RB/Ab shows a blood–brain barrier permeability. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects. Our study paves a new pathway to develop high-efficiency transcranial AD phototherapy. Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Herein, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillators (ScNPs@RB/Ab) for efficient deep-brain phototherapy. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects. [Display omitted] [ABSTRACT FROM AUTHOR]

The Nd-doped LaMgAl11O19 single crystals were synthesized by the floating zone method, and the photoluminescence and scintillation properties were evaluated. Under X-ray irradiation, several sharp emission peaks due to the 4f–4f transitions of Nd3+ were observed at 900, 1060, and 1340 nm in the near-infrared range, and the decay curves show the typical decay time for Nd3+. The samples show good afterglow properties comparable with practical X-ray scintillators. The 1% and 3% Nd-doped LaMgAl11O19 samples show a good linearity in the dynamic range from 6–60,000 mGy/h. [ABSTRACT FROM AUTHOR]