CHEMICAL PHYSICS LETTERS
·
2016
·
IF 1.86
Zhen Wei,Wei Zheng,Zhiyong Zhu,Xiongfei Guo
SrWO 4 :Er 3+ /Yb 3+ phosphors are synthesized by a solid state reaction . The XRD patterns indicate that the doping ions will not change the phase of SrWO 4 . Under the excitation at 980 nm, SrWO 4 :Er 3+ /Yb 3+ phosphors show emission bands in green and red regions. The temperature-dependence of upconversion efficiency and temperature-sensing properties of SrWO 4 :Er 3+ /Yb 3+ phosphors have been discussed according to the fluorescence intensity ratio of green emissions from 2 H 11/2 / 4 S 3/2 → 4 I 15/2 transitions of Er 3+ in the range of 95–775 K under the excitation at 980 nm. The maximum sensitivity of SrWO 4 :1%Er 3+ /6%Yb 3+ phosphor is found to be 0.01282 K −1 at 489 K.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 2
·175-178
·
IF 0.875
Lü Yang,Yang Min,Yang Bin,Liu Wei,Zhang Hongdan,Zhao Xudong,Liu Xiaoyang
SrWO 4 :Eu 3+ nanowires were synthesized at 160 °C within 10 min via a microwave-assisted hydrothermal method. In examining the influences of synthesis temperature and reaction time on the morphology of nanowires, it was found that any temperatures and reaction time except 160 °C and 10 min gave rise to poorer morphologies under otherwise equal conditions. The synthesized nanowires were characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM), energy dispersive X-ray(EDX) and Raman spectrometry, respectively. The results suggest that the samples are homogenous and dispersive single phase nanowires. The photoluminescence properties of the nanowires were determined with a spectrofluorometer. Two obviously sharp peaks at 395 and 464 nm and a broad peak centered at 290 nm were found in their excitation spectrum. Under excitation at 395 and 464 nm, the 5
D
0 → 7
F
2 transition is the dominant process which means Eu 3+ ion is located at a low symmetry site, while the 5
D
0 → 7
F
1 transition dominates under the excitation at 290 nm, showing a highly symmetric field around the Eu 3+ ion, which indicates the presence of the two local Eu 3+ environments.
研究领域:
材料科学
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纳米技术
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光学材料
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稀土化学
·
无机合成
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2023
·Vol. 29
·期 24
·e202204031
·
IF 4.3
Min Huang,Shuyi Zhang,Yongping Gan,Jin Liu,Zhanjun He,Tiejun Lin,Fei Yu,Yuanyuan Dai,Qiang Niu,Liangshu Zhong
Graphical Highly effective SrWO 4 /TiO 2 heterojunction photocatalysts were fabricated for photocatalytic methane oxidation into oxygenates with O 2 under mild conditions. The high-speed transfer channel between SrWO 4 and TiO 2 on SrWO 4 /TiO 2 photocatalysts promoted separation and transfer of photogenerated carriers, which enhanced the generation of oxygenates with high selectivity. Photocatalytic methane oxidation to oxygenates with promising performance remains as a grand challenge due to the low productivity and severe overoxidation. Herein, SrWO 4 /TiO 2 heterojunction was developed for photocatalytic methane oxidation with O 2 to liquid oxygenates ( Please replace “oxygenates” with “oxygenated”)products under mild reaction conditions. The optimized SrWO 4 /TiO 2 catalyst exhibited high productivity of 13365 μmol/g with high selectivity of 98.7 % for oxygenates. Benefited from the intimate heterojunction interface of SrWO 4 /TiO 2 , the constructed I-type heterostructure improved the separation and transfer of photogenerated carriers, and a high-speed transfer channel for photogenerated carriers was fabricated. Simultaneously, the special band structure can increase the amount of photogenerated electrons and holes on the TiO 2 surface, which promoted the formation of reactive oxygen species to enhance liquid oxygenates productivity.
研究领域:
材料科学
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催化化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 58
·36689-36697
·
IF 3.361
Hang Liu,Xiukai Jian,Mingtai Liu,Kailin Wang,Guangyao Bai,Yuhong Zhang
SrWO4 phosphors doped with Ho3+(Er3+)/Yb3+ are successfully prepared by a high temperature solid-state reaction method. The upconversion (UC) luminescence properties of all the samples have been investigated under 980 nm excitation. Strong green emissions are obtained in the SrWO4:Yb3+/Ho3+ and SrWO4:Yb3+/Er3+ samples with the naked eyes. In a temperature range going from 303 K to 573 K, the UC emission spectra of the phosphors have been measured. Then the temperature sensing properties also have been discussed via fluorescence intensity ratio (FIR) technology. For the SrWO4:Yb3+/Ho3+ phosphor, the FIR technologies based on thermal coupling levels (TCLs)(5F4,5F5) and non-thermal coupling levels (non-TCLs)(5S2, 5F4/5F5) are used for investigating the sensitivity. The results show that the maximum absolute sensitivity reaches 0.0158 K−1 with non-TCLs. As for Yb3+/Er3+ codoped SrWO4 phosphor, the maximum absolute sensitivity reaches 0.013 K−1 with TCLs (2H11/2,4S5/2) at a temperature of 513 K. These significant results demonstrate that the SrWO4:Ho3+(Er3+)/Yb3+ phosphors are robust for optical temperature sensors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiangpeng Geng,Wen Zhang,Dekai Guan,Yaxin Liu,Bin Ma
In this research, SrWO 4 substrates co-doped with Eu 3+ and Er 3+ were employed to fabricate phosphors with a homogeneous distribution of Eu and Er. The optimal doping concentrations of Eu 3+ and Er 3+ (3% and 4%, respectively) were determined experimentally, and the luminescence mechanism of the phosphor was thoroughly investigated. The concentration quenching mechanism was also analyzed, and thermal stability tests were performed. The experimental results indicate that, due to the thermal quenching effect, the luminescence intensities of both Eu 3+ and Er 3+ ions gradually decrease with increasing temperature. Based on the experimental findings and numerical calculations, the quenching activation energy was determined. The absolute sensitivity ( S a , 0.417% K −1 and 1.132% K −1 ) and relative sensitivity ( S r , 4.236% K −1 and 1.401% K −1 ) of the phosphors were obtained through simulations, and these values are greater than those reported in previous studies. The phosphors were then mixed with ink, and the obtained mixture was printed to produce a pattern, the colors of which became visible under different excitation light sources. The configuration displays a variety of colors at different temperatures, demonstrates effective applicability for anti-counterfeiting purposes, and exhibits multi-mode anti-counterfeiting functionality. These features indicate that the proposed phosphors meet the requirements of advanced anti-counterfeiting technologies.
研究领域:
材料科学
·
光学材料
·
固体物理
·
应用物理
·
安全技术
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Wang Jing,Bu Yanyan,Wang Xiangfu,Seo Hyo Jin
Optical thermometry based on the up-conversion intensity ratio of thermally coupled levels of rare earth ions has been widely studied to achieve an inaccessible temperature measurement in submicron scale. In this work, a novel optical temperature sensing strategy based on the energy transfer from charge transfer bands of W-O and Eu-O to Eu 3+ -Dy 3+ ions is proposed. A series of Eu 3+ /Dy 3+ co-doped SrWO 4 is synthesized by the conventional high-temperature solid-state method. It is found that the emission spectra, emission intensity ratio of Dy 3+ (572 nm) and Eu 3+ (615 nm), fluorescence color, lifetime decay curves of Dy 3+ (572 nm) and Eu 3+ (615 nm), and relative and absolute sensitivities of Eu 3+ /Dy 3+ co-doped SrWO 4 are temperature dependent under the 266 nm excitation in the temperature range from 11 K to 529 K. The emission intensity ratio of Dy 3+ (572 nm) and Eu 3+ (615 nm) ions exhibits exponentially relation to the temperature due to the different energy transfer from the charge transfer bands of W-O and Eu-O to Dy 3+ and Eu 3+ ions. In this host, the maximum relative sensitivity S r can be reached at 1.71% K −1 , being higher than those previously reported material. It opens a new route to obtain optical thermometry with high sensitivity through using down-conversion fluorescence under ultraviolet excitation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 45
·29338-29345
·
IF 4.036
Jun Chen,Xianfeng Yang,Chunyan Jiang,Yunfeng Wang,Lei Zhou,Mingmei Wu
Concentration quenching, which generally originates from serious energy migrations among the uniformly distributed luminescent centers in the host matrix, is a key factor to influence the luminescence properties of materials. Different from previous reports, we demonstrate a novel fluorescence-quenching mechanism attributable to the second-phase Eu2W2O9 in non-equivalent substituted SrWO4:xEu3+ phosphors. The crystal structure, elemental distribution, and luminescence properties of the as-prepared SrWO4:xEu3+ phosphors are systematically investigated. A second-phase Eu2W2O9 is confirmed when the Eu3+-doping concentration exceeds 20%, which produces the new structure defects and energy-transfer paths, resulting in fluorescence quenching in this material. This finding gives a new perspective to analyze the concentration-quenching mechanism of the non-equivalent substituted phosphors and can help in the design of new, efficient luminescence materials. In addition, the as-prepared SrWO4:xEu3+ phosphors exhibit a strong intrinsic excitation in the range of 355–425 nm, which is accompanied by the Commission Internationale de I'Eclairage (CIE) coordinates at (0.653, 0.347) and stable color purity of up to 94.52%. A packaged white light-emitting diode with CIE chromaticity coordinates of (0.398, 0.335), correlated color temperature of 3132 K, and color rendering index of 84.3 is fabricated by SrWO4:20%Eu3+ phosphors with blue BAM:Eu2+ and green YAGB:Tb3+ phosphors in a near-ultraviolet chip.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2018
·
IF 2.32
Huiling Song,Qun Han,Xiaoyun Tang,Xueru Zhao,Kun Ren,Tiegen Liu
In this paper, Nd 3+ /Yb 3+ codoped SrWO 4 phosphors for temperature sensing are investigated. Firstly, the doping ratio of Nd 3+ and Yb 3+ was optimized. Then, under a 980 nm excitation, the temperature response of the near infrared (NIR) upconversion emission spectra in the temperature range of 313 K–453 K was characterized. The results show that the NIR emission peaks increase notably with the increase of temperature. With the fluorescence intensity ratio (FIR) technique, thermal sensing property of the optimized phosphor was investigated. A maximum thermal sensitivity of 0.02857 K −1 ( I 801 / I 869 ) at 453 K was achieved, which is higher than that of the other previously reported similar materials. The minimum temperature uncertainty is about 1 K at 453 K. The results reveal that SrWO 4 : Nd 3+ /Yb 3+ is a promising material for optical thermometry.
研究领域:
光学材料
·
传感器与执行器
·
光子学
·
发光材料
·
温度传感
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）