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Scintillation Properties of Ce3+ Doped Silicon-Magnesium-Aluminum-Lithium Glass Scintillators by using Radiation Sources
摘要： Glass scintillators can be doped with different elements to improve their luminescence properties. In this study, we present 0.5 wt% Ce3+-doped (58?x)SiO2-4MgO-18Al2O3-20Li2O and (58?x)SiO2-4MgO-18Al2O3-20LiF glass scintillators. We used a pulsed laser to measure the laser-induced emission spectrum and the decay time with decreasing temperature from 300 K to 10 K. The light intensity of both glass samples increased with decreasing temperature from 300 K to 10 K. Additionally, the two glass samples exhibited a fast decay time of approximately 25 ns. In the photo-induced spectrum, an excitation peak at 312 nm and two emission peaks, at 370 nm and 700 nm, were observed in both the glass samples. The X-ray-induced emission intensity of former is approximately six times higher than that of latter, and only former glass sample exhibits a proton-induced emission spectrum.
关键词： Luminescence,Decay time,Ce3+,Glass scintillator
更新于2025-11-25 10:30:42
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Tricolor- and White Light–Emitting Ce <sup>3+</sup> /Tb <sup>3+</sup> /Mn <sup>2+</sup> -Coactivated Li <sub/>2</sub> Ca <sub/>4</sub> Si <sub/>4</sub> O <sub/>13</sub> Phosphor via Energy Transfer
摘要： Single-component tunable Li2Ca4Si4O13:Ce3+,Tb3+,Mn2+ phosphors were successfully synthesized at 950 °C. Li2Ca4Si4O13:Ce3+,Tb3+ exhibits two luminescence peaking at 430 and 550 nm, which originated from the allowed 5d → 4f transition of the Ce3+ ion and the 5D4 → 7FJ (J = 6, 5, 4, 3) transition of the Tb3+ ion, respectively. Moreover, by codoping Ce3+ ions in the Li2Ca4Si4O13:Mn2+ system, yellow-red emission from the forbidden transition of Mn2+ could be enhanced. Under UV excitation, dual energy transfers (ETs), namely, Ce3+ → Mn2+ and Ce3+ → Tb3+, are present in the Li2Ca4Si4O13:Ce3+,Tb3+,Mn2+ system. The ET process was confirmed by the overlap of the excitation spectra, variations in the emission spectra, ET efficiency, and decay times of phosphors. In addition, quantum yields and CIE chromatic coordinates are presented. The emission color of these phosphors can be tuned precisely from blue to green via ET of Ce3+ → Tb3+ and from blue to yellow via ET of Ce3+ → Mn2+. White light can also be achieved upon excitation of UV light by properly tuning the relative composition of Tb3+/Mn2+. This result indicates that the developed phosphor may be regarded as a good tunable emitting phosphor for UV light-emitting diodes.
关键词： phosphor,energy transfer,Mn2+,Tb3+,Li2Ca4Si4O13,Ce3+,white light-emitting diodes
更新于2025-11-14 15:29:11
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Photoluminescent behaviour of Ce3+ ions in mixed fluoride structures
摘要： Investigations were done to modify the photoluminescence (PL) spectra of a cerium (Ce3+) doped strontium fluoride (SrF2:Ce3+) phosphor for better sensitization for solar cell application. For optimum sensitization it is needed that Ce3+ emission overlaps with Lanthanide (Ln3+) ions’ excitation energy ranges. SrF2:Ce3+ emission, however, does not overlap well with different 4f-4f Ln3+ ions’ excitation ranges. The PL behavior of Ce3+ in Sr1-xMxF2:Ce3+ (where M = Ca, Ba, Mg, La) was therefore investigated. Noticeable changes were observed in the shape of the excitation and emission spectra of Ce3+. The Sr0.49Ba0.50Ce0.01F2 phosphor produced a significant red shift with a broad emission band. The excitation spectrum of this sample was blue shifted if compared to the singly doped sample.
关键词： fluoride structure,XPS,luminescence,Ce3+
更新于2025-11-14 15:28:36
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Energy Transfer from Ce3+ to Tb3+ in Yttrium and Gadolinium Orthoborates Obtained by Hydrothermal Synthesis
摘要： We studied the structure, IR absorption spectra, the spectral characteristics of photoluminescence and morphology of cerium- and terbium-doped orthoborates of gadolinium and yttrium obtained by hydrothermal synthesis at 200°C, as well as solid solutions of orthoborates on the basis of yttrium, gadolinium, and lutetium with composition RECe0.01Tb0.1BO3 (RE = Lu0.5Gd0.39, Lu0.5Y0.39, and Y0.5Gd0.39). The X-ray diffraction spectrum of yttrium orthoborate Y1 – x – yCexTbyBO3 is described by a hexagonal lattice with space group P63/m, which, after annealing at 970°C, transforms into a monoclinic lattice with space group C2/c. High-temperature annealing of the studied orthoborates leads to a multiple, more than two orders of magnitude, increase in the luminescence intensity of Tb3+ ions when the samples are excited in the absorption band of cerium ions. This effect is the result of a significant increase in the concentration of Ce3+ ions in the orthoborates at high temperatures. It is shown that the luminescence of terbium ions is due to energy transfer from Ce3+ to Tb3+, which proceeds with high efficiency (～85%) by the mechanism of dipole-dipole interaction between cerium and terbium.
关键词： orthoborates,luminescence,Ce3+,hydrothermal synthesis,energy transfer,Tb3+
更新于2025-11-14 15:14:40
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Effects of Mg2+/Si4+ doping on luminescence of Y3Al5O12:Ce3+ phosphors
摘要： A series of Mg2+/Si4+ codoped Y3Al5O12:Ce3+ phosphors were synthesized by a sol-gel method. X-ray diffraction, scanning election microscope, energy dispersive spectroscopy and fluorescent spectrophotometer were used to characterize the synthesized phosphors. The influence of codoped Mg2+/Si4+ ions on luminescence of Y3Al5O12:Ce3+ was investigated. The X-ray diffraction, scanning election microscope and energy dispersive spectroscopy results indicate that Ce3+, Mg2+ and Si4+ substitute Y3+ site, in the tetrahedral site and the substitution has no obvious influence on the phase and microstructure. And the Mg2+/Si4+ substitution leads to the red shift of emission band and the decrease of emission intensity.
关键词： Mg2+/Si4+ codoping,Luminescence,Y3Al5O12:Ce3+
更新于2025-09-23 15:23:52
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Dehydrogenation-driven to synthesize high-performance Lu2Si4N6C:Ce3+- a broad green-emitting phosphor for full-spectrum?lighting
摘要： Green phosphor Lu2Si4N6C:Ce3+ (LSNC:Ce3+) shows an ideal feasibility to the near ultraviolet LED (n-UV LED) for “Full-Spectrum Lighting” (FSL). However, it is complex to synthesize pure Lu2Si4N6C phase. Herein, we prepared LSNC:Ce3+ via a novel dehydrogenation-driven high temperature solid-state reaction method, which distinctly optimized the morphology, and then significantly enhanced the photoluminescent performance of LSNC:Ce3+. The improving mechanism ascribed to the stepwise dehydrogenation of LuH3 which was beneficial to further shear LuH3 particles. The LSNC:Ce3+ phosphor obtained by the optimized process exhibits excellent thermal stability, and its external quantum efficiency is 57.3 %. Interestingly, the intensities of excitation peaks decrease at 375 nm while it increases at 425 nm gradually with the Ce3+ concentration. It is reasonably ascribed to the different ability of photo-ionization in different 5d levels. Finally, the constructed w-LED with the titled phosphor exhibits a well-distributed warm white light with high color rendering index (Ra = 96.6, R9 = 96, R12 = 82). It indicates that the LSNC:Ce3+ gives assistance to compensation for the “spectrum chasm” in blue-green region, as well as contributes to the improvement of Ra and R9, that is beneficial for full-spectrum lighting.
关键词： Carbonitride,n-UV LED,Reaction mechanism,Full-Spectrum,Green phosphor Lu2Si4N6C:Ce3+
更新于2025-09-23 15:23:52
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Optical Pressure Sensor Based on the Emission and Excitation Band Width (FWHM) and Luminescence Shift of Ce3+ Doped Fluorapatite – High-Pressure Sensing
摘要： A novel, contactless optical sensor of pressure based on the luminescence red-shift and band width (full width at half maximum - FWHM) of the Ce3+-doped fluorapatite - Y6Ba4(SiO4)6F2 powder, has been successfully synthesized via a facile solid-state method. The obtained material exhibits a bright blue emission under UV light excitation. It was characterized using powder X-ray diffraction, scanning electron microscopy and luminescence spectroscopy, including high-pressure measurements of excitation and emission spectra, up to above ≈30 GPa. Compression of the material resulted in a significant red-shift of the allowed 4f→5d and 5d→4f transitions of Ce3+ in the excitation and emission spectra, respectively. The pressure-induced monotonic shift of the emission band, as well as changes in the excitation/emission band widths, have been correlated with pressure for sensing purposes. The material exhibits a high pressure sensitivity (dλ/dP ≈0.63 nm/GPa), and outstanding signal intensity at high-pressure conditions (≈90% of the initial intensity at around 20 GPa) with minimal pressure-induced quenching of luminescence.
关键词： Ce3+ doping,Contactless pressure gauge,Y6Ba4(SiO4)6F2 apatite phosphors,Lanthanide ions (Ln3+),Compression in DAC,Luminescent functional materials
更新于2025-09-23 15:23:52
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Electronic structure and luminescent properties of Ce3+-doped Ba3Lu2B6O15, a high-efficient blue-emitting phosphor
摘要： A high-e?cient blue-emitting phosphor Ba3Lu2B6O15: Ce3+ was synthesized by three-step solid-state method. XRD Rietveld re?nement analysis reveals that Ba3Lu2B6O15 is of cubic Ia3(——) system, owning a high-symmetric layer structure with two regular LuO6 octahedrons and one BaO9 polyhedron. Density functional theory (DFT) calculation result indicates BLB is a kind of direct band-gap material with broad band-gap of ~5.10 eV. Ba3Lu2B6O15:Ce3+ phosphor exhibits a bright blue emission under UV excitation with high quantum e?ciency of > 90%, and the possible reasons are discussed basing on structural and spectral data. Because of its excellent luminescent properties, Ba3Lu2B6O15:Ce3+ could be a promising candidate as a blue phosphor for NUV LED devices.
关键词： Ce3+,Luminescence,Phosphor,Structure
更新于2025-09-23 15:23:52
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Scintillation properties of Ce-doped Yb3Al5O12 single crystals
摘要： Yb3Al5O12 (YbAG) single crystals were prepared by the Floating Zone (FZ) method with and without doping with different concentrations of Ce, and then we evaluated their basic scintillation properties. All the samples showed scintillation with emission peaks in the range from 300 nm to 600 nm. The origin of this emission peak was attributed to the charge transfer luminescence of Yb3+. In addition, the Ce-doped samples showed three strong emission bands, in which the emission origin is also predominantly due to the charge transfer emission but the spectrum was deformed due to a self-absorption by the 4f-5d transitions of Ce3+. Scintillation decay profiles of all the samples were approximated by a sum of two exponential decay functions, and the obtained decay times were 1 and 9-10 ns. Among the present samples, the 0.5% Ce-doped sample showed the lowest scintillation afterglow level. All the samples demonstrated a full energy peak in the pulse height spectrum measured under 241Am 5.5 MeV α-ray irradiation. Among the present samples, the undoped sample showed the highest light yield with a value of 20 ph/5.5MeV-α.
关键词： Ce3+,Charge transfer luminescence,Garnet,Scintillation
更新于2025-09-23 15:23:52
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Improved thermal stability of Y3Al5O12:Ce3+ phosphor by SiO2 coating
摘要： In this paper, a heterogeneous precipitation method was adopted to coat a SiO2 layer on the surface of Y3Al5O12:Ce3+ phosphor. The surface morphologies, crystal phases, defect concentrations, luminescent properties and thermal stability of coated phosphors were investigated and compared with those of uncoated phosphor. A compact and homogeneous SiO2 layer on the surface of phosphor was determined by SEM-EDS, TEM, XRD and FT-IR results. Two thermoluminescent peaks were found at 112 oC and 248 oC on the thermoluminescence spectrum. Their intensities decreased slowly with the increasing coating amounts. It indicated that their corresponding defect concentrations were gradually reduced. Improved thermal stability was obtained by SiO2 coating in spite of a slight weakening of the emission intensity. The optimum theoretical coating amount was identified as 4%. Moreover, a structural modification mechanism on improved thermal stability of SiO2 coated Y3Al5O12:Ce3+ was proposed.
关键词： Y3Al5O12:Ce3+ phosphor,thermal stability,coating,structural modification mechanism
更新于2025-09-23 15:22:29