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Perovskite quantum dots (PEQDs) are next-generation quantum dot materials that have attracted attention in various areas such as display, radiation scintillator, and photodetector. However, PEQD defects that occur for various reasons hinder the commercialization of PEQDs. Herein, we reported a new strategy for a hybrid ligand comprising 1-octanethiol (OT) and octylammonium bromide that can passivate the defects of PEQD and effectively reduce the Stokes shift. First, the increase in the OT concentration in hybrid ligands leads to an increase in the PEQD size and a decrease in the Stokes shift. Second, OT in hybrid ligands can stabilize the PEQD solution by binding to an MA ion, which is easily degraded by atmospheric oxygen, thereby suppressing the generation of metallic Pb that serves as a defect in PEQDs. Consequently, PEQDs by hybrid ligands reduced the defects, particularly metallic Pb, leading to strong green emission with low Stokes shift with a photoluminescence quantum yield of 99.3 % and high stability under atmospheric conditions. [Display omitted] • Hybrid ligand can stabilize the perovskite quantum dot. • Hybrid ligand shows the highly luminescent perovskite quantum dot. • Hybrid ligand can control the perovskite quantum dot size and Stoke shift. • Hybrid ligand can eliminate the perovskite vacancies leading to defect. [ABSTRACT FROM AUTHOR]

A new (Gd,Lu,Y) 3 Al 2 Ga 3 O 12 :Ce, Mg scintillation material was produced in transparent ceramic form for the first time. 1.5-mm-thick samples for the evaluation performance test were produced from coprecipitated powders by sintering in an oxygen atmosphere at 1720 °C for 2 h. The scintillator ensures a coincidence time resolution of less than 100 ps when utilizing the silicon photo-multiplier (SiPM) readout. This finding suggest that the material is quite promising for positron emission tomographs (PET) utilizing time-off-flight (TOF) techniques for the registration of annihilation 511 keV gamma-quanta. A significantly lower production temperature, absence in the production cycle of precious metals like Ir and Pt, and high rate of crystalline mass production in the absence of high-pressure sintering in the manufacturing chain make the developed ceramic a competitor to a widely used (Lu,Y) 2 SiO 5 single crystalline scintillator, in particular, for full-body PET scanners. • A new (Gd,Lu,Y) 3 Al 2 Ga 3 O 12 :Ce, Mg scintillation transparent ceramic was produced by a pressure free sintering. • The scintillator provides the coincidence time resolution for 511 keV as less as 100 ps. • The material is quite promising for positron emission tomographs (PET) utilizing time-off-flight (TOF) techniques. [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 scientific work explores the development of luminescent nanocomposite materials for radiation sensors in Fiber Optic Dosimetry (FOD). The study emphasizes the use of YVO 4 :Eu3+ as a scintillator material due to its high luminescent efficiency. However, the challenge arises from its higher effective atomic number compared to soft tissue. To address this issue, the work explores the dispersion of YVO 4 :Eu3+ as nanoparticles (NPs) in a biocompatible polymeric matrix, specifically considering poly(methyl methacrylate) (PMMA) and poly(ethylene glycol) dimethacrylate (PEGDMA). Both PMMA/YVO 4 :Eu3+@TMSPM and PEGDMA/YVO 4 :Eu3+@TMSPM formulations were synthesized with minimal impact on the glass transition temperatures of the polymers. Under UV and beta particle excitation, these formulations exhibit emission spectra characteristic of Eu3+ f-f transitions. The decay times of the main emission peak at 620 nm were 615 μs, 584 μs, and 567 μs for the NPs, PEGDMA- and PMMA-based polymeric nanocomposites (PNCs), respectively. These decay times fall within the range suitable for scintillators in LINAC pulsed radiation facilities. Also, PEGDMA- and PMMA-based PNCs with varying contents of YVO 4 :Eu3+ NPs showed radioluminescence spectra under beta particle irradiation. This work demonstrates the feasibility of developing PEGDMA- and PMMA-based PNCs containing dispersed YVO 4 :Eu3+ NPs for their application as scintillators in radiotherapy dosimetry. [Display omitted] • Luminescent nanocomposites were developed with YVO 4 :Eu3+@TMSPM nanoparticles and PMMA or PEGDMA as polymeric matrices. • YVO 4 :Eu3+@TMSPM nanoparticles were incorporated in both polymer matrices by in-situ polymerization. • The addition of nanoparticles in both matrices did not show a significant effect on the T g of the polymers. • Polymer-based nanocomposites irradiated with β-particles show RL with the characteristic features of the Eu3+ emission. • Both materials could be suitable detectors for fiber optic dosimetry due to the decay time of the signal is around 600 μs. [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]

The presence of point defects associated with shallow traps has been identified as a limiting factor in the design of materials with desirable characteristics for applications such as scintillation and luminescence dosimetry, among others. In this context, this study aims to elucidate the dynamics inherent to the charge carriers in systems containing multiple traps and one single recombination centre. To unravel this complexity, we employed a synergetic approach combining Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) measurements with kinetic models. Specifically, for the Li and Ce co-doped MgB 4 O 7 , we verified that the electron population trapped in shallower traps exhibits a slower decay rate under optical stimulation compared to deeper traps. This behaviour led to a delay in the luminescence emission, as a result of charge re-trapping or even competition with other centres. This phenomenon can be attributed to its low photoionization cross-section associated with a high re-trapping rate, providing a rationale for these remarks. In addition, we observed that the shallow traps have a greater optical than thermal probability of being detrapped, indicating that they were not solely detrapped through thermal stimulation. Also, the magnitude of the thermal probability leads us to believe that there is an electron population different from zero in the conduction band at t = 0 (before optical stimulation). Lastly, this study paves the way for a deeper understanding of charge carrier dynamics in systems of multiple traps, improving the performance of existing materials for scintillation and dosimetry. • The electron populations trapped in shallower traps exhibited a slower decay rate under optical stimulation compared to intermediate and deep traps. • Shallow traps have a low photoionization cross-section and high probability of re-trapping. • Intermediate traps have a low probability of re-trapping, compared to shallow and deep traps. [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]

To investigate the feasibility of blue cubic zirconia as high-energy ray dosimeter materials, the X-ray/electron beam (EB) radiation and the subsequent ultraviolet–visible (UV) lighting/heat treatment were conducted on blue cubic zirconia. Furthermore, the optical absorption, elemental content, the valence states of Co and Zr, and the type of O elements of ZrO 2 was analyzed by ultraviolet–visible absorption spectroscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy and thermoluminescence spectroscopy to demonstrate the influence of internal defects formed by the above treatment methods on the color reversed of cubic zirconia. The experimental results showed that the color of ZrO 2 changed from blue to brownish yellow after irradiation and reverted to original color after heat treatment or UV lighting. Oxygen vacancies generated by Zr3+ ions occupying the Zr4+ ions site in ZrO 2 were increased after irradiation and were decreased after heating or lighting during the color reversible of the blue ZrO 2 , which is related to the electron transition between Co-3d orbit and O-2p orbit. • Different from scintillators and semiconductor detectors, which are usually used to verify high-energy radiation, the feasibility of cubic single crystal ZrO 2 as an efficient high-energy ray detector is investigated in this paper. The phase stability and discoloration mechanism of ZrO 2 single crystal were investigated by X-ray/electron beam irradiation, and then the color reversibility was realized by subsequent heat treatment or ultraviolet irradiation. It is also used as a radiation dosimeter material through thermoluminescence, which provides a reference for the ray detection and protection of photochromic materials. [ABSTRACT FROM AUTHOR]

Micro-patterning is important in many fields in order to improve, tune, or alter the properties of materials. For scintillating screens, micro-patterning is studied to extract more light, as well as to provide a better compromise between X-ray absorption efficiency and spatial resolution. This article presents an innovative way to micro-pattern scintillating screens by combining Ultrashort Pulse (USP) laser treatment followed by vertical Liquid Phase Epitaxy (LPE). Starting from planar micro-modified (010)-oriented LYSO:Ce substrates, micro-patterned LSO:Tb films comprising 50 μ m square pixels/pillars and covering a surface of 8 mmx8 mm are obtained up to 10 μ m thickness. For thicker films, the morphology of the pixels/pillars evolves towards a truncated pyramidal shape, limiting the maximal thickness to 30- 40 μ m before pixels start to overlap significantly. This is shown by optical, confocal and Scanning Electron Microscopy (SEM). According to X-ray Diffraction (XRD), the micro-patterned films grow along the (010) substrate orientation, with a close crystalline quality to the planar films. The micro-patterned LSO:Tb films display the green luminescence from the Tb 3 + ion, as confirmed by photo and radio-luminescence. Moreover, the light is effectively extracted from the pixels/pillars. Therefore, the described process could be extended to other oxide materials and pave the way for new opportunities in micro-patterning inorganic scintillators. • Growth of micro-patterned mono-crystalline LSO:Tb scintillating films through the Vertical Liquid Phase Epitaxy technique. • Ultrashort pulse laser treatment on LYSO:Ce substrates. • Green and efficient luminescence of micro-patterned LSO:Tb scintillators. [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]

In this research, different amounts of Ce-doped ZnO thin films were synthesized using the spray pyrolysis method. Structural, morphological and optical properties of these synthesized films were investigated. In XRD analyses, wurtzite (hexagonal) structures were observed in the films. In SEM analysis, there were changes in the surface morphology of the films with doping, and in cross-section measurement, the thickness of the films was measured to be approximately 1.2 μm. In UV–vis spectrometry analysis, it is seen that the effect of Cerium contribution on optical transmittance and band gap positively affects shielding. NaI(Tl) detector and gamma energies of 384, 1173, and 1333 keV have been used to investigate the radiation protection properties of these synthesized films. As a result of these measurements, linear attenuation coefficient (LAC) values have been obtained. Radiation shielding parameters have been calculated with these (LAC) values. The Mass Attenuation Coefficient (MAC), Half Value Layer (HVL), Tenth Value Layer TVL (and) Mean Free Path (MFP) values have been also calculated using this LAC result. According to these results, Ce-doped ZnO films were found to be effective in radiation shielding. • In this article, the effect of cerium doping ratio to ZnO on radiation shielding was examined. • Thin films were produced using the spray pyrolysis technique. • In experiments on radiation shielding properties, 133Ba 384 keV, 60Co 1173 keV and 60Co 1333 keV energy gamma rays were used. • It was determined that the increase in the Cerium rate had a positive effect on radiation shielding. • It was observed that cerium doping affected the energy band gap. [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]

Neodymium doping of photo-thermo-refractive (PTR) glass leads to a fast non-radiative depopulation of excited states of cerium ions, which are responsible for the glass photosensitivity. The non-radiative energy transfer from cerium to neodymium ions results in a decrease in the efficiency of photoelectron generation under UV irradiation. Emission spectra and fluorescence decay curves of cerium ions under UV excitation were investigated. Absorption spectra of the glasses were obtained as well to distinguish the reabsorption processes and the non-radiative energy transfer mechanisms. It was found that as Nd 2 O 3 concentration increases from 0 to 2 mol%, cerium ions average lifetime decreases from 44.5 to 28 ns, while the energy transfer efficiency reaches 37 %. It was also found that Förster resonance energy transfer may compete with other relaxation mechanisms and the Förster distance for the Ce3+-Nd3+ pair in PTR glass is ∼0.33 nm. This study has important implications for future research; it informs future studies on optimizing the photosensitivity of the PTR glass and choosing rare-earth activators. • Doping of photo-thermo-refractive glass with Nd3+ ions reduces the glass photosensitivity. • Non-radiative ET from Ce to Nd leads to fast depopulation of Ce and decreases the efficiency of photoelectron generation. • Energy transfer efficiency increases from 5 to 37 % when increasing neodymium concentration from 0.25 to 2 mol%. [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]

Lanthanide doped fluoride scintillators possess a diverse range of applications in the fields of computed tomography and medical imaging. In this study, CsLu 2 F 7 : Pr crystals have been synthesized by a simple hydrothermal method to realize X-ray excited optical luminescence (XEOL). Our results reveal that the reaction temperature and amount of cetyltrimethylammonium bromide (CTAB) can significantly change the morphology of the crystals; the suitable hydrothermal reaction conditions, the amount of CTAB, and the doping concentration of Pr3+ ions are favorable for the enhancement of the XEOL intensity; and the crystals exhibit good irradiation stability under prolonged X-ray excitation. In addition, we used the crystal to prepare scintillation films to realize XEOL imaging. This research provides crucial information to support an in-depth investigation into the XEOL performances of CsLu 2 F 7 doped with lanthanide ions. • CsLu 2 F 7 : Pr crystals were synthesized using a hydrothermal method. • The morphology was adjusted by changing the reaction temperature and CTAB. • CsLu 2 F 7 : Pr involved film can be used for X-ray imaging. [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]

Undoped and Tb-doped Ba 3 Y(PO 4) 3 single crystals were synthesized by the floating zone method. Photoluminescence (PL), scintillation, and dosimetric properties of the obtained single crystals were measured. The highest PL quantum yield value was obtained from the 15% Tb-doped crystal. In X-ray-induced scintillation spectra, the undoped crystal showed an emission peak due to self-trapped exciton at 400 nm. Tb-doped crystals showed emission peaks in the range of 375–620 nm, originated from 4f-4f transitions of Tb3+. In addition, the undoped and Tb-doped crystals showed luminescence peaks in similar locations to the scintillation spectra in thermally and optically stimulated luminescence (TSL and OSL). In TSL dose response functions, the 1% Tb-doped sample exhibited the highest TSL intensity, and the TSL signal was detectable from 0.01 mGy. In OSL dose response functions, the 5% Tb-doped sample exhibited the highest OSL intensity, and the OSL signal was observed from 0.1 mGy. • We synthesized undoped and Tb-doped Ba 3 Y(PO 4) 3 by the floating zone method. • The undoped and Tb-doped samples exhibited luminescence due to the STE and 4f-4f transitions of Tb3+, respectively. • The 1% Tb-doped sample exhibited the highest TSL intensity, which was observable from 0.01 mGy. [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]

UV photodetectors (PDs) find pivotal roles across diverse domains like space exploration, radiation monitoring, and electronics. Zinc oxide (ZnO), an n-type semiconductor with a wide bandgap, stands out as an attractive material for photodetection due to its remarkable UV responsivity. This study centers on assessing the role of Ce doping in enhancing the UV sensitivity of ZnO-based photodetectors when subjected to laser illumination (excitation wavelength: 374 nm). Synthesized through a hydrothermal approach, Zn 1-x Ce x O nanostructures with varying concentrations (x = 1.5, 3.5, 5.5, and 7.5 wt%) were subsequently deposited onto ZnO nanorods (NRs) via tape casting. A comprehensive array of characterization techniques was employed to analyze the structural, morphological, and optoelectrical properties of Ce:ZnO. Incorporating Ce to ZnO lattice induced a reduction in the density of oxygen vacancies, culminating in an enhancement of optoelectronic performance. This improvement encompassed aspects such as photocurrent and responsivity within a p-n heterojunction Ce: ZnO–Cu 2 O (CZC) UV-PD setup. The introduction of cerium led to a slight shift in the band gap energies, from 3.18 eV for pristine ZnO to 3.23–3.19 eV for the CZ samples. Impressively, Ce-doped ZnO (5.5 wt%) nanostructures exhibited enhanced performance in UV detection, showcasing a detectivity of approximately ∼42 × 109 (Jones), an expedient rise time of under 0.1 s, and a desirable decay time of 8.7 s for the CZC-3%. • The study investigated the effects of different concentrations of cerium on the characteristics of ZnO-based UV photodetectors. • Ce: ZnO was prepared by hydrothermal methods. • Ce: ZnO–Cu 2 O PDs operated without bias voltage when subjected to 375 nm UV light. • The Ce: ZnO–Cu 2 O PDs exhibited rapid responsivity and stability when exposed to on-off switching of UV light. [ABSTRACT FROM AUTHOR]

To develop glass scintillators, Eu 2 O 3 -doped tellurite glasses (TeO 2 –Nb 2 O 5 –SrO–Eu 2 O 3) (TNbSrEu) were prepared, and their luminescence characteristics were investigated. Several photoluminescence peaks at about 578, 592, 613, 652, and 701 nm were observed when excited by 530 nm excitation light. They originated from 4f→4f transition of Eu3+. Their photoluminescence decay times under 530 nm excitation light were approximately 0.7 ms, which was a typical time of 4f→4f transition of Eu3+. Further, some scintillation peaks originating from 4f→4f transition of Eu3+ were detected at 577, 593, 613, and 652 nm, and scintillation decay times were in the time region of 0.21–0.35 ms. Furthermore, the afterglow levels were from 560 ppm to 317 ppm, showing a decreasing trend in levels with increasing Eu 2 O 3 concentration. • To develop glass scintillators, Eu 2 O 3 -doped tellurite glasses (TeO 2 –Nb 2 O 5 –SrO–Eu 2 O 3) were prepared. • Some scintillation peaks originating from 4f.→4f transition of Eu3+ were detected. • The tellurite glasses showed a decreasing trend in afterglow levels with increasing Eu 2 O 3 concentration. [ABSTRACT FROM AUTHOR]

Photoluminescence and scintillation properties of Cu-doped LiCl single crystals synthesized by the Bridgman-Stockbarger method were evaluated. Under UV and X-ray irradiation, two emission bands were observed at 325 and 400 nm, and these emissions would be due to 3d94s1-3 d10 transition of Cu+ and Cu+ perturbed by near OH−, respectively. From pulse height spectra under 252Cf neutron irradiation, the 0.1% Cu-doped sample showed the highest light yield (LY) of 5600 photons/neutron among all the samples and the energy resolution of 8.3 %. The LY and the energy resolution of 0.1% Cu-doped LiCl single crystal were comparable with those of commercial Li-glass (GS20). Furthermore, Cu-doped LiCl was not sensitive to γ-ray, and neutron-γ discrimination performance of 0.1% Cu-doped LiCl single crystal was better than that of GS20. • Photoluminescence and scintillation properties of Cu-doped LiCl single crystals were evaluated. • Under UV and X-ray irradiation, an emission peak due to 3d94s1-3d10 transition of Cu+ was observed at 325 nm. • The light yield and energy resolution of 0.1% Cu-doped LiCl single crystal under 252Cf irradiation were comparable with those of commercial Li-glass (GS20). • The neutron-γ discrimination performance of 0.1% Cu-doped LiCl single crystal was better than that of GS20. [ABSTRACT FROM AUTHOR]

The studies of the influence of proton irradiation on the optical properties of the undoped Gd 3 Al x Ga 5-x O 12 (x = 0,1,2,3) single crystals were carried out. A set of induced absorption bands have been detected, which are most pronounced in Gd 3 Ga 5 O 12. The origin of the bands is discussed. It is shown that the intensity of the induced absorption bands gradually decreases and no additional bands appear as gallium is replaced by aluminum. The conclusion on the enhancement of the radiation hardness of Gd 3 Al x Ga 5-x O 12 with the substitution of Ga cations with Al is done. • The proton irradiation affects the absorption of Gd 3 Al x Ga 5-x O 12 crystals. • Induced absorption arises due to F centers and ions displacement defects. • Induced absorption is supressed as gallium is replaced by aluminum. • Substitution of Ga with Al ions improves radiation hardness of Gd 3 Al x Ga 5-x O 12. [ABSTRACT FROM AUTHOR]

Optical absorption, photo-excitation, gamma-ray and thermally stimulated luminescence of a cerium-doped scintillation crystal Lu 2 SiO 5 :Ce were studied prior and after irradiating with fast neutrons fluencies of 1015-5∙1017 cm−2 in reactor, and after gamma-irradiation from 60Co for comparison. It is shown that at neutron fluencies >1015 cm−2 F centers (absorption band 5.2 eV), Ce3+/Ce4+ (4.75 eV) and Ce3+/F + (4.25 eV), as well as Ce4++V O (2.85 eV) and V Lu or V Si (2.3 eV) centers are generated in the LSO:Ce crystal structure. These induced defects are generated more intensively under neutron irradiation than when irradiated with gamma-quanta to dose of 5·107 Gy. Basing on the analysis of the gamma-excited luminescence of Ce3+ centers after various neutron fluencies and the results of thermal and photo impacting, several energy transfer mechanisms were suggested: reabsorption of activator luminescence by color centers, as well as charge capture with the formation of hole and electronic centers. LSO:Ce crystals can be recommended as a scintillation detector of fast neutron up to a fluency of 1016 cm−2 with a gamma-ray up to a dose of 106 Gy. Additional doping of LSO:Ce with Ca2+ ions results in the stabilization of visible optical transparency to gamma-irradiation up to a dose of 107 Gy. • Neutron irradiation of LSO:Ce leads to a decrease of the Ce activator luminescence. • When Ca is introduced the γ-dose up to 107Gy do not change the optical transparency. • Neutron fluency 1015cm−2 generates color centers more effective than γ-dose 5·107Gy. • Annealing of neutron-induced defects recovers the Ce3+ activator gamma-luminescence. [ABSTRACT FROM AUTHOR]

Molybdenum doped ZnO was hydrothermally grown as the arrays of nanorods deposited onto the fused silica glass substrate. The molybdenum doping level varied from 1 to 30 %. The influence of Mo on the electronic and crystalline structure as well as luminescence and defects in the ZnO nanorods is under study of the bundle of experimental techniques complemented with density functional theory calculations. The tendency of Mo to create energy states within the bandgap of ZnO and their influence on the energy levels of native defects as well as excitons were proven by the synergy of experiment and theory. The improvement of the timing characteristics of the exciton- and zinc vacancy-related emission bands upon Mo doping (1–10 %) was observed. This paves the way for the defect engineering strategy in the search of effective and ultrafast scintillator with the improved light yield as well as compared to other materials. The new concept is based on the combination of the exciton and the defect emission. It is expected to have the potential of application in the detection of gamma rays implemented in time-of-flight positron emission tomography (TOFPET). The 20 and 30 % Mo doping levels resulted in the zinc molybdates creation strongly outnumbering ZnO nanorods. • ZnO:Mo nanorods were grown as deposited arrays. • Molybdenum is incorporated as regular and interstitial. • Energy state of Mo appear in the bandgap of ZnO. • Mo affects luminescence and scintillation properties, including timing. • Mo improved timing of the defect-related luminescence. [ABSTRACT FROM AUTHOR]

Effects of Sc3+ admixture on luminescence and scintillation properties were studied in Ce3+ - doped Lu 2 Y(Al 5-x Sc x)O 12 (x = 1, 1.5, 2) garnet single-crystalline films grown by the isothermal liquid phase epitaxy technique. The Ce3+ photoluminescence (PL) was slightly blue shifted with increasing Sc content due to a decrease in crystal field splitting of the Ce3+ 5d levels. In addition, the thermal activation energy of PL quenching, estimated from the temperature dependence of PL decay times, decreased with increasing Sc content. Lu 2 YAl 4 ScO 12 :Ce exhibited the highest light yield (LY) value of 420 photons/MeV at 5.5 MeV α particles along with a fast scintillation decay time constant (τ e) of 17.4 ns. At room temperature, the decrease of LY value with increasing Sc content could be attributed to the thermal ionization process. • Lu 2 Y(Al 5-x Sc x)O 12 :Ce garnet single-crystalline films were grown by the liquid phase epitaxy technique. • Lu 2 Y(Al 4 Sc)O 12 :Ce exhibits good thermal stability with T q = 400 K. • Activation energy of photoluminescence decreased with increasing Sc content. • Lu 2 Y(Al 4 Sc)O 12 :Ce exhibits light yield (at α-excitation) of 362 photons/MeV and fast scintillation decay time of 17.4 ns. [ABSTRACT FROM AUTHOR]

LaBr 3 :Ce 3+ is a compound with excellent scintillation properties, but its ultraviolet emission does not match well with the detection efficiency curves of silicon based photodetectors. In this work, Sm 2+ is studied as an activator for LaBr 3 as its near-infrared emission can be detected with close to 100% efficiency by such photodetectors. LaBr 3 :Sm 2+ single crystals were grown with and without co-doping of Ce 3+ or Pr 3+. The samples were studied by means of X-ray excited and photoluminescence spectroscopy at temperatures between 10 K and 300 K. Their spectroscopic properties are compared to LaBr 3 :Ce 3+ and LaBr 3 :Eu 2+. The effect of using Ce 3+ or Pr 3+ as scintillation sensitiser for Sm 2+ is assessed. It is found that energy transfer from host to Sm 2+ greatly improves upon Ce 3+ co-doping, but the quenching temperature of the Sm 2+ emission decreases. The quenching mechanism of both the Ce 3+ and Sm 2+ emission in LaBr 3 is elaborated on. Furthermore, the effect of charge compensating defects on the light yield and spectroscopic properties is discussed. • Sm2+ emission quenches via 5d electron ionisation to the conduction band in LaBr3. • Doping LaBr 3 with Ce3+ decreases the bottom of the conduction band. • The energy transfer efficiency from LaBr 3 to Sm2+ can be improved by Ce3+ co-doping. • Ce3+ co-doping increases the light yield of LaBr 3 :Sm2+ from 7,000 to 25,000 ph/MeV. [ABSTRACT FROM AUTHOR]

The emerging laser-driven phosphor-converted white laser diodes (w-LDs) demand highly efficient and thermally stable color converters. To this end, the Ce3+ luminescence in the rekindled La–Si–O–N host, and the impacts of NH 4 Cl flux and post-processing are investigated systematically. On the basis of the XRD results, well crystalline Ce3+-doped La 5 Si 3 O 12 N and LaSiO 2 N are obtained at 1600 °C for 5 h and 1500 °C for 4 h, respectively. Impressively, the representative La 5 Si 3 O 12 N:0.04Ce3+ and LaSiO 2 N:0.03Ce3+ exhibit a broad excitation band from 240 nm to 400 nm, peaking at around 360 nm, which is well matched with emission from near-UV (n-UV) chip. Under excitation by a n-UV laser, the La 5 Si 3 O 12 N:0.04Ce3+ and LaSiO 2 N:0.03Ce3+ produce bright blue light in a wide emission band from 360 nm to 550 nm. The CIE chromaticity diagram reveals the tunability of the hue of these phosphors. The quenching temperature is determined to be 396 K and 429 K for La 5 Si 3 O 12 N:0.04Ce3+ and LaSiO 2 N:0.03Ce3+ respectively, indicating superior thermal stability. The addition of 3 wt% NH 4 Cl flux much enhances the emission intensity of both La 5 Si 3 O 12 N:0.04Ce3+ and LaSiO 2 N:0.03Ce3+. Furthermore, the post-treatments markedly improve the luminescence properties by increasing the crystallinity, reducing the surface defect, and changing the morphology. Therefore, it is believed that the present work has promising applications in LD lighting and promoting the development of laser display. • Ce3+-activated La–Si–O–N compounds generate bright blue light in a wide emission band of 360∼550 nm pumped by n-UV laser. • The quenching temperature (T 0.5) of Ce3+-doped La–Si–O–N phosphors is 396∼429 K, indicating favorable thermal stability. • As Increasing the NH 4 Cl dosage up to 3 wt%, PL intensity attains a maximum 148–263% of that of the samples without flux. • The post-treatments greatly improve the luminescence by enhancing crystallinity, reducing cluster, and smoothing surface. [ABSTRACT FROM AUTHOR]

Scintillation and luminescence properties of a novel organic crystal scintillator, 1,4-bis(2-methylstyryl) benzene (bis-MSB), were measured and compared with those of the conventional trans-stilbene organic crystal scintillator. Although trans-stilbene has been used for beta or neutron detection, trans-stilbene cannot be applied at high temperature conditions due to a lower melting point (124 °C). Liquid scintillators or plastic scintillators also cannot be used at high temperature. Usually, bis-MSB has been used as dopant in liquid scintillators to obtain fast scintillation decay and high luminescence quantum yield, and its melting point is 181 °C higher than that of trans-stilbene. In this paper, we focused on bis-MSB in solid state. The bis-MSB and trans-stilbene crystals were grown by the self-seeding vertical Bridgman method using double quartz ampoules. The bis-MSB crystal had the fast decay time of ∼4.2 ns and the increased light yield of ∼12,000 ph/5.5 MeV(α), while trans-stilbene had the decay time of ∼8.5 ns and the light yield of ∼8500 ph/5.5 MeV(α). The photoluminescence quantum yield was almost constant up to 125 °C for bis-MSB and only up to 50 °C for trans-stilbene. We succeeded in obtaining the novel organic crystal scintillator which can operate even at higher temperature up to 125 °C. • The scintillation properties of the bis-MSB crystal were investigated. • Transparent crystals were grown by self-seeding vertical Bridgman method. • Bis-MSB had better scintillation properties compared to trans-stilbene. • The temperature dependence of luminescence quantum yield of bis-MSB was studied. [ABSTRACT FROM AUTHOR]

We synthesized 0, 0.02, 0.2, 1.0, and 10% Ce3+ doped CaF 2 AlF 3 AlPO 4 glasses; and then, we evaluated their photoluminescence (PL), scintillation and thermally stimulated luminescence (TSL) properties. Depending on the concentration of Ce3+, PL quantum yield (QY) ranged from 15.8 to 62.8%. When the materials were irradiated by X-rays, scintillation was observed with an emission peak around 330 nm due to 5d→4f transitions of Ce3+. The scintillation decay times ranged 14–25 ns. The glasses showed intense TSL, and the glow peak was broad peaking around 100 °C. The 0.2% and 1.0% Ce3+ doped samples demonstrated high sensitivity with a good linearity over 5 orders of magnitude (0.1 mGy–10 Gy). • We evaluated Ce-doped CaF 2 AlF 3 AlPO 4 glasses PL, Scintillation and TL properties. • 0.2% Ce-doped samples had the highest QY. • By measuring scintillation properties, all Ce-doped samples emitted around 320 nm. • We measured dose response of each sample. [ABSTRACT FROM AUTHOR]

Lu 2 SiO 5 :Ce is a well-known scintillator with high density, high light yield, and short decay time. Oxygen vacancies and Ce4+ have been demonstrated to degrade the scintillating properties. We investigate the effect of C doping on the stability and electronic properties of the oxygen vacancies and the Ce4+ in Lu 2 SiO 5. Stability of the C atom at the O site and the interstitial site depends on the O chemical potential. The C defects have strong interaction with nearby oxygen vacancies and Ce4+. Importantly, C doping can tune the amount of the oxygen vacancies and Ce4+ in Lu 2 SiO 5. C doping introduces defect bands in the band gap of Lu 2 SiO 5 with the energies ranging from 0.13 eV to 2.1 eV above the valence band maximum. Image 1 • C doping may suppress the oxygen vacancies in Lu 2 SiO 5. • C doping could tune the amount of Ce4+ in Lu 2 SiO 5. • C has strong interaction with other defects. • Defect states in the band gap are introduced by C doping. [ABSTRACT FROM AUTHOR]

Time-resolved luminescence of YAG-Ce (150 ppm) fiber crystal with Mg co-doping was studied under pulsed X-ray excitation and γ-rays (Cs 662 keV). The initial part of decay kinetics under X-ray excitation is faster than for direct cerium excitation (63 ns). Decay kinetics is also characterized by the presence of slow components with at least two characteristic times longer than Ce3+ radiation time. The slowest one which dominates for t > 500 ns in YAG-Ce without Mg co-doping practically vanishes for samples with 50 ppm co-doping. Decay kinetics under γ-rays are characterized by slower rise time than that under X-rays. These properties can be explained by competition of energy transfer and energy losses in track regions. The distribution of excitations in tracks produced by X-rays differs from that in tracks produced by γ-rays, since the energy of primary electron after γ-quantum conversion is much higher than after X-ray absorption. The stopping power for energetic electrons decreases with increase of electron energy, and therefore the density distribution after X-ray conversion is shifted to higher densities, Therefore, the acceleration of recombination and quenching of excitations is more prominent under X-ray excitation. Specific role of Ce4+ induced by Mg co-doping is also discussed in the paper. • Samples YAG-Ce,Mg grown by micro-pulling-down were studied under X-ray and γ-rays. • Luminescence decay becomes faster with increase of Mg concentration. • Slow component vanishes for samples with 50 ppm Mg co-doping. • Decay kinetics under γ-rays show rise part and is slower than under X-rays. • The difference is explained using of the excitation densities distribution in track. [ABSTRACT FROM AUTHOR]

The scintillation characteristics of Gd 3 Al 2 Ga 3 O 12 :Ce, Li (GAGG:Ce,Li) and Gd 3 Al 2 Ga 3 O 12 :Ce, Mg (GAGG:Ce,Mg) single crystals were compared. Radioluminescence spectra and photoluminescence decay curves were measured at various temperatures between 77 and 500 K to investigate the thermal luminescence quenching. At 662 keV γ rays, the LY value of 35,400 photons/MeV and energy resolution of 6.9% obtained for GAGG:Ce, Li are superior to those of 24,200 photons/MeV and 9.5% for GAGG:Ce,Mg. Scintillation decays are approximated by a double exponentials with a fast principal decay component of 47 ns (83%) for GAGG:Ce, Mg and 90 ns (86%) for GAGG:Ce,Li. Coincidence time resolution of 282 ps obtained for GAGG:Ce, Mg is better than that of 389 ps for GAGG:Ce,Li. GAGG:Ce, Mg shows a much lower afterglow and thermally stimulated luminescence intensity with respect to GAGG:Ce,Li. • Scintillation properties of Li+ and Mg2+ -codoped Gd 3 Al 2 Ga 3 O 12 :Ce are compared. • Gd 3 Al 2 Ga 3 O 12 :Ce, Mg exhibits better timing performance. • Gd 3 Al 2 Ga 3 O 12 :Ce, Mg shows lower afterglow and TSL intensity. • Gd 3 Al 2 Ga 3 O 12 :Ce, Li exhibits high light yield and good energy resolution. [ABSTRACT FROM AUTHOR]

Scintillators are used as radiation detectors because they absorb ionizing radiation and release energy as light. Inorganic glasses have significant advantages over inorganic crystals owing to their ease of fabrication, low cost, controllable shape, and thermal and chemical durability. However, large performance gaps, such as light yield and density, still exist between inorganic glasses and commercial inorganic crystals. Here, we present a demonstration of an inorganic scintillator based on phosphate glass with an alkali metal as the host and Ce3+ as the emission centers. This glass exhibits a high light yield of 2500 photons/MeV, which is higher than that of previously reported inorganic glass scintillators (approximately 2000 photons/MeV). The glass is transparent and has a fast decay time of approximately 30 ns, which is attributed to the 5d–4f optical transition of Ce3+, facilitating applications for inorganic glass scintillators for gamma- and X-ray detection. Furthermore, we investigated the difference in the energy-transfer efficiency of the fabricated inorganic glasses by changing the alkali metals. The energy transfer efficiency increases with an increase in the atomic number of the alkali metals; the thermoluminescence (TL) intensity decreases with an increase in the atomic number of the alkali metals. These results suggest that Cs is an optimum alkali metal to achieve a high light yield on phosphate glass scintillators, and they may be related to the difference in the number of electron–hole pairs that do not contribute to scintillation. • We fabricated a phosphate glass doped Ce3+ for gamma- and X-ray detection. • The fabricated glass scintillator exhibited a high light yield of 2500 photons/MeV. • Cs was an optimal alkali metal to achieve a high light yield. [ABSTRACT FROM AUTHOR]

In this work, Cs 2 LiLaBr 6 :1%Ce (CLLB:Ce) single crystal with the size of Ф26 mm × 80 mm were successfully grown by the Bridgman method. The optimal conditions of application were presented by coupling with R6231-100 PMT. The pulse spectra are recorded by the 4-channel digital converter DT5751 at a sampling rate of 1 GS/s. The energy spectra of the CLLB:Ce crystal were recorded under different PMT gain voltage. The best energy resolution is obtained (up to 3.8%) when the gain voltage of PMT is 3.65V. The non-proportionality of CLLB:Ce crystal was measured under varied radioactive sources while the background radioactive was discussed. Besides, the energy spectra of CLLB:Ce crystal were recorded when the temperature was varied from −30 °C to 50 °C. Finally, the discriminating ability of neutron and gamma was evaluated under 252Cf source and AmBe source, the FOM value is 1.4 and 1.2, respectively, which has a greatly potential application in the nuclear radiation detection. • Cs 2 LiLaBr 6 :1%Ce single crystal with the size of Ф26mm × 50 mm were successfully grown. • Cs 2 LiLaBr 6 :1%Ce has a good non-proportionality (3%). • CLLB:Ce crystal has a best scintillation properties at the temperature of 30 °C. • The FOM value of CLLB:Ce crystal is estimated about 1.4 under 252Cf source. [ABSTRACT FROM AUTHOR]

Zinc-gadolinium-fluoroborate glasses doped with cerium fluoride (CeF 3) were successfully fabricated to detect and shield X-ray and proton radiation. The doped glasses were studied at varying ZnO concentrations to investigate their properties, including density, transmittance, photoluminescence, and the oxidation states of dopants The glasses were tested for their sensitivity to detect X-ray and proton radiation, and calculations of the half-value layer and proton range were used to investigate their shielding properties. The results showed that an increase in ZnO concentrations induced a higher glass density and shifted the absorption edge to a longer wavelength (redshift) in the optical transmittance spectra. The cerium dopant mainly formed the Ce3+ oxidation state, resulting in a single broad band emission due to the 5d→4f transition of Ce3+ ions. The luminescence behavior of the doped glasses under x-ray irradiation showed a single broad emission at 375 nm. In contrast, under proton irradiation, the single broad emission shifted to a longer wavelength at 400 nm. The increase in ZnO concentration decreased light emission when exposed to x-rays and protons. The results also demonstrated that increasing ZnO concentrations improved the shielding properties of the glasses. We found that the glass with a 25 mol% ZnO concentration revealed a half-value layer of the 100 keV photon energy equal to 0.116 ± 0.001 cm, and a 70 MeV proton energy penetrated the maximum range in the glass at 1.308 ± 0.019 cm. We concluded that ZnO could be used to control the fraction between Ce3+ and Ce4+ ions in the cerium ions of the CeF 3 -doped glasses. • Fabrication of Ce3+ doped zinc-gadolinium-fluoroborate glass scintillators. • Study of scintillation, sensitivity, and shielding properties via variations in ZnO concentration. • Adding ZnO affected the fraction between Ce3+ ions in the glasses. • Spectra of the x-ray and proton induced luminescence. • GATE simulated the shielding properties, including the half-value layer and proton range. [ABSTRACT FROM AUTHOR]

Pr-doped CaWO 4 single crystals with dopant concentrations of 0.05–1% were synthesized by the floating zone method, and the photoluminescence and scintillation properties were evaluated. Emissions due to the 4f–4f transitions of Pr3+ were observed in visible–near-infrared ranges under visible light and X-ray irradiation. The X-ray-induced scintillation decay times were typical values of the transitions of Pr3+ when monitored at 380–900 nm. The afterglow levels when 20 ms passed after X-ray irradiation were calculated to be 573–730 ppm and increased as the dopant concentrations increased. In the integration-type scintillation detector property, 0.05, 0.1, and 0.5% Pr-doped samples showed good linearity between X-ray exposure dose rate and scintillation signals from 0.05 to 5 Gy/h. • Emissions due to 4f–4f transitions of Pr3+ appeared at visible–NIR ranges under visible light and X-ray irradiation. • The scintillation decay times were typical values of the transitions of Pr3+ when monitored at 380–900 nm. • Pr-doped CaWO 4 showed good linearity between X-ray exposure dose rate and scintillation signals. [ABSTRACT FROM AUTHOR]

The Ce3+-Yb3+ co-doped Na 2 O–CaO–SiO 2 –Al 2 O 3 –ZnO glasses were prepared by the melt-quenching method. The effects of ZnO replacing CaO on the structure and luminescent properties of glass were studied. The thermodynamic temperature and thermal stability of the glasses were determined by DSC. The change in the glass network structure was analyzed by FT-IR spectra. The excitation spectrum, emission spectrum and fluorescence lifetime of Ce3+ in glass were determined by fluorescence spectrometer. The down-conversion luminescence spectra of Ce3+-Yb3+ ions excited at 355 nm were measured. According to the emission spectra of Ce3+ ions under different excitation wavelengths, the multiple luminescence centers of Ce3+ ions are determined, and the chromaticity coordinates of CIE are calculated. Finally, the energy transfer between Ce3+ and Yb3+ was analyzed. The Ce3+-Yb3+ co-doped glass can convert ultraviolet and visible light to the response band of c-Si solar cells, so it is an ideal candidate for solar panel glass. Although Yb3+ cannot directly absorb the light in the range of 300–500 nm, the ultraviolet band can be down-converted and emitted to the response band of c-Si solar cells by Ce3+-Yb3+ co-doping in glass, and a strong broadband near-infrared emission occurs near 978 nm, which matches the best response spectrum of c-Si solar cells. Therefore, the Ce3+-Yb3+ co-doped glass is expected to be a suitable spectral converter to be used as solar cover glass, which has potential application value in improving the actual photoelectric efficiency of silicon-based solar cells. [Display omitted] • Substitution of ZnO for CaO in glass composition has a significant effect on structure and properties. • Phenomenon of multiple luminescence centers of Ce3+ ions in a glass matrix has been discussed. • CIE Chromaticity coordinates indicate that the luminescence color of glass transitions from blue to turquoise light. • Chromaticity coordinates excited by ultraviolet light indicate UV protection performance of cover glass to photovoltaic module. • It provides guiding significance for the functional improvement of solar cell cover glass at present. [ABSTRACT FROM AUTHOR]

(La 0.99 Yb 0.01) 2 Hf 2 O 7 (Yb:LaHO) crystal has been developed by the core heating method as a near-infrared-emitting oxide scintillator for a fiber reading remote-dosimetry system under the high-dose-rate region. This system consists of a scintillator, a long silica optical fiber and a detector unit. Near-infrared-emitting photons can be separated from significant fiber-derived noise mainly observed in the UV–blue range. The noise is generated in the optical fiber itself by gamma-rays and charged particles. The Yb:LaHO crystal had a maximum emission peak at 975 nm when excited by X-rays and a transmittance of approximately 29% at 977 nm. The afterglow intensity of the Yb:LaHO crystal under X-rays was 11% that of Cr:α-Al 2 O 3 (ruby) crystal. We demonstrated the applicability of the remote-dosimetry system with the Yb:LaHO crystal irradiated with gamma rays from a 60Co source with an activity of ∼77 TBq. The signal-to-noise ratio (SNR) of the Yb:LaHO crystal was 1.9 times higher than that of the ruby crystal at ∼ 1 kGy/h, and the lowest limit of the dynamic range was comparable between the Yb:LaHO and ruby crystals. The results of the SNR and afterglow intensity showed that the Yb:LaHO crystal is a more suitable scintillator than the ruby crystal for fiber reading remote-dosimetry systems. • (La 0.99 Yb 0.01) 2 Hf 2 O 7 crystal was grown by the core heating method. • (La 0.99 Yb 0.01) 2 Hf 2 O 7 had a maximum emission peak of ∼975 nm excited by X-rays. • Afterglow intensity of (La 0.99 Yb 0.01) 2 Hf 2 O 7 is ∼11% of Cr:α-Al 2 O 3. • Signal-to-noise ratio of (La 0.99 Yb 0.01) 2 Hf 2 O 7 was higher than that of Cr:α-Al 2 O 3. [ABSTRACT FROM AUTHOR]

In this paper, a new method to improve the color rendering performance of inorganic red pigment by adding phosphor is proposed. The optimal mixing ratios of (Ca,Sr)AlSiN 3 :Eu2+, (Sr,Ba) 2 Si 5 N 8 :Eu2+ and NaMgPO 4 :Eu2+ phosphors in the γ-Ce 2 S 3 red material are 20%, 10% and 5%, respectively. At the optimal mixing ratios; L* increased by 12.9%, 3.5% and 3%, separately; a* increased by 4.3%, 4% and 1.6% severally; C* increased by 7.9%, 4.3% and 1.5% in turn. Of course, the different properties of the phosphors themselves make the mixing ratios different. Subsequently, the mechanism of pigment fluorescent materials is further investigated by using Chromatometer, SEM, Fluorescence Photometer, UV–vis Spectrophotometer and Fluorescence Microscope. The results shows that, under the irradiation of sunlight, the fluorescent materials in the fluorescent pigments are excited by the light of specific wavelengths in the sunlight, producing an asymmetric broad-band emission in the visible red region. The light emitted as a second light source is diffusely reflected by the pigment particles, which plays a superimposed effect and finally improves the color rendering ability of the red γ-Ce 2 S 3 pigment that originally relies only on the reflected sunlight energy. • In this paper, a new method to improve the color performance of inorganic red pigment by adding phosphor is proposed. • The optimal mixing ratios of (Ca,Sr)AlSiN 3 :Eu2+, (Sr,Ba) 2 Si 5 N 8 :Eu2+ and NaMgPO 4 :Eu2+ in the γ-Ce 2 S 3 are 20%, 10% and 5%, respectively. At the optimal mixing ratios; L* increased by 12.9%, 3.5% and 3%, separately; a* increased by 4.3%, 4% and 1.6% severally; C* increased by 7.9%, 4.3% and 1.5% in turn. • The results shows that, the fluorescent materials in fluorescent pigments are excited by specific wavelengths of light in sunlight, producing an asymmetric broad-band emission in the visible red region. • As a second light source is diffusely reflected by the pigment particles, which plays a superimposed effect and finally improves the color ability of the γ-Ce 2 S 3 that relies only on reflection. [ABSTRACT FROM AUTHOR]

The LiI:Tl crystal is a candidate for thermal neutron measurements and rare event searches due to the advantage of the lithium and iodide isotopes in its composition. This study shows the pulse shape discrimination (PSD) capability of thermal neutron irradiation. Particle discrimination is essential for improving neutron measurement and rare event searches to reduce unwanted backgrounds. To investigate the pulse-shape characteristics of LiI:Tl crystals with different radiations, digital analysis of pulse shape has been considered. The raw pulses were fitted with a suitable pulse form. The fitted pulses were studied in both the time and frequency domains which improve the Figure-of-Merit over the charge comparison methods. Our results show the change of PSD for LiI:Tl crystals with different Thallium concentrations. The surface effect is discussed, and other related scintillation characteristics were also studied. [Display omitted] • LiI:Tl scintillation crystals were grown with different Thallium concentrations by using vertical Bridgman technique. • The decay time was measured by irradiated gamma rays, alpha particles, and thermal neutron. • Light yield and non-proportionality were measured by using gamma sources. • LiI:Tl scintillation crystal has capability of pulse shape discrimination for thermal neutron measurement. [ABSTRACT FROM AUTHOR]

Three series of Dy3+-, Tb3+-doped and Tb3+/Dy3+ co-doped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glasses with density of about 6.75 g/cm3 were successfully prepared by high temperature melt-quenching method. The luminescence properties of these rare earth ions doped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glass were systematically studied by transmittance, photoluminescence (excitation and emission spectra), time-resolved emission spectra (TRES) and X-ray excited luminescence (XEL) spectra, together with the luminescence decay curves. The optimal doping concentration of Dy3+ and Tb3+ ions in 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glasses was determined under UV and X-ray excitation, respectively. It is found there is an efficient energy transfer from Dy3+ to Tb3+ ions in 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glass in photoluminescence spectra. However, it is not true under X-ray excitation due to the complicated physical process. • The density of Dy3+-, Tb3+-doped and Tb3+/Dy3+ codoped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 scintillation glasses is up to 6.75 g/cm3. • The energy transfer process of Dy3+.→Tb3+ was confirmed through photoluminescence spectra, luminescence decay curves and TRES spectra. • The energy transfer efficiency of Dy3+ ions to Tb3+ ions is up to 97.6%. • The difference of energy transfer effect between XEL and PL process was explored. [ABSTRACT FROM AUTHOR]

Nominally Nd 0.1, 0.5, 1 and 2% doped YAlO 3 (YAP) single crystals were synthesized by the floating zone method to evaluate their optical and scintillation properties. In photoluminescence (PL), all the samples showed sharp emission lines in the UV-VIS region, and the PL quantum yield in this spectral range was 5–15%. The PL decay time of the 4F 7/2 → 4I 9/2 transition was evaluated to be around 150 ms. In scintillation emission spectrum under X-ray irradiation, several emission lines due to the 4f-4f transitions of Nd3+ were observed in the UV-VIS range. These emissions was found to consist of two decay constants of a few μs and 100–150 ms. When irradiated with 662 keV γ-rays from 137Cs, the Nd 0.1% doped sample exhibited the highest scintillation light yield of 12500 ph/MeV determined by pulse height analysis. • Undoped and Nd differently doped YAP crystal scintillators were prepared. • Optical and scintillation properties of the undoped and Nd-doped YAP were evaluated. • Nd 0.1% doped YAP showed a clear photoabsorption peak in the pulse height spectrum. • The scintillation light yield of Nd 0.1% doped YAP was 12500 ph/MeV. [ABSTRACT FROM AUTHOR]

Abstract This contribution describes the fabrication of an ultrafiltration membrane scintillator based on ZnS:Ag. A solid state reaction method was used for the synthesis of ZnS:Ag, with particular emphasis on investigating the effects of the reaction temperature on the ZnS host, and of the Ag concentration on the radioluminescence (RL) output. The reaction temperature was found to control the crystallite size between 3 and 10 nm for temperatures between 75 and 500 °C, while the RL output was maximized for an Ag concentration of 0.2 mol%. Modified membranes were coated with ZnS:Ag powders via ultrafiltration and their response to ionizing radiation was characterized by means of RL measurements. Highlights • Optimization of ZnS:Ag synthesis. • Fabrication of ultrafiltration membrane scintillator. • Radioluminescence of membrane scintillator. [ABSTRACT FROM AUTHOR]

Abstract We synthesized Al 2 O 3 transparent ceramics doped with different concentrations of Eu (0.001, 0.01, 0.1 and 1.0%) by the spark plasma sintering (SPS) method, and then we investigated their photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties. In the PL, the samples showed a broad emission peak at 400 nm due to the 5d-4f transitions of Eu2+ and several sharp emission peaks across 550–750 nm due to the 4f-4f transitions of Eu3+ and the 3d-3d transitions of Cr3+ impurity ion. In addition to these peaks over 550–750 nm, in scintillation, the samples exhibited two broad peaks over 300–400 nm possibly due to not the 5d-4f transitions of Eu2+ but F and F+ centers. In TSL, the glow curve consisted of peaks at approximately 100, 160, 210 and 320 °C. The TSL intensity of the 0.001% Eu-doped sample was the highest, and the TSL response was confirmed to be linear to irradiated X-ray dose in the range from 0.1 to 1000 mGy. Highlights • We developed Eu-doped Al 2 O 3 transparent ceramics by spark plasma sintering (SPS) method. • TSL glow peaks at approximately 100, 160, 210 and 320 °C were observed in the Eu-doped samples. • The TSL response was confirmed to be linear to the irradiated X-ray dose range from 0.1 to 1000 mGy. [ABSTRACT FROM AUTHOR]

Abstract Ce:(Gd,La) 2 Si 2 O 7 (Ce:La-GPS) and Al co-doped Ce:(Gd,La) 2 Si 2 O 7 (Al,Ce:La-GPS) single crystals were grown by the micro-pulling-down method to improve the mechanical, optical and scintillation properties. In a tensile test, the maximum strain and stress values in the stress-strain curve of the Al,Ce:La-GPS single crystal compared to the Ce:La-GPS single crystal and the result suggests that there is a possibility of the improvement on the mechanical property by Al co-doping. In addition, the light yield of the La-GPS single crystal under γ-ray irradiation was slightly increased and the decay time was accelerated by the Al co-doping. Highlights • Al co-doped Ce:La-GPS single crystals were grown by the μ-PD method. • It is a possibility that Al co-doping improves the mechanical property of the La-GPS. • Emission peaks originated from 5 d-4f transitions of the Ce3+ ion were observed. • The light yield under γ-ray irradiation was slightly increased by Al co-doping. • Scintillation decay times were accelerated by Al co-doping. [ABSTRACT FROM AUTHOR]

Abstract Eu-doped Ba x Sr 1- x Al 2 O 4 (x = 0, 0.1, 0.3 and 0.5) single crystals were synthesized by the floating zone method and then characterized for scintillation applications. All the crystal samples exhibit photoluminescence and scintillation with a broad emission around 510 nm. The decay time constants of the latter emission are typical for the 5d-4f transitions of Eu2+. From the pulse height spectra measured under 137Cs gamma-ray, the estimated light yields of Eu:SrAl 2 O 4 , Eu:Ba 0.1 Sr 0.9 Al 2 O 4 Eu:Ba 0.3 Sr 0.7 Al 2 O 4 , and Eu:Ba 0.5 Sr 0.5 Al 2 O 4 crystal samples are 42,000, 30,000, 22,000 and 20,000 photons/MeV, respectively. The observed light yields are notably high, and the fact indicates that Eu:Ba 0.5 Sr 0.5 Al 2 O 4 crystals are good candidates of scintillator materials for gamma-ray measurements. Graphical abstract Image 1 Highlights • Eu-doped (Ba,Sr)Al 2 O 4 single crystals were synthesized by the floating zone method. • The samples exhibit PL and scintillation with a broad emission around 510 nm. • From pulse height spectra, the light yields of Eu:SrAl 2 O 4 and Eu:Ba 0.5 Sr 0.5 Al 2 O 4 crystals are 42,000 and 20,000 photons/MeV. [ABSTRACT FROM AUTHOR]

Abstract We have investigated scintillation and photoluminescence (PL) properties of Sr 2 CeO 4 ceramics. The ceramic samples were synthesized by the solid state reaction method sintered at different temperatures (1100, 1200, 1300 and 1400 °C). All the Sr 2 CeO 4 ceramic samples showed PL spectrum with a broad feature peaking around 460 nm. From decay constants of the PL emission, it was confirmed that the origin was due to the charge transfer (CT) transitions of O2—Ce4+ ions. In addition, all the samples showed scintillation induced by X-rays with a spectrum peaking around 500 nm as similarly seen in PL. All of the samples exhibited a clear photoabsorption peak in the pulse height spectra measured under 137Cs γ-ray irradiation, and the absolute scintillation light yield (LY) was the highest for the sample sintered at 1200 °C, and the value was 3200 ph/MeV. Highlights • We have synthesized Sr 2 CeO 4 ceramics by solid-state reaction. • We have characterized the optical and scintillation properties of Sr 2 CeO 4 ceramics. • The scintillation light yield was evaluated to be about 3200 photons/MeV under 137Cs γ-rays. [ABSTRACT FROM AUTHOR]