JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 12
·10487-10493
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IF 2.324
He Qinjiang,Fu Renli,Zhu Haitao,He Hong,Song Xiufeng,Liu Xuhai
Eu 2+ doped strontium aluminate phosphors Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.1) were synthesized via a novel halide-assisted solid-state reaction method. The phase structure and photoluminescence properties of Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ were characterized via X-ray diffraction (XRD) and fluorescence spectrophotometer. The XRD patterns indicate that the α-Sr 4 Al 2 O 7 phase structure with negligible impurities were produced in the samples of Ca y Sr 4−x−y Al 2 O 7 :xEu 2+ (x ≤ 0.1 and y ≤ 0.1) at 1450 °C. Photoluminescence results show that the Ca y Sr 4−x−y Al 2 O 7 :xEu phosphor with NH 4 I as reductant presents typical intense Eu 2+ red emission bands centered at 610 nm while excited by 450 nm. Accordingly, samples without NH 4 I only exhibit two weak Eu 3+ emission peaks located at 598 and 619 nm, respectively. It can be ascribed to the reduction characteristic of I − ion. Furthermore, by partial replacement of Sr 2+ with Ca 2+ in Sr 4 Al 2 O 7 host, the emission intensity is enhanced up to 260% with emission peak red shifted by 5–10 nm. These results indicate that partial substitution of Sr 2+ by Ca 2+ is an efficient way to increase the proportion of longer wavelength emission and luminescence intensity for Sr 4 Al 2 O 7 :Eu phosphors.
研究领域:
材料科学
·
光学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2026
·
IF 2.6
Zhichao Zhang,Jun Zhou,Jinhui Wang,Guotao Chu,Xuerui You,Chunping Liang,jifan Hu
Eu2+-doped whitlockite-type phosphors have attracted considerable attention owing to their structurally tunable frameworks and diverse luminescence colors. However, the intricate composition–property relationships present significant challenges for rational material design. In this study, a composition-based machine learning model was established to predict emission wavelengths. Through systematic evaluation of nine algorithms, the random forest regression (RFR) model was identified as the most effective, achieving a coefficient of determination (R2) of 0.817 on the independent test set. Leveraging SHAP (SHapley Additive exPlanations) analysis to interpret feature contributions, we established a data-driven material design framework for Eu2+-doped whitlockite-type phosphors. Guided by this framework, a series of Ca8-xSrxMgLa(PO4)7 (x = 0-8) solid-solution phosphors were synthesized. The experimentally measured emission peaks exhibit excellent agreement with the predicted values, with all deviations falling within ±4% error margin. This work establishes a composition-only machine learning framework for predicting emission properties and accelerating the rational design of complex-structured luminescent materials.
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高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 103
·期 3
·865-875
·
IF 2.606
Jia Jiannan,He Mengting,Wang Yunpeng,Zhang Wei,Wan Jun,Zhang Yuting,Xu Qiang,Chen Shiguo,Qiao Xvsheng,Fan Xianping
A propylene oxide (PO)-driven fast sol-gel route followed with a post high temperature calcination were utilized to synthesize Ca x Sr 1- x Al 2 O 4 : Eu 2+ cationic solid solution phosphors with micro-spherical morphologies and improved internal quantum efficiencies. The polyethylene oxide (PEO) was also employed to induce the phase separation of Ca x Sr 1- x Al 2 O 4 : Eu 2+ precursors to get monodispersed spherical morphologies in the sol-gel system. Benefit from uniform copolymerization of each chemical components and pyrolysis of organic matter, Ca, Sr, Al and O were homogenously distributed in the produced Ca x Sr 1- x Al 2 O 4 : Eu 2+ cage like microspheres. It helps to efficiently trap incident light and to improve the PL efficiencies. By changing the ratio of Ca/Sr, infinite solid solution polycrystalline phosphors, Ca x Sr 1- x Al 2 O 4 : Eu 2+ microspheres with x = 0~1, can be obtained and their PL emission can be gradually tuned from green to white to blue. Micro-spherical SrAl 2 O 4 : Eu 2+ , Ca x Sr 1- x Al 2 O 4 : Eu 2+ and CaAl 2 O 4 : Eu 2+ phosphors exhibited internal quantum efficiencies as high as 71.1, 35.3~45.9 and 75.3%, respectively.
Graphical abstract
研究领域:
材料科学
·
化学
·
光学
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DOI
高影响因子
Inorganic Chemistry Frontiers
·
2026
·
IF 6.2
Chenyang Zhan,Zihao Wang,Sisi Liang,Zhi-Ying Zhao,Hanru Chen,Jiahe Yu,Haomiao Zhu
Alkaline earth lithoaluminates with the UCr4C4-type structure have demonstrated considerable potential in achieving narrow-band emissions from Eu 2+ . However, obtaining single-phase powder samples with green-emitting remains challenging. In this study, we address this issue by co-doping Ba 2+ into the novel UCr4C4-type system Sr5/6-xBaxLi17/6Al7/6O4:Eu 2+ , which significantly enhances phase purity and structural homogeneity. This approach not only reduces the emission bandwidth from 66 nm (2241 cm -1 ) to 51 nm (1830 cm -1 ) but also induces a blue shift to 529 nm, fine-tuning the emission into the desired deep green region. Through detailed mechanistic studies-including low-temperature spectroscopy and luminescence decay analysis-we identify the presence of multiple Eu 2+ emission centers associated with distinct Sr 2+ sites. Ba 2+ doping is shown to promote dominant Eu 2+ emission in the green spectral region, thereby facilitating spectral narrowing.The optimized phosphor achieves a high absorption efficiency of 64.6% and an external quantum yield of 22.2%. When integrated into a white LED prototype, it enables a color gamut covering 97.6% of the NTSC (National Television System Committee) standard, outperforming a commercial β-SiAlON:Eu 2+ -based device. This study provides an effective cationic codoping strategy for designing high-performance narrow-band oxide phosphors and highlights a promising candidate for nextgeneration display technologies.
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DYES AND PIGMENTS
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2022
·
IF 5.122
Jiaqi Dang,Ruifeng Zhu,Wenhui Fang,Ye Hu,Ying Wu,Shixian Xin,Min Li,Bozhen Chen,Hong Zhao,Zengxi Li
It is very crucial to develop a simple and fast-responsive sensor for the detection of water content in organic solvents . Herein, three different europium-organic frameworks (Eu-MOFs): amorphous Eu-2-aminoterephthalic acid (amEu-NH 2 BDC), crystalline Eu-2-aminoterephthalic acid (cryEu-NH 2 BDC) and amorphous Eu-1,4-benzenedicarboxylic acid (amEu-BDC) are synthesized, respectively. amEu-NH 2 BDC is employed as fluorescence probe for the determination of water in ethanol. Results indicate that amEu-NH 2 BDC exhibits good performance due to its dual-wavelength fluorescence (FL) with the ligand (NH 2 BDC)-centered blue luminescence at 430 nm and Eu-centered red luminescence at 615 nm. With the increase of water contents in ethanol, the emission intensity at 430 nm increases dramatically, while that at 615 nm decreases under a single excitation at 270 nm. By measuring the ratio of emission intensity at 430 nm and 615 nm (I 430 /I 615 ), a wide concentration range from 1% to 99.5% water in ethanol is obtained with a lower detection limit value of 0.024% (S/N = 3). Besides, in the presence of water in ethanol, the fluorescence color of amEu-NH 2 BDC changes from red to blue under 365 nm UV light. Thus, the visual device for the detection of water is realized by using amEu-NH 2 BDC. Combined with the fluorescence lifetime and density functional theory, it is shown that red luminescence weakens due to dynamic quenching and non-radiative vibration energy transfer, and blue luminescence is enhanced due to the hydrogen bonding between water and carboxyl groups in the ligand, which enhances the intramolecular charge transfer process. The proposed method has characteristics of rapid response, excellent stability, high sensitivity and selectivity. Importantly, it can be successfully applied to monitor the content of water in white spirit samples.
研究领域:
材料科学
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分析化学
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光学传感
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高影响因子
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