Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 13
·4408-4420
·
IF 7.059
Shaoying Wang,Balaji Devakumar,Qi Sun,Jia Liang,Liangling Sun,Xiaoyong Huang
Inorganic phosphors with broadband near-ultraviolet (near-UV) excitation and efficient visible emission are highly important for fabricating high-performance near-UV-pumped white light-emitting diodes (LEDs). Herein, we report on novel efficient near-UV-excitable Ce3+/Tb3+ ion co-activated Ca2YHf2Al3O12 (CYHA) green-emitting garnet phosphors, which were successfully prepared through a high-temperature solid-state reaction process. X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, photoluminescence, CIE color coordinates, the internal and external quantum efficiency, and temperature-dependent emission spectra were used to characterize the samples. Interestingly, due to the efficient energy transfer from Ce3+ to Tb3+ ions in CYHA, the CYHA:Ce3+,Tb3+ samples presented a wide excitation band in the 370–470 nm region peaking around 408 nm owing to the 4f–5d transition of Ce3+ ions, and under 408 nm excitation they showed intense characteristic sharp green emission around 543 nm corresponding to the 5D4 → 7F0–6 transitions of Tb3+ ions. The energy transfer mechanism from Ce3+ to Tb3+ ions was ascribed to the quadruple–quadruple interaction, and the energy transfer efficiency reached as high as 93.2%. Notably, the composition-optimized CYHA:0.03Ce3+,0.6Tb3+ sample exhibited a high internal quantum efficiency (IQE) of 78.5% and external quantum efficiency (EQE) of 56%, which were much higher than those of the Tb3+ singly-activated CYHA:0.6Tb3+ sample (IQE = 8%, EQE = 2.2%). Finally, a prototype white LED device was made by combining a 400 nm near-UV-emitting LED chip with a phosphor blend of the as-prepared CYHA:0.03Ce3+,0.6Tb3+ green phosphors, commercial BaMgAl10O17:Eu2+ blue phosphors and commercial CaAlSiN3:Eu2+ red phosphors, which emitted bright warm-white light with good CIE chromaticity coordinates of (0.391, 0.356), a low correlated color temperature of 3528 K and a high color rendering index of 92.3 under 120 mA driving current. This work opens up new opportunities for the development of efficient color converters toward near-UV-pumped warm-white LEDs with high color rendering index.
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 Materials Chemistry C
·
2021
·Vol. 9
·期 48
·17504-17510
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IF 7.393
Bochao Sun,Yuqing Xie,Yunlong Zhao,Xiang Li,Junfeng Chen,Yushou Song,Lei Zhao,Zhigang Li,Hongtao Zhao,Jing Ren,Jianzhong Zhang
Transparent Ce3+-doped nano-glass composites (nano-GCs) embedded with pure and Gd3+-mixed KLaF4 nanocrystals (NCs) are prepared by a cost-effective and reproducible glass-making and thermal treatment method. The nano-GCs can be readily cast into various sizes and shapes. The growth of the Gd3+-mixed NCs and the enrichment of Ce3+ in the NCs are unambiguously revealed. Significantly enhanced emissions of Ce3+ with a photoluminescence quantum yield as high as 92.7% are observed in the nano-GCs embedded with the Gd3+-mixed NCs. The integral X-ray excited emission intensity of the nano-GC is 170% that of the Bi4Ge3O12 (BGO) single crystal. A light output of about 853 ± 8 ph per MeV with an energy resolution of 22.27% is obtained using the nano-GC for γ-ray (662 keV) detection. The Monte Carlo simulation is carried out to understand the differences in X- and γ-ray responses. As a proof-of-concept, a real-time remote X-ray fiber dosimeter is constructed using a scintillating fiber made out of the nano-GC, which shows an excellent linear response with the irradiation dose, good thermal stability and radiation hardness.
研究领域:
材料科学
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光学
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核技术应用
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Minhong Xu,Guoxiang Pan,Yue Meng,Yuhua Guo,Tao Wu,Haifeng Chen
MgAlCe ternary hydrotalcites-like compounds (MgAlCe-HTlc) with different Al 3+ /Ce 3+ molar ratio were synthesized by co-precipitation method. In addition, MAlCe-HTlc (M: Co, Ni, Zn) with Al 3+ /Ce 3+ molar ratio 0.95: 0.05 were also synthesized. The attained LDH were characterized by SEM, EDX, XRD, FT-IR, TG-DTA, XPS and UV-Vis DRS techniques. The results indicated that the synthesized MgAlCe-HTlc appeared to be the typical layered structure when it contains Al 3+ and Ce 3+ ions simultaneously. Three kinds of attained MAlCe-HTlc also had typical layered structure of LDH. Furthermore, the thermal stability of MgAlCe-HTlc decreased by the substitution of Ce 3+ for Al 3+ ions. When Mg 2+ was replaced by Co 2+ , Ni 2+ or Zn 2+ , the decomposition temperatures reduced. The Ce 3d spectrum of Mg 3 Al 0.8 Ce 0.2 -HTlc before and after used indicated presence of mixed valence states of Ce 3+ and Ce 4+ . The MgAlCe-HTlc exhibited a relatively high degradation capacity for methylene blue (MB), while degradation ability of Mg 3 Al 0.95 Ce 0.05 -HTlc/H 2 O 2 was highest. The remaining rate of the MB was about 6.46% after irradiation for 80 min. The order of degradation effects about MB was as follow: MgAlCe-HTlc>ZnAlCe-HTlc>CoAlCe-HTlc≈NiAlCe-HTlc. In addition, the effects of different parameters such as pH of the solution, catalyst type and dosage, concentration of MB, as well as the stability of catalyst were investigated. The photocatalytic degradation mechanism of MB showed that the OH, h + and superoxide anion produced in Mg 3 Al 0.95 Ce 0.05 -HTlc/H 2 O 2 system were all active species , while OH played a major role.
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 43
·15433-15442
·
IF 4.174
Yini Mao,Zhiyi Wang,Rui Ye,Li Jiang,Shanshan Hu,Jun Yang
Octahedral [CaY]F2 crystals with an average particle size of 1 μm were synthesized via a mild one-step hydrothermal route without employing any surfactants. Various morphologies, including cubes, truncated cubes, truncated octahedrons, and spheres, were achieved via manipulating the amount of EDTA used, and a possible growth mechanism was proposed based on the surface energies of different crystal planes and the influence of the surfactant. XRD, SEM, EDS, TEM, HRTEM, and PL analysis were used to characterize the products. The effects of the morphologies and Li+ doping concentrations on the luminescence intensities of the [CaY]F2:Ce3+/Tb3+ phosphors were explored, and the strongest luminescence intensity is obtained when the sample is cubic with (100) crystal faces and the doping concentration of Li+ is 0.25 mol%. Additionally, multicolor emission (blue → aquamarine blue → green) was obtained from [CaY]F2:Ce3+/Tb3+ phosphors via adjusting the doping concentration of Tb3+, which resulted from the Ce3+ → Tb3+ energy transfer behavior; the energy transfer here happened through a dipole–dipole mechanism. This work may result in the as-synthesized phosphors having great application potential in many optoelectronic device fields, such as in displays and multicolor lighting.
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 ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Mingye Ding,Chunhua Lu,Le Chen,Zhenguo Ji
Traditional FIR (fluorescence intensity ratio)-based optical thermometers, requiring narrow energy gap between two thermally coupled states (TCS) of single rare-earth ion, have inherent drawbacks including low signal discriminability and large measuring error. To overcome the intrinsic limitation, a new thermometry strategy involving the usage of dual-emitting activators with diverse temperature-dependent emission behaviours has been proposed. Impressively, β-NaYF 4 :Ce 3+ /Tb 3+ phosphor exhibits good temperature sensing performance, excellent signal discriminability and superior thermal stability by using the linearly temperature-dependent FIR between Ce 3+ and Tb 3+ as detecting parameter. Hopefully, the developed dual-emitting sample could have a promising application in self-calibrated luminescent thermometry and this strategy provides a reference for developing high-performance optical thermometers.
研究领域:
材料科学
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光学工程
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无机化学
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生物医学工程
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纳米技术
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传感器
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 18
·1251
·
IF 2.8
Zheng Jinjie,Shen Honglie,Li Yufang,Li Hechao,Yue Zhen
Novel efficient visible and near-infrared emitting phosphors NaY(MoO 4 ) 2 (NYM):Ln 3+ (Ln = Ce and Yb) were proposed in this work. The crystal structure, lattice vibration characteristics, morphology, and luminescent properties of NaY(MoO 4 ) 2 phosphors were described. Sensitization of Ln 3+ from the host with various doping concentrations was investigated. The yellow-green emission was achieved in Ce 3+ single-doped NYM phosphors at UV ultraviolet excitation sensitized by the MoO 4 2− group. Under UV excitation, characteristic emissions of Ce 3+ at 400–700 nm and Yb 3+ at 1000 nm of NYM:Ce,Yb were observed, enabling the spectral down-conversion applications. With the increasing concentration of Yb 3+ , the emission intensity as well as the lifetime of Ce 3+ decreased, confirming the energy transfer from Ce 3+ ions to Yb 3+ ions. And the energy transfer coefficient was 27% for NYM:0.01Ce,0.10Yb phosphor. These results indicate that the as-prepared phosphors have potential applications in optical and photonic devices.
研究领域:
材料科学
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光学材料
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发光学
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无机化学
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光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
He Mei,Jingcheng Huang,Guixin Wang,Kun Chen,Huili Wang,Xuedong Wang,Wenwei Wang
Herein, we engineered a novel pH-responsive ratiometric assay by virtue of the composite system of Ce 3+ -enhanced glutathione-encapsulated copper nanoclusters (GSH-CuNCs-Ce 3+ ) and N-doped carbon quantum dots (N-CQDs). The GSH-CuNCs-Ce 3+ and N-CQDs were fabricated using one-pot chemical reduction and hydrothermal approaches, respectively, and their morphologies as well as physical and chemical properties were testified in detail by a series of characterization techniques. At 350 nm excitation wavelength, the GSH-CuNCs-Ce 3+ /N-CQDs system (GCC-NC) featured the 440/650 nm dual-emitting property. The ratios of fluorescence intensities (F 650 /F 440 ) demonstrated a strong pH-dependence from 3.0 to 5.0 with a coefficient of determination of 0.9982. Consequently, the GCC-NC system was feasible for constructing a pH-responsive dual-emitting fluoroprobe. Based on the catalytic effect of acetylcholinesterase on acetylcholine to yield acetic acid and further trigger varying solution pH, the as-constructed GCC-NC fluoroprobe was satisfactorily applied for detecting malathion . Under optimized conditions, the newly developed GCC-NC fluoroprobe supplied a wider linear range (0.25–200 μM), lower detection limit (0.075 μM), satisfactory recoveries (96.3–106.2%) and higher precision for malathion in several kinds of fruit juice samples. The fortified experiments by malathion’s structural analogues and metal ions provided compelling evidence that this fluoroprobe had strong anti-interference capacity and high specificity for malathion. These findings render us to believe that the as-constructed pH-responsive dual-emitting fluoroprobe holds great promise in trace malathion assay in food matrices.
研究领域:
分析化学
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食品安全
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Li Xu,Xidong Wang,Luhan Wang,Shuyang Bao,Yu Wang,Xiaojuan Liang,Weidong Xiang
Inorganic fluorescent glass films have been widely considered in the field of high power laser lighting because of their excellent comprehensive properties as fluorescent conversion materials. Herein, we adjust the optimum sintering temperature to prepare a series of La3Si6N11:Ce3+ phosphor-in-glass films (LSN PiFs) with excellent optical properties on a single sapphire structure. The prepared LSN PiF has ultrahigh internal quantum efficiency (IQE) (98%) and excellent thermal stability. The thermal conductivity at room temperature can reach 9.8 Wm–1 K–1. When the temperature is 100 °C, the fluorescence intensity can still be maintained. The LSN:Ce phosphor particles did not react with the glass matrix and retained the original luminescence properties. Moreover, by further adjusting the concentration and thickness of LSN PiF, the luminous flux and luminous efficiency of LSN PiF under optimal conditions can reach 1071.73 and 207.58 lmW–1 under the excitation of 460 nm, which is the optimal result reported so far. In addition, the color rendering index (CRI) and low color temperature (CCT) are 64.05 and 5612.6 K, respectively, and the color coordinates are all close to the white light region. All the results show that LSN PiF has great application prospects in the high quality and high brightness laser lighting field.
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 ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Han Xia,Lei Lei,Wanqing Hong,Shiqing Xu
Non-contact optical thermometry based on fluorescence intensity ratio (FIR) exhibits potential application in strong electromagnetic and corrosive environment. However, most of the reported systems exhibit high temperature sensitivity only at a narrow temperature range, which limit their practical application. In this work, a novel Ce 3+ /Mn 2+ /Eu 3+ tri-doped GdF 3 nano-thermometry based on different thermal behaviours between Eu 3+ and Mn 2+ ions is constructed. The calculated relative sensitivity in the whole measured temperature range are beyond 1.08% K −1 and the maximum S a is about 0.078 K −1 for the 50Ce/8Mn/2Eu: GdF 3 NCs , which are superior to several other inorganic nano-thermometry at the same temperature. In addition, these colorimetric temperature sensing materials exhibit potential application in anti-counterfeiting field as well.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Reziwanguli Yantake,Palidan Aierken,Taximaiti Yusufu,Zhou Shihang,Aierken Sidike
Broadband cyan-emitting phosphors with strong absorption between 300 and 400 nm are ideal replacements for traditional blue and green phosphors used in commercial light-emitting diodes (LEDs). In this paper, a series of K 1-x AlSiO 4 : xCe 3+ (x = 0.02–0.06) broadband cyan phosphors were prepared using the traditional high-temperature solid state method and the cation un-equivalent substitution strategy. It was found that the KAlSiO 4 matrix has a monoclinic structure with high symmetry. The experimental and theoretical optical band gaps of the host were 5.6 eV and 4.86 eV, respectively. After doping with Ce 3+ , strong absorption was observed in the near ultraviolet region. The optimum Ce 3+ doping concentration in the host was 0.04 as indicated by the strongest observed emission intensity. The full width at half maximum of the emission spectra of the series of samples are all greater than 120 nm and covered the blue and green wavelength ranges (370–600 nm). The luminous intensity of the K 0 · 96 AlSiO 4 : 0.04Ce 3+ phosphor at 150 °C was 91.1% of that at room temperature, and the Gaussian peak of the emission spectrum slightly broadened. These results were also combination with theoretical DFT calculations. It was found that the phosphor had very good thermal stability and rigidity. The phosphor was also mixed with a commercial red phosphor, interfaced with a UV chip and packaged into an LED. This LED was characterized and had a color rendering index greater than 90 across a broad range of drive currents. This work highlights the utility of the fabricated phosphor as means of simplifying white-light LED fabrication.
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 Materials Chemistry C
·
2015
·Vol. 3
·期 31
·8132-8141
·
IF 4.696
W. B. Dai,S. Ye,E. L. Li,P. Z. Zhuo,Q. Y. Zhang
Yellow-emitting phosphors activated by Ce3+ are key components of white light-emitting diodes (LEDs) based on the blue (Ga,In)N LED. The need to replace incandescent and/or halogen lamps with warm white LEDs has driven LED phosphor development toward compositions beyond the Ce3+-doped garnets used in cool white LED packages. In this contribution, for pointing out how chemical substitutions play a crucial role in tuning the optical properties, we investigate the structural and optical properties of oxyfluoride solid-solutions and borate phosphors, specifically the (La,Ca)3(Al,Si)O4(O,F):Ce3+ yellow-green phosphors and the Ca3La3(BO3)5:Eu3+ red phosphors, via a combination of density functional theory, synchrotron X-ray detection, pair-distribution-function analyses and spectroscopy measurements. By incorporating these phosphors with a new phosphor-capping method on InGaN light-emitting diodes, we obtain the warm white light that meets the spectral and efficiency requirements for high-efficacy solid state warm white lighting lamps. We believe that solid-solutions between distinct and structurally related phosphor systems can be a good strategy to broaden possibilities for using in warm white LED phosphors.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2023
·
IF 3.8
Kai Jia,Lunshuai Nie,Yixi Guo,Xiujun Deng,Zhehui Weng,Yizhou Li,Haidong Ju
Phosphors with simple preparation, high luminous efficiency and excellent thermal stability are highly desirable for commercial white light-emitting diodes (W-LED). In the paper, a new garnet-type green phosphor LuMgAl 5 SiO 12 :Ce 3+ (LMASO:Ce 3+ ) has been successfully prepared by a high-temperature solid-state reaction. The crystal structure and photoluminescence properties were investigated in detail. X-ray diffraction and the Rietveld refinement demonstrated the crystal structure of LMASO belongs to cubic systems with an Ia 3 ¯ d (2 3 0) space group. The unit cell parameters of LMASO:0.08Ce 3+ phosphor were found to be a = 11.90418 Å and V = 1686.935 Å 3 . LMASO:Ce 3+ phosphors have two excitation bands with peaks at 340 and 436 nm, attributed to the 4f → 5d transition of Ce 3+ ions. Under excitation at 436 nm, LMASO:0.08Ce 3+ phosphor exhibits a broad and asymmetric emission band in the 450–700 nm range. Notably, a W-LED device was created by combining a 455 nm blue LED chip with the obtained green sample and the commercially available red CaAlSiN 3 :Eu 3+ phosphor. The device emitted a bright warm white light with a low correlated color temperature of 3584 K and a high color rendering index of 96.0 at a drive current of 40 mA. The article indicates that LMASO:Ce 3+ samples can serve as a potential green phosphor for W-LEDs, and offers a new strategy for designing efficient phosphors.
研究领域:
材料科学
·
光学工程
✓ 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）