ACS Applied Electronic Materials
·
2020
·
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
·
光学工程
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DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Xingzhuo Xiong,Zihao Xu,Biao Xu,Chunyu Li,Wubin Dai
Borate-based phosphors have emerged as ideal host materials for near-ultraviolet ( n UV) pumped phosphor-converted white light-emitting diodes (pc- w LEDs) owing to their mild synthesis conditions, broad transparency window, and excellent chemical and thermal stability. Cubic Ba 3 Y 2 B 6 O 15 (BYB) features a highly symmetric lattice structure, providing stable binding sites for rare-earth ions. Its [YO 6 ] octahedral structure allows for controllable lattice distortion, making it an ideal host for multivalent rare-earth luminescent systems. In this study, Ce 3+ , Eu 3+ , Eu 2+ , and Ca 2+ co-doped BYB nanophosphors were prepared in an Ar atmosphere. The partial substitution of Ba 2+ by Ca 2+ promotes the generation of more oxygen vacancies, which in turn induces the self-reduction of Eu 3+ to Eu 2+ . The phosphor exhibits strong absorption characteristics at 365 nm. Acting as an efficient sensitizer, Ce 3+ can simultaneously transfer energy to Eu 2+ and Eu 3+ . By tuning the Ca 2+ content, the Eu 3+ /Eu 2+ ratio and the emission color can be continuously adjusted, achieving a smooth transition from blue-green to orange-red. This Ca 2+ mediated strategy stabilizes the coexistence of Eu 2+ and Eu 3+ , addressing the key limitations of traditional single-phase phosphors. It provides a novel approach for developing high-performance n UV-excited warm white phosphors and demonstrates potential for widespread application in highly efficient pc- w LED devices.
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Xueqin Liu,Nian Wang,Yu Li,Kang Wang,Xiaomin Fan,Xiang Guo,Xinyong Gong,Ruirui Cui
A conventional high-temperature solid-state reaction was used to synthesize Eu 3+ -doped Ca 3 La 2 (BO 3 ) 4 red phosphors, aiming to overcome the low color rendering index and high correlated color temperature of WLEDs caused by insufficient red spectral components. The XRD patterns indicate that Eu 3+ incorporation does not produce detectable impurity phases, while ionic-radius and charge-balance considerations suggest that Eu 3+ preferentially occupies La 3+ sites. Under 393 nm near-ultraviolet excitation, the samples exhibit intense red emission peaking at 612 nm, attributed to the 5 D 0 → 7 F 2 transition. The optimal doping concentration is 1.3, and concentration quenching is governed by dipole-dipole interactions with a calculated critical distance of 7.19 Å. The internal quantum efficiency reaches 67.21%, and the fluorescence lifetime is 2.64 ms. Thermal stability evaluation shows that at 473 K, the emission intensity retains 70.95% of its room-temperature value, yielding an activation energy of 0.1757 eV. A neutral white LED device was fabricated by encapsulating the optimally synthesized phosphor together with commercial green- and blue-emitting phosphors onto a 365 nm chip, achieving a correlated color temperature of 4767 K and a color rendering index of 91.1. Additionally, anti-counterfeiting ink formulated from this phosphor shows bright red luminescence under UV excitation. Collectively, Ca 3 La 2 (BO 3 ) 4 : Eu 3+ serves as an efficient red phosphor with excellent thermal stability, making it highly promising for solid-state lighting and anti-counterfeiting applications.
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高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 40
·13835-13844
·
IF 4.029
Luqing Xi,Yuexiao Pan,Mengmeng Zhu,Hongzhou Lian,Jun Lin
A novel red phosphor, NaHF2:Mn4+ (NHF:Mn), was obtained via substituting Na+ located at the center of the octahedron coordinated with six F− ions with Mn4+ in the host lattice of NHF. The phase purity and the exact composition of the obtained NHF:Mn were confirmed by X-ray powder diffraction (XRD), Rietveld refinement, energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and infrared (IR) spectroscopy, respectively. The luminescence intensity of NHF:Mn was enhanced by optimizing the synthetic conditions. A series of warm white light-emitting diodes (WLEDs) with a color rendering index (CRI) higher than 88.0 and correlated color temperatures (CCT) between 3146 and 5172 K were obtained by encapsulating the as-prepared red phosphor NHF:Mn with the yellow one Y3Al5O12:Ce3+ (YAG:Ce) on blue chips. The advantage of the synthetic strategy to obtain NHF:Mn can be extended to develop novel Mn4+ doped red phosphors via substituting for central ions with unequal electric charge in the centers of octahedra.
研究领域:
材料科学
·
光学工程
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Z.H. Xu,C. Wang,X.Z. Xiong,W.B. Dai
Borate-based phosphors, as a critical class of luminescent materials, have garnered significant attention due to their stable crystal structures, wide bandgaps, excellent thermal stability, and robust spectral tunability, making them essential components in white light-emitting diodes ( w LEDs) technologies. In this work, a high-symmetry Ba 3 Y 2 B 6 O 15 (BYB) phosphor co-doped with Bi 3+ , Tb 3+ , Eu 3+ , and Lu 3+ was synthesized via a multi-step sol-gel method. Different photoluminescence (PL) behaviors of Bi 3+ , Tb 3+ and Eu 3+ in BYB were systematically revealed. By modulating the PL spectrum via energy transfer (ET) from Bi → Tb → Eu, ‘cool’ white-light emission was achieved. A strategy of replacing Y 3+ with Lu 3+ was adopted to adjust the crystal field splitting and symmetry. This modification broadens the blue light coverage range in Bi 3+ PL, increases the hypersensitive transition of Eu 3+ ( 5 D 0 → 7 F 2 ), increase the intensity of red emission. They achieved their optimal balance ultimately. The improved structural compactness and rigidity reduced electron-phonon coupling effects, endowing the phosphor with superior chemical/thermal stability. Finally, a high-performance phosphor-converted w LED (pc- w LED) device with chromaticity coordinates of (0.361, 0.358), a luminous efficacy (LE) of 95.2 lm/W, was fabricated by integrating the optimized BYB: Bi/Tb/Eu/Lu phosphor with a UV LED chip using remote ‘cap’ packaging, demonstrating exceptional performance.
研究领域:
材料科学
·
光学工程
·
无机化学
·
固态照明
·
功能材料
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Pengju Xia,Wanyuan Li,Kaiting Wu,Yifeng Lei,Wubin Dai
In the process of studying newfangled phosphor-converted white-light-emitting diodes (pc-wLEDs), some basic and important objectives of phosphor, i.e., high chemical/thermal stability, color rendering index (CRI), and low correlated color temperature (CCT), should pass muster simultaneously. Herein, for the first time, a series of photoluminescence (PL) color-tunable single-phase Ca3Y(GaO)3(BO3)4: Dy3+/Sm3+/La3+ (CYGB: Dy/Sm/La) phosphors with good dispersivity, crystallinity, and size uniformity have been designed and synthesized via a facile solid-state reaction method. Structurally, based on XRD and Rietveld refinements, the tendentious occupations of Dy/Sm/La on the Y3+ site with a 9-coordinated number (CN) over other cationic sites are in line with the facts that the ionic radius and charge difference of Dy/Sm/La are much closer to Y3+ in 9-CN than Y3+ in 7-CN and Ca2+ in both 9- and 7-CN. Spectrally, thanks to the “cool” white PL from 4f–4f transitions of Dy and red-emitting from Sm, polychromatic PL including “warm” white light with high efficiency could be realized in CYGB: Dy/Sm via the regulation of doping content and energy transfer (ET). Intriguingly, the “abnormal” phenomena of zero-thermal-quenching in the range from room temperature (RT) to 573 K were observed, probably owing to the synergistic effects of electron–phonon coupling, ET, and structural defects. Moreover, by tridoping La3+ to legitimately adjust the site environments, the PL of both Dy/Sm could be further tuned because they all include hypersensitive transitions that are closely related to the crystal field environment. Finally, as a proof-of-concept fabrication, the pc-wLED assembled by a combination of the composition-optimized CYGB: Dy/Sm/La and an n-UV LED chip via remote “capping” packaging shows attractive performances, indicating its potential as an efficient phosphor for n-UV wLEDs.
研究领域:
材料科学
·
光学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2019
·
IF 2.961
Yang Liu,Mingfu Zhang,Lijun Xu,Wei Xia
Transparent Ce 3+ :YAG ceramics have great potentials in WLEDs due to their ultra-high thermal endurance property and thermal stability of luminescence. However, it is still a challenging issue to enhance their light extraction ability. In the study, the transparent Ce 3+ :YAG ceramics were fabricated using the uniform Ce:Y 2 O 3 submicron spheres by a solid-state reactive sintering method under vacuum without any sintering additives. The content of the residual pores and grain boundaries, which acted as the “light-scattering centres” to improve the absorption of blue light, were adjusted by changing sintering temperature . The luminous efficacy of the WLED with the sample sintered at 1700 °C was as high as 104.6 lm/W, due to the appropriate quantity of the “light-scattering centres”. The microstructures, transmittance , excitation and emission spectra , luminous characteristics of the samples were studied. The results showed that the preparation progress could significantly enhance the luminous efficacy in the WLED with transparent ceramics.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jiang Guo,Junlan Guo,Jing Gao,Jiexin Chen,Ya Yang,Yue Yang,Lingling Zheng,Yanyan Li,Lei Zhao,Bin Deng,Ruijin Yu
Novel orange-red-emitting LaNb 2 VO 9 (LNV): x Sm 3+ ( x = 0–35 mol%) phosphors were successfully synthesized through the traditional high-temperature solid-state reaction method. The crystal structure, SEM images, particle size distribution , XRD spectra, optimal concentration, zero-thermal-quenching behaviors, and luminescent stability of the samples were exhaustively studied. In particular, the phosphors presented broadband excitation that consisted of O 2− →V 5+ and O 2− →Sm 3+ charge transfer bands (CTB). Under 308 nm excitation, LNV:5 mol%Sm 3+ phosphor emitted orange-red light with high intensity at the wavelength of 598 nm due to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ ions. The sample with the optimal doping concentration of 5 mol% exhibited zero-thermal-quenching. Furthermore, a white light-emitting diode (WLED) with the Commission Internationale de L'Eclairage (CIE) coordinate of (0.347, 0.348) and the superior color rendering index (CRI, R a ) of 90 was smoothly fabricated. With the LNV: 5 mol%Sm 3+ phosphor, the level 1–3 structure of latent fingerprints (LFPs) and the detailed features of lip prints were clearly detected under ultraviolet irradiation. Ultimately, the phosphor effectively detected LFPs in various daily life circumstances. Consequently, the zero-thermal-quenching orange-red LNV:Sm 3+ phosphors have several promising applications in WLEDs and personal identification.
研究领域:
材料科学
·
光学工程
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高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-9
·
IF 17.694
Wang Yunhu,Wang Kunpeng,Dai Fangxu,Zhang Kai,Tang Haifeng,Wang Lei,Xing Jun
Artificial lighting consumes almost one-fifth of global electricity. As an efficient solid-state lighting technology, white light-emitting diodes (WLEDs) have received increasing attention. However, the white luminescence of the traditional WLEDs comes from multi-component emitters, which leads to complex device structure and unstable emitting color. Therefore, developing single-component materials with white-light electroluminescence is of significance for artificial lighting applications. Here, we fabricate single-component white-light electroluminescence devices based on an aromatic carbon nitride material and improve the performance of WLEDs by adjusting the carrier transport. The carbon nitride LEDs emit warm-white light, of which color coordinates and color temperature are (0.44, 0.52) and 3700 K. The optimized LEDs display a very low turn-on voltage of 3.2 V and achieve a milestone in the maximum luminance and external quantum efficiency of 1885 cd m −2 and 1.20%. Our findings demonstrate the low-cost carbon nitride materials have promising potential for single-component WLEDs application.
研究领域:
材料科学
·
光电
·
固态照明
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DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Dan Zhang,Taifang Zhang,Mekhrdod Kurboniyon,Peng Wang,Chonggeng Ma
A novel garnet-type phosphor, Gd2–yYyLuAl4GaO12: Ce3+, was synthesized via a high-temperature solid-state reaction to address the demand for efficient green-emitting materials in solid-state lighting. By employing a cation substitution strategy (Y3+/Gd3+ codoping), the photoluminescence performance was significantly enhanced: the quantum efficiency increased from 86.79 to 96.86%, accompanied by a tunable emission shift from yellow to green (560–520 nm). Moreover, the thermal stability at 423 K improved dramatically from 40.79 to 92.98%, surpassing those of commercial green phosphors. Structural and spectral analyses revealed that the optimized crystal field splitting and enhanced lattice rigidity, induced by cation substitution, effectively suppressed nonradiative transitions, thereby boosting both quantum efficiency and thermal stability. A prototype white light-emitting diode (WLED) fabricated with Y2LuAl4GaO12: Ce3+ phosphor exhibited excellent performance, including a high color rendering index (Ra = 91), low correlated color temperature (CCT = 3043 K), and good color stability under varying driving currents. These findings highlight the significant promise of Gd2–yYyLuAl4GaO12: Ce3+ as a superior green-emitting phosphor for advanced WLED systems, providing a feasible pathway for designing outstanding thermal stability and color-tunable luminescent materials via cationic engineering.
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DOI
PubMed
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·Vol. 43
·期 10
·2100-2107
·
IF 5.2
Jing Yan,Junyu Hong,Xiaohui Li,Bojana Milićević,Lei Zhou,Chunyan Jiang,Mingmei Wu
Nowadays, high-quality phosphor-converted white light-emitting diodes (pc-WLEDs) ought to include cyan-emitting phosphors allowing for full-spectrum light similar to sunlight. Herein, we report a garnet-structured Ce 3+ -doped SrLu 2 Ga 1.5 Al 2.5 SiO 12 (SLGASO) phosphor that significantly compensates for the absence of cyan light, known as the “cyan cavity”. The SLGASO host crystallizes into a cubic structure with the I a 3 ¯ d space group. The cell parameters were determined using Rietveld refinement. Under 430 nm blue excitation, SLGASO:Ce 3+ emits intense cyan-green light in the 450–700 nm wavelength range. The representative SLGASO:0.07Ce 3+ phosphor has an internal quantum efficiency (IQE) of 95.4% and excellent thermal stability, remaining 92.7% of its initial emission intensity at 152 °C. After 155 d of immersion in water, the luminous intensity of SLGASO:0.07Ce 3+ remains constant, confirming its waterproofness. Furthermore, a pc-WLED device with luminous efficiency (LE) of 101.58 lm/W, color rendering index ( Ra ) of 91, correlated color temperature (CCT) of 4536 K, and Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of (0.3555, 0.3390) was fabricated by combining as-prepared cyan-green-emitting SLGASO:0.07Ce 3+ , yellow-emitting Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ), and red-emitting (Ca,Sr)AlSiN 3 :Eu 2+ phosphors, as well as a 450 nm blue chip. These findings indicate that SLGASO:0.07Ce 3+ phosphor can bridge the cyan gap and improve the performance of as-fabricated full-visible-spectrum WLEDs.
研究领域:
材料科学
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光学材料
·
固态照明
·
无机化学
·
光电子学
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DOI
高影响因子
Science China-Materials
·
2026
·
IF 7.4
Wang Qianqian,Pan Shifeng,Li Haibo,Zhang Menghuan,Zhou Zhennan,Liu Wei,Ouyang Gangfeng
Organic-inorganic hybrid copper(I) halide semiconductors have attracted extensive attention for applications in phosphor-converted white light-emitting diodes (pc-WLEDs), X-ray imaging, and photodetectors because of their superior photo/radioluminescence, structural diversity, and eco-friendliness. In our previous work, we proposed a novel strategy for synthesizing highly efficient blue-emitting copper(I) halide hybrids by combining coordinated anionic inorganic modules with cationic derivatives. However, the complexity of the synthesis process has limited the practical application of this approach. To address this challenge, we report a facile, efficient, and rapid solution-based ultrasonic treatment method for synthesizing high-performance blue-emitting phosphors with this structural motif using inexpensive and commercially available tetraethylammonium halides (TEAX, X = Cl, Br, and I). The synergistic interplay of ionic and covalent bonds in these compounds endows them with a high photoluminescence quantum yield (PLQY) of 70% and excellent stability. These materials exhibit a thermally activated delayed fluorescence (TADF) mechanism, delivering outstanding performance in pc-WLEDs and X-ray imaging. Their exceptional properties highlight their significant potential for use in optoelectronic devices and X-ray scintillators. This work provides an important reference for the rapid synthesis of high-performance copper(I) halide hybrid phosphors and paves the way for their commercial application.
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高影响因子
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