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Cd2+ cation doped CsPbCl3 single crystals were synthesized, and their luminescent properties were investigated under excitation with synchrotron radiation quanta with energy greater than Eg and at a sample temperature of 12 K. Pure single crystals exhibit a narrow band of exciton emission at 416.7 nm. Doping the single crystals leads to a high-energy shift of the excitonic luminescence, the appearance of new luminescent bands, the broadening of the luminescent bands, an increase in the decay time constants, and a significant enhancement of the luminescence intensity. The observed changes in luminescent parameters upon doping are discussed in terms of the crystal structure ordering, a decrease in the number of defects responsible for capturing charge carriers at the stage of electronic excitation thermalization, and a decrease in defects that quench excitonic luminescence. Doped single crystals with decay times of the order of 0.4 ns and intensities that significantly exceed the intensity of pure single crystals can be promising scintillation materials for positron emission tomography in the time-of-flight mode. [ABSTRACT FROM AUTHOR]

For a long time, single crystals of the organic compound TPB (1,3,5-triphenylbenzene) have been viewed as a scintillator material for indirect X-ray detection. We here attempt to explore their potential for direct detection. A TPB single crystal with a size of up to 20 × 6 × 4 mm3 and without obvious growth steps was obtained using a solvent volatilization method. It has an orthorhombic structure with a high-quality FWHM of as low as 0.059 and preferred grown orientations along (131) and (220). AFM images clarify the two-dimensional nucleation growth mechanism. The fitted bandgap of the as-grown crystal is about 3.65 eV. TPB detectors with vertical and coplanar electrodes with a resistivity of 2.56 × 1013 Ω cm and 6.68 × 1013 Ω cm, respectively, were prepared. The mobilities for electrons (μe) and holes (μh) for the coplanar device were calculated to be 1.12 cm2 V−1 s−1 and 1.02 cm2 V−1 s−1, respectively. Under a 50 kV X-ray beam, the detection limit is as low as 0.35 μGy s−1, and the sensitivity reaches 2.72 μC Gy−1 cm−2. The TPB devices have the ability to detect 241Am@5.49 MeV α particles, showing the full-energy peak collected from the holes with an energy resolution of 39.13% at 700 V. The mobility lifetime product of the TPB devices for electrons (μτ)e and holes (μτ)h were calculated to be up to 2.24 × 10−5 cm2 V−1 and 4.04 × 10−5 cm2 V−1, respectively. The TPB detector could present a spectral response to 241Am@59.5 keV γ-rays from the holes with an energy resolution of 44.25% at 1000 V, which shows the potential for both direct and indirect detection of high-energy radiation. [ABSTRACT FROM AUTHOR]

The current mainstream planar X‐ray imaging techniques face significant challenges for accurately capturing the internal structure of curved objects, since the variable distances between the curved objects and the flat‐panel scintillation screen cannot eliminate the distortion in X‐ray imaging. Though large‐area and transparent curved scintillation screens are much more desirable. Here, organic–inorganic hybrid Mn‐based single crystals ([CH3Ph3P]2MnX4, X = Cl, Br, I) exhibiting high photoluminescence quantum yield (PLQY) and low melting temperature have been employed to prepare transparent glass for X‐ray scintillation imaging application through a low‐temperature melting strategy. The [CH3Ph3P]2MnBr4‐glass shows high PLQY (47.8%), high‐resolution X‐ray imaging performance (12.3 lp mm−1), low limit of detection (25.33 nGy s−1), and impressive X‐ray irradiation stability (102 Gy). Furthermore, high‐contrast X‐ray imaging at a low dose (6.865 µGy per exposure, 14.5 times lower than the chest radiograph) is achieved. Based on the low glass transition temperature (Tg = 53.6 °C) and easy‐shapeable properties of [CH3Ph3P]2MnBr4‐glass scintillator, the large‐area curved scintillation screen with a series of sizes of Φ 2×4 – Φ 8×4 cm2 can be easily fabricated and show high X‐ray imaging quality. These findings provide a paradigm for future research in shapeable X‐ray scintillators, unlocking new possibilities for curved and 3D X‐ray imaging. [ABSTRACT FROM AUTHOR]

Ce‐doped Cs2LiLaBr6 (CLLB) scintillator crystals, known for their superior neutron/gamma dual‐mode detection capability and exceptional scintillation properties, have garnered significant attention for both fundamental science and practical applications. The role of Ce3+ cations as luminescent centers is pivotal, influencing the scintillation properties as their concentration varies. While the effects of Ce3+ concentration on scintillation performance are well‐documented, the ramifications for crystalline structure remain less explored. In this study, high‐quality CLLB:Ce single crystals are fabricated(atomic packing factor of maximum doped Ce is 0.04%) using the vertical Bridgman (VB) method and subsequently characterized their crystalline structure by neutron diffraction, X‐ray diffraction (XRD), and elemental analysis. The findings reveal a correlation between Ce3+ concentration and the crystal cell parameters, presenting intriguing deviations from Vegard's law. Such observations suggest the potential presence of alternative defects, potentially Li+ interstitials, in CLLB:Ce. This work offers critical insights for advancing the understanding and optimization of CLLB:Ce scintillators. [ABSTRACT FROM AUTHOR]

A facile and low-cost strategy to fabricate CsPbBr3 single crystals is essential for developing perovskite optoelectronic devices. Herein, we have presented a room temperature anti-solvent precipitate method for growing sub-centimeter-sized CsPbBr3 single crystals. The as-prepared CsPbBr3 single crystal has an orthorhombic structure, and phase transition occurs as the measured temperature increases. The as-grown CsPbBr3 single crystal also shows abundant surface morphologies including footsteps, precipitated crystals, cracks, and pits. Subsequently, a metal–semiconductor–metal (MSM)-structured photodetector was fabricated based on the CsPbBr3 single crystal. Under 525 nm green light illumination, the photodetector exhibits an obvious response and the photocurrent linearly increases with the increase in the light intensity. The rise time of the photodetector increases from 0.82 s to 2.19 s as the light intensity is enhanced from 15 mW/cm2 to 160 mW/cm2, indicating that more time is required to reach to a stable photocurrent. However, the decay time is as fast as ~0.82 ms, irrelevant of the light intensity. The photocurrent, under continuous light illumination, was further studied and this indicates that a stronger light intensity can accelerate the attenuation of the device. [ABSTRACT FROM AUTHOR]

Background: A CZT (cadmium zinc telluride) PET (positron emission tomography) system is being developed at Stanford University. CZT has the promise of outperforming scintillator‐based systems in energy and spatial resolution but has relatively poor coincidence timing resolution. Purpose: To supplement GATE (GEANT 4 Application for Emission Tomography) simulations with charge transport and electronics modeling for a high‐resolution CZT PET system. Methods: A conventional GATE simulation was supplemented with electron‐hole transport modeling and experimentally measured single detector energy resolution to improve the system‐level understanding of a CZT high‐resolution PET system in development at Stanford University. The modeling used GATE hits data and applied charge transport in the crystal and RC‐CR processing of the simulated signals to model the electronics, including leading‐edge discriminators and peak pick‐off. Depth correction was also performed on the simulation data. Experimentally acquired data were used to determine energy resolution parameters and were compared to simulation data. Results: The distributions of the coincidence timing, anode energy, and cathode energy are consistent with experimental data. Numerically, the simulation achieved 153 ns FWHM coincidence time resolution (CTR), which is of the same order of magnitude as the raw 210 ns CTR previously found experimentally. Further, the anode energy resolution was found to be 5.9% FWHM (full width at half maximum) at 511 keV in the simulation, which is between the experimental value found for a single crystal of 3% and the value found for the dual‐panel setup of 8.02%, after depth correction. Conclusions: Developing this advanced simulation improves upon the limitations of GATE for modeling semiconductor PET systems and provides a means for deeper analysis of the coincidence timing resolution and other complementary electron‐hole dependent system parameters. [ABSTRACT FROM AUTHOR]

The urgency for cost‐effective, high‐resolution, flexible X‐ray imaging detectors is generating great demand for scintillators with low‐temperature processability, high scintillation yield, and negligible afterglow. X‐ray imaging materials are currently dominated by inorganic scintillators in the form of rigid films and bulk crystals, which have inherent limitations including high‐temperature, complex synthesis, and considerable challenges toward advanced nonplanar imaging. Here, high‐performance and flexible X‐ray scintillators based on novel zero‐dimensional (0D) (BTPP)2MnX4 (BTPP = benzyltriphenylphosphonium; X = Cl, Br) halides are reported. They emit bright green light originating from the 4T1‐6A1 transition of Mn2+ under X‐ray excitation. In particular, (BTPP)2MnBr4 single crystals exhibit excellent air‐ and radiation‐stability, a high scintillation yield of 53 000 photons MeV−1, a low detection limit of 89.9 nGyair s−1, and an ultralow afterglow comparable to commercial Bi4Ge3O12 (BGO) single crystals. Moreover, the (BTPP)2MnCl4@polydimethylsiloxane (PDMS) flexible scintillation screens achieve a high spatial resolution of 14.1 lp mm−1 and realize high‐quality imaging results of nonplanar objects. This study demonstrates that the flexible scintillation screens based on low‐dimensional Mn(II) hybrid halides have significant potential for low‐dose and high‐resolution X‐ray imaging applications. [ABSTRACT FROM AUTHOR]

This article details work performed on the synthesis and characterization of an inorganic mixed‐cation double halide perovskite, Cs2Ag.6Na.4In.85Bi.15Cl6 (CANIBIC). Single crystals have been created via a hydrothermal reaction, milled into a powder, and pressed into pellets, while nanocrystals have been directly synthesized via mechanosynthesis. A computational model is constructed to predict the X‐ray diffraction pattern of CANIBIC; this model aligns very well with the X‐ray diffraction pattern measured for CANIBIC crystal powder. This model can therefore be developed in the future as a tool to predict lattice parameters and crystal structures of other novel double‐halide perovskites. Photoluminescence spectra obtained from each format show broad emission centered at 630 nm, as is typical for self‐trapped exciton emission; self‐trapped exciton emission is also confirmed by investigating photoluminescence intensity as a function of laser power. Nanocomposites are produced via the loading of nanocrystals of CANIBIC into PMMA. Although nanocomposite disks consisting of a small proportion of CANIBIC nanocrystals in PMMA have a smaller mass attenuation coefficient than a pressed pellet of CANIBIC, these disks have comparatively bright radioluminescence due to their optical transparency. These nanocomposite disks are therefore a particularly useful format for the practical use of the CANIBIC scintillator. [ABSTRACT FROM AUTHOR]

Metal‐halide perovskites have emerged as one of the most promising contenders for the next‐generation X‐ray scintillators on account of their large absorption coefficients, high light yields, and low‐cost fabrication. However, the existing X‐ray scintillators are plagued either by poor stability or high toxicity. Here, highly stable and flexible CsCu2I3@polymethyl methacrylate (PMMA) composite films are fabricated simply by a facile one‐step drop‐coating technique. Benefiting from the reasonable light yields (24 100 photons MeV−1), short photoluminescence decay time (207 ns), and flat surface, a low detection limit of 39 nGyair s−1 and a record‐high resolution of up to 25 lp mm−1 are demonstrated in these CsCu2I3@PMMA composite films. The X‐ray imaging tests show that the CsCu2I3@PMMA composite films display excellent properties in the dynamic and irregular objects imaging. In addition, the CsCu2I3@PMMA composite films exhibit a desirable endurance to the high‐energy X‐ray's irradiation and the water erosion (photoluminescence quantum yield remains up of 90% of its initial value even after submersion in water for 300 h). This work provides a potential to develop eco‐friendly and highly stable halide perovskite materials for high‐resolution X‐ray imaging. [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]

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]

In this study, a new Cs4SrI6:Yb2+,Sm2+ near‐infrared (NIR) emitting scintillator was developed using sensitization strategy. It was found that Yb2+ sensitization significantly enhances the NIR radioluminescence (RL) of Sm2+, providing a new approach of designing highly emissive sensitized NIR scintillators. By studying the optical spectra and decay kinetics of Cs4SrI6:Yb2+,Sm2+, it was revealed that the energy transfer pathways involve both radiative and nonradiative processes. The gamma spectroscopy performance of Cs4SrI6:Yb2+,Sm2+ single crystals was studied by using the high‐quantum‐efficiency avalanche photodiode (APD) as the readout. Our results highlight the importance of using sensitization strategy of achieving NIR emitting scintillators and demonstrate the significant potential for radiation detection applications. [ABSTRACT FROM AUTHOR]

Low‐dimensional copper‐based halide single crystals are considered excellent scintillators for indirect X‐ray detection, but their potential in direct X‐ray detection has not been investigated. Herein, high‐quality pure Cs3Cu2I5 and Li‐doped Cs3Cu2I5:Li single crystals are grown by the Bridgman method. The Li+ dopant enhances the photoelectric properties of the Cs3Cu2I5 single crystal by extending the carrier lifetime, improving the carrier mobility from 6.49 to 9.52 cm2 V−1 s−1, and increasing the mobility‐lifetime (µτ) product from 1.4 × 10−4 to 2.9 × 10−4 cm2 V−1. The sensitive direct X‐ray detector with a vertical device configuration of Au/Cs3Cu2I5:Li single crystal/PCBM/Au is fabricated and demonstrated to have a high sensitivity of 831.1 µC Gyair−1 cm−2 and low detection limit of 34.8 nGyair s−1. Furthermore, the detector shows negligible baseline current drift and excellent stability upon X‐ray radiation. [ABSTRACT FROM AUTHOR]

Scintillators, which can convert high‐energy ionizing radiation (e.g., X‐ or γ‐rays) into ultraviolet‐visible light, have been widely applied in medical and industrial fields. Developing new scintillation materials with high performance and low cost is very desirable in order to address the growing application demands. Among them, single‐crystal scintillators of organic‐inorganic hybrid metal halides (OIMHs) have attracted much attention because of their excellent optical transparency, suppressed light scattering, and facile solution preparation methods. Herein, three new centimeter‐sized (2‐DMAP)2MnX4 (2‐DMAP+ = 2‐dimethylaminopyridinium, X = Cl, Br, I) single crystals with high crystal quality are synthesized via the solvent evaporation method. Benefiting from the high optical transparency and remarkable luminescence property, (2‐DMAP)2MnBr4 delivers a high X‐ray light yield of 22 000 photons MeV−1, a low limit of detection of 9.50 nGy s−1, and an excellent X‐ray imaging spatial resolution of 20–25 lp mm−1. Moreover, the regulation of single‐crystal thickness from 0.31 mm to 3.03 mm can be easily achieved via a simple solution post‐treatment method, which has a significant influence on the transmittance, spatial imaging resolution, and detection limit. This work demonstrates a promising single‐crystal scintillator for the application of high‐resolution X‐ray imaging with low preparation cost and tunable thickness. [ABSTRACT FROM AUTHOR]

trans-Stilbene single crystals are of great interest for researchers as scintillators characterized by a high specific light yield. Bulk trans-stilbene single crystals have been grown from an anisole solution. The transmission and photoluminescence spectra have been recorded, and the single-crystal photoluminescence quenching kinetics has been investigated. The scintillation properties of an element (17 × 12 × 5 mm in size) prepared from a grown trans-stilbene crystal, irradiated by γ radiation and X rays, have also been investigated. It is shown that the specific light yield of the obtained crystal is no less than that of a scintillation detector based on a trans-stilbene crystal (31.5 × 10 mm) grown from melt. [ABSTRACT FROM AUTHOR]

Yttrium‒aluminum garnet single crystals, including cerium-doped ones, have been grown from melt by Bagdasarov's method. A comparative spectroscopy study of garnet single crystals and specially prepared ceramics of the same composition has been carried out. The comparative analysis suggests that an increase in the concentration of cerium ions in the garnet crystals improves the spectral-luminescence and scintillation characteristics of the latter and facilitates effective quenching of the substrate luminescence. Ways of optimizing the synthesis conditions to improve the efficiency of scintillators based on {Y Cex}3Al5O12 garnet crystal have been proposed. [ABSTRACT FROM AUTHOR]

In comparison with single crystal scintillators, glass scintillators are more promising materials for their benefits of easy preparation, low cost, controllable size, and large-scale manufacture. The emission of Eu3+ ion at 612 nm matches well with the photoelectric detector, making it suitable for the activator in glass scintillators. Therefore, the research on Eu3+ doped glass scintillators attract our attention. The photoluminescent and scintillating properties of Eu3+-activated boroaluminosilicate glass scintillators prepared by the conventional melt-quenching method were investigated in this work. The glass samples present good internal quantum yield. Under X-ray radiation, the optimal sample reveals high X-ray excited luminesce (XEL), and its integrated intensity of XEL is 22.7% of that of commercial crystal scintillator Bi4Ge3O12. Furthermore, the optimal specimen possesses a spatial resolution of 14 lp/mm in X-ray imaging. These results suggest that Eu3+-doped boroaluminosilicate glass is expected to be applied in X-ray imaging. [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]

Conventional photonic crystals with a single period are capable of enhancing the light output of scintillators based on the partial elimination of internal total reflection. However, the enhancement often comes along with a strong wavelength dependence, leading to a severe spectrum distortion. Here, the nanostructures for wavelength-independent light extraction enhancement, namely, multi-size spherical nanostructures, are designed and fabricated. The nanostructure can efficiently outcouple the scintillation light and at the same time significantly weaken the wavelength dependence. The light output of the scintillators with the nanostructures obtains noticeable enhancement with a ratio of 1.7, having weak wavelength dependence, which is in contrast to the enhancement by single-periodic photonic crystals. In addition to the applications on the scintillators, we anticipate that these wavelength-independent light output enhancement schemes could be expanded to other important fields, such as white light-emitting diodes and display devices. [ABSTRACT FROM AUTHOR]

Cerium-doped lutetium-yttrium oxyorthosilicate (Ce:LYSO) is a well-known single crystal scintillator used in medical imaging and security scanners. Recent development of high power UV LED, matching its absorption band, questions the possibility to use Ce:LYSO in a new way: as LED-pumped solid-state light source. Since Ce:LYSO is available in large size crystals, we investigate its potential as a luminescent concentrator. This paper reports an extensive study of the performance in close relation to the spectroscopic properties of this crystal. It gives the reasons why the Ce:LYSO crystal tested in this study is less efficient than Ce:YAG for luminescent concentration: limited quantum efficiency and high losses coming from self-absorption and from excited-state absorption are playing key roles. However, we demonstrate that a Ce:LYSO luminescent concentrator is an innovative source for solid-state lighting. Pumped by a peak power of 3400 W in quasi-continuous wave regime (40 µs, 10 Hz), a rectangular (1 × 22 × 105 mm3) Ce:LYSO crystal delivers a broadband spectrum (60 nm FWHM) centered at 430 nm. At full output aperture (20 × 1 mm2), it emits a peak power of 116 W. On a squared output surface (1 × 1 mm2) it emits 16 W corresponding to a brightness of 509 W cm–2 sr–1. This combination of spectrum power and brightness is higher than blue LEDs and opens perspectives for Ce:LYSO in the field of illumination namely for imaging. [ABSTRACT FROM AUTHOR]

Metal‐halide perovskites, especially for 3D halide perovskite single crystals (SCs), are emerging as the promising scintillators. However, the strong self‐absorption and low light yield of these perovskites restrict their practical applications. Quantum cutting can convert a high energy photon into multiple low energy photons, endowing a large Stokes shift and high photoluminescent quantum yield (PLQY). Here, this work reports a novel quantum cutting material, CsPbClxBr3−x:Yb3+ perovskite SCs, with the PLQY of 149% and a Stokes shift >550 nm, successfully conquering the issues of poor PLQY induced by the thermal quenching and the large self‐absorption in perovskite SCs. Benefiting from the extremely high PLQY and negligible self‐absorption effect, the first high‐performance quantum cutting scintillators based on CsPbClxBr3−x:Yb3+ perovskite SCs are developed, exhibiting high transmittance, large X‐ray absorption/conversion efficiency, outstanding light yield of ≈1.12 × 105 photons MeV−1, and a detection limit as low as 176.5 nGyair s−1. Finally, a single‐pixel X‐ray imaging is achieved by integrating CsPbCl3:Yb3+ SCs with silicon photomultiplier. This work sheds light on exploring highly competitive scintillators beyond the scope of traditional perovskites. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid copper(I)‐based halides have attracted great interest in the field of optoelectronics due to their low cost, non‐toxicity, large Stokes shift, and high photoluminescence quantum yields (PLQYs). Here, bulk zero‐dimensional (0D) organic‐inorganic hybrid copper(I)‐based (R,S‐2‐mpip)2Cu2I6 (mpip = methylpiperazinium, C5H14N22+) single crystals have been grown with equal stoichiometric ratios of R‐ and S‐2‐mpip ligands by chirality–racemization strategy for the first time. Interestingly, (R,S‐2‐mpip)2Cu2I6 single crystals exhibit strong blue–green photoluminescence (PL) located at 520 nm with large Stokes shift of about 230 nm and high PLQY of about 65.96%, which originates from self‐trapped excitons (STEs). More importantly, (R,S‐2‐mpip)2Cu2I6 single crystals also exhibit the strong radioluminescence (RL) at 520 nm, the fast X‐ray scintillation response with a light yield of about 47 000 photon MeV−1 and low detection limit of 6.48 nGyairs−1 when exposed to X‐ray irradiation condition, which is superior to that of other copper(I) iodide‐based hybrids. Based on the excellent characteristics, X‐ray imaging systems based on (R,S‐2‐mpip)2Cu2I6 single crystals exhibit the clear images of "QFNU" logo and crystal symbol pattern. This work not only deepens the understandings of material design and fundamental properties of these racemate systems, but also provides guidance for the further applications in the multi‐functional optoelectronics. [ABSTRACT FROM AUTHOR]

We investigated the correlation between the surface finish and luminescence properties of chemically polished cerium-doped single-crystal Gd3Al2Ga3O12 scintillators (Ce:GAGG), from the crystallographic perspective. The intrinsic defects in the crystals were identified via photoluminescence spectroscopy followed by scanning electron microscopy and X-ray diffraction to analyze their surface morphologies. Finally, the samples were individually wrapped with an enhanced specular reflector (ESR), coupled with a photomultiplier tube, placed inside a dark box, connected to a digitizer, and irradiated with a 137Cs radioactive source to evaluate the relative light (signal) output and energy resolution of each sample. The as-cut (rough) Ce:GAGG single-crystal samples, that were chemically polished with phosphoric acid at 190°C in air for 60 min, demonstrated a 33.1% increase in signal amplitude (light output to photosensor) and 2.4% (absolute value) improvement in energy resolution, which were comparable to those obtained for the mechanically polished sample. For these samples, the surface roughness was found to be ~430 nm, which was approximately half of that of the mechanically polished sample. The chemical polishing method used in this study is a cost-effective and straightforward technique to improve structural imperfections and can facilitate the treatment of inorganic scintillators with complex shapes and/or on a large scale. [ABSTRACT FROM AUTHOR]

All‐inorganic halide perovskites appear as a promising class of scintillators for radiation detection applications due to their excellent optoelectronic properties. Herein, a self‐activated perovskite CsEuBr3 single crystal is developed as an efficient X‐ and γ‐ray scintillator. Single crystals of CsEuBr3 are grown by the Bridgman method. The phase structure, stability, photophysics properties, and scintillation performance of CsEuBr3 single crystals are studied. Under X‐ray irradiation, its emission peaks at 445 and 510 nm, associated with Eu2+ 5d–4f and defect‐related emission, respectively, are studied. Under 137Cs gamma irradiation, it has a decent light yield of 22 000 ± 2000 photons MeV−1 and an energy resolution of 6.2 ± 0.4% at 662 keV with a scintillation decay of 510 ns. [ABSTRACT FROM AUTHOR]

Halide perovskites are among the most attractive research hotspots in optoelectronic applications due to their excellent luminescence properties. In this paper, Li+ was successfully incorporated into a one-dimensional perovskite CsCu2I3 host and constructed as a novel neutron/gamma detection scintillator via the Bridgman method. XRD and ICP-MS were carried out, and the results were discussed. The Li-doped CsCu2I3 crystal exhibits a main emission peak at 575 nm originating from strongly localized 1D exciton emission and a high photoluminescence quantum efficiency of 18.7%. The CsCu2I3:Li crystal has a light yield of 10 900 photons per MeV and an energy resolution of 11.5% under 137Cs irradiation. The figure-of-merit (FoM) of the CsCu2I3:Li crystal has been estimated (about 0.8) under 252Cf radiation source. The crystal has a potential application for dual gamma–neutron detection. [ABSTRACT FROM AUTHOR]

X‐Ray‐induced luminescence behavior of Si/Ge‐doped GaN single crystals is observed and analyzed in combination with undoped GaN. Similarities between radioluminescence (RL) and photoluminescence (PL) indicate an analogous physical process. Under X‐Ray irradiation, the gallium nitride (GaN) single crystals doped with Si/Ge elements intensely emit tunable visible light ranging from 1.8 to 2.2 eV, and an ultraviolet (UV) emission of ≈3.3 eV is aroused by the intrinsic direct band‐edge transition of GaN. Due to the difference in the physical properties of excitation source and the self‐absorption effect, the UV signal in RL has a dramatic reduction (especially for undoped GaN) and redshift, which is also considered to be the obvious difference between the two spectra. RL results obtained herein along with PL demonstrate that the visible luminescence of Si/Ge‐doped GaN is mainly attributed to DAP or/and e‐A recombination, which is supported by density functional theory (DFT) calculations. [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]

In this study, the infrared optically stimulated luminescence (IRSL) of single crystals of Ce3+ doped yttrium aluminum garnet (YAG) was investigated for the first time. It was found that infrared stimulation of these crystals, following previous exposure to beta radiation, produces a strong luminescence signal. The highest luminescence efficiency was exhibited by the YAG crystal with 0.1% of Ce. With this crystal, it was possible to measure as low doses as 0.1 mGy. Moreover, IRSL is mainly related to the TL peak at a relatively high temperature of c.a. 175 °C, which leads to quite good stability of the signal in time. These properties create good prospects for potential applications of YAG:Ce in dosimetric radiation measurements [ABSTRACT FROM AUTHOR]

Ce:LuAG crystal is an excellent scintillation material, but cracking and inclusion defects often occur when Ce:LuAG is grown by Czochralski method. In this paper, the effects of temperature gradient, pulling speed, rotation speed and thermal strain on crystal defects were analyzed by combining theory with practice, and the solution was put forward. The suitable technological parameters for growing Ce:LuAG crystal with high quality are given: the temperature gradient above the melt is about 5 ° / mm, the shoulder angle is 30° ~ 60°, the pulling speed is 1. 0 ~ 1. 5 mm/ h, and the crystal rotation speed is 15 ~25 r/ min. Finally, good quality of Ce:LuAG single crystal with a diameter of 30 mm and an equal diameter length of 50 mm is successfully grown, and the crystal core area is small. [ABSTRACT FROM AUTHOR]

Low output power has long been the bottleneck of micro-radioisotope batteries as power supplies for the wireless sensor network, implantable medical equipment, and outer space exploration. Recently, x-ray radioluminescent batteries demonstrated the great potential to break the deadlock. In this work, we fabricated an x-ray radioluminescent battery with near milliwatt output power and demonstrated various potential applications. A 100% improvement on the conversion efficiency of 2.46% and the highest output power of 136.1 μW/cm2 were achieved when adopting a thallium doped cesium iodide (CsI:Tl) single-crystal scintillator in the battery. Subsequently, a 2 × 2 battery array was fabricated with a maximum output power of 466.9 μW and was used to power devices including micro-LEDs and a wireless sensor system with temperature monitoring. This demo system shows the feasibility of x-ray radioluminescent batteries as a long-lifetime micropower. The tremendous progress will draw broad attention on micro-nuclear batteries and inspire further exploration on the applications in the field of medical devices, space explorations, and Internet of Things. [ABSTRACT FROM AUTHOR]

β-Ga2O3 is a potential fast semiconductor scintillator with no significant self-absorption and excellent stability. However, the relatively low light yield of β-Ga2O3 at room temperature limits its practical application. In order to improve its scintillation performance, Al3+ doped β-Ga2O3 single crystals are investigated. By doping 5%Al3+ (atomic concentration), the light yield of β-Ga2O3 is increased from 4394 to 6816 ph/MeV. The increased light yield may be attributed to the decreased free electron concentration and inhibition of Auger nonradiative recombination. The thermal quenching effect can also be moderated by the increase in the thermal activation energy induced by Al3+ doping. The results indicate that Al3+ doping is an effective method to increase the light yield of β-Ga2O3. [ABSTRACT FROM AUTHOR]

Anti‐counterfeiting has become a serious issue around the global world; fluorescence‐based tags are praised for the low‐cost and facile decryption process. However, the high‐level anti‐counterfeiting application requires incorporating multifunctional luminescent materials with response to different excitation sources. Herein, a dimeric Cu(I)‐halide‐clusters‐assembled single‐crystal (AEP)2Cu2I6·2I·2H2O (AEP = N‐aminoethylpiperazinium) concerning a high down‐conversion photoluminescence quantum yield (PLQY) value of near unity is reported (λex = 305 nm), which can also be activated by the near‐infrared light and X‐ray. The ultrafast spectroscopy and density functional theory calculations reveal that the broad‐band emission originates from the recombination of self‐trapped excitons. Remarkably, the high PLQY and excellent attenuation capability for X‐ray confers an outstanding light yield of 55 650 photons MeV−1 to (AEP)2Cu2I6·2I·2H2O, which is 5.25 times higher than the standard bismuth germaniumoxide scintillator. Such multi‐light‐stimulus response endows (AEP)2Cu2I6·2I·2H2O with great application potential in anti‐counterfeiting, solid‐state lighting devices, and digital radiography. [ABSTRACT FROM AUTHOR]

Corundum (α‐Al2O3) is a technologically important material and, in particular, widely used in optical applications such as luminescent radiation dosimeters, cryogenic scintillators, and is being considered as a promising candidate for windows in future fusion reactors. Its optical and mechanical properties are controlled by the presence of radiation‐induced (in particular, by fast neutrons) defects. Herein, the thermal stability and recombination kinetics of primary anion Frenkel defects—the F and F+ electronic centers and oxygen interstitials—in fast‐neutron‐irradiated α‐Al2O3 single crystals are analyzed. Theory is developed considering the formation of both neutral and charged oxygen Frenkel defect pairs; defect migration, interaction and recombination. Based on ab initio calculations and new theoretical kinetics analysis, for the first time, a coexistence is demonstrated, in comparable concentrations, of two interstitial types—neutral O atoms and negatively charged O− ions (with attributed optical absorption band maxima at 6.5 eV and 5.6 eV, respectively); and their diffusion parameters, necessary for the prediction of secondary defect‐induced reactions and defect/material thermal stability, are obtained. [ABSTRACT FROM AUTHOR]

Low‐dimensional organic–inorganic hybrids have emerged as promising X‐ray scintillators due to efficient radioluminescence properties. Herein, stable and efficient X‐ray scintillator based on 0D (C40H38P2)MnBr4 hybrid single crystals grown by a facile solution‐processing method is reported. Its crystal structure is determined to be triclinic with P1¯ space group. It has good stability against moisture and irradiation. (C40H38P2)MnBr4 with tetrahedrally coordinated Mn2+ exhibits green emission peaking at 518 nm originating from d–d 4T1→6A1 transition of Mn2+ ion with a high photoluminescence quantum yield (PLQY) of 74.2%. Under X‐ray excitation, it shows high scintillation yield of 32 000 photons MeV−1, a decent detection limit of 288 nGyair s−1, and a low afterglow comparable to that of Bi4Ge3O12 (BGO). [ABSTRACT FROM AUTHOR]

Inch-sized Mn-based halide single crystal films, (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 , with tunable thickness from 0.12 mm to 0.72 mm were designed and used directly in the X-ray imaging. The high light yield of 56,457 and 78,937 photons/MeV and high spatial resolution exceeding 20 lp/mm demonstrates the great potential of large size single crystal scintillator screen for commercial high-resolution X-ray imaging applications. [Display omitted] • Inch-sized Mn-based halide single-crystalline films with tunable thickness from 0.12 mm to 0.72 mm were designed and grown. • The inch-size single crystals of (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 exhibit high light yield of 56457 and 78937 photons/MeV under X-rays. • The (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 single crystal screens exhibit outstanding spatial resolution of 21.02 and 25.61 lp/mm. Hybrid metal halides are emerging candidates for X-ray imaging. Due to the poor uniformity, low transmittance and high light scattering of polycrystalline film scintillator screen, resulting in low resolution of X-ray imaging, it is essential a challenging to explore new large-area and single crystal scintillator with high light yield and high resolution. Herein, inch-sized Mn-based halide single crystals, (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 , with tunable thickness films from 0.12 mm to 0.72 mm were designed and grown. The crystals of (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 with high photoluminescence quantum yield (PLQY) of 62.42 % and 99.10 % exhibit high light yield of 56,457 and 78,937 photons/MeV under X-ray, which is 1.7 and 2.37 times higher than that of the commercial LYSO scintillator. Both the crystals show high X-ray radiation resistance even exposed to X-ray for 60 mins with a high dose rate of 504 mGy s−1. The high photochemical stability under the continuous UV and X-ray irradiation contributes them towards X‑ray imaging. With such significant merits, the high spatial resolutions about 21.02 and 25.61 lp/mm are achieved on the (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 single crystal films, which demonstrates the great potential of large size single crystal screen for commercial high-resolution X-ray imaging applications. [ABSTRACT FROM AUTHOR]

CaNb 2-x Ta x O 6 (x = 0, 0.2, 0.5 and 1) single crystals were fabricated by the floating zone method, and their photoluminescence (PL) and scintillation properties were evaluated. Under excitation at 280 nm, CaNb 2-x Ta x O 6 single crystal showed a broad emission band at 400–600 nm. From the decay time constant, the observed emission was attributed to the charge transfer (CT) from the Nb5+ to the O2−. Under X-ray irradiation, an emission peak was observed at 470 nm, and the scintillation decay time profile suggested that the origin of the emission was also CT from the Nb5+ to the O2−. CaNb 2 O 6 showed the highest light yield of 15,000 ph/MeV and the lowest afterglow level of 6.03 ppm among the synthesized samples. • We have synthesized CaNb 2-x Ta x O 6 (x = 0, 0.2, 0.5 and 1) single crystals by floating zone method. • CaNb 2-x Ta x O 6 (x = 0, 0.2 and 0.5) single crystals showed the broad emission band due to the charge transfer from Nb5+ to O2−. • The light yields (LY) of CaNb 2-x Ta x O 6 single crystals were 15,000 (x = 0), 7000 (x = 0.2), and 6000 ph/MeV (x = 0.5). • Afterglow levels (AGL 20) of CaNb 2-x Ta x O 6 (x = 0, 0.2, and 0.5) were 6.03, 10.2, and 19.8 ppm, respectively. • The LY and AGL 20 of CaNb 2 O 6 single crystals were comparable with a part of commercial scintillators such as Bi 4 Ge 3 O 12. [ABSTRACT FROM AUTHOR]

Intrinsic luminescence in Ce-doped (Lu,Y) 2 SiO 5 (or LYSO:Ce) single crystals have been studied by means of excitation luminescence spectroscopy in the vacuum ultraviolet energy range under synchrotron radiation. A previously unreported luminescence band with emission at 250 nm has been discovered as well as its thermal behavior was described in the temperature range 10–120 K. The excitation spectra as well as time-resolved properties of this band suggest that this emission corresponds either to the singlet component of self-trapped exciton or to a self-trapped exciton in the lutetium sublattice of LYSO single crystals. • New previously unreported intrinsic emission band at 250 nm has been observed in LYSO single crystals. • Temperature dependencies of intrinsic luminescence have been measured and analyzed. • Two possible origins of new 250 nm emission are proposed and discussed. [ABSTRACT FROM AUTHOR]

This study provided the first in-depth investigation of the effects of large dopant incompatibility (Pr3+ and La3+ ions) on the small host lattice element (Lu3+) in Lu 3 Al 5 O 12 (LuAG) single crystal. The growth of such complex crystals from the melt presented many challenges. By engineering the ionic radius ratio of RE- and M-site cations, a single-crystal phase stabilized by configurational entropy was achieved. This investigation elucidated the crystallization behavior of configurationally disordered rare-earth aluminum garnet oxide (Lu 1−x−y Pr x La y) 3 Al 5 O 12 from the melt and characterized its functional properties, including microstructural, optical, photoluminescence, and scintillation properties, between 5 and 300 K. Relaxation of the imposed strain energy led to local perturbations and destabilization of the garnet structure. Multielemental EDS mapping, micro-Raman spectroscopy, and thermoluminescence revealed the mechanism by which atomic size mismatch drove a smooth transition from the garnet to the perovskite phase in high entropy garnets. The optical, photoluminescence, and scintillation measurements provided fundamental insights into property changes driven by incompatibility doping. Standard and modified Judd-Ofelt theory analysis of absorption spectra determined the phenomenological Judd-Ofelt parameters Ω λ and radiative lifetimes. Atomic size mismatch engineering offers a promising approach to overcoming the limitations of conventional eutectic synthesis methods. • Perovskite inclusions, driven by atomic size mismatch, extend from rim to core. • Controlled incompatible La3+,Pr3+ codoping in LuAG modify functional properties. • Scintillation light yield improved up to 30% in La3+ codoped LuAG:Pr crystals. • (La,Pr)AlO 3 perovskite forms due to size mismatch of La3+ and Pr3+ with Lu3+. • Lattice disorder affects the intensity ratio of Pr³⁺ 5d→4 f and 4 f→4 f emissions. [ABSTRACT FROM AUTHOR]

• Raman spectral analysis confirmed the presence of Sn through the Ag(10) phonon mode. • Sn:β-Ga 2 O 3 crystal shows an enhancement in intensity of X-ray induced emission spectrum. • Sn:β-Ga 2 O 3 crystal shows enhancement in scintillation light yields. High-quality single crystals of both pure and Sn:β-Ga 2 O 3 single crystals were grown using the optical floating zone technique and a comprehensive study of its luminescence and scintillation properties was carried out. The pure and Sn:β-Ga 2 O 3 grown crystals were oriented along (1 0 0) by Laue diffraction pattern and its monoclinic structure was confirmed using a single crystal XRD. X-ray induced luminescence spectrum shows a maximum emission peak at 365 nm. The cut off wavelength was observed around 258 nm and the optical band gap was calculated to be 4.64 eV from UV–Vis-NIR transmission spectroscopy. The room temperature Raman spectra were recorded and the various vibration modes were investigated. Low temperature (10 to 300 K) and high temperature (325 to 675 K) TL measurements were carried out on X-ray irradiated crystals and its TL kinetic parameters such as activation energy (eV) and frequency factor (S) were calculated. Scintillation decay time profiles were measured for both pure and Sn-doped crystals under 137Cs γ-ray excitation. The calculated scintillation light output is 2300 Ph/5.5 Mev for Sn:β-Ga 2 O 3 crystal under α-particle excitation from 241Am radiation source. [ABSTRACT FROM AUTHOR]

CsI(Tl) scintillator has been widely used in X-ray flat-panel detectors due to excellent performance characteristics including a suitable Si-photodiode emission wavelength, excellent optical output, and fast decay time. Here, a solution-based space-confined growth method was presented to achieve CsI(Tl) scintillator single-crystal flakes with controllable thickness. The grown CsI(Tl) single-crystal flake exhibits a comparable light yield (∼72,000 photons/MeV) and a lower afterglow level (0.1% @ 21 ms, 0.01% @ 118 ms) in comparison to that by the traditional melting method. This space-confined method allows for the achievement of a single crystal thickness of only 0.27 mm, making it suitable for direct application in X-ray detection and other related fields. It may open up new possibilities for the development of halide scintillator single crystals. A solution-based space-confined growth method enables the growth of high-quality CsI(Tl) single crystal flakes with controlled thickness for X-ray flat-panel detectors. [Display omitted] • A space-confined solution method is used to grown CsI(Tl) single-crystal flakes. • The thickness of the CsI(Tl) flake grown using this method can be controlled to be as thin as approximately 0.27 mm. • The CsI(Tl) flake exhibits a lower afterglow and a comparable light yield in comparison to that by the melting method. [ABSTRACT FROM AUTHOR]

This paper describes the low temperature growth of triglycine sulphate (TGS) and deuterated l -alanine triglycine sulfate (DLaTGS) crystals using a slow cooling method. The dielectric, ferroelectric and pyroelectric properties of the grown crystals were investigated using LCR meter, Sawyer–Tower-modified circuit, and temperature ramping method, respectively. Powder X-ray diffractometer (XRD) was used to determine the crystal structure of the grown crystals. Fourier Transform Infrared (FTIR) spectroscopy was used in the range of 400–4000 cm−1 and the functional groups of the grown crystals have been identified. The results and analysis of DLaTGS detectors at 1 kHz using the black body testing station exhibit a novel behavior at room temperature with relatively low noise-equivalent power (NEP). The proposed results show a specific detectivity (D*) between (2.09–2.29) × 108 (cm Hz1/2/W) with relatively low NEP between (5.05–5.55) × 10−10 W/√Hz. Further, the temperature-dependent pyroelectric coefficient of DLaTGS detector indicates effective operation below its Curie temperature of approximately 60 °C, exhibiting pyroelectric properties ideal for various sensing and detection applications in IR region. While the proposed results of DLaTGS detectors can be used in many IR applications, including spectroscopy, remote sensing, gas analysis, thermal imaging, and medical diagnostics, one of their drawbacks is their cost. This cost can be a limiting factor for some applications, especially those that require large arrays of detectors or where cost-effectiveness is a significant concern. [Display omitted] • A Controlled temperature decrease method is used to grow TGS and DLaTGS crystals. • Slow cooling of solution is crucial for the formation of high-quality TGS and DLaTGS crystals. • The XRD patterns of undoped and doped TGS are indistinguishable from each other. • DLaTGS detectors exhibit high detectivity and a relatively low noise level. • The high cost of DLaTGS can be a limiting/factor for applications requiring large arrays or cost-effectiveness. [ABSTRACT FROM AUTHOR]

Trans -stilbene single crystal possesses the advantages of high luminescence efficiency, short response time, stable radiation/strong light resistance and remarkable neutron/gamma pulse shape discrimination (PSD) properties, rendering it arguably the leading candidate for organic scintillators. Here, by the improvement of the thermal field, solvent and sealing on our self-designed equipment, precise growth control resulted trans -stilbene single crystal with high crystalline quality (half peak width of rocking curve of 46.58 arcsec) and size of more than 60 mm. Then we fabricated crystal wafers for the first time to conduct systematic physicochemical measurements to reveal the intrinsic properties of the material. The high-quality single crystals were found to possess high optical transmittance (80%), fast decay time of 2.85 ns (68.49%) and high photoluminescence quantum yield (90.5%), which are more suitable for fast neutrons detection requirements. Thirdly, we conducted a comprehensive exploration of the radiation response of high-quality trans -stilbene single crystals to alpha particles and gamma rays. The results showed a record neutron/gamma discrimination performance with a FOM value of 4.33, which is the highest reported value so far. This work paves the way for practical applications of trans -stilbene and may provide guidance for the selection of detectors for monitoring ionizing radiations under multiple irradiations background. • Large-sized and high-quality trans -stilbene single crystals were grown by our independently designed growth equipment. • The fabrication of wafers from the as-grown single crystals were firstly realized to measure the physical/chemical properties. • The n/γ discrimination of trans -stilbene single crystals showed a FOM value of 4.33, which is the highest value so far. [ABSTRACT FROM AUTHOR]

lthough single crystal scintillators have excellent performance, they have some drawbacks such as high cost, complicated elaboration method and difficulty of growth on large-scale. Glass scintillators are widely investigated to replace single crystal scintillators because of their simple fabrication method and low cost. In this paper, a series of transparent borosilicate aluminate glass scintillators doped with Tb3+ were successfully prepared by traditional melt-quenching method. The structural, luminescent, and X-ray excited scintillating properties were investigated. These glass samples show high stability and high transparency, and present good luminescent and scintillating properties. Sample with Tb3+ doping concentration of 10% has the best scintillating performance. The integrated intensity of X-ray excited luminescence is 66.6% of that of commercial Bi 4 Ge 3 O 12 single crystal scintillator, and the quantum efficiency (under 378 nm excitation) is 70.3%. Our findings suggest that Tb3+-doped borosilicate aluminate glasses with high light yield might be used as potential scintillators. [ABSTRACT FROM AUTHOR]

Low‐dimensional perovskite halides have shown a great potential as X‐ray detection materials because of efficient exciton emissions originating from strongly spatially localized charge carriers. Nonetheless, most of them have a scintillation yield far below their theoretical limits. Here, it is found that the harvesting efficiency of produced charge carriers can be significantly enhanced via a small amount of In+ doping in these highly localized structures. A bright and sensitive zero‐dimensional Cs3Cu2I5:In+ halide with efficient and tunable dual emission is reported. The radioluminescence emission of Cs3Cu2I5:In+ crystals under X‐ray excitation consists of a self‐trapped exciton emission at 460 nm and an In+‐related emission at 620 nm at room temperature. In+ doping enhances the photoluminescence quantum efficiency (PLQY) of Cs3Cu2I5 from 68.1% to 88.4%. Benefiting from the higher PLQY, Cs3Cu2I5:In+ can achieve an excellent X‐ray detection limit of 96.2 nGyair s−1, and a superior scintillation yield of 53 000 photons per MeV, which is comparable to commercial CsI:Tl single crystals. As a result, a remarkable X‐ray imaging resolution of 18 line pairs mm–1 is demonstrated, which is so far a record resolution for single crystal perovskite‐based flat‐panel detectors. These results highlight the importance of efficient harvesting of carriers (and excitons) in low‐dimensional perovskites for radiation detection applications. [ABSTRACT FROM AUTHOR]

A large number of experiments carried out at charged particle accelerators indicate that the radiation dose accumulated by the scintillation materials contained in detectors is significant. For example, in experiments at the Large Hadron Collider, the radiation dose in scintillation detectors can reach 10 Mrad and will increase in the future. In this connection, the search for new radiation-resistant scintillation materials is especially important. Irradiation can significantly alter the characteristics of the scintillator material. The aim of this work was to study the features of possible radiation damage and transformations in composite scintillators under the action of ionizing radiation. We focused on composite scintillators, which are transparent non-luminescent gel-compositions containing grains of scintillation oxide single crystals. A comparative analysis of the spectra of the relative light yield, transmission, and luminescence, as well as their dependence on the accumulated dose for various composite scintillators, has been carried out. Possible mechanisms of radiation changes occurring in scintillators under irradiation are proposed and the influence of these processes on the radiation resistant of composite scintillators is analyzed. In this work, as in previous works in this series, we irradiated composite scintillators on a linear electron accelerator. The electron energy was 10 MeV. We irradiated with a low (0.2 Mrad/h) and a high (1500 Mrad/h) dose rate. At low dose rate, cracking occurs at lower radiation dose values (about 100–200 Mrad) than under irradiation at a high dose rate (up to 500 Mrad). The luminescent characteristics of the scintillator changed insignificantly until the gel composition fixing single-crystal grains cracked. After destruction of the gel composition, an abrupt deterioration in the properties of the sample took place. [ABSTRACT FROM AUTHOR]

Alkaline tungstate crystals are promising scintillation materials for rare events search, especially for WIMP investigations. Na2W2O7 single crystals doped with 1.0 mol.% chromium and cerium ions are grown from melt by low-thermal-gradient Czochralski technique (LTG Cz) developed at Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciece (Novosibirsk, Russia) for obtaining large oxide scintillating crystals of high optical quality. Obtained doped Na2W2O7 single crystals 25 mm in length and 30 mm in diameter. The photoluminescence excitation and emission spectra, as well as the decay curves in the temperature range of 77-300 K are measured and colorimetric parameters are estimated. Comparative studies of the photoluminescence properties of Na2W2O7 crystals undoped and doped with Ce3+ and Cr3+ ions in the temperature range of 77-300 K are is carried out. It is shown that while the introduction of cerium and chromium ions in the Na2W2O7 crystal lattice does not significantly a effect the colorimetric parameters and optical properties, it does not increase mechanical hardness of the crystals and decreases the tendency to cracking along cleavage planes. The emission color chromaticity coordinates, сorrelated color temperature and color purity for Na2W2O7:Ce and Na2W2O7:Cr crystals are calculated. The photoluminescence lifetimes are calculated and a strong temperature dependence of the lifetimes in the range 77-300 K is shown. [ABSTRACT FROM AUTHOR]

Ce0.03Gd2.97Ga2Al3O12 (Ce:GGAG) single crystals were successfully grown by the traveling solvent floating zone method (TSFZ). A series of compositions, where the mole ratio is Gd2O3 : Al2O3 = 25 : 75, 27 : 73, 29 : 71, were investigated as solvents. The 25 mol% Gd2O3-75 mol% Al2O3 solvent component was found to be the most effective in stabilizing the molten zone to obtain a crystal rod with uniform diameter. The crystal cracks were relieved clearly due to the improved molten zone stabilization during the crystal growth process. XRD patterns of the obtained crystals prove the garnet structure without any evident second phase. The characteristic Ce3+ emission located at around 540 nm was presented in the photoluminescence and X-ray excited luminescence spectra. The scintillation light yield reaches up to 34 132 pho MeV−1 and scintillation decay time was optimized to 64 ns with a high fast decay component of about 85%. The TSFZ method demonstrated the growth feasibility of Ce:GGAG crystals that have an incongruent-melting trend with lower Ga/Al ratio in the compositions. [ABSTRACT FROM AUTHOR]

Europium-doped lutetium oxide (Lu2O3:Eu) single crystal is grown by vertical Bridgman method for the first time. Correlated measurements of X-ray diffraction, X-ray fluorescence spectra, optical transmittance, photoluminescence excitation, photoluminescence (PL), PL decay, and X-ray excited luminescence (XEL) spectra are performed. The transmittance of about 80% above 300 nm indicates that the crystal is of good optical quality. By measuring actual Eu3+ concentration, the effective segregation coefficient of Eu3+ in the Lu2O3:Eu crystal is calculated to be 0.75. In the PL spectrum, the dominant emission peaks at 612 and 630 nm originate from the 5D0→7F2 transitions of Eu3+ in C2 site. It is worth mentioning that several emission peaks between 575 and 605 nm mainly ascribe to the transitions of different 5D0 levels to the split 7F1 levels of Eu(C2) or Eu(C3i). PL decay spectra indicate the decay time of 612 nm emission can be determined about 1.0 ms. The decay curve of 582.6 nm emission can be fitted into triple components, and the 5.3 and 1.4 ms components are attributed to Eu3+(C3i) and Eu3+(C2), respectively. The XEL strongest emission of Lu2O3:Eu sample is around 612 nm with a bright red luminescence that matches silicon photodetectors sensitivity. [ABSTRACT FROM AUTHOR]