JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·6577-6585
·
IF 3.9
Yuting Zhang,Huan Tu,Guoying Zhao,Jingshan Hou,Yufeng Liu,Xin Qiao,Zhongzhi Wang,Bo Li,Ji-Guang Li,Feng Wang,Yongzheng Fang
Compared with other fluorescent crystal phases, garnet has better structural stability in a glass matrix and renders precisely controllable emissions due to the abundant lattice control positions. In this work, we regulate the coordination field of Ce 3+ ion based on the co-substitution method and achieve the spectra regulation in the yellow–green range. We used Ba 2+ –Si 4+ cations to replace Y 3+ –Al 3+ cations in Y 3 Al 5 O 12 (YAG) matrix to obtain blue-shift of the emission peak from 552 to 539 nm. The centroid shift and crystal field splitting decrease with the decreasing covalency of the bond between the Ce 3+ ion and the surrounding anions owing to the higher electronegativity of Si 4+ ions than Al 3+ ions. The corresponding fluorescent films were prepared by a low-temperature co-sintering process based on the as-made Ba 2+ –Si 4+ co-substituted phosphor. X-ray powder diffractometer and scanning electron microscopy images showed that the fluorescence crystals were less eroded and evenly dispersed in the glass matrix. Spectral analysis showed that the garnet phase was protected by using lead-free borosilicate glass with a low melting point, and the quantum efficiency of phosphor-in-glass (PiG) retains 98% of the corresponding phosphor. By adjusting the ratio of garnet phosphor to commercial red nitride phosphors, a warm white fluorescence with a color rendering index of 80.3 and color temperature of 3899 K was obtained. The prepared warm white film has potential application value in the whole spectra field.
研究领域:
材料科学
·
光电子学
·
固态照明
·
无机化学
·
晶体场理论
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Baofeng Zheng,Yanhua Song,Zhibo Zheng,Yanxia Zhao,Qing Yang,Zhan Shi,Bo Zou,Haifeng Zou
A novel green-light-emitting silicon-based oxynitride phosphor Ca4Y3Si7O15N5:Eu2+ with low thermal quenching and ideal pressure sensitivity is reported. The Ca3.99Y3Si7O15N5:0.01Eu2+ phosphor can be efficiently excited by 345 nm ultraviolet light and shows very low thermal quenching (integrated and peak emission intensities at 373 and 423 K were 96.17, 95.86, and 92.73, 90.66% of those at 298 K, respectively). The correlation between high thermal stability and structural rigidity is investigated in detail. The white-light-emitting diode (W-LED) is assembled by depositing the obtained green-light-emitting phosphor Ca3.99Y3Si7O15N5:0.01Eu2+ and commercial phosphors on a ultraviolet (UV)-emitting chip (λ = 365 nm). The CIE color coordinates, color rendering index (Ra), and corrected color temperature (CCT) of the obtained W-LED are (0.3724, 0.4156), 92.9, and 4806 K, respectively. In addition, when subjected to in situ high-pressure fluorescence spectroscopy, the phosphor exhibits an evident red shift of 40 nm with an increase in pressure from 0.2 to 32.1 GPa. The phosphor has the advantage of high-pressure sensitivity (dλ/dP = 1.13 nm GPa–1) and visualization with pressure changes. The possible reasons and mechanisms are deeply discussed in detail. Based on the above advantages, Ca3.99Y3Si7O15N5:0.01Eu2+ phosphor is expected to have potential applications in W-LEDs and optical pressure sensing.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·Vol. 36
·期 2
·1727-1743
·
IF 3.1
Liu Shili,Yao Xuemei,Zhang Xinyue,Sheng Kai,Wang Chenyi,Zhu Tong,Yu Ruijin,Xing Guoxiu
In this study, a series of Ce 3+ , Eu 2+ , and Ce 3+ /Eu 2+ co-doped oxyapatite Ba 2 La 3 (SiO 4 ) 2 (PO 4 )O (BLSPO) phosphors were synthesized by the high-temperature solid-phase method. The crystal structure, luminescent properties and application prospects of the material were systematically studied. BLSPO crystallizes in the P 6 3 / m space group (No. 176), exhibiting experimentally confirmed high crystallinity. Photoluminescence and excitation spectroscopy analysis indicated that the BLSPO: Eu 2+ phosphor could be effectively excited at 370 nm and was highly suitable for use in LED chips. The emission spectrum of BLSPO: Eu 2+ phosphor shows a broadband emission peak of Eu 2+ ions, with the peak at 510 nm. Through Gaussian fitting, this peak can be further fitted to two different emission centers at 507 nm and 536 nm, corresponding respectively to the M(I) and M(II) coordination environments within the BLSPO matrix. Under 315 nm excitation, the BLSPO: x Ce 3+ phosphor demonstrates a broad emission band peaking around 428 nm, with experimental results identifying 10 mol% as the optimal cerium ion doping concentration for maximal performance. In the BLSPO: Ce 3+ , Eu 2+ co-doped system, the energy transfer mechanism between Ce 3+ and Eu 2+ was studied, and the energy transfer efficiency η value gradually increased from 0% to 86.96% with the increase of Eu 2+ concentration. The mechanism of energy transfer is dipole-dipole interaction mechanisms. The thermal stability of the BLSPO:10 mol%Ce 3+ , 10 mol%Eu 2+ samples was tested, and the sensitivity factors S a and S r reached their respective maximum values of 2.61 × 10 − 2 K − 1 and 0.99% K − 1 at 480 K. The thermal stability test of BLSPO:5 mol%Eu 2+ shows that at 420 K, the sample maintains 52% of its initial luminous intensity. Therefore, the CIE chromaticity coordinates of the green LED packaged with BLSPO:10 mol% Eu 2+ phosphor is (0.263, 0.466), the CIE chromaticity coordinates of the w-LED are (0.335, 0.355), the color rendering index ( R a ) is 92, and the correlated color temperature (CCT) is 5366 K.
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Zijing Zhou,Anlin Zhang,Li Zhou,Ziyue Hu,Yixuan Zhao,Jiexin Chen,Yanyan Li,Lei Zhao,Bin Deng,Ruijin Yu
In the present work, a series of zincate CaY 2 Sb 2 (ZnO 4 ) 3 :Eu 3+ phosphors were successfully obtained via the conventional solid-state method at high temperature. The phase purity, morphology, element mapping, photoluminescence excitation/emission (PLE/PL), and decay time of the obtained phosphors were investigated systematically. Results show that the synthesized samples demonstrate the strongest red-emitting peak at 610 nm under the n-ultraviolet (n-UV) 395 nm excitation. The Judd-Ofelt parameters (Ω 2 , Ω 4 ), radiative transition rates, and branching ratios ( β 0 J, J = 2, 4) of CaY 2 Sb 2 (ZnO 4 ) 3 :Eu 3+ to explore the Eu 3+ -coordinated environment in the host matrix. The concentration quenching of CaY 2 Sb 2 (ZnO 4 ) 3 :2 x Eu 3+ phosphors happened until at high doping concentration of x = 50 mol%. CaY 2 Sb 2 (ZnO 4 ) 3 :100 mol%Eu 3+ sample presented the excellent thermal stability with abnormal thermal quenching behavior. Compared with the commercial Y 2 O 3 :Eu 3+ red phosphor , the luminescent intensity of the prepared phosphor is 1.14 times stronger. The high internal quantum efficiency (IQE) of CaY 2 Sb 2 (ZnO 4 ) 3 :100 mol%Eu 3+ phosphor is 79.20%. In addition, the fabricated red and white light-emitting diodes (w-LEDs) both emit bright light. The w-LED demonstrates a high color rendering index ( R a = 96) and a low correlated color temperature (CCT = 5249 K). Therefore, the prepared red-emitting phosphor has a promising application in w-LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·Vol. 45
·期 15
·18876-18886
·
IF 3.45
Nan Zhang,Zhijun Wang,Huacheng Zhang,Yili Sun,Tianyu Yuan,Chunjing Tao,Zhiping Yang,Panlai Li
Red-emitting Sr 0.8 Ca 0.19 AlSiN 3 :0.01Eu 2+ phosphor with halide fluxes for use in the production of white light-emitting diodes (white LEDs) with high-colour rendering indices (CRIs) was prepared through the high-temperature solid-state method. Fluoride (NaF, SrF 2 , BaF 2 , CaF 2 , AlF 3 ·3H 2 O and CeF 3 ), chloride (NH 4 Cl, BaCl 2 , MgCl 2 , NaCl and LiCl) and composite fluxes (NaF + SrF 2 , SrF 2 +NH 4 Cl and NaF + NH 4 Cl) were applied in the phosphors. NaF, SrF 2 , NH 4 Cl and NaF + SrF 2 fluxes had prominent effects on the characteristics of Sr 0.8 Ca 0.19 AlSiN 3 :0.01Eu 2+ phosphors. Sr 0.8 Ca 0.19 AlSiN 3 :0.01Eu 2+ phosphors with various powder morphologies can be obtained through the addition of fluxes, which are conducive for phosphor formation. The powder morphologies of phosphors incorporated with NaF + SrF 2 were preferable to those of powders incorporated with other fluxes. This result indicated that the incorporation of NaF + SrF 2 into Sr 0.8 Ca 0.19 AlSiN 3 :0.01Eu 2+ yielded phosphors with high luminescent intensity and quantum efficiency , excellent thermal stability, narrow full widths at half-maximum (FWHM, 75.2 nm), uniform rod-like morphologies with large particle sizes (D 50 = 16.99 μm) and good particle dispersion . White LEDs with high CRIs were obtained by combining prepared phosphors (NaF + SrF 2 additive) with the commercial green-emitting phosphors Y 3 (Al,Ga) 5 O 12 :Ce 3+ and (Sr,Ba) 2 SiO 4 :Eu 2+ . White LEDs with Y 3 (Al,Ga) 5 O 12 :Ce 3+ and (Sr,Ba) 2 SiO 4 :Eu 2+ phosphors had correlated colour temperatures (CCTs) of 3064 and 3023 K, respectively, and CRIs of 81.8 and 92.4, respectively. Therefore, NaF + SrF 2 can be used as a favourable flux for the production of Sr 0.8 Ca 0.19 AlSiN 3 :0.01Eu 2+ .
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Jiasong Zhong,Xiao Chen,Daqin Chen,Meijiao Liu,Yiwen Zhu,Xinyue Li,Zhenguo Ji
Developing a novel non-rare-earth activated oxide red phosphor with admirable luminescent performance and low cost is still of great interest in the field of energy-saving warm white light-emitting diodes (w-LEDs) illumination. Here, Li 3 Mg 2 SbO 6 :Mn 4+ (LMSO:Mn 4+ ) red-emitting phosphor has been successfully prepared with cheap raw materials via a traditional solid-state method. Crystal structure, morphology, composition as well as optical properties are studied in detail. The prepared LMSO:Mn 4+ phosphor exhibits a broad and deep red emission band in the range of 600–750 nm with the maximum centered at 666 nm, which is ascribed to the Mn 4+ : 2 E g → 4 A 2g transition in [SbO 6 ] octahedral environment. Moreover, the nephelauxetic effect of Mn 4+ in the LMSO matrix is evaluated by investigating the crystal field strength (Dq) and Racah parameters (B and C). Importantly, LMSO:0.01Mn 4+ phosphor demonstrates good thermal stability and high quantum efficiency. By embedding LMSO:Mn 4+ and Y 3 Al 5 O 12 :Ce 3+ phosphors with various ratios in the TeO 2 -based glass host, a series of phosphors-in-glass(PiG) composites are achieved and demonstrate to remain the original optical properties of phosphors. Remarkably, by coupling PiG color converters with a blue LED chip, high-power w-LEDs devices with tunable optoelectronic parameters are constructed, with the correlated color temperature evolving from cool white (6783 K) to warm one (4014 K) and the color rendering index increasing from 72.2 to 88.7.
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Shaokun Ling,Xiaoyan Qin,Chang chen,Kai Meng,Yifeng Yan,Junyun Ming,Sen Liao,Yingheng Huang,Lei Hou
Despite long-term development of LEDs, problems urgent to resolve is still existing. The most outstanding problem to tackle is luminescent stability at high temperature working situation. In this study, a novel type of β-NaYF 4 based phosphor incorporated with Eu 3+ and Tb 3+ is reported. A series of β-NaYF 4 :0.065Eu 3+ , x Tb 3+ ( x = 0.001, 0.002, 0.003, 0.004, 0.005) phosphors were synthesized by hydrothermal method . The sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ possesses optimal luminescent property at room temperature. The mechanism of energy transfer from Tb 3+ to Eu 3+ ion is quadrupole-quadrupole interactions. The sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ demonstrates zero thermal quenching (ZTQ) property at 303 K to 383 K. According to XRD and XPS characterizations, nonequivalent replacement between intrinsic ion Na + and Y 3+ were discovered, which finally leads to production of crystal defects. According to electron paramagnetic resonance (EPR) characterization and density functional theory (DFT) calculation, the type of crystal defect of β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ is confirmed to be V Y vacancies which are the predominant defect of crystal. The depths and densities of defects were calculated according to data of thermoluminescence spectra (TL spectra). Crystal defects play the role of electrons traps that could store electrons. Electrons stored in traps will be excited to excitation state of Eu 3+ under the thermal stimulation to offset undesirable impact of thermal quenching (TQ), which leads to ZTQ property of the sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ . The CRI and CCT of fabricated WLED are 3830 K and 84.1, respectively.
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产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2023
·Vol. 33
·期 4
·1305-1315
·
IF 2.7
Wang Rui,Li Shumiao,Huang Hanjiang,Liu Botong,Gao Lu,Qu Meiru,Wei Yanying,Wei Jianfei
An environmentally friendly PET-based Carbon Dots (PET-CDs) with excellent fluorescence properties were prepared with waste PET bottle, pyromellitic acid and ammonia water as raw materials by one-step hydrothermal method. The preparation mechanism of PET-CDs was as follows: PET first underwent ammonolysis reaction to produce terephthalic acid diamide and ethylene glycol, and then dehydrated and carbonized with pyromellitic acid to form PET-CDs. The as-prepared PET-CDs exhibit excitation-independent emission properties in the range from 340 to 440 nm, and the fluorescence quantum yield is as high as 87.36%. In terms of structure, PET-CDs is a spherical structure with an average particle size of 2.0 nm, and its surface contains carboxyl and amino groups. The PET-CDs were dispersed in a PVA matrix to obtain an light blocking films(LBFs) for 250–450 nm light with excellent properties, and its transparency for 450–700 nm light is good. In addition, PET-CDs was used in the fields of LED, and it was found that the color coordinate for the LED assembled with PET-CDs and 395 nm LED chips is (0.55, 0.44) and the correlated color temperature is 2018 K.
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
·
2022
·
IF 6.814
Zhi Zhou,Shuqing Feng,Shujie Gai,Peixin Gao,Chen Xu,Mao Xia,Wenbang Tang,Xuedan Lu
Industrial Seedling Raising (ISR) is increasingly becoming an important part of Modern Agriculture because of its efficient utilization of land, water, and fertilizer as well as its advantages of being not easily affected by the weather. However, the high cost and high energy consumption of light sources for plant growth is limiting the popularization of ISR technology. Phosphor-converted light-emitting diodes (pc-LEDs) make use of relatively affordable red phosphor and blue light chips, providing an adjustable spectrum to optimize plant growth. To identify the energy-saving light quality of pc-LEDs, we investigated the effects of a variety of light qualities on the growth of tobacco seedlings. Y 3 Al 5 O 12 :Ce 3+ , CaAlSiN 3 :Eu 2+ , KAl 11 O 17 :Eu 2+ phosphors were combined with the blue light chip according to different proportions to produce the following light sources: CK (white light), T1 (blue light), T2 (red light), T3 (red: blue light ratio = 1:4), T4 (red: blue light ratio = 4:1). The tobacco variety Xiangyan7 grown continuously under T1, T2, T3, and T4 significantly increased the leaf area, stem length, biomass, root area and main root length compared with those grown under white light. Among the five kinds of light qualities tested, T4 treatment exerted the best effect on leaf development and biomass increase, while T2 exerted the best effect on stem elongation . The cytological analysis demonstrated that the promotion of the cell size and cell number of leaf epidermal cells by T1-T4 might contribute to the leaf expansion. Further analysis at the molecular level suggested that the light quality affected the RNA levels of the genes involved in cell division and expansion. When tobacco seedlings reached the same biomass, T1-T4 light sources saved 71%, 86%, 80% and 89% of electric energy respectively compared with white light. Therefore, the application of specific pc-LEDs not only reduces the cost of light source production, but also saves energy consumption, offering great potential for ISR technology to cut costs and increase efficiency.
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Guo-Qiang Li,Zheng-Yang Huo,Qian-Yuan Wu,Zhuo Chen,Yin-Hu Wu,Yun Lu,Hong-Ying Hu
Recently, ultraviolet light-emitting diodes (UV-LEDs) and chlorine combined system has been employed as an emerging advanced oxidation process . However, UV-LEDs were commonly considered as monochromatic UV sources. In this study, the obvious quantum yields of chlorine photolysis under 265 nm and 280 nm LEDs irradiations were investigated with treating LEDs as polychromatic UV sources. Particularly, Φ obs-poly of HOCl and OCl⁻ for 265 nm LED were found to be 1.50 and 0.70 mol E −1 , respectively, whereas Φ obs-poly of HOCl and OCl⁻ for 280 nm LED were 1.28 and 0.64 mol E −1 , respectively. It was identified that Φ obs-poly were 5.66–14.63 % lower than Φ obs-mono . This suggests that obvious quantum yield using peak emission wavelength would overestimate the true quantum yield. The production of radical species in LED UV/chlorine systems were determined by the degradation of BA , and illustrated by a mathematical model. Different trends were observed for 265 nm and 280 nm LED UV/chlorine systems as pH increased from 5.0 to 10.0. As pH increased, the formation of OH continuously decreased in both 265 nm and 280 nm LED systems. The formation of Cl increased at neutral pH and more Cl and OH were formed due to the higher molar absorbance coefficient at 280 nm. The chlorine dose-dependent effects on radical productions at pH of 5.0, 7.5 and 10.0 were also assessed. At pH of 5.0, OH was the main radical product and had linear correlation with chlorine dose. At pH of 7.5, the productions of OH and Cl showed similar profiles that increased rapidly at low chlorine dosage and then slowed down.
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产品关联
DOI
PubMed
高影响因子
LUMINESCENCE
·
2025
·Vol. 40
·期 11
·e70338
·
IF 3
Futian Mi,Turghun Muhammad,Kui Zhang,Yao-Qun Li
Carbon dots (CDs) exhibit diverse application potential in various fields due to their unique optical properties. However, CDs synthesized by conventional methods typically have complex compositions and lack efficient separation and purification techniques, limiting their performance in specific applications. In this work, we synthesized CDs via a solvothermal method and, for the first time, employed synchronous fluorescence spectroscopy (SFS) to determine the relative content of each CD type during synthesis. By leveraging SFS's high selectivity and resistance to spectral overlap, we analyzed the mixture's composition, successfully identifying blue fluorescent CDs (B-CDs), green fluorescent CDs (G-CDs), and orange fluorescent CDs (O-CDs). The optimal synthesis conditions for G-CDs were 180°C for 5 h. A sensor array was constructed using the obtained CDs as sensing elements for distinguishing and recognizing metal ions, and the sensor array has shown good recognition and discrimination ability for various metal ions. G-CDs and O-CDs were mixed with polyvinylpyrrolidone (PVP) to prepare CDs/PVP composite materials, demonstrating their potential in light emitting diode (LED) applications. SFS simplifies the synthesis and purification of CDs, providing key guidance for controlled CD synthesis, increased yield, and optimized fluorescence.
研究领域:
材料科学
·
分析化学
·
纳米技术
·
光学传感器
·
发光器件
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Zhiqin Zheng,Peizhang Xie,Panpan Yi,Jun Zhao,Lihong Liu,Facheng Yi
Nowadays, ultraviolet (UV) and blue converted phosphors have played a key role in the solid-state lighting field, and the white light is usually produced by mixing multiple phosphors. In this work, we report a type of UV converted single white phosphor, i.e. , Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ .Various techniques, such as powder X-ray diffraction (XRD), scanning electron microscopic (SEM), photoluminescence (PL) spectra, and quantum efficiency (QE), have been used to characterize the samples. In Bi 3+ doped samples, upon excitation within the wavelength range of 250–380 nm can lead to three Bi 3+ emission bands ( i.e. , 358 nm, 415 nm, and 516 nm), but only one emission band peaking at 415 nm appears when the excitation wavelength exceeds 380 nm. Structural analysis and discussion on the PL intensity variation reveal there are three Bi 3+ luminescent centers at two different La 3+ sites and one Ba 2+ site. The Bi 3+ concentration-induced luminescent quenching is dominated by the d-d interaction. In view of the spectral overlap between the Bi 3+ emissions and the Eu 3+ excitation spectra , the energy transfer from Bi 3+ to Eu 3+ of the Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ is studied, and it is dominated by a dipole-quadrupole ( d - q ) interaction. Moreover, upon excitation at 365 nm, the emissions broadly tuning from blue, white and to red are achieved by varying the Eu 3+ content. For the white Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ sample, high temperature PL results show that it does not have severe degradation of emission intensity after increasing the temperature from 25 to 300 °C, exhibiting a good thermal stability . To show the potential application in the lighting fields, we fabricate a white light LEDs device by depositing this white phosphor on a 365 nm UV LED chip. As a result, the values, i.e. , a color rendering index (CRI) of 95, luminous efficiency of 80 lm/W, and color temperature (CT) of ~4215 K at chromaticity (0.382, 0.398), are achieved.
研究领域:
材料科学
·
发光材料
·
固态照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）