JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Liupeng Pan,Shunli Liu,Xiaolu Zhang,Olayinka Oderinde,Fang Yao,Guodong Fu
We report a kind of dopant (Eu 2+ ) and co-dopant (Dy 3+ ) co-doped strontium magnesium silicate phosphor synthesized via microwave irradiation in a weak reductive atmosphere of active carbon. X-ray diffraction (XRD) patterns illustrated that the samples were nearly pure Sr 2 MgSi 2 O 7 phase, in which the Sr 2 MgSi 2 O 7 host phase has the maximum fraction of tetragonal crystallography Sr 2 MgSi 2 O 7 phase. A series of long afterglow luminescent materials were synthesized to investigate the best synthetic conditions. The results showed that the optimal concentration of H 3 BO 3 and the best sintering time were 5 wt% and 30 min, respectively. The phosphors made from the microwave irradiation method demonstrated excellent luminescence performance and the microwave irradiation method provide a strategy for the synthesis of other alkali earth aluminate and silicate, or other luminescent materials.
研究领域:
材料科学
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发光材料
·
合成方法
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 36
·9454-9460
·
IF 4.696
Zhiyong Mao,Zhijuan Lu,Jingjing Chen,Bradley D. Fahlman,Dajian Wang
In this work, tunable luminescence of dicalcium silicate doped with Eu2+ ions is demonstrated based on crystal engineering. Five types of dicalcium silicate polymorphs (γ-, β-, αL′-, αH′-, α-Ca2SiO4) are synthesized by incorporating a crystal-phase stabilizer (CPS), in order to afford variable accommodation frameworks for the Eu2+ activator. Tunable luminescence is observed as the polymorph transforms from one crystal form into another. In addition, the luminescence of Eu2+ in peculiar crystal-phase Ca2SiO4 hosts is further customized by crystal-site engineering, which regulates the coordination environment of Eu2+ in multiple types of Ca2+ sites. The luminescence properties of our Eu2+-doped dicalcium silicate polymorphs show promising prospects for LED lighting applications.
研究领域:
材料科学
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光电子学
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晶体学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2025
·
IF 7.2
Jiaxuan Zhang,Guantong Chen,Yuanhong Liu,Ronghui Liu,Longqian Ouyang,Wei Xiao
The Eu 2+ -activated sulfide green phosphor SrGa 2 S 4 :Eu 2+ has attracted significant attention for its narrow emission band, high color purity, and strong emission intensity, making it a promising candidate to replace β -SiAlON:Eu 2+ in white light-emitting diode (LED) backlights for ultra-wide-color-gamut liquid crystal displays. However, the practical application of SrGa 2 S 4 :Eu 2+ is limited by its poor thermal stability, which results in diminished luminescence at high temperatures. This study proposes a host structure optimization strategy through partial O-S substitution to enhance the thermal stability. Density functional theory (DFT) analysis reveals that oxygen doping stabilizes the Eu 2+ centers and increases the bandgap of the SrGa 2 S 4 host. A series of Sr 1– x Ga 2 S 4– y O y :Eu 2+ phosphors were synthesized via a high-temperature solid-state reaction method. The effects of O-S substitution on crystal structure and luminescent properties were systematically investigated through fluorescence decay curves, diffuse reflectance spectra, and polyhedral distortion analysis. Structural refinement demonstrates that O doping increases the distortion of Ga-S 4 tetrahedra, amplifying the repulsion between Eu 2+ luminescent centers and anions, thereby widening the bandgap and improving thermal stability. With the increasing of O content, the thermal stability progressively enhances. The luminescence intensity of Sr 0.95 Ga 2 S 3.5 O 0.5 :0.05Eu 2+ at 150 °C improves from 55.4% to 76.5% compared to Sr 0.95 Ga 2 S 4 :0.05Eu 2+ . The optimized phosphor exhibits a green emission peak at 535 nm under 460 nm excitation, with a full width at half maximum (FWHM) of 48 nm, and 140% of the room-temperature emission intensity of commercial β -SiAlON:Eu 2+ . This work provides a feasible new strategy to enhance the thermal stability of sulfide-based green phosphors for advanced optoelectronic applications.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Optical Materials
·
2024
·
IF 0
Xunsheng Zhou,Binqing Zhao,Lu Yao,Wanting Gui,Longfei Chen,Chao Li,Shi Zhang,Cai Lin Wang
Eutectic scintillators with 6Li-containing thermal neutron absorbers are capable of efficient thermal neutron detection due to lamellar or rod-like optical waveguide structures formed by directional solidification. However, developing stable and bright eutectic scintillators with excellent neutron imaging capability remains a challenge. Here, the performance parameters for the scintillator have been substantially improved by the Al3+ codoping strategy in the LiF-CaF2:Eu2+ system. Due to the Al3+ codoping, the photoluminescence quantum yield (PLQY) is enhanced from 55% to 80%, the light yield is increased from 11,000 to 16,000 photons/thermal neutron, and the scintillation decay time is shortened by about 30 ns. It was shown that Al3+ codoping can effectively reduce the low-frequency shallow-energy level traps. Furthermore, large-sized (50 × 50 × 1.5 mm) translucent LiF-CaF2:Eu2+, Al3+ eutectic ceramics have been fabricated for an Anger-logic position-sensitive detector to realize two-dimensional (2D) thermal neutron detection. A codoped LiF-CaF2 eutectic scintillator provides a ∼1 mm spatial resolution and thermal neutron detection efficiency 16% higher than that of a commercial GS20 scintillator. This research paves the way for the application of large-area eutectic scintillators for efficient thermal neutron detection.
研究领域:
材料科学
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核物理
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光学
✓ 已验证
DOI
JOURNAL OF RARE EARTHS
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2023
·
IF 4.9
Xiaorong Li,Ge Gao,Kaiyu Wang,Zhaoqiong Chen,Zejiang Gao,Qingyong Qin,Li Chen,Bingsuo Zou
With the increasing demand for non-contact fluorescence intensity ratio-based optical thermometry, novel phosphor materials with high-efficiency, dual-emitting centers, and differentiable temperature sensitivity are highly desired. In this work, rare earth Eu 2+ ions were incorporated into CsCu 2 I 3 microcrystals by solid–state reaction. Under a single UV excitation, the as-synthesized samples exhibit two emissions: 452 nm blue emission from the 5d→4f transition of Eu 2+ and 582 nm yellow emission from self-trapped exciton emission of CsCu 2 I 3 . The photoluminescence quantum yield reaches to 50%. The dual-band emission of Eu 2+ -doped CsCu 2 I 3 shows different temperature responses in the range of 260–360 K. Based on fluorescence intensity ratio technology, the maximum absolute sensitivity and relative sensitivity are 0.091 K –1 (at 360 K) and 2.60%/K (at 260 K), respectively. These results suggest that Eu 2+ -doped CsCu 2 I 3 could be a good candidate for highly sensitive optical thermometer.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Lei Lei,Deyu Wang,Yongfu Kang,Yoann de Rancourt de Mimérand,Xiaoyun Jin,Jia Guo
The combination of a phosphor with semiconductor photocatalysts can provide photoactivity in the dark. Indeed, the phosphor acts as a “light battery”, harvesting photons during irradiation and later re-emitting light that can be used by the catalytic phase when in conditions of total darkness. This allows for continued activity of the composite catalyst, even in conditions of unstable light stimulation. In this study, we assess the use of a heterojunction, namely graphitic-C3N4/Ag3PO4, that enables efficient photoactivity specifically under visible light stimulation, in combination with a phosphor that exhibits green–blue phosphorescence (510 nm), that is SrAl2O4:Eu2+,Dy3+. Our findings showed that this combination was particularly interesting, noticeably displaying significant photoactivity in darkness, after short periods of activation by visible light. After finding the right combination and optimal ratios for maximum efficiency, the resulting catalyst composite was immobilized on resin supports with a fractal surface, printed by LCD-SLA 3D printing. The immobilization was effectuated via an aqueous-phase plasma-aided grafting (APPAG) process, using cold plasma discharge (CPD) and using vinylphosphonic acid (VPA) as a coupling agent. Whereas the colloidal photocatalyst displayed a serious problem of partial physical separation between the catalytic phase, g-C3N4/Ag3PO4, and the phosphor, the immobilization of the composite catalyst on polymer supports allowed solving this issue. Photodegradation assessments confirmed that the hybrid supported phosphor-enhanced catalyst was active, notably in dark conditions, as well as fairly photostable. This study offers new prospects for the fabrication of polymer-based panels for water purification, with round-the-clock activity and that are, in addition, extremely easy to recover and reuse, by comparison with colloidal catalysts.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Chengke Tan,Junhang Tian,Jihuan Xie,Yingnan Liu,Qi Liu,Weidong Zhuang
Luminescent properties of phosphors can be modified and improved by constructing energy transfer. In this article, a series of Ce3+- and/or Eu2+-doped Ca-α-sialon phosphors were synthesized through the traditional solid-state reaction method. The construction of an efficient energy transfer enables the modulation of a wide range of light colors, thereby facilitating a gradual color change from blue-green (0.1844, 0.2535) to yellow (0.4282, 0.5051). Moreover, the codoping of Ce3+ enhances the luminescence intensity of Eu2+ by approximately 2.2 times. Within the experimental gradient, the energy-transfer efficiency can reach up to 58.7%, and the energy-transfer mechanism is a quadrupole–quadrupole interaction. Gaussian fitting of the emission spectrum of the codoped samples reveals that the intensities of the Eu2+ and Ce3+ emission peaks of the codoped samples at 423 K are 78 and 87% of those at room temperature, respectively. Moreover, the thermal stability of the characteristic peaks of Ce3+ in the codoped samples is significantly enhanced compared to those doped alone. These excellent properties highlight the potential application of CaSi9Al3ON15/Ce3+, Eu2+ phosphor in white light WLEDs.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2023
·
IF 3.5
Jiachen Chen,Jin Li,Beining Li,Zhuocheng Chen,Xue Bai,Long Zhang,Jin He
The development of advanced luminescent materials is highly desirable for developing the energy-efficient lighting technology. However, it is still challenging to achieve stable full-color tuning in the same matrix upon a single-beam light excitation so as to ensure the high color stability and consistency. Herein, Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous glass via the dipping strategy is fabricated, which can emit blue, green and red emissions simultaneously by simply modifying the thermal treatment temperature. This full-color tuning is attributed to the dual roles of the thermal reduction of Eu 3+ to Eu 2+ in Al 2 O 3 -SiO 2 glass and simultaneous emissions of Eu 3+ /Eu 2+ /Tb 3+ activators. The densification of nanoporous glass via sintering could effectively decrease the amount of hydroxyl groups that present in the glass matrix, resulting in 5 times enhancement of the photoluminescence intensity and longer photoluminescence lifetime of rare earth (RE) ions. The thermal reduction of Eu 3+ to Eu 2+ is due to the reduction environment provided by Al 3+ ions in the Al 2 O 3 -SiO 2 glass. The energy transfer (ET) from Eu 2+ to Tb 3+ , Eu 2+ to Eu 3+ and Tb 3+ to Eu 3+ have been investigated in detail. Based on the ET mechanism, rational PL spectra design was demonstrated by varying the concentration of Eu 3+ ions in solution. The Color Correlated Temperature (CCT) and the Color Rendered Index (CRI) values of the white light emission glass are 7420 K (Cold-white emission) and 80.85, the temperature dependent photoluminescence (TDPL) analysis reflects the white light emission glass possesses high thermal stability and excellent thermal restorability. This facile fabrication and full-color tuning of Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous Al 2 O 3 -SiO 2 glass may provide a novel luminescent material for white-light emitting diodes (WLEDs) application.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 10
·3671
·
IF 3.4
Xiangqian Kong,Zhihua Qiu,Lina Wu,Yunfei Lei,Lisheng Chi
Rare earth luminescent materials demonstrate significant advantages in lighting and energy saving, and detection etc. In this paper, a series of Ca2Ga2(Ge1-xSix)O7:y%Eu2+phosphors were synthesized by high-temperature solid-state reaction and characterized by X-ray diffraction and luminescence spectroscopy methods. The powder X-ray diffraction patterns reveal that all the phosphors are isostructural with a space group ofP4¯21m. The excitation spectra of Ca2Ga2(Ge1-xSix)O7:1%Eu2+phosphors exhibit significant overlapping of the host and the Eu2+absorption bands, which facilitates Eu2+absorbing the energy to increase its luminescence efficiency when excited by visible photons. The emission spectra show that the Eu2+doped phosphors have a broad emission band with a peak centered at 510 nm arising from the 4f65d1→4f7transition. Variable temperature fluorescence reveals that the phosphor has a strong luminescence at low temperature but has a severe thermal quenching effect when temperature rises. The optimal Ca2Ga2(Ge0.5Si0.5)O7:1.0%Eu2+phosphor shows promise for application in the field of fingerprint identification based on the experimental results.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Xinyi Zhang,Jian-Feng Sun
An intriguing novel perovskite-type Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with desirable properties for potential application in the field of white light-emitting diodes was first time synthesized. The Rietveld structural refinement, scanning electron microscopy and high resolution transmission electron microscopy were used to determine the crystallographic parameters, morphology and microstructure of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor. The first principle calculation based on the density functional theory further provided a theoretical understanding of the band structure for the undoped Cs 4 Mg 3 CaF 12 and indicated that it has a large direct band gap of 7.1 eV. Upon the excitation of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor in the broad range of 250–450 nm, the bright blue light emission was observed with the maximum at 474 nm and a full width at half-maximum of 2808 cm −1 that was attributed to the electric-dipole allowed 4f 6 5 d 1 →4f 7 transition of Eu 2+ ions. Based on the Dexter’s theory, the concentration quenching mechanism among Eu 2+ in the Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor was validated to be the dipole-dipole interaction, and the critical distance was determined to be 23.34 Å. On the basis of temperature-dependent luminescence measurement, an analysis of the origins of thermal quenching behavior was presented. The Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor not only has favorable thermal stability with emission intensity reduction by 20% at T = 473 K in reference to the room temperature level, but also shows the integrated PL intensity 95% as high as that of BaMgAl 10 O 17 : Eu 2+ , internal quantum efficiency of 64% and color purity of 85%. The results of this work indicate that the blue-emitting Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with promising luminescence properties has a capacity for incorporation as a component to the near-UV based phosphor-converted WLEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 24
·6418-6424
·
IF 7.779
Tianqing Zhang,Xiliang Jiang,Rujia Chen,Bingyan Liu,Weiling Yang,Ce Li,Hai Lin,Huisheng Liu,Chun Li,Fanming Zeng,Zhongmin Su
In the process of developing high-performance LCDs, narrow-band emitting phosphors with excellent performance are indispensable. In this study, a narrow-band blue phosphor BaZnAl10O17:Eu2+ with an emission peak at 433 nm (which can be excited by near-ultraviolet light) and a full width at half maximum of 46 nm was found. The synthesized BaZnAl10O17:Eu2+ phosphor exhibits low thermal quenching behavior. There is only 16.4% loss in emission intensity at 423 K compared to the initial intensity at room temperature. Using the narrow-band emission phosphor BaZnAl10O17:Eu2+ as the blue light source, the prepared white LED device excited using a near-ultraviolet chip emits high-brightness white light (CCT = 4436 K, Ra = 93.96), whose CIE coordinates are (0.3387, 0.3785) and CG can reach 99% of the NTSC standard. The narrow-band blue-emitting BaZnAl10O17:Eu2+ phosphor has potential application value in white light-emitting diodes.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Zhenggang Zou,Jiawei Zhu,Fulin Lin,Yijian Sun,Jianhui Huang,Jinsheng Liao,Guoliang Gong,Herui Wen
The development of Eu 2+ -activated oxide materials with high efficiency, fast decay and narrow bandwidth emission in the visible region is still challenging for the field of luminescence and scintillation applications. Generally, Eu 2+ in oxide hosts can emit intense and broad 5d-4f emission in the visible region, but efficient emitting with stable bivalence of Eu is rare in inorganic oxide system. In this work, a series of ASL:Eu 2+ (Sr 1-x La x Mg x Al 12-x O 19 ) powder samples with various La, Mg doping ratios were designed and synthesized to modulate the UV or X-ray excited luminescence properties , including redshift, quantum yield , and decaying lifetime. Moreover, an ASL:Eu 2+ crystal with the optimal ratio x = 1/3 was grown, its scintillation performance was compared with standard Bi 4 Ge 3 O 12 crystal sample and evaluated in detail. These results indicate that the ASL:Eu 2+ crystal is potential scintillator as a kind of X-ray detection and provide a reference for the further development of high-performance Eu-activated oxide scintillation materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）