JOURNAL OF ELECTRONIC MATERIALS
·
2018
·Vol. 47
·期 8
·4929-4935
·
IF 1.566
Lu Zuizhi,Fu Anjie,Xia Siyu,Guan Anxiang,Meng Yingbin,Zhou Liya
Ba 2 Mg 2 Al 6 Si 9 O 30 (BMAS):Ce 3+ , Tb3 + phosphor powder was synthesized by a high-temperature solid-state method. The excitation spectra of BMAS:Ce 3+ , Tb 3+ phosphors showed a strong and broad absorption band, which ranged from 220 nm to 380 nm. With the excitation of 350 nm, the characteristic emission peaks centered at 544 nm of Tb 3+ and at 420 nm of Ce 3+ were observed. With increased Ce 3+ concentration from 0.01 to 0.13, energy-transfer efficiency increased from 3.26% to 76.59%. Adjustment of the Ce 3+ to Tb 3+ ratio can induce the emission peak of the samples to change from blue to green.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Dong Li,Yuexiao Pan,Xunan Wei,Jun Lin
Red phosphors based on Mn 4+ doped fluorides emitting narrow red light under the excitation of blue GaN chips, which can help to improve the luminescence efficiency and color rendering index (CRI) of white light-emitting diodes (WLEDs). In this paper, we carried out a room-temperature synthesis method to obtain a new phosphor of CsNaGe x Sn 1-x F 6 :Mn 4+ (CNGSFM) which contains double-central ions Ge 4+ and Sn 4+ . By controlling the different ratios of the central ions Ge 4+ /Sn 4+ , the contraction and expansion of the matrix lattice CNGSF can be freely changed, which provides a new direction for exploring the trimming method of the lattice effect on the luminescence performance of phosphors. Mn 4+ in CNGSFM shows weak stability and its luminescence quenches fastly in humid environments , so that we explored a facile strategy to improve its humidity resistance. Furthermore, the quenched luminescence of the CNGSFM can be restored through surface modification. Therefore, our results not only establish the tunable mechanism between luminescence performance and microstructure, but also provide a feasible strategy to improve the humidity resistance of Mn 4+ doped double-composite fluoride 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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Xiaoqing Guo,Shuangju Song,Xue Jiang,Jingru Cui,Yunshuai Li,Wenqing Lv,Haiyan Liu,Yuanyuan Han,Liyong Wang
In this present work, a room temperature coprecipitation method for the synthesis of CaMoO 4 @SiO 2 :Ln (Eu 3+ , Tb 3+ , Dy 3+ ) phosphors was reported. These particles were characterized using X-ray diffraction (XRD), Energy dispersive spectrometer (EDS), Fourier Transform IR spectroscopy (FTIR), scanning electron microscope (SEM), UV-visible spectrophotometer and photoluminescence (PL) respectively. The results indicated that emission intensity of SiO 2 modified samples increased by about 2 times, compared with no-silica modified samples. Multicolor phosphors were also designed by changing the lattice activators (Eu 3+ , Tb 3+ , Dy 3+ ). To further explore its applications, the transparent photoluminescent film was developed through the incorporation of polyvinyl alcohol (PVA), and selective and sensitive detection performance on dichromate was demonstrated in detail. In addition, red emission LED devices was assembled with as-prepared phosphors. The present results provide not only the high-performance phosphors modified by silica , but also a deep explanation of the structure-property relationship of the as-prepared sample. Based on these findings, it can be foreseen that these microparticles will be applied in versatile filed.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2017
·Vol. 123
·期 6
·1-10
·
IF 1.455
Mou Yongren,Kang Ming,Liu Min,Wang Feng,Chen Kexu,Sun Rong
In order to investigate the effect of amphiphilic additional agents on the morphology (particle shape, particle size and particle size distribution) and photoluminescence performance of calcium carbonate phosphor, the phosphors AA-CaCO 3 :Eu 3+ (AA = glycerol or sodium dodecyl sulfate) were synthesized by the microwave-assisted co-precipitation method using glycerol (Gly) and sodium dodecyl sulfate (SDS) as amphiphilic additional agents (AA), respectively. The phase structure, morphology and luminescent properties of the as-synthesized samples were characterized by X-ray diffraction, scanning electron microscope, laser diffraction particle size analyzer and Fluorescence spectrophotometer, respectively. The results showed that the phase structure and morphology of AA-CaCO 3 :Eu 3+ changed along with different types and amount of amphiphilic additional agents evidently. The particle size of Gly-CaCO 3 decreased to 1.383 µm when the volume ratio reached 8:2 (Gly:H 2 O). Photoluminescence (PL) spectra show that all the AA-CaCO 3 :Eu 3+ phosphors exhibit strong red emission peak originating from electric-dipole transition 5 D 0 → 7 F 2 (614 nm) of Eu 3+ ions and the amphiphilic molecules (Gly and SDS) had a huge influence on photoluminescence intensity.
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
·
2017
·
IF 2.986
Qi Qiu,Manjie Huang,Weimeng Zheng,Chaoyan Xuan,Yong Wan,Bo Zhang,Zhongkuan Luo,Weizhong Lv
Systematic study on the impact of the pH value was performed in the preparation of YAG:Ce nanophosphor powders by reverse titration method. Therefore, we used wider range of the pH values from 5.0 to 8.3 for the synthesis, correlating closely with ratio R of the total metal ions to precipitant ammonium hydrocarbonate in the solution from 1:3 to 1:9. The calcination temperatures of 1050 °C and 1300 °C were tested for the crystallization of YAG:Ce nanophosphors. Acidic condition is more preferable for improved YAG:Ce nanophosphors through XRD spectra analysis for the type of crystals and the crystal size. The molar ratio Y 3+ /Al 3+ in the precursor was controlled at the level of R =1:3 to keep the stoichiometric ratio of YAG:Ce. SEM images showed the YAG:Ce nanophosphors prepared at acidic condition having smaller crystal size and improved dispersibility. Fluorescence spectrum displayed much stronger emission at R =1:3. The molar ratio R is a vital factor to control the quality of the YAG:Ce powders. The nanophosphors prepared at R =1:3 possessed the best fluorescence emission.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Xiaoqian Song,Qianyi Guo,Zhenlu Cai,Jianrong Qiu,Guoping Dong
Carbon quantum dots (CQDs) with multi-color emission are synthesized through hydrothermal method by varying the ratio of citric acid (CA) and urea, the solvent (water, ethyl alcohol, and dimethylformamide), the hydrothermal temperature, and reaction time. The CQDs emit bright fluorescence which can be gradually tuned from blue to red continuously, almost covering the whole visible spectrum. The emission peaks of the CQDs shift from 450 nm to 650 nm with the surface groups and structures changing. Importantly, all solid state CQDs@SiO 2 nanophosphors are successfully synthesized by reversed-phase micromulsion method. Based on these solid state phosphors, multi-color CQDs@SiO 2 phosphors-based light-emitting diodes (LED) and white light-emitting diode (WLED) with a Commission Internationale de L’ Eclairage (CIE) value of (0.3497, 0.3045) are fabricated in a low-cost, environment-friendly way.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Sisi Liang,Decai Huang,Jie Hu,Dejian Chen,Kunyuan Xu,Haomiao Zhu
Mn 4+ -doped oxide phosphors with emission in deep-red region are promising for the application of plant cultivation lighting. However, it remains a great challenge to synthesize these phosphors with high blue-light absorption efficiency, which is pivotal for their practical commercial applications. Herein, we conducted a local crystal field regulation strategy to notably improve the luminescent property of the Mg 14 Ge 5 O 24 :Mn 4+ phosphor. For instance, by introducing F - ions into the host, the absorption efficiency in blue-light region increased remarkably from 13% to 28%. By further substitution of Ti 4+ for Ge 4+ ions, the absorption efficiency further increased to 50%. Meanwhile, the achieved internal photoluminescence quantum yield is up to 92% for the Mg 28 Ge 5.42 Ti 2 O 38 F 10 :Mn 4+ phosphor under 422 nm blue-light excitation. Besides, the phosphor exhibits excellent photoluminecence thermal stability, i. e., the emission intensity at 423 K retained 96% of that at room temperature. By means of X-ray absorption near-edge structure and extended X-ray absorption fine structure analysis, the effect of introducing F - and Ti 4+ ions on the local coordination and valence of Mn ions in the hosts and the luminescent property of the phosphors are discussed in detail. Finally, LEDs were packaged by combining blue diode chips and Mg 28 Ge 5.42 Ti 2 O 38 F 10 :Mn 4+ phosphor, and their validity for promoting growth of plants were successfully demonstrated.
研究领域:
材料科学
·
光学
·
植物学
✓ 已验证
DOI
高影响因子
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