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Polystyrene film nanocomposites of 0.3mm thickness with embedded LaPO4-Pr nanoparticles (40 wt. %) have been synthesized. The luminescent and kinetic properties of these polystyrene composites with embedded LaPO4-Pr nanoparticles upon pulse X-ray excitation have been studied. The luminescence intensity of this polystyrene material significantly increases as it is loaded with inorganic LaPO4-Pr nanoparticles. Nanocomposite films reveal luminescence spectra typical for polystyrene activators (p-Terphenyl and POPOP) and two components of decay time kinetics of luminescence with 12 ns and 2.8 ns time constants, depending on nanoparticle sizes. The component with 12 ns decay constant arises due to the radiative transfer of the 5d-4f-emission of the Pr3+ ions in the LaPO4 nanoparticles to the polystyrene. The decay component with the time constant 2.8 ns originates from luminescence of polystyrene matrix excited by electrons emitted from nanoparticles due to the photoeffect. This nonradiative mechanism of energy transfer from nanoparticles to polystyrene matrices is determinative for nanoparticles, as their sizes are smaller than a mean free path of an electron. [ABSTRACT FROM AUTHOR]

Ce differently (0, 0.01, 0.1, 1, 2 and 5% with respect to Mg) doped LiMgAlF 6 ceramics were synthesized by the spark plasma sintering (SPS) method. In photoluminescence (PL), emission bands appeared at 300 nm with 30 ns day time, and these emission properties were almost the same in scintillation under X-ray irradiation. Further, thermally stimulated luminescence (TSL) was observed after X-ray irradiation, and the primary glow peak temperature was 160 °C with a lower detection limit of ∼10 mGy. • Ce-doped LiMgAlF 6 ceramics were prepared by the spark plasma sintering method. • Photoluminesence and scintillation properties were investigated. • Thermally stimulated luminescence properties were evaluated. [ABSTRACT FROM AUTHOR]

The photoluminescence and scintillation properties of n-bromophenethylammonium lead chloride ((n-BrPEA) 2 PbCl 4) (n = 4, 3, and 2) and phenethylammonium lead chloride ((PEA) 2 PbCl 4) have been investigated. All the samples showed broad emission peaks at 400–700 nm upon excitation by UV light or X-ray. The decay time constants of 8–28 ns were obtained which originated from the recombination of self-trapped exciton (STE) within inorganic layers. The afterglow levels at 20 ms after 2 ms of X-ray irradiation of (4-BrPEA) 2 PbCl 4 and (3-BrPEA) 2 PbCl 4 (76 and 55 ppm) were better than (PEA) 2 PbCl 4 (379 ppm). The light yield of (4-BrPEA) 2 PbCl 4 (3100 photons/5.5 MeV-α) was higher than (PEA) 2 PbCl 4 (1400 photons/5.5 MeV-α). • (BrC 6 H 4 C 2 H 4 NH 3) 2 PbCl 4 crystals were grown by the slow cooling method. • All the crystals showed the luminescence due to the recombination of the self-trapped excitons confined in inorganic layers. • The (4-BrC 6 H 4 C 2 H 4 NH 3) 2 PbCl 4 crystal showed the highest QY in the present crystals. • The light yields of the (4-BrC 6 H 4 C 2 H 4 NH 3) 2 PbCl 4 crystals surpassed that of the unsubstituted crystal. [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]

Ce,Mg:Lu 2 YGa x Al 5-x O 12 (x = 1.5, 2, 2.5, 3) ceramic scintillators were fabricated by oxygen sintering combined with air annealing using nano-powders synthesized by the co-precipitation method. The Ce3+ 5d 1 → 4f (2F 5/2 , 2F 7/2) luminescence band was blue shifted with increasing Ga content due to the decrease in the crystal field splitting of the 5d levels. At room temperature (RT), the decrease of photoluminescence decay time and scintillation decay time was observed with increasing Ga content. At 662 keV γ-rays, the sample Ga2 exhibited high light yield (LY) of 28,700 photons/MeV, fast scintillation decay times of 17.7 ns (17 %) + 45.7 ns (83 %), and good time resolution of ∼220 ps. At RT, the decrease of LY value for the samples Ga2.5 and Ga3 could be attributed to the larger thermal ionization of the excited Ce3+ centers. • Scintillation properties of Ce,Mg:Lu 2 YGa x Al 5-x O 12 (x = 1.5, 2, 2.5, 3) ceramics are investigated. • All ceramic samples show fast effective scintillation decay time less than 47 ns. • Sample x = 2 shows high LY of ∼28,700 ph/MeV @662 keV γ rays. • Samples x = 2 and 2.5 show good coincidence time resolution of 220 ps. [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]

Scintillators are of significance for X-ray excited luminescence (XEL) imaging from scientific research to medical diagnostics application. Rare earth fluoride nanocrystals possess distinctive luminescent properties originated from the abundant energy level of lanthanide activators, showing potential applications as next-generation scintillators. Herein, high Z atomic rare earth element lutetium was chosen to synthesized NaLuF 4 -based nanoscintillators by Tb doping. Core-shell structure was fabricated to further enhance the XEL emission intensity. The NaLuF 4 -based nanoscintillators was demonstrated more efficient XEL emission with 3-folds increase compared to NaYF 4 nanocrystals. NaLuF 4 nanocrystals with a 25 mol% Tb doping and an inert shell coating exhibited excellent scintillation performance with detection limit as low as to 57.05 nGy air s−1. X-ray imaging demonstrated a high spatial resolution of 10.5 lp mm−1 using a scintillator film made from as-prepared NaLuF 4 -based nanoscintillators. Finally, such NaLuF 4 -based scintillators film have been applied in X-ray imaging application for a chip and a biological specimen. This study proposed an effective strategy to enhance XEL for rare earth fluoride, providing the ability for high-quality X-ray imaging. • Enhanced luminescence of X-ray excitation nanocrystals were demonstrated by selecting NaLuF 4 -based and core-shell structure. • The nanoscintillators exhibited excellent X-ray scintillation performance, achieving efficient X-ray luminescence imaging. [ABSTRACT FROM AUTHOR]

X-ray Excited Optical Luminescence (XEOL) from rare earth doped whitlockite phosphates and silicate garnets [Ca 9 La(PO 4) 7 and Ca 9 Lu(PO 4) 7 , doped with 1 mol% Ce3+; Ca 3 Sc 2 Si 3 O 12, doped with 0.5 mol% Pr3+, 1 mol% Eu3+ and 1 mol% Tb3+], was obtained upon X-ray excitation with a tunable synchrotron light source. Excitation at photon energies across the M 5,4 -edge of the dopants reveals additional information not normally obtainable with conventional UV/visible or an X-ray line source (Al K α). It is found that despite the low concentration, photoluminescence yields excited with photon energy at the M 5,4 -edge of the rare-earth dopant can positively and negatively affect the overall energy transfer to the optical center. The implication of these observations is discussed. The application of XEOL in the investigation of X-ray scintillators is illustrated. [Display omitted] • X-ray Excited Optical Luminescence (XEOL) from rare earth doped phosphates and silicates is investigated. • Excitation at the M5,4-edge of the dopants reveals additional information not obtainable with UV/visible light. • Excitation at the M5,4-edge can positively and negatively affect the overall energy transfer to the optical channel. • The application of XEOL in the investigation of X-ray scintillators is illustrated. [ABSTRACT FROM AUTHOR]

• CuI thin films have been synthesized in iodine solution at room temperature. • An apparent NBE peak can be recognized both in PL and XEL spectra. • Iodine-rich condition is beneficial to improve the XEL yield of CuI thin films. CuI is considered as a potential candidate for fast scintillator material due to the fast decay time. However, the ever-reported CuI scintillator usually demonstrates a more intensive deep-level emission with the decay time as long as 2.82 μs, which is unfavorable for the application as a fast scintillator material. In present work, γ-phase CuI were synthesized by iodizing Cu thin films in iodine solution at room temperature. An apparent near band-edge emission (NBE) is observed both in photoluminescence and X-ray excited luminescence spectra. By analyzing the variation of the relative intensity ratio of the sub-peaks composing NBE against different fabrication conditions, it can be deduced that Cu vacancy and surface chemisorbed iodine are responsible for the above luminescence behavior. It is hoped that these findings may boost the exploration of CuI thin films as fast scintillator materials. [ABSTRACT FROM AUTHOR]

(n-ClC 6 H 4 C 2 H 4 NH 3) 2 PbCl 4 ((n-ClPEA) 2 PbCl 4) (n = 2, 3, and 4) and (n-C 6 H 5 C 2 H 4 NH 3) 2 PbCl 4 ((PEA) 2 PbCl 4) crystals were synthesized by the slow-cooling method, and the photoluminescence (PL) and scintillation properties were evaluated. All the samples showed self-trapped excitons luminescence at 400–700 nm. The PL quantum yields of the (n-ClPEA) 2 PbCl 4 (n = 2, 3, and 4) and (PEA) 2 PbCl 4 crystals were 2.2, 0.9, 11.2, and 2.2 %, respectively. In the pulse-height spectra of 241Am α-rays (5.5 MeV), full energy absorption peaks were observed, and the light yields of (n-ClPEA) 2 PbCl 4 (n = 2, 3, and 4) and (PEA) 2 PbCl 4 crystals were respectively calculated to be 530, 490, 2,800, and 1,400 photons/5.5 MeV-α with typical errors of ± 10 %. [ABSTRACT FROM AUTHOR]

We have investigated the scintillation properties of Ce-doped Li2O-ZnO-P2O5 glasses. The samples were prepared using a conventional melt-quenching method with low heating temperatures from 900 to 950 °C. All the samples showed halo patterns in their X-ray diffraction (XRD) patterns. In the X-ray-induced scintillation spectra, each sample showed a single emission peak that can be ascribed to luminescence due to the 5d-4f transitions of Ce3+ ions. In the pulse height spectra of the samples, thermal neutron detection peaks were observed. Their light yields were estimated to be approximately 90-180 photons/neutron. Although the Cedoped Li2O-ZnO-P2O5 glasses show low light yields, they can be regarded as thermal neutron scintillators that can be produced with low heating temperatures. [ABSTRACT FROM AUTHOR]

The photoluminescence (PL) and scintillation properties of (C6H5C2H4NH3)2Pb1-xCuxBr4 (x = 0.05, 0.1, 0.25, and 0.5) single crystals prepared by the poor-solvent diffusion method were evaluated. In the PL profiles, free- and bound-exciton luminescence peaks at 410 and 440 nm were observed, respectively. The PL quantum yields (QYs) of the x = 0.05, 0.1, 0.25, and 0.5 samples were 20.0, 19.3, 18.4, and 16.7% with 2% errors, respectively. In the scintillation profiles, a bound-exciton luminescence peak was observed at 440 nm. Under γ-ray exposure with 137Cs, a photoabsorption peak was observed in all the samples, and the scintillation light yields of the x = 0.05, 0.1, 0.25, and 0.5 samples were estimated to be ~12000, ~11000, ~10000, and ~9700 ph/MeV with 10% errors, respectively. [ABSTRACT FROM AUTHOR]

The increasing demand for radiation detection in many applications has led to demanding requirements for scintillators. Realizing low‐dose, pollution‐free, and reliable X‐ray detection has become a key technical challenge. Here, a triplet‐enhanced lanthanide radioluminescence (RL) material Ga3+/Tb3+ metallacrowns (Tb‐1) is reported. This Tb‐1 crystal emits bright green luminescence under ultraviolet light or X‐ray excitation, and the emission intensity is 286 and 242 times that of Tb3+ in inorganic salt, respectively. Tb‐1 crystal is further passivated by trioctylphosphine oxide (TOPO), and the enhanced RL intensity is equivalent to that of commercial Tl‐doped cesium iodide scintillator. In addition, RL of Tb‐1–TOPO has an extremely narrow full width at half maximum and an excellent linear response to the X‐ray dose rate. The detection limit is calculated to be 0.146 μGy s−1, which is 38 times lower than typical medical imaging doses. Triplet‐enhanced lanthanide RL provides new ideas for replacing scintillators that require high temperature synthesis processes such as inorganic phosphors and ceramics, and provides a new alternative scintillator material for flexible X‐ray monitoring, bioimaging, radiotherapy, and other applications. [ABSTRACT FROM AUTHOR]

All-inorganic perovskite quantum dots have been widely used in solar cells, LED, laser and scintillator in recent years. However, the essence of ion migration in perovskite lattice can cause the ion vacancies exist, which can directly affect the luminescence process. Herein, we focus on the effect of monovalent cation vacancies on the CsPbBr 3 lattice, and realize the adjusting lattice structure of the CsPbBr 3 QDs to change the luminescence lifetime by controlling the formation of monovalent cation vacancies. The results show that the existence of monovalent cation vacancies can be controlled by controlling dosages of Cs + precursor and can make the CsPbBr 3 lattice produce local lattice micro distortion and reduce luminescence lifetime, which is beneficial to realize the rapid and efficient X-ray imaging of scintillating crystals. Experimental result is also verified by density functional theory (DFT). [ABSTRACT FROM AUTHOR]

Lithium iodides are very efficient single‐crystal scintillators for thermal neutron detection. Doping with silver, as activator ions, has shown to improve its limitation of discriminating gamma background by introducing pulse shape discrimination ability. To improve the scintillation performance, single crystals of LiI:Ag, codoped with different concentration of Sr ions, are grown and characterized in details. A systematic investigation of radioluminescence, thermoluminescence, and scintillation properties along with the decay kinetics provides better understanding about the role of defect structure in scintillation mechanism. The extra charge, provided by Sr2+ ions, is found to alter the defect structure with relative reduction of the contribution from the deeper trap centers in comparison with the shallow traps. Consequently, it leads to a significant improvement of light yield quenching under higher excitation density of charged particle irradiation. The 0.1% Sr codoped crystals provide a better discrimination ability of neutron and gamma radiations for simultaneous detection. [ABSTRACT FROM AUTHOR]

The luminescent property of 2D perovskite materials promotes their applications in light emitting diodes, phosphor powders, and scintillators. Recently, an interesting extrinsic low‐energy broadband luminescence is hotly investigated. However, the understanding of such emissions is still at the early stage. In this study, based on a modified solvent evaporation method, centimeter‐size (BDA)PbI4 (BDA = NH3C4H8NH32+) single crystals are grown which, besides the band–band emission, show a large Stokes‐shifted broadband luminescence. We find such emission can be effectively excited by sub‐gap photons and conclude defects‐induced shallow traps are the corresponding luminescence centers. Density functional theory (DFT) calculations indicate that in‐plane iodine vacancies can introduce shallow electron traps in the band gap and give rise to the broadband emission. [ABSTRACT FROM AUTHOR]

Ce‐doped yttrium aluminum garnet (YAG) is among the efficient rare‐earth garnet scintillators and phosphors. Herein, a computational and experimental study of complex F‐type defect centers formed in YAG by doping with cerium and carbon is addressed. The formation energies determined by ab initio calculations of different defects and atomic chemical potentials in YAG:Ce,C are discussed in O‐poor and O‐rich conditions corresponding to the crystal growth under Ar+CO reducing atmosphere, and postgrowth annealing in air, respectively. It is shown that as‐grown crystals contain numerous positively charged defects responsible for F‐type center formation, whereas mainly negative‐charged defects are remained after the annealing in air. The negatively charged defects located nearby Ce luminescence center occupying Y site may stabilize cerium in the tetravalent state and promote a hole transport to this luminescence center. This describes a high scintillation efficiency of Ce,C‐doped garnets. Furthermore, YAG:C and YAG:Ce,C with a high carbon concentration, in addition to luminescence peaked at 400 ns ascribed to F+‐type centers, possess a fast luminescence peaked around 650 nm that may be attributed to the complex defect centers. These unveiled features of the luminescence process in rare‐earth garnets may contribute to the development of efficient luminescence materials. [ABSTRACT FROM AUTHOR]

In recent years, several coordination polymers of different dimensions and metal–organic frameworks were tested and expected to be good candidates for closing the gap between organic and plastic scintillators on the one hand side and inorganic scintillators on the other hand side. In the present work, we report the synthesis and characterization of a novel one-dimensional scintillating coordination polymer based on cadmium(II), N,N'-(1,4-phenylenedicarbonyl)di-glycinate, and 2,2'-bipyridine. Crystals could be obtained from water–methanol solutions and the structure was determined by single-crystal diffraction. The coordination polymer exhibits scintillation under X-ray excitation and laser as well as UV-light induced photoluminescence with fast decay times. Photoluminescence and X-ray excited optical luminescence (XEOL) properties and decay times were performed using a two-dimensional photon counting streak camera system with a time resolution up to 20 ps. The non-covalent interactions and supramolecular assemblies as a potential multiplier of the scintillating effect were investigated with the aid of a Hirshfeld surface analysis. The quality and phase purity of the used crystals and pellets was clarified by powder diffraction and Rietveld refinement. [ABSTRACT FROM AUTHOR]

We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV-excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV-excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials: (i) sodium salicylate, an often used XUV scintillator; (ii) fluorescent labeling molecule 4-carbazole benzoic (CB) acid; and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples and identify decay mechanisms of molecules following XUV and soft-x-ray excitation. [ABSTRACT FROM AUTHOR]

This study reports host-controlled luminescence from 4f0 and 4f 1 Ce levels in SrZnO2, probed through x-ray absorption near edge and photoluminescence spectroscopies. O K-edge perceived the presence of Ce 4f states at the bottom of conduction band and 5d states merging with conduction band. Due to such an arrangement, a fast radiative emission (11.15 ns, average) is observed through charge transfer excitation from host to empty 4f0 Ce levels. Ce content is found to vary the site occupancy, which is then modifying the population of 4f0 and 4f 1 energy states by altering Ce–O bond covalency. This study proposes the Ce-doped SrZnO2 system as a potential system for scintillators and lighting materials. [ABSTRACT FROM AUTHOR]

We evaluated the photoluminescence (PL), scintillation, and dosimetric properties of Ce–doped Mg2SiO4 single crystals. As the PL and optically-stimulated luminescence (OSL) properties, the Ce–doped Mg2SiO4 showed the emission from 5d to 4f transitions of Ce3+. In the scintillation and thermally-stimulated luminescence (TSL) properties, two emission peaks due to Ce3+ and defect centers were observed. The Ce–doped Mg2SiO4 showed OSL by stimulating at 600 nm and TSL by heating at 50, 160, 195, and 370 °C. In OSL, linearly proportional responses were confirmed from 10 mGy for the 0.5 and 1% Ce–doped samples to 100 mGy for the 0.1% Ce–doped sample. In TSL, the undoped and Ce–doped samples had the linearity response from 100 to 0.01 mGy, respectively. [ABSTRACT FROM AUTHOR]

Dy3+-, Tb3+-activated, and Tb3+/Dy3+-coactivated oxyfluoride borogermanate scintillating glasses with the density of about 6.50 g/cm³ were successfully synthesized by a melt-quenching method. The structure and optical properties including transmittance, photoluminescence (excitation and emission spectra), photoluminescence decay, and X-ray excited luminescence (XEL) behaviors were studied in detail. Our results reveal that the energy transfer efficiency from Dy3+ to Tb3+ ions increases with an increase of Tb3+ concentration. The energy transfer mechanism is determined to be electric dipole–dipole interaction. However, the XEL intensity of Tb3+ decreases with the incorporation of sensitizer Dy3+ into borogermanate scintillating glass, which may result from the different mechanisms under ultraviolet light and X-ray excitation. [ABSTRACT FROM AUTHOR]

Crack-free La3+-substituted BaCl2 single crystals without and with Eu2+ as an activator were successfully grown using the micro-pulling-down method. Luminescence bands from BaCl2 without and with the Eu2+ activator were assigned as mainly intrinsic and extrinsic, respectively. Therefore, BaCl2 as a host material is suitable for investigating the effects of the emission mechanism on the non-proportionality curves and energy resolution plots. First, the scintillation characteristics of BaCl2:La3+ (11 at. %) and BaCl2:La3+ (7.7 at. %): Eu2+ (0.5 at. %) single crystals were determined along with those of BaCl2 and BaCl2:Eu2+ (0.5 at. %) crystals. Second, the nonproportionality curves from the different emission origins in BaCl2 were confirmed to be consistent with phenomenological models. Third, the non-proportionality curves and energy resolution plots originating from intrinsic (without Eu2+) and extrinsic (with Eu2+) luminescence were compared. The results experimentally demonstrated that the emission mechanism influenced scintillator non-proportionality curves. [ABSTRACT FROM AUTHOR]

Crack-free La3+-substituted BaCl2 single crystals without and with Eu2+ as an activator were successfully grown using the micro-pulling-down method. Luminescence bands from BaCl2 without and with the Eu2+ activator were assigned as mainly intrinsic and extrinsic, respectively. Therefore, BaCl2 as a host material is suitable for investigating the effects of the emission mechanism on the non-proportionality curves and energy resolution plots. First, the scintillation characteristics of BaCl2:La3+ (11 at. %) and BaCl2:La3+ (7.7 at. %): Eu2+ (0.5 at. %) single crystals were determined along with those of BaCl2 and BaCl2:Eu2+ (0.5 at. %) crystals. Second, the nonproportionality curves from the different emission origins in BaCl2 were confirmed to be consistent with phenomenological models. Third, the non-proportionality curves and energy resolution plots originating from intrinsic (without Eu2+) and extrinsic (with Eu2+) luminescence were compared. The results experimentally demonstrated that the emission mechanism influenced scintillator non-proportionality curves. [ABSTRACT FROM AUTHOR]

Fluorescent type nuclear battery consisting of scintillator and photovoltaic device enables semipermanent power source for devices working under harsh circumstances without instant energy supply. In spite of the progress of device structure design, the development of scintillators is far behind. Here, a Cs3Cu2I5: Mn scintillator showing a high light yield of ~67000 ph MeV−1 at 564 nm is presented. Doping and intrinsic features endow Cs3Cu2I5: Mn with robust thermal stability and irradiation hardness that 71% or >95% of the initial radioluminescence intensity can be maintained in an ultra-broad temperature range of 77 K-433 K or after a total irradiation dose of 2590 Gy, respectively. These superiorities allow the fabrication of efficient and stable nuclear batteries, which show an output improvement of 237% respect to the photovoltaic device without scintillator. Luminescence mechanisms including self-trapped exciton, energy transfer, and impact excitation are proposed for the anomalous dramatic radioluminescence improvement. This work will open a window for the fields of nuclear battery and radiography. Fluorescent-type nuclear batteries are a promising semi-permanent power source, but performance is hindered by scintillator development. Here the authors report a scintillator with high light yield and stability, which leads to improved performance. [ABSTRACT FROM AUTHOR]

X-ray luminescent diamond composite films with embedded yttrium-aluminum nanoparticles were designed. Additionally, the stability limits of single-phase solid solutions in systems based on yttrium-aluminum and yttrium-scandium-aluminum garnets doped with cerium were determined. The most intense X-ray luminescence was achieved with the [Y 2·98 Ce 0.02 ]{Al 2 }Al 3 O 12 powder. The composition-optimized nanoparticles were embedded into a polycrystalline diamond matrix to form a diamond-YAG:Ce composite. For the obtained composite, an intense X-ray luminescence from the Ce3+ ions near 550 nm was demonstrated. The designed composites may be used as adjustable and durable scintillating materials for a wide range of applications. [ABSTRACT FROM AUTHOR]

Profiling of particle beams is one of the most important diagnostic procedures for operating any kind of accelerator. In this work, the proton beam profilers, based on fluence measurements performed by recording the changes of carrier lifetime in Si material and scintillation intensity of thin GaN layers, caused by radiation induced defects and emission centres, are presented. The beams of penetrative (26 GeV/c) and stopped (1.6 MeV) protons have been examined. It is shown that the penetrative particle regime should be employed to appropriately record 2D fluence distribution profiles. It is also illustrated that the presented profiling techniques can be applied for scanning of other charged (namely, pions) and neutral (neutrons) particle beams. [ABSTRACT FROM AUTHOR]

• (Gd 1-x Ce x) 3 (Ga 0.995 Cr 0.005) 5 O 12 single crystals were grown by micro-pulling down method. • The emission wavelengths of these crystals were approximately 730 nm. • Cr was segregated in the center part of the crystals. • The relationship between Cr segregation and emission intensity was investigated. • The correlation coefficients of thoes relationships were around 0.9. For the decommissioning of Fukushima Daiichi Nuclear Plants, a novel real-time dose-rate monitor consisting of a scintillator, 100-m long optical fiber and CCD spectrometer has been proposed, and this scintillation material is required to have an emission wavelength of longer than approximately 650 nm. In this paper, as a candidate material for the system, we focused on Ce/Cr co-doped Gd 3 Ga 5 O 12 (Ce/Cr:GGG) single crystals grown by the micro-pulling down method. Since the light output of this material was expected to depend on the Cr3+ concentration, we investigated the relationship between Cr segregation and luminescence properties in Ce/Cr:GGG crystal. Generally, a single photon counting method is not available to evaluate its light output accurately due to the long decay time, we used a novel technique "emission-intensity two-dimensional- mapping method" (2D-image method) to verify the light intensity at each point of the sample. This method realized estimation of the light intensity within the sample, though segregation of Cr3+ is observed. The results showed that Cr was concentrated in the center part along the radial direction in the grown crystals, while all parts had an emission wavelength of approximately 730 nm excited by X-ray. Using the 2D-image method, emission intensity was found to correspond to the Cr concentration, and its correlation coefficients between emission intensity and Cr concentration were over 0.8. We found that our material is available for the monitoring system when the Cr dense part of the crystal is cut and used. [ABSTRACT FROM AUTHOR]

• CeF 3 -doped CaF 2 transparent ceramics were fabricated by spark plasma sintering. • The transparent ceramics showed luminescence due to the 5d→4f transitions of Ce3+. • A direct correlation between scintillation light yields and TSL/OSL intensities was demonstrated. We report on the luminescence properties of CaF 2 transparent ceramics having various concentrations of CeF 3 (0.1 %, 0.5 %, and 1 %). Scintillation emissions centered at approximately 318, 345, and 386 nm derived from the 5d→4f transition of Ce3+ were detected, and scintillation light yields were determined to be 8600 photons/MeV (0.1 % CeF 3), 1930 photons/MeV (0.5 % CeF 3), and 1850 photons/MeV (1 % CeF 3) under gamma-ray irradiation from 241Am. The Ce-doped CaF 2 transparent ceramics showed thermally stimulated luminescence (TSL) with a broad glow peak at around 115–145 °C, and their dose response curves were determined over a broad dose range (0.01–3 mGy). Moreover, optically stimulated luminescence (OSL) exponential decay curves were obtained under 500 nm stimulation light, and dose response curves were obtained in the dose range of 0.1–100 mGy. The minimum detectable dose was estimated to be 0.1 mGy. A direct correlation between scintillation light yields under gamma-ray irradiation and TSL/OSL intensities was demonstrated. [Display omitted] [ABSTRACT FROM AUTHOR]

Cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) powders were synthesized using the co-precipitation method. The influence of sintering temperature on the crystallization and luminescence characteristics of LYSO:Ce powders was investigated via X-ray diffraction (XRD) and photoluminescence (PL). The XRD measurements indicate that the crystallization of LYSO:Ce powders was affected by sintering temperature. PL results show that with the increase of sintering temperature, LYSO:Ce samples have better luminescence properties. A dosimeter was also fabricated using LYSO:Ce powders with 0.3 mol% Ce doping concentration for an optimum result. Radioluminescence properties of the radiation dosimeter were studied using calibrated 60Co gamma sources in the dose range from 232.66 to 1022.26 mGy. The results show that the dosimeter response under γ-rays irradiation has a certain linear response and stability, indicating its potential applications in remote radiotherapy and real-time radiation monitoring. • LYSO:Ce crystal powder as scintillitor material was synthesized by co-precipitation method. • LYSO:Ce with different sintering temperature has been systematically investigated. • A dosimeter was made with the optimal LYSO:Ce crystal powder for low dose gamma radiation. [ABSTRACT FROM AUTHOR]

(C 4 H 9 NH 3) 2 PbI 4 and (C 6 H 5 C 4 H 8 NH 3) 2 PbI 4 single crystals were synthesized by the slow cooling method, and their optical and scintillation properties were evaluated. Both samples had sharp X-ray diffraction peaks with intervals of (0 0 2 l) (l = 5–7). Absorption edges of (C 4 H 9 NH 3) 2 PbI 4 and (C 6 H 5 C 4 H 8 NH 3) 2 PbI 4 were confirmed at 535 and 520 nm, respectively. They showed luminescence due to the recombination of excitons at 500–700 nm. Scintillation decay times at 0.5–0.7 ns were obtained by approximation of decay curves. The light yields of (C 4 H 9 NH 3) 2 PbI 4 and (C 6 H 5 C 4 H 8 NH 3) 2 PbI 4 were respectively evaluated to be 1200 and 1500 photons/5.5 MeV-α by measuring full absorption peaks of 241Am α-rays. • (C 4 H 9 NH 3) 2 PbI 4 and (C 6 H 5 C 4 H 8 NH 3) 2 PbI 4 single crystals were grown by the slow cooling method. • Luminescence due to the recombination of free excitons was observed. • Scintillation decay times of sub-nanoseconds were observed. • Light yield of (C 6 H 5 C 4 H 8 NH 3) 2 PbI 4 was 1500 photons/5.5 MeV-α. [ABSTRACT FROM AUTHOR]

0.05, 0.1, 0.5, and 1.0 % Dy-doped YVO 4 single crystals were prepared by the optical floating zone technique to obtain photoluminescence (PL) and scintillation properties. All the samples showed the emission owing to charge transfer from V5+ ions to O2− ions inside [VO 4 ]3- and the 4f–4f transitions of Dy3+ ions. Light yields exhibited 37,000 (0.05 % Dy), 42,000 (0.1 % Dy), 44,000 (0.5 % Dy), and 39,000 photons/MeV (1.0 % Dy), based on the pulse height spectra. In afterglow properties, afterglow levels were 37.7 (0.05 % Dy), 25.7 (0.1 % Dy), 23.2 (0.5 % Dy), and 20.6 (1.0 % Dy) ppm. • We have synthesized Dy-doped YVO 4 single crystals by floating zone method. • We have characterized the photoluminescence, and scintillation properties of the Dy-doped YVO 4 single crystal. • Pulse height spectra revealed that the light yield of 0.05, 0.1, 0.5, and 1.0 % Dy-doped YVO 4 single crystals was 37,000, 42,000, 44,000, and 39,000 photons/MeV, respectively. • In afterglow properties, afterglow levels were 37.7 (0.05 % Dy), 25.7 (0.1 % Dy), 23.2 (0.5 % Dy), and 20.6 (1.0 % Dy) ppm. [ABSTRACT FROM AUTHOR]

• G2 glass matched with F2 glass (Schott) was used to draw fiber. • A linear increase and efficient response at 374 nm were obtained in G2 glass with X-ray radiation. • G2 glass material has an ideal and stable optical response. • G2 glass fiber has an emission at about 375 nm and a short fluorescence lifetime (2.22 ns). In order to enrich the application demands of neutron detection field, this study prepared a series of Ce3+/Gd3+ co-doped borosilicate scintillating glass materials. The ultraviolet (UV) absorption edges were all below 400 nm. The optical band gap was shortened from 3.48 eV to 3.24 eV as well as the optical basicity increased from 0.4941 to 0.5063 with the added concentration of Gd3+ ions. When the samples were excited by a 330 nm light source, the central wavelength of the emission spectra was 375 nm. The fluorescence lifetime of the sample was 30.99 ns. The emission intensity of the G2 sample increases linearly with the increase of X-ray excitation current, and has a stable optical response at 374 nm. The G2 glass fiber with the highest fluorescence intensity had a prominent emission peak at 375 nm and the fluorescence lifetime of 2.22 ns. [ABSTRACT FROM AUTHOR]

We fabricated BaCaBO 3 F (BCBF) with various Dy concentrations (0.1 %, 1 %, and 5 %), and evaluated the luminescence properties for radiation dosimetry. Sharp scintillation peaks originating from the 4f → 4f transition of Dy3+ were observed. Furthermore, thermally stimulated luminescence (TSL) glow curves were recorded, and a TSL glow peak at approximately 120 °C was observed. The 0.1 % Dy-doped BCBF exhibited the highest TSL intensity, and dose response curves of the 0.1–1 % Dy-doped BCBF were obtained in the 0.1–10000 mGy range. Moreover, at least seven activation energy levels related to TSL were confirmed by the TSL isothermal decay analysis. [ABSTRACT FROM AUTHOR]

Optical and scintillation properties of 50 AE O-50SiO 2 -1SnO (AE = Mg, Ca, Sr, Ba) glasses were investigated. In photoluminescence (PL) and scintillation, the glasses showed a luminescence peak around 400 nm which was attributed to the T 1 -S 0 transitions of Sn2+. The afterglow levels of the AE = Mg and Ba glasses were better than that of a commercial Tl-doped CsI scintillator. The light yields of the glasses were quantitatively acquired and the AE = Ba glass showed the highest light yield of 63 ph/5.5 MeV-α of among the glasses. [ABSTRACT FROM AUTHOR]

This work is dedicated to investigation of the luminescent properties of the prospective photoconversion material based on the crystal of Ce3+ doped Ca 3 Sc 2 Si 3 O 12 (CSSG) garnet. The GSSG:Ce crystal was grown using the micro-pulling-down (μPD) method. The CSSG:Ce crystal exhibited an intensive photoluminescence (PL) emission band with two sub-bands peaked at 504 and 545 nm, corresponding to 5d-4f (2F 5/2;7/2) transitions. Furthermore, we have investigated also the formation of cerium multicenters in the GSSG:Ce crystal using analyses of the structure of Ce3+ photoluminescence emission and excitation spectra under excitation of the luminescence of this crystal by synchrotron radiation. The formation of Ce3+-multicenters in CSSG:Ce garnet is caused by the local inhomogeneity of the dodecahedral sites of garnet lattice due to localization of the hetero-valent Sc3+ and Si4+ cations in the octahedral and tetrahedral positions of the garnet host. The existence of Ce3+ multicenters resulted in a significant enhancement of the Ce3+ emission band in the red range and improving the performance of conventional YAG:Ce phosphor. The next task of our work was to evaluate the possibility of application of the GSSG:Ce crystal as a light phosphor-converter (pc) for white light-emitting diodes (WLEDs). In the frame of this task, we have successfully developed a prototype of WLED by employing the CSSG:Ce crystal as a phosphor-converter (pc) with blue 450 emitting LED as well as investigated the color characteristics of this pc-WLED. • Ca 3 Sc 2 Si 3 O 12 :Ce (CSSG:Ce) crystal was grown by micropulling down method. • Presence of two different Ce1 and Ce2 emission centers was detected CSSG:Ce crystals. • Luminescent properties and energy structure of F+ and F centers in CSSG host were studied. • Prototypes of a white LED based on CSSG:Ce phosphor and blue LED were developed. [ABSTRACT FROM AUTHOR]

(C 6 H 5 C 2 H 4 NH 3) 2 Pb 1- x Ca x Br 4 (x = 0.05, 0.1, and 0.25) crystals were grown by the solvent diffusion method and evaluated for the photoluminescence and scintillation properties. When irradiated by X-rays, emission peaking at 440 nm due to exciton emission was observed. The pulse height spectra of (C 6 H 5 C 2 H 4 NH 3) 2 Pb 1- x Ca x Br 4 under 137Cs γ-ray irradiation demonstrate that the light yields were 20,000, 17,000, and 16,000 ph/MeV in x = 0.05, 0.1, and 0.25 samples, respectively. Ca-substitution significantly enhances the photoluminescence quantum yield and scintillation light yield. • (C 6 H 5 C 2 H 4 NH 3) 2 (Pb,Ca)Br 4 crystals were evaluated for the photoluminescence and scintillation properties. • (C 6 H 5 C 2 H 4 NH 3) 2 (Pb,Ca)Br 4 crystals exhibit a sharp emission peaking at 440 nm due to exciton luminescence. • Pulse height spectra under 137Cs γ-rays demonstrate the light yields was 20,000 ph/MeV. • Ca-substitution enhances both the photoluminescence and scintillation properties. [ABSTRACT FROM AUTHOR]

ZnO:Ga (GZO), as well as other band-edge luminous materials, exhibits fast time response properties, which makes it suitable for application as an ultraviolet scintillator for transient radiation detection. However, due to the serious self-absorption problem and low external quantum efficiency, the luminescence intensity cannot be intensified by increasing the volume of the crystals. To alleviate this problem, CsPbBr 3 quantum dot (QD) films were used to enhance the radioluminescence (RL) intensity of GZO. The effects of CsPbBr 3 QD films on the emission spectrum, intensity and angular distribution were experimentally analyzed under three different modes, namely, coating on the imaging surface, incident surface and both surfaces. The CsPbBr 3 QD film on the imaging surface could change the external quantum efficiency and luminescence angular distribution of GZO via its various surface morphologies. When CsPbBr 3 QD films were coated on both surfaces, the luminescence intensity reached 2.43 times that of GZO, while the proportion of emitted light from GZO was less than 6 %. Based on the experimental results, the principle of the enhancement and the difference among the three coating modes were discussed. The enhancement caused by CsPbBr 3 QD films on GZO was considerable and could be simply duplicated on many other materials, expanding their application in the field of detection and imaging. • Radioluminescence intensity of ZnO:Ga can be enhanced by coating perovskite films. • Scintillation performance of CsPbBr 3 QD film-coated ZnO:Ga was investigated. • Tuning the angular distribution by CsPbBr 3 QD film is beneficial for X-ray imaging. [ABSTRACT FROM AUTHOR]

Ce3+ activated high-density lanthanum lutetium germanate glass was fabricated by melt quenching method. Their densities, fluorescence decay curves, transmittance spectra, and luminescence excited by UV light and X-ray were measured and investigated. The densities of the glasses are between 5.90 g/cm3 and 5.97 g/cm3. The glasses present blue emission upon 379 nm light and X-ray. The blue emission lifetimes of the glasses are between 11.26 ns and 18.83 ns. The results shows that Ce3+ activated high-density lanthanum lutetium germanate glass would be a potential fast-event X-ray detection scintillating material. • Ce3+ doped germanate glasses with density around 6 g/cm3 were prepared. • The glass showed blue emissions upon UV light and X-ray. • The blue emission lifetimes were in the range of 11.26–18.83 ns. [ABSTRACT FROM AUTHOR]

Gd3+ and Ce3+ doped and co-doped NaCaYF 6 were synthesized noting the lack of luminescence studies in this material by using hydrothermal method. Synthesized NaCaYF 6 is also known by the mineral name Gagarinite. X-ray diffraction studies of prepared sample performed to confirm the identification of the phase pure fluoride compound. Energy dispersive spectra (EDS) and elemental mapping also recorded to confirm the compositions. Photoluminescence (PL) studies performed for recording PL Excitation (PLE) and PL Emission (PL) Spectra. Characteristic luminescence of Gd3+ ions and Ce3+ ions were observed in NaCaYF 6. The PLE of Ce3+ doped NaCaYF 6 phosphor shows broad excitation band centered at 294 nm with other weak shoulder peak at 272 nm. A typical double humped broad band emission obtained for the 294 nm excitation. Emission peak of 322 nm appears due to Ce3+ (5d–4f) transition with an additional shoulder peak at 315 nm. The PL spectra of the Gd3+-doped NaCaYF 6 excited at 272 nm consists of a dominant UVB emissions at 311 nm due to the transitions 6P 7/2 → 8S 7/2 of Gd3+ ions. No concentration quenching for Ce3+ was observed while luminescence of Gd3+activator got quenched at 1 mol %. The peculiarity of Gd3+ emission was the long lifetime of the order of 10 ms. Luminescence characteristics are explained using the known energy level diagrams for the lanthanide activators. The results revealed that Gd3+ and Ce3+ doped NaCaYF 6 compound could find a promising application for the UV-emitting phototherapy lamps. [Display omitted] • Novel results on observation of UV emission in NaCaYF 6 :Ln3+ (Ln3+ = Ce, Gd) materials are reported for the first time. • The samples of pristine and Ln3+ doped NaCaYF 6 have been prepared by the Hydrothermal method. • Characteristic line emission for Ce and Gd doped NaCaYF 6 are observed. • This can be useful in various UV applications. [ABSTRACT FROM AUTHOR]

High-quality lutetium aluminum garnet doped with various Pr3+ concentrations ((Lu 1- x Pr x) 3 Al 5 O 12 , abbreviated to Pr:LuAG) single crystals were grown by the optical floating zone method. The concentration of Pr3+ dependence on microstructure, luminescence and scintillation properties were systematically studied. Based on the results of Rietveld refinement, the doping of Pr3+ leads to lattice distortion and lowers its symmetry. The symmetry of the LuO 8 dodecahedron center is lowest at 0.010, as confirmed by the Raman spectra. When excited at 450 nm and X-rays, the primary emission peak at 614 and 300 nm, respectively, induced by Pr3+ 4 f 2-4 f 2 and 4 f 5 d -4 f 2 transitions. The optimal doping concentration is 0.010. The electric dipole-electric dipole interaction between adjacent Pr3+ was responsible for the concentration quenching in the Pr:LuAG single crystals. (Lu 0.990 Pr 0.010) 3 Al 5 O 12 shows the shortest average scintillation decay time (22.55 ns) and highest light yield (23,842 ± 2300 ph./MeV) under 662 KeV 137Cs gamma-ray irradiation. In terms of overall luminescence and scintillation performance, 0.010 doping was the best for Pr3+ doped LuAG single crystals. • High quality Pr:LuAG single crystal was grown by optical floating zone method. • Pr ions lead to the enhanced translational motion of rare earth ions in Pr:LuAG. • Electric dipole-electric dipole interaction induced concentration quenching of Pr3+. • 0.010 Pr:LuAG single crystal has the best scintillation and luminescence properties. [ABSTRACT FROM AUTHOR]

Four phenanthroimidazole-functionalized coumarins (C-PI-Bu , C-PI-CN, C-PI-TRZ, and C-PI-Cz) containing a 7-diethylaminocoumarin unit and a phenanthroimidazole (PI) unit with different phenyl substituent at the N 1-position, were successfully synthesized and characterized by NMR (1H and 13C), high-resolution mass spectrometry and elemental analysis. The structure-property relationships of the compounds were revealed by systematically investigating their thermal stability, photophysical and electrochemical properties. All four compounds exhibit bright blue-green emission with high fluorescence quantum yield (75.36 %–97.00 %) in dichloromethane solution and green emission in the solid-state. The organic light-emitting diodes (OLEDs) with a device of ITO/PEDOT:PSS (30 nm)/TBADN:coumarin derivative (x, wt%) (25 nm)/TPBi (35 nm)/Liq (2 nm)/Al (150 nm) were fabricated and characterized. The above OLEDs showed the best EL performances with a maximum brightness (L max) of 8500 cd/m2, a maximum current efficiency (CE max) of 3.45 cd/A, and a maximum external quantum efficiency (EQE max) of 1.30 %. [Display omitted] • Four phenanthroimidazole-functionalized coumarins were synthesized for OLEDs. • The phenanthroimidazole-functionalized coumarins exhibited strong emission in solution and in solid-state. • Devices containing the cyanophenyl substituted compound showed L max of 8500 cd/m2, CE max of 3.45 cd/A, and EQE max of 1.30 %. [ABSTRACT FROM AUTHOR]

The low-energy ultraviolet or visible photons can be produced by the interaction between the scintillator materials and ionizing radiation. For this reason, scintillator materials are widely used as radiation detectors, which are prevalently utilized in different applications such as nuclear medicine imaging, homeland security, high-energy physics, oil drilling explorations, etc. Herein, a high-atomic-number (Z) zirconium-based metal-organic framework nanoflower material CJLU-1 (Zr 6 (μ 3 -O) 4 (μ 3 -OH) 4 (OH) 6 (TCA) 2 (H 2 O) 6) (H 3 TCA = tri-carboxylic acids 4,4′,4″-nitrilotribenzoic acid) was synthesized and can effectively convert X-ray into visible light. CJLU-1 is composed of secondary structural unit hexagonal Zr metal cluster and connected by TCA ligands. The photo luminescence spectra (PL) emission peak and excitation peak of CJLU-1 are at 470 nm and 395 nm respectively. CJLU-1 exhibited radioluminescence (RL) peak with a maximum at 480 nm under steady-state excitation with X-rays. Moreover, by accommodating different guest molecules such as xylene and RhB in the same MOF material, intensity-tunable X-ray scintillation can be facilely achieved, providing a new class of scintillating materials with luminescence intensity tunability. The high-Z hexagonal Zr clusters, which are arranged in an orderly fashion, absorb and interact with the ionizing radiation and sensitize the adjacent organic ligands TCA to produce efficient RL. This work contributes to the development of high-Z zirconium-based MOFs and RL intensity-tunable scintillation materials towards future practical nuclear sensing applications. A high-atomic-number (Z) zirconium-based metal-organic framework nanoflower material CJLU-1 was synthesized and can effectively convert X-ray into visible light. [Display omitted] • A zirconium-based MOF was constructed and realized tunable radioluminescence upon accommodation of guest molecules. [ABSTRACT FROM AUTHOR]

Hexagonal-structure Mg 4 Ta 2 O 9 (MTO) powders doped by 0.25 at% RE (RE = La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3 +, Yb3+, Lu3+, Y3+, Sc3+) were synthesized. All the rare earth-doped samples were checked by X-ray diffraction (XRD) and confirmed to be monophasic powders. Among them, Mg 4 Ta 2 O 9 doped by 0.25 at% Gd3+ and Sc3+ had higher X-ray excited luminescence (XEL) emission peak intensities, 3.05 and 2.79 times of MTO, respectively. The optimal concentrations of Gd3+ and Sc3+ were investigated based on XEL main emission peak intensity changing with the amount of dopants in the range of 0∼1.0 at%. The optimal XEL emission peak intensities were measured 3.32 and 3.09 times of MTO for MTO: 0.8 at% Gd3+ and MTO: 0.4 at% Sc3+, respectively. The photoluminescence (PL) emission peaks at around 370 nm correspond to two excitation peaks at 158 and 215 nm. The excitation peak at 158 nm is about 10 times more than that of at 215 nm in intensity. The emission spectra excited by vacuum ultraviolet light at 158 nm and ultraviolet light at 215 nm were investigated associated with scintillation emission mechanism. MTO: 0.8 at% Gd3+ and MTO: 0.4 at% Sc3+ show potential application in security inspection, industrial detection, etc. • Single-phase Mg 4 Ta 2 O 9 : 0.25 at% RE (RE = La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3 +, Yb3+, Lu3+, Y3+, Sc3+) samples were synthesized. • Single-phase Mg 4 Ta 2 O 9 : x at% M (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; M = Gd3+, Sc3+) samples were synthesized. • MTO: 0.8 at% Gd3+ among MTO: x at% Gd3+ and MTO: 0.4 at% Sc3+ among MTO: x at% Sc3+ have the highest excitation peaks at 158 and 215 nm. • MTO: 0.8 at% Gd3+ and MTO: 0.4 at% Sc3+ have highest relative main XEL emission peak intensities of 3.27 and 3.09 times of MTO, respectively. • The scintillation emission mechanism of improving XEL properties of Mg 4 Ta 2 O 9 scintillators by rare-earth doping is thoroughly analyzed. [ABSTRACT FROM AUTHOR]

Crystalline ceramic material (Gd,Y) 3 Al 2 Ga 3 O 12 codoped with Ce and Tb (GYAGG: Ce, Tb) was demonstrated to be a high light yield scintillator. The luminescence kinetics was proven to be formed by the combining of the direct Tb3+→Ce3+ and inverse Ce3+→Tb3+ transfer of electronic excitations. This forms a mechanism leading to the increase of the slow component fraction in the scintillation and limits the application of the material, when a fast response is required. However, a high light yield opens an opportunity to utilize the developed material for application in the detectors operating in a current measurement mode and, in long living, as high-flux sources of optical photons under the ionizing radiation of a different type. • (Gd,Y) 3 Al 2 Ga 3 O 12 : Ce, Tb is high light yield scintillator. • Both direct Tb3+→Ce3+ and inverse Ce3+→Tb3+ transfers form luminescence kinetics. • Prospective material for a high-flux of optical photons under the ionizing radiation. [ABSTRACT FROM AUTHOR]

Luminescence and scintillation properties of Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,Mg (0.02, 0.05 %) garnet crystals grown by the micro-pulling down method were investigated. The onset temperature for luminescence quenching at ∼365 K is determined from the temperature dependence of photoluminescence decay time. At room temperature, the Mg (0.05 %) sample exhibits high integral scintillation efficiency of ∼445 % of BGO crystal, light yield value of 23,500 photons/MeV, and fast scintillation decay times of 20 ns (15 %) + 54 ns (85 %). The higher radioluminescence intensity of the Mg (0.05 %) sample correlates with an appearance of its lower themally-stimulated luminescence intensity in 77–500 K range. • Luminescence and scintillation properties of Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,Mg (Mg = 0.02 %, 0.05 %) crystals are investigated. • Both crystals show onset of luminescence quenching at 365 K. • Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,0.05%Mg shows light yield of 23,500 photons/MeV. • Lu 2 YAl 2.5 Ga 2.5 O 12 :Ce,0.05%Mg shows scintillation decay time of 20 ns (14 %) + 54 ns (86 %). • Thermoluminescence characteristics are investigated. [ABSTRACT FROM AUTHOR]

Novel Sm3+ activated oxyfluoride glass was synthesized via the melt-quenching approach with subsequent heat treatment. The X-ray diffraction measurement discloses the amorphous nature of prepared glasses. And, FTIR illustrates the molar surplus of Bi 2 O 3 raises the network connectivity by creating bridging oxygen sites in the structure. The Judd-Ofelt (J-O) intensity parameters exhibit Ω 4 >Ω 2 >Ω 6 trend, witnessing the rigidity of the glass structure and ionic bonding between Sm3+ ions and surrounding ligands. The 4G 5/2 → 6H 7/2 transition of Sm3+ is the most applicable for reddish-orange lasers due to their higher values of radiative transition probability, branching ratio, and stimulated emission cross-section. The optimum emission intensity is obtained with 30 mol% Bi 2 O 3 and the corresponding decay time is 1.40 ms. Additionally, the F30 glass sample was lit in a reddish-orange region having a CCT value of 1689 K. The thermal luminescence quenching of the prepared glass was studied and the thermal stability parameters activation energy was estimated. Further, the contactless optical thermometry capability of the glass sample was explored within the range of 303 K–603 K using the luminescence intensity ratio (LIR) technique. Thus, the above studies on the glass sample suggest that it can be used as an active medium in lasers, contactless optical temperature sensing, and high-energy scintillator applications. [Display omitted] • Spectroscopic and structural characteristics of NaF– B 2 O 3 – Bi 2 O 3 –Sm 2 O 3 are explored. • These oxyfluoride glasses shows more rigidity with Ω 4 >Ω 2 >Ω 6 trend. • The reddish-orange emission is originated from 4G 5/2 → 6H 7/2 transition. • The optimum emission intensity has been observed with the 30 mol% doping of Bi 2 O 3. [ABSTRACT FROM AUTHOR]

The HERMES (High Energy Rapid Modular Ensemble of Satellites) Pathfinder mission aims to develop a constellation of nanosatellites to study astronomical transient sources, such as gamma-ray bursts, in the X and soft γ energy range, exploiting a novel inorganic scintillator. This study presents the results obtained describing, with an empirical model, the unusually intense and long-lasting residual emission of the GAGG:Ce scintillating crystal after irradiating it with high energy protons (70 MeV) and ultraviolet light (∼ 300 nm). From the model so derived, the consequences of this residual luminescence for the detector performance in operational conditions has been analysed. The suitability of this detector for the HERMES Pathfinder nanosatellites was demonstrated by the low contribution of the afterglow, 1–2 pA at peak, to the input current of the front-end electronics. [ABSTRACT FROM AUTHOR]

(K,Rb) 2 CuBr 3 crystals were fabricated by the slow cooling method, and their photoluminescence (PL) and scintillation properties were examined. Emission bands were observed at 350–550 nm under UV and X-ray irradiation. PL quantum yields of K 2 CuBr 3 , (K 0.25 ,Rb 0.75) 2 CuBr 3 , (K 0.5 ,Rb 0.5) 2 CuBr 3 , (K 0.75 ,Rb 0.25) 2 CuBr 3 , and Rb 2 CuBr 3 were respectively 75.8, 71.0, 82.3, 96.9, and 96.3%. The scintillation decay curves were approximated by a sum of three exponential functions, and the decay time constants due to recombination of self-trapped excitons were 58–63 μs. The afterglow levels of the K and Rb-mixed samples at 20 ms passed after X-ray irradiation decreased to 10–40 ppm, compared with those of K 2 CuBr 3 and Rb 2 CuBr 3. Among these samples, (K 0.75 , Rb 0.25) 2 CuBr 3 showed the highest light yield of 7400 ph/MeV among the samples calculated from the pulse height spectra of 137Cs γ-rays (662 keV). • (K,Rb) 2 CuBr 3 crystals were synthesized by the slow cooling method. • The afterglow levels of the (K,Rb) 2 CuBr 3 were 10–40 ppm. • (K 0.75 ,Rb 0.25) 2 CuBr 3 showed the highest light yield (7400 ph/MeV) in prepared samples. [ABSTRACT FROM AUTHOR]