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Organic–inorganic perovskite (OIP) nanoparticles exhibit excellent luminescence properties and photovoltaic efficiency and can be used in bulk and thin films. In this study, a mechanically robust OIP quantum dot dispersion layer was deposited on glass substrates via a rapid synthesis process. First, hierarchical nanoporous structures with a thickness of 1.5 μm were formed on the glass surface. These structures were dipped in a precursor liquid and then dried. Thereafter, OIP crystals of methylammonium lead bromide (MAPbBr 3) with sizes of 5–10 nm were precipitated inside nanopores. The low-temperature luminescence properties of the obtained samples at 4–110 K were compared with those of spin-coated films and bulk MAPbBr 3. The emission peak wavelength of the sample precipitated in the nanopores on the glass surface (with an energy of 2.16 eV) was lower than that of the bulk sample (with an energy of 2.01 eV), and its luminescence intensity was two orders of magnitude higher than that of the bulk sample. The proposed method can be used to fabricate solar cells, electroluminescent devices, and scintillators. [ABSTRACT FROM AUTHOR]

Tellurite glass (TeG) and its glass-ceramics (TeGC435 and TeGC455), with a composition of 10Eu 2 O 3 –10BaO–80TeO 2 , were prepared and their luminescence properties were evaluated. TeG was prepared via the melt quenching technique, while TeGC435 and TeGC455 were fabricated by heat treating TeG at 435 and 455 °C, respectively, for 5 h each. The Eu 2 Te 6 O 15 crystal phase was formed in TeGC435 and TeGC455. Both the glass and glass-ceramics showed sharp photoluminescence and scintillation peaks, attributed to the 4f→4f transitions of Eu3+. The highest quantum yield was obtained for TeG, whereas the highest integrated scintillation intensity was obtained for TeGC455. The scintillation intensity of TeGC455 was approximately 10% of that of the Bi 4 Ge 3 O 12 single crystal. Furthermore, typical decay times derived from the 4f→4f transitions were obtained for TeG, TeGC435, and TeGC455 during photoluminescence and scintillation. [ABSTRACT FROM AUTHOR]

We fabricated organic–inorganic perovskite nanocrystals in nanoporous glasses (OIPiG) where (C6H5C2H4NH3)2PbBr4 (Phe) was incorporated into about 4 nm diameter pores and evaluated their photoluminescence and scintillation properties, compared with the Phe single crystal. Both the samples showed emissions due to the recombination of free excitons in the inorganic layer under 280 nm excitation light. In scintillation, a weak and broad scintillation peak possibly due to the free excitons and bound excitons was observed in the OIPiG, while the Phe single crystal showed efficient scintillation due to free exciton emissions with a peak approximately at 435 nm. The scintillation decay time constant (4.4 ns) due to the free excitons for the OIPiG was found to be faster than that (6.6 ns) for the Phe single crystal. In addition, the afterglow levels were confirmed to be 340 ppm for the OIPiG and 20 ppm for the Phe single crystal. The afterglow level of the OIPiG was higher than that of the Phe single crystal but was almost equivalent to that for the commonly used inorganic scintillator CsI:Tl. [ABSTRACT FROM AUTHOR]

We fabricated organic–inorganic lead chloride-based compounds with an ether diamine: (NH 3 C 2 H 4 OC 2 H 4 OC 2 H 4 NH 3)PbCl 4 (EDBEPbCl 4), (NH 3 C 3 H 6 OC 4 H 8 OC 3 H 6 NH 3)PbCl 4 (BBEPbCl 4), and (NH 3 C 3 H 6 OC 2 H 4 OC 2 H 4 OC 3 H 6 NH 3)PbCl 4 (DGBEPbCl 4). After the fabrication of these crystals, their luminescence characteristics were investigated. A broadband emission that might be derived from self-trapped excitons (STEs) was detected, and photoluminescence quantum yields of these crystals were 16 % (EDBEPbCl 4), 2.9 % (BBEPbCl 4), and 2.7 % (DGBEPbCl 4). In the scintillation spectra, a broadband peak was also observed from the fabricated crystals, and they exhibited a decay time of 12 ns (EDBEPbCl 4), 11 ns (BBEPbCl 4), and 11 ns (DGBEPbCl 4) in scintillation. Further, their pulse height spectra under alpha-ray were recorded using 241Am. The highest light yield was observed from EDBEPbCl 4 (2000 photons/5.5 MeV-α) and its light yield was higher than that of a zinc oxide single crystal. • We fabricated organic–inorganic lead chloride-based compounds with an ether diamine. • Broadband photoluminescence and scintillation were observed from the fabricated compounds. • (NH 3 C 2 H 4 OC 2 H 4 OC 2 H 4 NH 3)PbCl 4 showed the highest light yield of 2000 photons/5.5 MeV-α under alpha-ray. [ABSTRACT FROM AUTHOR]

Eu 2 O 3 -doped 40K 2 O–20Ta 2 O 5 –40Ga 2 O 3 gallate glasses were synthesized, and their radiation response characteristics were studied systematically. According to their photoluminescence spectra, they showed intense emissions with sharp peaks centered at around 580, 594, 613, 656, and 706 nm when irradiated by 380 nm light. The sharp peaks originate from the 4f-4f transitions of Eu3+. Moreover, these sharp peaks were also detected when excited by X-ray, and the 1.0% Eu 2 O 3 -doped gallate glasses showed the largest luminescence intensity under UV light and X-ray. Furthermore, the afterglow levels of the Eu 2 O 3 -doped 40K 2 O–20Ta 2 O 5 –40Ga 2 O 3 gallate glasses were determined to be approximately 300 ppm. These levels are close to the levels of TI-doped CsI single crystals. [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]

Antimony based organic–inorganic hybrid compounds (Ph 4 P) 2 SbCl 5 (Ph 4 P: tetraphenylphosphonium) and (DTA) 2 SbCl 5 (DTA: dodecyltrimethylammonium) with a zero-dimensional structure were fabricated, and the optical and scintillation characteristics were evaluated. A broadband photoluminescence possibly due to self-trapped exciton (STE) emission appeared at 692 nm for (Ph 4 P) 2 SbCl 5 and 630 nm for (DTA) 2 SbCl 5 under 370 nm excitation light. The quantum yields were 98 % for (Ph 4 P) 2 SbCl 5 and 97 % for (DTA) 2 SbCl 5. Under X-ray, the broad emission peak was also detected at 670 nm for (Ph 4 P) 2 SbCl 5 and at 615 nm for (DTA) 2 SbCl 5. Furthermore, scintillation decay time constants were 4.9 μs for (Ph 4 P) 2 SbCl 5 and 5.0 μs for (DTA) 2 SbCl 5. Moreover, the scintillation light yield of (Ph 4 P) 2 SbCl 5 was estimated to be about 12,000 photons/MeV, whereas the light of (DTA) 2 SbCl 5 could not be determined. In addition, afterglow levels were 56 ppm for (Ph 4 P) 2 SbCl 5 and 130 ppm for (DTA) 2 SbCl 5. • Antimony based organic–inorganic hybrid compounds (Ph 4 P) 2 SbCl 5 and (DTA) 2 SbCl 5 were fabricated. • The compounds showed a broad emission due to self-trapped excitons with a high quantum yield. • The scintillation light yield of (Ph 4 P) 2 SbCl 5 was estimated to be about 12,000 photons/MeV. [ABSTRACT FROM AUTHOR]

We prepared Ca 2 BO 3 Cl with different concentrations (0.1 %, 0.5 %, and 1.0 %) of Eu 2 O 3 for radiation dosimetry. Sharp photoluminescence peaks derived from 4f → 4f transition of Eu3+ appeared at 575, 590, 610, and 645 nm. On the other hand, the Eu 2 O 3 -doped Ca 2 BO 3 Cl exhibited a broad scintillation peak at around 600 nm due to 5d → 4f transition of Eu2+, and sharp peaks at approximately 590 and 610 nm derived from 4f → 4f transition of Eu3+. Furthermore, a major thermally-stimulated luminescence glow peak was detected at 250 °C, and a linear response in the range of 1–3000 mGy was observed from the Eu 2 O 3 -doped Ca 2 BO 3 Cl. [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]

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]

Glass compounds have gained attention as scintillating materials owing to their large production possibility, easy shaping and flexible glass composition, and various glasses such as silicate, germanate and borate glasses have been considered for scintillator applications. Herein, Eu 2 O 3 -doped bismuth gallate glasses having a composition of 5K 2 O–70Bi 2 O 3 –25Ga 2 O 3 were synthesized for the development of new glass scintillators by the melt-quenching method. After the fabrication of the undoped and Eu 2 O 3 -doped bismuth gallate glasses, their optical and scintillation characteristics were evaluated. The Eu 2 O 3 -doped bismuth gallate glasses showed photoluminescence (PL) and scintillation with sharp peaks centered at approximately 596 and 612 nm due to the electronic 4f → 4f transitions of Eu3+. The PL and scintillation spectra revealed that the concentration dependence of the PL quantum efficiency for the Eu 2 O 3 -doped bismuth gallate glasses was well correlated with that of the scintillation intensity. The decay time constants of the 0.5% and 1.0% Eu 2 O 3 -doped bismuth gallate glasses under visible light and X-ray irradiation were approximately 0.55 ms and 0.15 ms, respectively. In addition, the undoped and Eu 2 O 3 -doped bismuth gallate glasses exhibited afterglow levels of 330–660 ppm, and their moderate levels were found to be almost comparable to the afterglow level of Tl-doped CsI. [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]

We investigated photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties of BaCaBO 3 F doped with different concentrations of Eu (0, 0.1, 1.0, and 10.0%) to develop phosphor materials for radiation measurement. The Eu-doped samples showed emissions with several sharp peaks due to the 4f-4f transitions of Eu3+ in PL and scintillation while no emission peak was observed in the undoped sample. The decay time constants of the Eu-doped samples in PL and scintillation were about 1.16–1.20 ms and 0.75–1.10 ms, respectively. In addition, the Eu-doped samples showed TSL due to the 4f-4f transitions of Eu3+. The thermal activation energies of the Eu-doped samples were calculated by TSL isothermal analysis, and the analysis suggested that eleven trapping centers with different activation energies involved in TSL might exist in the Eu-doped samples. [ABSTRACT FROM AUTHOR]

A bulk sample of an organic–inorganic (OI) perovskite crystal of (C6H5C2H4NH3)2PbBr4 with a layered structure showing excellent luminescent properties was rapidly synthesised. The raw materials of OI crystal were impregnated into nanoporous glass having 4-nm pores and dried, obtaining a translucent sample of OI nanocrystals in glass (OIiG). An absorbance shoulder was observed at E = 3.04 eV for OIiG, which was attributed to exciton bands, and photoluminescence (PL) duration times of τ1 = 2.8 ns and τ2 = 8.6 ns were recorded for OIiG. In contrast, for a single-crystal sample, E = 2.94 eV, τ1 = 4.1 ns, τ2 = 11.0 ns. Compared to those of the single-crystal sample, the OIiG has a higher absorbance energy, and the duration time was shorter. The exciton activation energy was 195 meV for OIiG, in contrast with 121 meV for single crystal. We propose that these changes are due to the size effect because the particle size (3–4 nm in diameter) in the OIiG is close to the Bohr radius of layer-structured OI crystals. [ABSTRACT FROM AUTHOR]

We evaluated photoluminescence and radiation response properties of organic–inorganic perovskite-type compounds with various hydroxyl alkyl amines or alkyl ether amines (HOC n H 2n NH 3) 2 PbCl 4 (n = 2: C2–OH, n = 3: C3–OH, n = 4: C4–OH), (CH 3 CH 2 OC n H 2n NH 3) 2 PbCl 4 (n = 2: 2-Ethoxy, n = 3: 3-Ethoxy), and (CH 3 C 2 H 4 OC 3 H 6 NH 3) 2 PbCl 4 (3-Butoxy). A clear broadband emission peak attributed to self-trapped excitons (STEs) was detected from the C2–OH, C3–OH, and 2-Ethoxy crystals under 310 nm excitation light. Additionally, they showed a fast decay time of 3.5 ns (C2–OH), 5.5 ns (C3–OH), and 3.0 ns (2-Ethoxy), which was ascribed to the recombination of STEs. In the scintillation spectra, the C2–OH, C3–OH, and 2-Ethoxy crystals exhibited a broad emission originating from the recombination to STEs. Furthermore, they exhibited a fast scintillation decay time of 2.2 ns (C2–OH), 3.5 ns (C3–OH), and 1.1 ns (2-Ethoxy) due to the recombination of STEs. Moreover, the light yield of the C3–OH crystal under alpha-ray was the highest, and the yield was estimated to be 1100 photons/5.5 MeV-α, which was higher than that of a ZnO single crystal. • Several PbCl 6 4--based perovskite compounds were fabricated for radiation measurements. • The compounds showed a broad emission due to self-trapped excitons. • (HOC 3 H 6 NH 3) 2 PbCl 4 crystal showed a higher scintillation light yield than a ZnO crystal. [ABSTRACT FROM AUTHOR]

We synthesized strontium aluminoborate glasses doped with different concentrations of Tb (0.1, 0.5, 1.0 and 5.0 mol.%) by the conventional melt-quenching technique, and investigated their photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties to develop phosphor materials for radiation dosimetric methods. The Tb-doped samples showed PL and scintillation with sharp peaks approximately at 485, 540, 545, 580 and 620 nm due to the 4f-4f transitions of Tb3+. The 1.0% Tb-doped sample exhibited the highest intensity in PL and scintillation among the samples investigated. In addition, the Tb-doped samples showed TSL with a main glow peak approximately at 75 °C measured after X-ray irradiation of 1000 mGy. The TSL intensity of the 0.1% Tb-doped sample was the highest, and the 0.1–1.0% Tb-doped samples showed TSL with a linear response feature over the dose range of 0.1–1000 mGy. • We synthesized Tb-doped strontium aluminoborate glasses by the conventional melt-quenching technique. • The samples showed luminescence and scintillation due to the 4f-4f transitions of Tb3+. • The 0.1–1.0% Tb-doped samples showed TSL with a linear response feature over the dose range of 0.1–1000 mGy. [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 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]

Abstract We have investigated scintillation and thermally-stimulated luminescence (TSL) dosimetric properties of Al 2 O 3 transparent ceramics doped with different concentrations of C ions (0.001, 0.01 and 0.1%). The samples were synthesized by the Spark Plasma Sintering (SPS) technique. All the samples showed scintillation with emission peaks at 310, 410 and 693 nm under X-ray irradiation. Based on the scintillation decay times measured, the origins of emissions at 310, 410 and 693 nm were attributed to F+ centers, F centers and Cr3+ impurity ions, respectively. The samples show notable TSL with a glow curve consisting of peaks at 30, 100, 165, 230, 330 and 405 °C with much higher intensities than those of undoped Al 2 O 3 transparent ceramics. A TSL response was confirmed to be linear to the irradiation dose over a range from 0.1 to 1000 mGy. [ABSTRACT FROM AUTHOR]

Abstract We synthesized NaPO 3 -Al(PO 3) 3 glasses with different concentrations of Tb (0.3, 1.0, 3.0 and 10.0 mol%) by the conventional melt-quenching technique. After the synthesis, their photoluminescence (PL), scintillation and TSL properties were characterized systematically. All the glass samples showed intense PL and scintillation having a spectrum of sharp peaks at around 490, 540, 590 and 620 nm due to the 4f-4f transitions of Tb3+. The intensities of PL and scintillation were the highest for the 10.0% Tb-doped glass among the samples investigated. In thermally-stimulated luminescence (TSL), the intensity was the highest for the 1.0% Tb-doped sample. We also demonstrated dose response of TSL, and the 0.3% and 1.0% Tb-doped samples exhibited a linear response to X-ray dose over a dose range of 10–10000 mGy. Highlights • We synthesized NaPO 3 -Al(PO 3) 3 glasses with different concentrations of Tb by the conventional melt-quenching technique. • The samples showed luminescence and scintillation due to the 4f-4f transitions of Tb3+. • TSL response of 0.3 and 1.0% Tb-doped samples increased monotonically with X-ray dose over a dose range of 10–10000 mGy. [ABSTRACT FROM AUTHOR]

We have developed SrF 2 translucent ceramic by using the spark plasma sintering (SPS) method, and investigated scintillation properties and thermally stimulated luminescence (TSL) glow curves, in comparison with a SrF 2 crystal. Both of the samples showed scintillation with emission peaks at 300 nm under X-ray irradiation. Based on the scintillation decay times measured, the origin of emission at 300 nm was attributed to self-trapped excitation. The scintillation light yield of the SrF 2 translucent ceramic was evaluated to be about 8900 photons/MeV under 57 Co γ-rays. In addition, the afterglow level of the translucent ceramic was lower than that of the crystal. [ABSTRACT FROM AUTHOR]

Scintillation and dosimetric properties of 6 LiF-CaF 2 eutectic composites doped with different concentrations of Ce (0, 0.1 and 0.5%) were investigated. The Ce-doped samples showed scintillation due to the 5 d-4f transitions of Ce 3+ and self-trapped excitons (STE) at 320–340 and 300 nm, respectively. Furthermore, the Ce-doped samples exhibited thermally-stimulated luminescence (TSL) with glow peaks around 150 °C after X-ray irradiation of 1000 mGy. The TSL response of the 0.5% Ce-doped sample increased monotonically with X-ray dose over a dose range of 0.1–1000 mGy. Moreover, the Ce-doped samples showed optically-stimulated luminescence (OSL) with peaks at 320–340 nm due to the 5 d-4f transitions of Ce 3+ under 630 nm stimulation light after X-ray irradiation of 1000 mGy. [ABSTRACT FROM AUTHOR]

We report on the fabrication of Tb-doped barium fluoride translucent ceramics, and their scintillation and dosimetric characteristics. The Tb-doped barium fluoride ceramics were fabricated by spark plasma sintering. Scintillation derived from the 4f→4f transitions of Tb3+ under X-rays was observed from the Tb-doped barium fluoride ceramics. Their decay times under X-rays were about 10 ms. Further, thermally-stimulated luminescence originating from the transitions was detected, and their dose responses were observed in the range of 0.1–100 mGy. Moreover, the Tb-doped barium fluoride ceramics exhibited optically-stimulated luminescence (OSL), and three exponential decay components were detected in the OSL decay curves. • Tb-doped BaF 2 translucent ceramics were fabricated by spark plasma sintering. • The ceramics showed scintillation, TSL, and OSL due to the 4f-4f transitions of Tb3+. • The lowest detectable limits of this ceramic were 0.1 mGy for TSL and 10 mGy for OSL. [ABSTRACT FROM AUTHOR]

Photoluminescence (PL) and thermally-stimulated luminescence (TSL) properties of Sn-doped zinc sodium phosphate glasses were evaluated. We synthesized the glass samples by the conventional melt-quenching method under ambient atmosphere. The glasses were highly transparent in 400–2700 nm. Depending on the concentration of Sn, PL quantum yield ( QY ) ranged from 7.7 to 25.7%, and the PL QY increased with increasing the concentration of Sn. The Sn-doped samples showed PL with a broad feature due to the 5sp→5s 2 transition of Sn 2+ . The PL decay constants were 4.72–4.83 μs, and any dependence on the concentration of Sn was not observed. The glasses showed intense TSL, and the glow curves had a broad feature peaking at 110 °C. Among the present samples, the 0.5% Sn-doped sample exhibited the highest sensitivity with a good linearity over 5 orders of magnitude (0.1–10000 mGy). In addition, the TSL fading characteristics were evaluated, and the integrated TSL intensities after two days were 5.5% (undoped), 41% (Sn:0.1%), 38% (Sn:0.2%), 40% (Sn:0.5%) and 35% (Sn:1.0%), respectively. [ABSTRACT FROM AUTHOR]

Apatite crystals with chemical compositions of 0.5% Ce-doped Sr 2 (Gd 1- x Lu x ) 8 (SiO 4 ) 6 O 2 ( x  = 0.1, 0.2, 0.4, 0.5, 0.6) were synthesized by the Floating Zone method, and then we evaluated their photoluminescence (PL) and scintillation properties. All the Ce-doped samples exhibited PL and scintillation with an intense broad emission in 400–550 nm in which the origin was attributed to the 5d-4f transition of Ce 3+ , and the emission peak became broader with increasing the concentration of Lu 3+ . Both PL and scintillation decay time profiles were best-approximated by a sum of two exponential decay functions, and the origin of slower component was attributed to the 5d-4f transition of Ce 3+ . In the X-ray induced afterglow measurements, the Ce-doped Sr 2 (Gd 0.4 Lu 0.6 ) 8 (SiO 4 ) 6 O 2 sample exhibited the lowest afterglow level. Furthermore, the Ce-doped Sr 2 (Gd 0.5 Lu 0.5 ) 8 (SiO 4 ) 6 O 2 and Sr 2 (Gd 0.4 Lu 0.6 ) 8 (SiO 4 ) 6 O 2 samples showed a clear full energy deposited peak under 5.5 MeV 241 Am α-ray irradiation, and the estimated absolute scintillation light yields were around 290 and 1300 ph/5.5 MeV-α, respectively. [ABSTRACT FROM AUTHOR]

Strontium aluminoborate glasses with different concentrations of Ce (0, 0.01, 0.05, 0.1 and 0.5 mol%) were synthesized by the conventional melt-quenching technique. After the synthesis, photoluminescence (PL), scintillation and dosimetric properties of the samples were evaluated systematically. In the photoluminescence and scintillation spectra, a sharp peak around 370 nm due to the 5d-4f transitions of Ce was observed. The 0.05% Ce-doped sample showed the highest intensity in PL and scintillation among the samples investigated. The 0.01–0.1% Ce-doped samples also showed thermally-stimulated luminescence (TSL) with a glow peak of around 90 °C after X-ray irradiation. The TSL response of 0.01–0.05% Ce-doped samples increased monotonically with X-ray dose over a dose range of 10 − 1 –10 4 mGy. [ABSTRACT FROM AUTHOR]

Ce-doped Sr 2 Y 8 (SiO 4 ) 6 O 2 , Sr 2 Gd 8 (SiO 4 ) 6 O 2 and Sr 2 Lu 8 (SiO 4 ) 6 O 2 (SrYS, SrGS and SrLuS, respectively) apatite crystals were grown by the Floating Zone method, and their optical and radioluminescence (RL) properties were characterized. In the photoluminescence (PL) and RL spectra, we observed an emission band between 400 and 500 nm for all the samples, which were due to the 5d-4f transition of Ce 3+ . The RL decay time profiles were approximated by a sum of two exponential decay functions, and the origin of faster decay component was due to the 5d-4f transition of Ce 3+ . Among all the samples, SrGS sample showed the lowest afterglow level. In the pulse height spectrum, all the samples showed a full energy absorption peak under 241 Am 5.5 MeV α-ray irradiation. The absolute scintillation light yields of SrYS, SrGS and SrLuS were around 31, 76 and 940 ph/5.5 MeV-α, respectively. [ABSTRACT FROM AUTHOR]

We have synthesized the Al 2 O 3 transparent ceramic by using spark plasma sintering (SPS) and investigated the dosimeter and scintillation properties for X-ray detections, in comparison with the single crystal. Under X-ray irradiation, emissions at 300, 400 and 693 nm were observed in both the samples. To identify the origins of these emissions, scintillation decay times were investigated. Based on the results, emissions at 300, 400 and 693 nm are attributed to F + centers, F centers and Cr 3+ impurity ions, respectively. The thermally-stimulated luminescence (TSL) glow curves of both the samples showed a main peak around 50 °C. In addition, glow peaks were observed at 190, 290 and 360 °C. The TSL spectra had broad emission bands in the 300, 400 and 693 nm, which approximately agreed with the scintillation spectra. The TSL response was confirmed to be linear to the irradiation dose for transparent ceramic over the dose range from 0.3 to 1000 mGy while the sensitivity of the single crystal was lower and the response range confirmed was from 30 to 1000 mGy. [ABSTRACT FROM AUTHOR]

MgO translucent ceramics doped with different concentrations of Tb (0.01, 0.05, 0.1, 0.5%) were prepared by the Spark Plasma Sintering (SPS) method. Further, the optical, scintillation, dosimeter properties of were evaluated systematically. In the photoluminescence (PL) and scintillation spectra, sharp emission peaks due to the 4f-4f transitions of Tb 3+ were observed. In the PL and scintillation decay curves, the decay time constants were a few ms which were on a typical order of the 4f-4f transitions of Tb 3+ . The thermally-stimulated luminescence (TSL) glow curves exhibited glow peaks around 80, 160 °C after X ray irradiation of 10 mGy. The intensity of TSL peak at 160 °C exhibited a linear response against X-ray dose over a dose range of 0.1–10 mGy. The optically-stimulated luminescence (OSL) under 590 nm stimulation exhibited strong emissions due to Tb 3+ around 385–550 nm after X-ray irradiation. As in TSL, the intensity of OSL peak showed a linear response to X-ray dose, and the dynamic range confirmed was 0.1–1000 mGy. [ABSTRACT FROM AUTHOR]

• Pr3+-activated gallate glasses were fabricated by the melt-quenching method. • The gallate glasses showed luminescence due to the 4f-4f transitions of Pr3+. • The gallate glasses exhibited TSL with a lowest detectable limit of 1 mGy. Rare-earth-activated glasses have attracted research attention for radiation measurements for decades because of several practical merits, including their amenability towards mass production, large-volume fabrication, easing shaping, and their low cost. Various glass materials (e.g., borate and silicate glasses) have been characterized. In this study, photoluminescence, scintillation, and thermally stimulated luminescence (TSL) characteristics were observed for Pr3+-activated gallate glasses (69Ga 2 O 3 –20K 2 O–(11-x)La 2 O 3 –xPr 2 O 3). Clear photoluminescence and scintillation peaks derived from the 4f-4f transitions of Pr3+ appeared in the range of 480–670 nm, where the photoluminescence and scintillation decay time constants attributable to the 4f-4f transitions of Pr3+ were on the order of microseconds. The thermoluminescence of these glasses was also investigated, where a broad TSL glow peak was detected at approximately 90°C. The lowest measurable dose limit is approximately 1 mGy. Moreover, isothermal decay curve analysis suggested that nine trap levels are associated with the TSL. [Display omitted] [ABSTRACT FROM AUTHOR]

Eu 2 O 3 -doped tellurite glasses (15WO 3 –5Al 2 O 3 –80TeO 2) were fabricated and their scintillation characteristics were investigated. Typical emissions originating from the 4f→4f transitions of Eu3+ were observed at 580, 592, 614, 653, and 702 nm when irradiated with visible light. The quantum yield of the Eu 2 O 3 -doped glass increased as the Eu 2 O 3 concentration increased, and the 5.0% Eu 2 O 3 -doped glass exhibited the largest quantum yield of 76%. Further, scintillation originating from the 4f→4f transition of Eu3+ was also detected under X-ray irradiation, and the integrated scintillation intensity depended on the quantum yield. The afterglow levels of the glasses decreased with increasing the Eu 2 O 3 concentration, and the level of the 5.0% Eu 2 O 3 -doped glass was 193 ppm, which was close to that of the Tl-doped CsI. • Eu 2 O 3 -doped tellurite glasses were synthesized by melt-quenching method. • Photoluminescence and scintillation due to the 4f-4f transitions of Eu3+ were observed. • The afterglow levels of the Eu 2 O 3 -doped tellurite glasses were 193–553 ppm. [ABSTRACT FROM AUTHOR]

Photoluminescence and thermally-stimulated luminescence (TSL) characteristics of BaCaBO 3 F doped with various amounts of Tm were evaluated. The Tm-doped BaCaBO 3 F showed an emission with a sharp peak around 460 nm originating from the 4f-4f transition of Tm3+ in photoluminescence and scintillation. Their photoluminescence and scintillation decay times for the Tm-doped BaCaBO 3 F were 0.68–0.73 and 1.28–1.55 ms, respectively. Furthermore, the TSL dynamic range of the glow peaks at 190 °C for the 0.5% Tm-doped BaCaBO 3 F was from 0.1 mGy to 1000 mGy. Furthermore, the TSL isothermal analysis of the Tm-doped BaCaBO 3 F suggested that at least 12 different activation energies related to TSL were confirmed. • Tm-doped BaCaBO 3 F was fabricated by the conventional solid-state reaction. • Tm-doped BaCaBO 3 F showed efficient TSL with several glow peaks. • Linear TSL dose response was confirmed to be in the dose range from 0.1 to 1000 mGy. [ABSTRACT FROM AUTHOR]

• Eu 2 O 3 -doped tellurite glasses were synthesized by the melt-quenching method. • The samples showed photoluminescence and scintillation due to the 4f-4f transitions of Eu3+. • The lowest afterglow level (43 ppm) was comparable to the afterglow level of Bi 4 Ge 3 O 12. Eu3+-activated tellurite glasses with a composition of xEu 2 O 3 –(10-x)SrO–5Al 2 O 3 –85TeO 2 (x = 0.1, 0.5, 1.0, 5.0) were prepared with an aim to detect high energy radiation, and their photoluminescence (PL) and scintillation characteristics were investigated for scintillator applications. Some luminescence peaks attributable to the 4f-4f transitions of Eu3+ appeared at approximately 578, 592, 613, 652 and 700 nm under visible light (530 nm). The PL decay times under the visible light (530 nm) were about 0.89–0.93 ms, and they were found to be typical times for the 4f-4f transition of Eu3+. As scintillation properties, sharp scintillation peaks appeared at approximately 578, 591, 612 and 652 nm, and their scintillation decay times originating from the 4f-4f transition of Eu3+ were detected across the time range from 0.060 to 0.362 ms. Moreover, their afterglow levels were 43–387 ppm, and the level was found to decrease with the increase in the concentrations of Eu 2 O 3. [Display omitted] [ABSTRACT FROM AUTHOR]

Crystals of organic–inorganic layered perovskite-type compounds with a methoxyphenethylamine (nOCH 3 -C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 (n = 2, 3, 4) were synthesized by a temperature gradient method, and their radiation response properties were evaluated for scintillator applications. The perovskite-type compounds with a methoxyphenethylamine exhibited luminescence due to the exciton recombination when excited by ultraviolet light and X-ray. The quantum efficiency (0.12) of the perovskite-type compound with a 4-methoxyphenethylamine was the highest among the fabricated crystals. Furthermore, scintillation light yields of the perovskite-type compounds with a methoxyphenethylamine were evaluated by pulse height spectra using 241Am gamma-ray source. Their obtained yields of (2OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 , (3OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 , and (4OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 crystals were 3600, 6100 and 11,000 photons/MeV, respectively. In addition, fast decay times on the order of a few nanoseconds under X-ray irradiation were observed in the (2OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 (6.7 ns), (3OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 (4.5 ns), and (4OCH 3 –C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 crystals (6.8 ns) owing to the free exciton recombination. • The organic–inorganic compounds with a methoxyphenethylamine were synthesized by the temperature gradient method. • An emission peak due to exciton emissions with a decay time constant of several nanoseconds was detected. •The scintillation light yield of the compound with a 4-methoxyphenethylamine was about 11,000 photons/MeV. [ABSTRACT FROM AUTHOR]

Glasses are promising functional materials as phosphors with an aim to use in radiation measurements because of easy shaping, low fabrication cost and large volume fabrication possibility. In this study, Eu3+-activated gallate glasses having glass compositions of 20K 2 O–11La 2 O 3 –(69−x)Ga 2 O 3 –xEu 2 O 3 (x = 0.1–1.0) were synthesized, and their photoluminescence, scintillation and thermoluminescent characteristics were investigated. Clear luminescence peaks at around 574, 591, 614, 653 nm ascribed to the electronic 4f-4f transitions of Eu3+ appeared when the Eu 2 O 3 -doped gallate glasses were irradiated by visible light and high energy X-ray. The photoluminescence and scintillation intensities of the 0.5% Eu 2 O 3 -doped gallate glass were found to be the highest. Furthermore, a thermoluminescent glow peak appeared at around 90 °C in the glow curve. The 0.1% Eu 2 O 3 -doped gallate glass showed the highest glow peak intensity unlike photoluminescence and X-ray induced scintillation spectra, suggesting that the Eu 2 O 3 -doped gallate glasses showed a complimentary relationship between scintillation and thermoluminescent intensities. • Eu 2 O 3 -doped gallate glasses were synthesized by the melt-quenching method. • The samples showed photoluminescence and scintillation due to the 4f-4f transitions of Eu3+. • The samples exhibited a complimentary relationship between scintillation and thermoluminescencnt intensities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Organic–inorganic perovskite compounds with a chlorophenethylamine were fabricated by the temperature gradient method. • An emission peak due to exciton emissions with a decay time constant of several nanoseconds was detected. • The scintillation light yields of the compounds with a chlorophenethylamine were about 7000 photons/MeV. We fabricated crystals of organic–inorganic layered perovskite-type compounds with a chlorophenethylamine (nCl-C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 (n = 2, 3, 4) by a temperature gradient method, and evaluated their photoluminescence and radiation response characteristics. An emission peak due to exciton emissions with a decay time constant of several nanoseconds was clearly detected in the fabricated perovskite-type compounds with a chlorophenethylamine. Furthermore, some broad emission peaks possibly due to bound excitons trapped at unknown defects with a decay time of approximately twenty nanoseconds were also observed in the perovskite-compounds with a chlorophenethylamine, especially 2-chlorophenethylamine. Moreover, the pulse height spectra under 241Am gamma-ray irradiation (about 60 keV) showed that the scintillation light yields of the (2Cl-C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 , (3Cl-C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 and (4Cl-C 6 H 4 C 2 H 4 NH 3) 2 PbBr 4 were 7500, 5000 and 8300 photons/MeV, respectively. In addition, the perovskite-compounds with a chlorophenethylamine exhibited low afterglow levels about 10 ppm, and the low levels were found to be comparable to an afterglow level of Ce-doped Gd 2 SiO 5. [ABSTRACT FROM AUTHOR]

The article discusses the proposed compact beam-shaping device with a reflective aspherical surface which is used to change a circular symmetric Gaussian beam into an even distribution on a target plane. It was designed by estimation utilizing a polynomial for practical use. The beam shaping by the estimated surface was numerically assumed and the even intensity distribution on the target plane was obtained. The proposed beam-shaping device can be implemented for many purposes.

We evaluated photoluminescence, scintillation and thermoluminescent characteristics of BaCaBO 3 F doped with various amounts of Tb to fabricate new thermoluminescent phosphors for radiation measurements. Sharp peaks centered at 491, 542 and 589 nm originating from the electronic 4f→4f transitions of Tb3+ appeared in the BaCaBO 3 F doped with Tb in photoluminescence spectra and X-ray induced scintillation spectra. These derived decay times under ultraviolet light and X-ray were approximately 1.25–1.36 ms and 1.28–1.50 ms, respectively. Moreover, the BaCaBO 3 F doped with Tb showed efficient thermally stimulated luminescence (TSL). They exhibited two TSL glow peaks at around 90 and 210 °C. Their dynamic ranges of the TSL glow peaks at around 90 °C and 210 °C were 1–1000 mGy for the 0.1–0.5% Tb-doped BaCaBO 3 F, and 10–1000 mGy for the 0.5% Tb-doped BaCaBO 3 F, respectively. Moreover, thermal activation energies were evaluated by the isothermal decay analysis, suggesting that at least twelve trapping levels could be formed in the BaCaBO 3 F doped with Tb. • Tb-doped BaCaBO 3 F were fabricated by the conventional solid-state reaction for radiation dosimetry. • Tb-doped BaCaBO 3 F showed efficient TSL with glow peaks at around 90 and 210 °C. • At least twelve trapping levels were confirmed by the isothermal decay curves. [ABSTRACT FROM AUTHOR]

Calcium borate chlorides (Ca 2 BO 3 Cl) with different concentrations of Dy3+ were fabricated by the conventional solid-state reaction with an aim to develop themoluminescent materials for radiation dosimetry, and their scintillation and thermally-stimulated luminescence (TSL) properties were evaluated systematically. Several scintillation peaks at approximately 485, 580 and 675 nm due to the 4f-4f transitions of Dy3+ appeared in the Dy3+-doped Ca 2 BO 3 Cl, and the 1.0% Dy3+-doped Ca 2 BO 3 Cl showed the highest scintillation intensity. In the temporal scintillation profiles, the decay time constants of the Dy3+-doped Ca 2 BO 3 Cl were about 0.6 ms, which was a typical value for the 4f-4f transitions of Dy3+. Furthermore, the Dy3+-doped Ca 2 BO 3 Cl showed efficient TSL with glow peaks at 110 and 250 °C originating from the 4f-4f transitions of Dy3+. Among the sample investigated, the 1.0% Dy3+-doped Ca 2 BO 3 Cl exhibited the highest TSL intensity, and the linear dose response of the TSL glow peak at 250 °C was confirmed to be in the dose range from 0.1 to 100 mGy for the 1.0% Dy3+-doped Ca 2 BO 3 Cl. • Dy-doped calcium borate chlorides were fabricated by the conventional solid-state reaction for radiation dosimetry. • The chlorides showed efficient TSL due to the 4f-4f transitions of Dy3+ with a glow peak at 250 °C. • Linear TSL dose response was confirmed to be in the dose range from 0.1 to 100 mGy. [ABSTRACT FROM AUTHOR]

Borate glasses are considered to be host materials for thermoluminescent phosphors owing to their high thermally-stimulated luminescence (TSL) sensitivity and low effective atomic number. Herein, we fabricated the Dy-doped B 2 O 3 –Al 2 O 3 –SrO glasses to develop the phosphors for radiation dosimetry, and investigated their photoluminescence (PL), scintillation and TSL properties, systematically. The Dy-doped samples showed clear emission peaks at 480 and 570 nm due to 4f-4f transitions of Dy3+ in PL, and the 0.5 % Dy-doped sample exhibited the highest quantum efficiency of 0.24 under excitation wavelength of 350 nm among the sample tested. The decay time constants of the Dy-doped samples were 0.25–0.84 ms, which were typical values for the 4f-4f transition of Dy3+. In scintillation, the Dy-doped samples showed emissions with sharp peaks at 480 and 570 nm with the decay time constants of 0.51–0.86 ms due the 4f-4f transitions of Dy3+. The scintillation intensity of the 0.5 % Dy-doped sample was the highest among the samples investigated. Furthermore, the Dy-doped samples exhibited TSL with a main glow peak at approximately 90 °C after X-ray irradiation of 10,000 mGy, and the dynamic range of the 0.1–1.0 % Dy-doped samples was found to be 0.1–10,000 mGy. [ABSTRACT FROM AUTHOR]

(C 6 H 5 C 2 H 4 NH 3) 2 Pb 1 − x Sr x Br 4 (x = 0. 1 , 0.25 and 0.5) single crystals were grown by the poor-solvent diffusion method to evaluate their scintillation properties. When X-rays were irradiated upon the sample, the solids demonstrated scintillation with a spectrum of band peaking around 430 nm due to exciton emission from the inorganic layer. The pulse height spectra under 137Cs gamma-rays irradiation were measured by using (C 6 H 5 C 2 H 4 NH 3) 2 Pb 1 − x Sr x Br 4 (x = 0. 1 and 0.25) crystals, and the estimated scintillation light yields were 19,700 and 18,500 ph/MeV for x = 0. 1 and 0.25 samples, respectively. [ABSTRACT FROM AUTHOR]

We evaluated photoluminescence (PL) and scintillation properties of TeO 2 –Al 2 O 3 -WO 3 glasses with different concentrations of Nd (0, 0.1, 0.5 and 1.0 mol.%). The glass samples were fabricated by the conventional melt-quenching method. The Nd-doped samples showed sharp emission peaks due to the 4f-4f transitions of Nd3+ in PL and scintillation. The 0.5% and 1.0% Nd-doped samples showed high PL quantum efficiencies and scintillation intensities among the sample tested. Furthermore, the decay time constants for the Nd-doped samples in PL and scintillation were 140–206 and 110–123 μs, respectively. In addition, the undoped and Nd-doped samples showed thermally stimulated luminescence (TSL) with a weak glow peak approximately at 285 °C, and the detection limit of TSL (10 Gy) was much higher than that of common TSL materials. Image 103126 • We have developed tellurite glasses with different concentrations of Nd by the conventional melt-quenching technique. • The samples showed scintillation due to the 4f-4f transitions of Nd3+. • The samples showed TSL with a weak glow peak approximately at 285 °C. [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]

Abstract We have synthesized 0.001, 0.01 and 0.1% Ca-doped MgO transparent ceramics by the Spark Plasma Sintering (SPS) method, and then we investigated the optical, scintillation and dosimeter properties. In scintillation spectra, some emission bands appeared around 340, 400, 440, 600 and 750 nm. After X-ray irradiation, all the Ca-doped samples showed TSL with a glow peak ∼140 °C, and the 0.01% Ca-doped sample showed an additional broad peak ∼250 °C. The TSL spectrum consists of a broad peak over 300–500 nm and some peaks around 600 and 750 nm. The TSL response was confirmed to linearly increase with irradiation dose over a dose range from 0.1 to 100 mGy. [ABSTRACT FROM AUTHOR]

Abstract We have prepared Sm:MgF 2 ceramics by the spark plasma sintering technique and studied the radio-photoluminescence (RPL) properties. RPL is a phenomenon seen in selected phosphors in which a new photoluminescence (PL) emission centre is generated by ionizing radiations such as X-rays. In the present system, RPL is observed with two different emissions in the blue and near infrared (NIR) ranges due to M(C 2h) and M(C 1) centres. The dynamic range using the former centre is in the high dose range above 100 Gy while the former centres have a sensitivity below 100 Gy. In addition, heat-treating an irradiated 0.01%Sm:MgF 2 sample induces the reduction of the Sm3+-ion, i.e. Sm3+ → Sm2+). These centres are metastable, and their concentration can be increased or decreased by heat-treatment and exposing to UV light. [ABSTRACT FROM AUTHOR]

A series of bulk Ga 2 O 3 were prepared by four different methods (Floating Zone (FZ), Edge-defined Film-fed Grown (EFG), spark plasma sintering (SPS) and conventional sintering in air) to obtain in single crystal and ceramic forms. In photoluminescence (PL), all the samples showed defect-related luminescence due to recombination between donors and acceptors; however, the peak position was different in each sample. The PL and scintillation decay curves were approximated by a sum of two exponential decay functions, and emission origins were attributed to to recombination between donors and acceptors. Pulse height spectrum of 241 Am α-ray irradiation was demonstrated by using the present samples, and we confirmed that the one prepared by the EFG method indicated a clear full energy absorption peak, and the estimated light yield was 3200 ± 320 ph/5.5 MeV-α. [ABSTRACT FROM AUTHOR]

Sn-doped Ga 2 O 3 single crystals were synthesized by the Floating Zone (FZ) method. In photoluminescence (PL) under the excitation wavelength of 280 nm, we observed two types of luminescence: (1) defect luminescence due to recombination of the donor/acceptor pairs which appears at 430 nm and (2) the nsnp-ns 2 transitions of Sn 2+ which appear at 530 nm. The PL and scintillation decay time curves of the Sn-doped samples were approximated by a sum of exponential decay functions. The faster two components were ascribed to the defect luminescence, and the slowest component was owing to the nsnp-ns 2 transitions. In the pulse height spectrum measurements under 241 Am α-rays irradiation, all the Sn-doped Ga 2 O 3 samples were confirmed to show a full energy absorption peak but the undoped one. Among the present samples, the 1% Sn-doped sample exhibited the highest scintillation light yield (1,500 ± 150 ph/5.5 MeV-α). [ABSTRACT FROM AUTHOR]

In this study, we developed Li 3 PO 4 -B 2 O 3 glasses doped with different concentrations (0, 0.1, 0.2, 0.5, and 1.0%) of Ce and studied the optical, dosimetric and scintillation properties. The Ce-doped samples showed scintillation and photoluminescence (PL) due to the 5d–4f transitions of Ce 3+ with a broad spectral feature peaking around 350 nm. The scintillation and PL decay times were 55–62 ± 0.03 ns and 29–31 ± 0.03 ns, respectively. The PL quantum yield ( QY ) was about 15.3 ± 2% for the 0.1%-doped sample, and it decreased with increasing the concentration of Ce. The thermally-stimulated luminescence (TSL) was observed in all the samples after irradiating with X-rays, and the 0.1% Ce-doped sample showed the highest sensitivity with the dynamic range confirmed from 0.1 mGy to 10 Gy, which was equivalent to commercial detectors. Moreover, optically-stimulated luminescence (OSL) was observed in the 0.1%Ce-doped sample after X-ray irradiation. Overall, doping with Ce enhanced the PL, scintillation, TSL and OSL properties. The optimal concentration of Ce was 0.1% to be used for radiation detector applications. [ABSTRACT FROM AUTHOR]

In this study, we developed Li 3 PO 4 -B 2 O 3 glasses doped with different concentrations of Tb (0.1, 0.3, 1.0, 3.0, and 10.0%) as well as undoped glass, and then the prepared glasses were studied for the optical, dosimeter and scintillator properties. The Tb-doped samples indicated radioluminescence and photoluminescence (PL) due to the 4f-4f transitions of Tb 3+ with sharp spectral features peaking around 375, 410, 435, 480, 540, 590 and 620 nm. The luminescence decay times of radioluminescence and PL were 2.3–2.7 ms and 2.7–2.9 ms, respectively. The shorter radioluminescence decay time than that of PL indicated quenching effect of excited states in radioluminescence. As the concentration of Tb increased, both the radioluminescence intensity and PL quantum yield ( QY ) increased, and the 10.0% Tb-doped sample showed the highest radioluminescence intensity and QY (54.3%). In addition, thermally-stimulated luminescence (TSL) was observed after irradiating with X-rays. The sensitivity was the highest for the 3.0% Tb-doped sample having a dynamic range from 0.1 mGy to 10 Gy, which was equivalent to commercial dosimeters. The comprehensive studies suggested that X-ray generated charges are captured at TSL-active centers more effectively at lower concentrations of Tb whereas the recombination probability at Tb center during irradiation increases with the concentration of Tb. Consequently, the optimal Tb concentration was 10% as scintillator and 3.0% for TSL dosimeter, among the present samples. [ABSTRACT FROM AUTHOR]

The undoped ScAlMgO 4 crystal was synthesized by the Floating Zone (FZ) method, and we evaluated the optical and scintillation properties. The transmittance spectrum showed the absorption edge around 200 nm. VUV-excited emission/excitation spectrum was characterized at a synchrotron facility (UVSOR). Our experiment revealed that the emission was around 400 nm by 200 nm excitation, and the excitation band was 170–210 nm for the latter emission peak. The decay time characterized by 280 nm excitation was 8.3 and 43 ns. Under X-ray irradiation, an emission was observed around 400 nm as for VUV excitation, and the latter decay time constants were 0.23 and 2.2 μs. In addition, the afterglow level at 20 ms after X-ray irradiation was around 0.1% of the intensity during irradiation. [ABSTRACT FROM AUTHOR]