ECS Journal of Solid State Science and Technology
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2024
·Vol. 13
·期 3
·036001
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IF 1.8
Gai Yang,Xianke Sun,Honglei Yuan,Weijie Yang
Various types of Eu2+ activated phosphors show potential applications in light emitting diodes. In this work, the Eu2+ activated KGaSi2O6 phosphors were synthesized using high-temperature solid-state reactions. The crystallization and oxidation states, luminescence spectra, decay characteristics, and thermal stability were researched. Depending on excitation of NUV light, the Eu2+ activated KGaSi2O6 phosphors emitted green-yellow light originating from the 4f65d1 → 4f7 transitions of Eu2+. In the light of emission data measured at different temperatures, the activation energy was calculated as 0.33 eV. The warm white light with a correlated color temperature of 3909 K and a color rendering index of 81.9 was emitted by the WLED device consisting of near ultraviolet LED chips, KGaSi2O6:Eu2+ and CaAlSiN3:Eu2+ phosphors.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Luhui Zhou,Peng Du,Weiping Li,Laihui Luo,Guozhong Xing
We report on the development of a new class of highly sensitive luminescent optical thermometers building blocks via engineering multicolor-emitting Eu2+-activated Li4(Sr1–xCa1+x)(SiO4)2 phosphors. Since the Eu2+ ions occupied two diverse sites in the host, the resultant compounds emitted two distinct emissions in blue and yellow regions. In particular, the blue emission is ascribed to the Sr2+ sites, while the yellow emission is attributed to Ca2+ sites. By adjusting the content ratio between Ca2+ and Sr2+ ions, the emitted color can be changed from yellowish-brown to blue upon 365 nm excitation. Furthermore, with the aid of the fluorescence intensity rate technology, the temperature-sensing ability of the synthesized phosphors is revealed by means of detecting the inequable responses of the blue and yellow emissions to the temperature. When x = 0.4, the maximum relative sensitivity of the developed samples is 1.181% K–1. Importantly, the sensor sensitivities of the resultant phosphors can be adjusted by engineering the composition. These features elaborate that the Eu2+-activated Li4(Sr1–xCa1+x)(SiO4)2 phosphors with high sensor sensitivities present as one of most promising candidates for noninvasive optical thermometers.
研究领域:
材料科学
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光学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xiaoping Jiang,Yue Guo,Lixi Wang,Qitu Zhang
Dynamic photoluminescence and photochromism are two critical technologies applied in advanced anti-counterfeiting and encryption. In this work, an innovative phosphor of CaAl 12 O 19 :Eu 2+/3+ combining the features of dynamic photoluminescence and photochromism is developed for the first time. After being irradiated by a portable 254 nm ultraviolet lamp, the photoluminescent color of the phosphor can dynamically change from red to magenta in dark field, and the surface color can dynamically alter from white to light brown in bright field. Based on these two appealing features, an application in advanced anti-counterfeiting and encryption is designed which can write, encrypt, and erase information successfully, thus guaranteeing information security. Furthermore, a composite material of CaAl 12 O 19 :Eu 2+/3+ /PDMS is fabricated for application in advanced anti-counterfeiting and encryption in both dark and bright fields, which is difficult to be replicated.
研究领域:
材料科学
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光学
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信息安全
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DOI
高影响因子
ACS Applied Electronic Materials
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2020
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IF 0
Fei Tang,Haoqi Li,Kangzhen Tian,Shijie Xu,Xiaojun Wang,Chenhui Xie,Honggang Ye,Yongge Cao
Hunting for a type of green phosphor with outstanding properties is of much significance for improving the performance of display backlights. In this work, a series of efficient Eu2+-activated RbLi7Si2O8 (denoted as RLSO:Eu2+) green phosphors with different doping concentrations were prepared via a low-temperature solid-state reaction approach under a reduced atmosphere. Photoluminescence (PL) measurements show that the prepared green phosphor with 8 atom % doping concentration of Eu exhibits the best internal quantum yield (IQY) of 95.8%. Besides, the phosphor delivers a good anti-thermal quenching behavior at temperatures <200 K, that is, there is no significant drop in luminescence intensity. Such thermal behavior is well consistent with the temperature dependence of measured luminescence lifetimes. The spectral analysis of the low-temperature luminescence spectrum with a semiclassical time-dependent approach reveals that three electronic levels of the Eu2+ ion coupled with a common low-frequency vibrational phonon mode with an energy of 21 meV shall be responsible for the high-efficiency luminescence of the prepared phosphor. Using the as-prepared green phosphor and K2SiF6:Mn4+ red phosphor, a white light-emitting diode (LED) device with high luminous efficacy (111.08 lm/W) and wide color gamut (112% NTSC) is fabricated on an InGaN blue chip.
研究领域:
材料科学
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光学工程
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DOI
ACS Photonics
·
2018
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IF 6.88
Zuobin Tang,Gangyi Zhang,Yuhua Wang
A dipotassium hafnium trisilicate K2HfSi3O9 with wadeite structure was synthesized by solid-state reaction for the first time. Its detailed crystal structure and electronic structure were determined using XRD Rietveld refinement and density functional theory (DFT), respectively. An expected asymmetric emission band was observed in K2HfSi3O9:Eu2+ due to Eu2+ ions occupying the two symmetrically inequivalent K+ (K1 and K2) ion sites in the host lattice. The K2HfSi3O9:Eu2+ has obvious heat-sensitive luminescent features (25 °C, blue emission; 250 °C, green emission), which can be rationalized by the energy transfer from Eu1 to Eu2 under thermal stimulation. Moreover, we developed promising phosphor K2HfSi3O9:Eu2+,Sc3+ by employing the crystal-site engineering method, and tuned the emission color from blue to green with the variation of Sc3+ ions. The target phosphor K2HfSi3O9:2%Eu2+, 6%Sc3+ shows strong absorption in the spectral range of ∼250–490 nm and a narrow green-emitting band (fwhm ∼59 nm) peaking at ∼507 nm with zero emission loss at ambient temperature up to 200 °C. Such robust thermal performance was explained by possible transfer energy from the defect levels to the 5d band of Eu2+, and certified by the thermoluminescence spectrum and the decay curves in the temperature range of 25 to 250 °C. Combing this excellent green phosphor with n-UV (395 nm) or blue chips (450 nm), pc-WLEDs with high luminance, adequate color rendering index, and correlated color temperature were obtained.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
OPTICAL MATERIALS
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2025
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IF 4.2
Tao Wei,Lei Xu,Duanduan He,Heyun Xu,Fei Long,Chaoyong Deng,Xucheng Li
A series of Eu 2+ -activated β-Ca 3 (PO 4 ) 2 -type Ca 9 MgNa(PO 4 ) 7 phosphors were successfully synthesized via high-temperature solid-state reaction. The substitution effects of Zn 2+ for Mg 2+ and Li + for Na + on the local coordination environments and luminescence characteristics of Eu 2+ were systematically investigated. The results demonstrate that Eu 2+ ions predominantly occupy the Ca1/Ca2, Ca3, and Na sites in Ca 9 MgNa(PO 4 ) 7 , corresponding to emission peaks at blue(1), blue(2), and green, respectively. Zn 2+ substitution for Mg 2+ induces lattice expansion, which reduces the occupancy probability of Eu 2+ at Ca1/Ca2 sites while lowering the formation energy of Ca3 sites, thereby significantly enhancing Ca3 and Na + site emissions but reducing Ca1/Ca2 site intensity. Subsequent Li + substitution for Na + causes contraction of the Li/NaO 6 polyhedra, reducing the capacity of the Na sites to accommodate Eu 2+ . Concurrently, the adjacent Ca(3)O 9 polyhedra undergo expansion, promoting preferential Eu 2+ occupancy at the Ca3 sites and consequently enhancing the emission intensity at blue(1).
研究领域:
材料化学
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无机化学
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发光材料
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固体物理
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光学材料
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2025
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IF 6.2
Junwei Zhang,Hui Lin,Shuo Zhu,Yuetong Zhen,Ruijin Hong,Zhaoxia Han,Dawei Zhang
The rapid advancement of high-power solid-state lighting highlights the importance of developing phosphor ceramics with high resistance to thermal quenching of its luminescence. Herein, a series of Eu 2+ co-doping MgAl 2 O 4 : Mn 2+ phosphor ceramics were synthesized by spark plasma sintering. The significant green light enhancement at 516 nm is attributed to Eu 2+ -Mn 2+ energy transfer. The introduction of Eu 2+ increases the concentration of electron trap levels and improve the luminescence intensity at 423 K from 80% to 110%, compared with the counterparts at room temperature. The strong correlation between trap levels and oxygen vacancies was demonstrated by the X-ray photoelectron spectroscopy and electron paramagnetic resonance analysis. Finally, the application demonstration of the optimized sample was explored through its integration with a 400 nm LED chip. This study proposes a strategy of leveraging trap levels to induce anti-thermal quenching behavior, providing some insights for the development of highly thermally stable phosphor ceramics.
研究领域:
材料科学
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发光材料
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固态照明
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陶瓷学
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光电子学
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产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 3
·1778-1788
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IF 4.186
Xiao Ma,Zhifeng Huang,Hailong Yuan,Yujuan Zhou,Meijuan Li,Fei Chen,Qiang Shen
Rare-earth-doped transparent glass shows great potential in white light-emitting diodes (wLEDs) application due to its excellent optical and luminous properties. Currently reported commercial wLEDs have a drawback in red emission missing, which leads to a relatively low color rendering index (CRI) and a relatively high correlated color temperature (CCT). In this work, Ce@Eu Sr–Si–O glass is fabricated using a high-temperature quenching method. The white light is available when the ratio of Ce 3+ /Eu 3+ equals 1, and the emitting color can be adjusted from blue to red by controlling the ratio of Ce 3+ /Eu 3+ . To further optimize the white light, Eu 3+ ions can be reduced to Eu 2+ according to the reaction of 6Eu 3+ + 2N 3− → 6Eu 2+ + N 2 ↑ by introducing Si 3 N 4 . As a result, the standard white light emission can be achieved in the Ce@Eu silicate glass contributed by the blue light from Ce 3+ , red light from Eu 3+ , and yellow–green light from Eu 2+ (two elements, three emission). This glass shows excellent luminous properties, such as a color coordinate is (0.3651, 0.3269) in CIE 1931 color coordinate diagram, a CRI is over 70, a high quantum yield of 36.02%, and a CCT of 4117 K.
研究领域:
材料科学
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光学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Lei Fu,Di Wu,Yanfei Xiao,Wanfang Zou,Jinfen Kuang,Yan Liang,Fu Du,Jiaqing Peng,Xinyu Ye
Blue phosphor Sr 5−x-y R y (PO 4 ) 3 Cl:xEu 2+ (R = La, Gd, Lu) was prepared via solid-state reaction process, in which R 3+ replaces part of Sr 2+ ions in the matrix to benefit Eu 2+ luminescence. The change of Eu 2+ /Eu 3+ values were studied by XPS , and the results shown that the incorporation of R 3+ in the matrix resulted in the values increase of Eu 2+ /Eu 3+ . And substitute R 3+ non-equivalently for Sr 2+ , the modified Sr 5−x-y R y (PO 4 ) 3 Cl:xEu 2+ phosphors show better luminescence intensity and thermal stability. The emission intensity of Sr 4.72 Lu 0.2 (PO 4 ) 3 Cl:0.08Eu 2+ is 1.97 times of Sr 4.95 (PO 4 ) 3 Cl:0.05Eu 2+ . Moreover, the thermal quenching of Eu 2+ photoluminescence could be reduced. Compared to the commercial BAM:Eu 2+ phosphor, the stabilities of all Sr 4.72 R 0.2 (PO 4 ) 3 Cl:0.08Eu 2+ (R=La 3+ , Gd 3+ and Lu 3+ ) phosphors are better than that of BAM:Eu 2+ at the temperatures below 100 °C. The luminescent intensity of Sr 4.72 Lu 0.2 (PO 4 ) 3 Cl:0.08Eu 2+ maintains 95% while BAM:Eu 2+ is only 88% of the initial intensity at 150 °C. By combining Sr 4.72 Lu 0.2 (PO 4 ) 3 Cl:0.08Eu 2+ , Y 3 (Al,Ga) 5 O 12 :Ce 3+ and CaAlSiN 3 :Eu 2+ with 400 nm near-ultraviolet LED chip, a white-light-emitting diode was obtained. The fabricated WLED device with CIE color coordinates x = 0.3896, y = 0.3788, low CCT (3775 K) and high Ra (95.1), has enormous potential application in full-spectrum lighting field.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
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IF 3.3
Jingshan Hou,Jie Shi,Langping Dong,Jianghua Wu,Ganghua Zhang,Haijie Chen,Wei Gao,Yongzheng Fang
The discovery of pure-red emitting phosphor is great meaningful for the achievement of high color rendering index white light emitting diodes , but still a challenge due to the strict crystal field limitations. In this work, we demonstrate the preparation of a 630 nm pure-red emitting Ca 3 Si 2 O 7 :Eu 2+ phosphor for the first time through a CO reduction strategy. The changes in crystal field strength caused by different methods for the preparation of Ca 3 Si 2 O 7 :Eu 2+ are investigated and discussed based on the understanding of the thermodynamic theory and structure resolution. Finally, a white light-emitting diode with a high color rendering index (Ra = 98) is accomplished by combining the as-prepared Ca 3 Si 2 O 7 :Eu 2+ pure-red emitting phosphor with a 375 nm chip and the commercial used blue and green phosphors. The results also demonstrate the generalizability of the weak reduction strategy for the exploration of “redder” Eu 2+ doped phosphors.
研究领域:
材料科学
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光电子学
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固态物理
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无机化学
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照明技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
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2024
·
IF 5.7
Weiguang Ran,Jiayi Geng,Ziyou Zhou,Chunyuan Zhou,Fukai Wang,Ming Zhao,Tingjiang Yan
The development of efficient and thermally stable narrow-band-emitting phosphors is crucial for wide color gamut display applications. Herein, we have developed a novel narrow-band green-emitting RbK2Na(Li3SiO4)4:Eu2+ phosphor with remarkable luminescence properties. The phosphor exhibits a main green emission band at 535 nm, with a narrow full width at half maximum of 51 nm, attributed to its unique rigid structure and highly symmetric cationic sites. Furthermore, it demonstrates excellent thermal stability, retaining 90.95% of the integrated emission intensity at 500 K compared to that at 100 K, and exhibits a high internal quantum efficiency of 82.51%. By combining RbK2Na(Li3SiO4)4:5%Eu2+ with commercial red K2SiF6:Mn4+ phosphors and blue GaN chips, a white light-emitting diode device with a wide color gamut (103% NTSC) was prepared, demonstrating the potential of the RbK2Na(Li3SiO4)4:Eu2+ phosphor for liquid-crystal backlight applications.
研究领域:
材料科学
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光电技术
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显示技术
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DOI
高影响因子
Optical Materials Express
·
2022
·Vol. 12
·期 10
·4117-4132
·
IF 3.074
Zihan Zhao,Zihan Zhao,Ran Zhang,Ran Zhang,Hao Song,Yanjie Zhang,Yanjie Zhang,Yanjie Zhang,Xiuping Wu,Desheng Li,Bing Li,Bing Li
As blue emitting component in phosphor-converted white-light-emitting-diodes (pc-wLEDs) encapsulated with near-ultraviolet (NUV) chips, Eu2+ activated fluorapatite structure phosphors play key roles because of strong structural stability and excellent photoluminescent properties. A series of M5(PO4)3F: Eu2+ (M = Ca, Sr) samples have been newly prepared by deposition-precipitation process (DP) and exhibited a 6.7-fold enhancement of photoluminescent (PL) intensity due to the highly dispersed Eu2+ luminescence centers when compared with the reference samples synthesized via traditional solid-state reaction method (SSR). Detailed analysis of crystal field around Eu2+ and the nonlinear fitting of PL spectra concludes that Eu2+ activators with the 4f6 → 4f75d transition preferentially replace Ca1 in 4f symmetry sites leading to a fitted peak at 446 nm and the other sites of 6h are contributed to the 479 nm emitting of Eu2+ ions. Remarkably, tunable chromaticity of DP-M5(PO4)3F: Eu2+ with high color purity (97.79%) retains steady photoelectric converting and full width at half maxima (FWHM) of 46 nm in the device of DP-FAp: 0.03Eu2+@365 nm LED under diverse driving currents, which perfectly satisfies the requirements of excitation light source for oral photocuring materials. Further, the 123.4% color gamut of National Television System Committee (NTSC) standard is efficiently obtained by matching Sr5(PO4)3F: Eu2+, CsPbBr3 and Lu3Al5O12: Mn4+ phosphors with a 365 nm chip (1 W) to achieve high-quality white light (CRI value reaches to 86, CCT is 7107 K and CIE chromaticity coordinate arrives at (0.292, 0.376), indicating a potential candidate for dentistry curing light and high-quality NUV excited pc-wLEDs.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）