OPTICAL MATERIALS
·
2020
·
IF 2.779
Yanying Bi,Hang Yang,Xiaohan Yun,Hang Zhang,Xiangjie Ma,Guogang Li,Yujun Liang,Yongjun Chen
Currently, the development of highly efficient emission tunable phosphor materials is necessary for improving the lighting quality of UV light based white emitting diodes (WLEDs). Herein, a series of new blue-emitting Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ (CM/ZP: Eu 2+ ) phosphors were successfully synthesized through a high temperature solid phase reaction process. Interestingly, through constructing Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ solid solutions based on a complete substitution of Mg 2+ by Zn 2+ , the controllable blue-shift emission from 441 to 418 nm could be realized. This result could be attributed to the selective occupation of different Ca 2+ ions for Eu 2+ ions due to distortion of coordination polyhedron. The corresponding full width at half maximum (FWHM) exhibits a gradual narrowing from 66 to 27 nm after [Zn→Mg] replacement, and the color purity of Eu 2+ emission in Ca 7 Zn 2 P 6 O 24 (CZP) could reach 93.2%. Finally, the thermal quenching resistance of the as-prepared Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ phosphors show remarkably excellent performance. Moreover, the thermal stabilities working at 150 °C of CMZP: Eu 2+ were gradually improved from 71% for CZP: Eu 2+ to 97% for CMP: Eu 2+ of original photoluminescence intensity. Generally, the cation substation induced selective occupation of Eu 2+ to control FWHM is an efficient design to achieve emission-tunable phosphors, and the developed narrow-band Ca 7 (Mg, Zn) 2 P 6 O 24 : Eu 2+ blue-emitting phosphors could serve as potential blue phosphors for WLEDs application.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 36
·9255-9263
·
IF 5.256
Luqing Xi,Yuexiao Pan,Mengmeng Zhu,Hongzhou Lian,Jun Lin
A kind of red-emitting phosphor NaKSnF6:Mn4+ (NKSF:Mn) has been obtained from NaF and KF with a certain molecular ratio in HF solution at room temperature. The phosphor NKSF:Mn exhibits superior optical properties including high color purity with narrow-band emissions as well as better chromaticity coordinates compared to the red phosphors Na2SnF6:Mn4+ (NSF:Mn) and K2SnF6·H2O:Mn4+ (KSFH:Mn). The composition and structure of NKSF:Mn have been identified by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The formation mechanism of NKSF:Mn is discussed and the morphology, thermal stability, and optical properties of NKSF:Mn have been investigated. The luminescence intensity of NKSF:Mn has been improved by optimizing synthetic parameters. A white light-emitting diode (WLED) fabricated using a blue GaN chip, a yellow YAG:Ce phosphor, and the as-prepared red phosphor NKSF:Mn exhibits superior warm white light with a color rendering index (CRI) of 90.3 at a correlated color temperature (CCT) of 3746 K.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
Nanoscale
·
2018
·Vol. 10
·期 47
·22237-22251
·
IF 7.233
Guo-Hui Pan,Huajun Wu,Shuai He,Liangliang Zhang,Zhendong Hao,Xia Zhang,Jiahua Zhang
The most common yellow phosphor for wLEDs, Y3Al5O12:Ce3+ (YAG:Ce3+), suffers from a deficiency of red in its spectral content of light. In this paper, a new strategy is provided to tailor the Ce3+ spectral profile through surface-located dye molecules of ATTO-Rho101, which feature intense, broad absorption in the green-yellow spectral region of Ce3+ emission as well as bright red emission. Sphere-shaped and highly dispersed micrometer and nanometer-sized YAG:Ce3+ (micro/nano-YAG:Ce3+) was synthesized through a modified solvothermal method. Surface SiO2 coating and simultaneous dye embedding were performed on the solvothermally derived YAG:Ce3+, heat-treated micro-YAG:Ce3+ and commercial phosphors. Efficient radiative transfer/reabsorption from Ce3+ in the inner core of YAG to the dye molecules in the SiO2 outer shell, irrespective of the size of the phosphors, was demonstrated in the accumulated YAG:Ce3+@SiO2 + dye powder upon blue light excitation; this enhanced its red emission. Fluorescence microscopy was demonstrated to be a powerful tool to identify the reabsorption phenomenon of the powdered materials. Packaging the heat-treated micro-YAG:Ce3+@SiO2 + dye phosphors on blue LED chips yielded a warm wLED (Ra ∼ 93), but an Ra of only ∼79 was obtained for the wLED with commercial YAG:Ce3+@(SiO2 + dye)5 due to the low concentration of phosphors dispersed in the epoxy resin and the resulting decreased reabsorption by dye molecules. Surface-protonated amine species were found to induce Ce3+ → Ce4+ oxidation upon activation by heating or photoirradiation and then quench the photoluminescence (PL) of micro-YAG:Ce3+ even after surface modification by SiO2, YAG or being embedded in an epoxy resin matrix. High calcination temperatures greatly improved the PL stability of micro-YAG:Ce3+ through the removal of surface-capped species. The dye in the silica matrix showed high stability against heating and irradiation due to the so-called “caging effects”; however, decreased photo-stability was found in commercial YAG:Ce3+@(SiO2 + dye)5 due to the incomplete and/or loose SiO2 layer grown during multiple surface modifications.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiaoyi Liu,Feng Hong,Ge Pang,Haiming Cheng,Xiaosong Yu,Hu Wang,Guixia Liu,Dan Li,Xiangting Dong,Jinxian Wang,Wensheng Yu
Novel narrow-band red-emitting K 3 WO 2 F 5 ·2H 2 O:Mn 4+ and its paraffin wax (PW)-coated phosphor (K 3 WO 2 F 5 ·2H 2 O:Mn 4+ @PW) were synthesized via simple co-precipitation method. Optical properties of the phosphors have been systematically analyzed. Meanwhile, the energy transfer process in the phosphor was discussed in detail, which provides a feasible basis for broadening the application range of the phosphor when excited by UV-light. The thermostability of K 3 WO 2 F 5 ·2H 2 O:Mn 4+ sample was analyzed via investigating the temperature-dependent photoluminescence properties. More importantly, the luminescence properties and hydrophobic stability of the phosphors coated with PW were superior to those of K 3 WO 2 F 5 ·2H 2 O:Mn 4+ and K 2 SiF 6 :Mn 4+ . The luminescence intensity of K 3 WO 2 F 5 ·2H 2 O:Mn 4+ @PW decreased by only 24.5% after the phosphor was immersed in water for 360 min. K 3 WO 2 F 5 ·2H 2 O:Mn 4+ @PW was used as red component to fabricate the warm white light-emitting diode, which presents excellent photoelectric parameters Ra = 90.1 and CCT = 3664 K) and remarkable stability in the range of 20–200 mA driving current. These results demonstrated that K 3 WO 2 F 5 ·2H 2 O:Mn 4+ @PW red composition has the ideal application value in WLEDs.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Qi Wu,Mengmeng Fu,Chenzhang Gu,Yinzhen Wang,Lu Yao,Cailin Wang
Red phosphors with good thermal stability, high color temperature and color purity are critical in high power warm white LED devices. Herein, a series of single and co-doped Tb 3+ ,Eu 3+ polychromatic phosphors with pyrochlore structure based on Gd 2 Zr 2 O 7 have been prepared for the first time by a conventional solid phase reaction method. Compared to single doped Eu 3+ phosphors, Tb 3+ ,Eu 3+ co-doped phosphors possess following advantages: improved UV absorption, increased photoluminescence intensity, extended luminescence range and improved thermal stability. At room temperature, the Gd 2 Zr 2 O 7 :Tb 3+ ,Eu 3+ phosphors exhibited a gradual shift from yellow-green emission at 544 nm to orange-red emission at 613 nm with increasing doping of Eu 3+ ions. Energy transfer efficiency has been evaluated to be 71% by analyzing the fluorescence lifetime of Tb 3+ ions. The concentration quenching mechanism under different conditions was analyzed in detail and it was concluded that the quenching of Tb 3+ is caused by dipole-dipole interaction. In addition, the activation energy (ΔE a ) of the Gd 1.92 Zr 2 O 7 :0.03Tb 3+ ,0.05Eu 3+ phosphor was calculated to be as high as 0.2674 eV compared to other Tb 3+ , Eu 3+ co-doped phosphors, demonstrating its high thermal stability. WLEDs devices based on Gd 1.92 Zr 2 O 7 :0.03Tb 3+ ,0.05Eu 3+ phosphors have been prepared, which have low correlated color temperature (CCT) (5283 K), high color rendering index Ra = 85.5 K) and CIE coordinates chromaticity coordinate (0.3371,0.3333). All of the results show that Gd 2 Zr 2 O 7 :Tb 3+ ,Eu 3+ phosphors provide a new avenue to develop high quality red emission and high thermal stability phosphors for WLEDs.
研究领域:
材料科学
·
光电
·
光子学
·
固体物理
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 26
·51467-51475
·
IF 5.6
Wenjie Wang,Jianyan Ding,Quansheng Wu
In recent years, multi-mode fluorescent anti-counterfeiting technology has been regarded as a promising replacement for traditional single-fluorescent-pattern-based methods in ensuring information security. This advancement necessitates phosphors with multi-mode photoluminescent properties. In contrast to the conventional complex approach involving the integration of downshifting and upconversion phosphors, this study demonstrates the achievement of multiple visible-light emissions in Bi 3+ -activated scandium silicate NaSrScSi 2 O 7 , which exhibits sensitivity to near-ultraviolet light. Under the excitation at 370 nm, Bi 3+ -activated NaSrScSi 2 O 7 emits a narrow-band blue light, yet it can emit a broad-band cyan light under the excitation at 340 nm. The significant photoluminescence property of Bi 3+ ion is proved to originate from special crystal structure of NaSrScSi 2 O 7 , which provides multiple crystallographic sites for accommodating Bi 3+ ion. Benefiting from the characteristic of NaSrScSi 2 O 7 , the sample performs excellent thermal and chemical stability. A warm WLED device has been fabricated by using as-prepared sample. Finally, a pattern produced by Bi 3+ -activated NaSrScSi 2 O 7 is proved to emit distinguishing visible light under the common 365 nm and 340 nm near-ultraviolet lamp, which is considered to pave a simple approach for realizing high-level fluorescent anti-counterfeiting technology.
研究领域:
材料科学
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光学材料
·
固态化学
·
发光学
·
防伪技术
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 18
·7049-7057
·
IF 8.067
Yingyuan Chen,Feilong Liu,Ziwang Zhang,Junyu Hong,Maxim S. Molokeev,Ivan A. Bobrikov,Jianxin Shi,Jianbang Zhou,Mingmei Wu
Red-light-emitting materials, as pivotal components of warm white light-emitting diodes (WLEDs), have drawn increasing public focus. Among these, Mn4+-doped red light-emitting fluorides have drawn considerable attention when combined with an InGaN chip; however, they suffer from poor water stability under humid conditions. In this work, a novel fluoride red phosphor, Cs30(Nb2O2F9)9(OH)3·H2O:xMn4+ (CNOFM), with good water resistance was synthesized for the first time using a facile co-precipitation method at ambient temperature. Experiments were implemented for the precise analysis of its crystal structure, optical properties, micro-morphology, thermal behavior, and waterproof properties. 6.66% Mn4+-doped CNOFM maintained a stable crystal structure and possessed strong PL intensity located at 633 nm with high color purity of 96%. CNOFM showed better thermal and waterproof stability compared with the commercial K2SiF6:Mn4+ red phosphor. Without any surface modifications, the PL intensity remained at about 83% of the initial value after immersion in water for 60 min, and the mechanism was investigated. Finally, a warm WLED with a CRI of 92.3 and CCT of 3271 K was fabricated using the CNOFM red phosphor.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
L. Yue,X.Z. Zheng,P.J. Xia,C. Wang,Y.F. Lei,M. Xu,W.B. Dai
Rare-earth (RE) and/or transition metal (TM) ions (co)doped phosphors have garnered much attention for promoting development in the fields of solid state lighting (SSL) and displays. It is a meaningful work to design high-quality phosphor via intelligent assembling from wide variety of compounds with RE/TM ions. Herein, the lanthanum borophosphate La 7 O 6 (BO 3 )(PO 4 ) 2 (LOBP) and Bi/Eu were selected as host and dopants for constructing the phosphor LOBP: Bi/Eu via solid phase synthetic method due to simple synthesis, chemical/thermal stability, rich cationic sites, appropriate bandgap, and controllable optical tuning from synergistic effect of cyan (Bi) and red (Eu) emissions, respectively. The structure and site occupations were analysed via XRD and Rietveld refinements , showing Bi 3+ ions were only resided in La 3+ sites within the monoclinic matrix (P2 1 /n) and appeared greater inclination towards the La sites with coordinate number ( CN ) = 8 as compared with CN = 7 due to the closer ion radius ratio. While Eu 3+ ions entered into the two distinct La sites with almost the same probability. The morphology and elemental mapping were obtained via SEM/EDS, exhibiting irregular particle shape with micron-level size, and the chemical composition met expectation. Through energy transfer (ET) from Bi to Eu under n -UV excitation, the adjustable photoluminescence (PL) from cyan traversing white and finally to red could be achieved. The concentration quenching for both singly- (Bi) and co-doped (Bi/Eu) phosphors were charged by the d-d interactions. Finally, the stable as-fabricated n -UV pumped w LED via coupling the composition-optimized white-emitting LOBP: 2%Bi, 7%Eu to a commercial 305 nm n -UV LED chip shows splendid performances.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 9
·4325-4341
·
IF 3.5
P. J. Xia,X. Z. Zheng,L. Yue,Y. F. Lei,M. Xu,W. B. Dai
For further development of light sources, white light-emitting diodes (wLEDs) have attracted widespread attention as promising next-generation light sources fabricated via the combination of phosphors and LED chips. However, latent defects, such as chemical/thermal instability, low color rendering index (CRI) and high correlated color temperature (CCT), of current mainstream wLEDs seriously hinder their further large-scale implementation. Herein, in order to overcome these limitations, single-phase color-tunable gaudefroyite (Ca3Y(GaO)3(BO3)4 (CYGB)) tridoped with Bi3+/Tb3+/Eu3+ ions was synthesized for the first time and detailed characterisation was performed via high-temperature solid-state reaction and structural/spectral analyses, respectively. Radius difference percentage calculations and Rietveld refinements indicate that dopants occupy both Y3+ and Ca2+ sites but preferably the Y3+ site over the Ca2+ site due to the same valence state. Through subtly regulating the (co)doping contents and skillfully utilizing the energy transfer (ET) strategy from the allowed transition of blue light-emitting Bi to the forbidden transition of green/red light-emitting Tb/Eu, the color hue (including white light) of highly efficient PL can be easily tuned according to the need. Meanwhile, composition/content-optimized white light-emitting CYGB:2%Bi/10%Tb/12%Eu also shows splendid chemical/thermal stability. Finally, as a proof-of-concept experiment, the CYGB:2%Bi/10%Tb/12%Eu phosphor-converted wLED (pc-wLED) was fabricated and encapsulated via the up-to-date remote ‘capping’ method, which imparted attractive performances. Altogether, the stable CYGB:Bi/Tb/Eu phosphor is a promising candidate for application in lighting/display fields.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2026
·
IF 4.6
Pan Shifeng,Tong Hua,Li Haibo,Wang Yuansheng,Zhou Ziyang,Liu Wei,Ouyang Gangfeng
Currently, mainstream white light-emitting diodes (WLEDs)
fabricated
by combining a blue LED chip with Y 3 Al 5 O 12 :Ce 3+ yellow phosphor suffer from poor color rendering,
unstable color temperature, and blue light hazards due to the lack
of a red spectral component. In this study, a low-cost, easily synthesizable,
nontoxic, and highly stable red-emitting Cu(I)-based hybrid material, Cu 2 I 2 (2-et-3-mepz) (2-et-3-mepz = 2-ethyl-3-methylpyrazine),
is developed. This red-emitting material exhibits intense red emission
under ultraviolet/blue light excitation, with an emission peak at
628 nm and CIE chromaticity coordinates of (0.628, 0.372), which are
close to the standard red light. Experimental and theoretical analyses
reveal that its luminescence mechanism primarily originates from hybrid
metal/halide-to-ligand charge transfer ( 3 M/HLCT) and cluster-centered
( 3 CC) transitions. A WLED device fabricated by combining Cu 2 I 2 (2-et-3-mepz) with commercial blue and green phosphors
achieves an Ra value as high as 93.0. Furthermore, Cu 2 I 2 (2-et-3-mepz) also exhibits excellent scintillation performance
with a light yield of 12,647 photons MeV –1 . A flexible
scintillation screen prepared using this material achieves a spatial
resolution of 9.45 lp mm –1 , demonstrating its potential
application value in X-ray imaging. This work not only achieves high-performance
WLED devices but also provides a new strategy for developing low-cost,
environmentally friendly red-emitting materials.
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DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2026
·
IF 2.8
Hou Dusong,Gao Danhong,Liu Hongwei,Deng Hanling,Lu Qianyao,Xiong Fan,Shao Hengwei,Lu Yuanyuan,Wang Mengxin,He Xinjian,Huang Sheng
The advancements in flexible display technology impose stringent demands on the optical properties and environmental stability of perovskite luminescent materials. Addressing the core challenges of poor environmental stability and optical performance degradation in methylammonium lead bromide (MAPbBr 3 ) quantum dots, this study proposes a dual-stability strategy combining “internal crystallization regulation” with “external physical protection.” A ZnO/MAPbBr 3 /PVDF composite film was prepared through synergistic modification with zinc oxide (ZnO) and polyvinylidene fluoride (PVDF), with the optimal ZnO content identified as 40 μL. Under these conditions, the composite film exhibited a green light emission full width at half maximum (FWHM) as low as 19.88 nm and a photoluminescence quantum yield (PLQY) of 76.06%, demonstrating high color purity. After heating at 100°C for 60 min, the PL intensity decayed by only 30%, and after 168 h of immersion in water, it retained 65% of its initial PL intensity, indicating significantly enhanced environmental tolerance. When this film served as the green conversion layer integrated with red CsPbI 3 quantum dot films and GaN blue LEDs to form a white light-emitting diode (WLED), the device achieved a color gamut coverage of 126% of the NTSC standard and 94% of the Rec. 2020 specification. Research indicates that ZnO enhances crystalline integrity by regulating MAPbBr 3 nucleation and growth, while PVDF forms a compact hydrophobic barrier. Their combined effect enhances both the film’s optical performance and environmental stability, enabling WLEDs with ultrawide color gamut that meet the requirements of high-performance flexible display and lighting applications.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 16
·25366-25373
·
IF 3.83
Quansheng Wu,Xiaotong Zeng,Xiaojie Li,Jianfeng Wang,Weiqing Liu,Shanshan Ye,Jianyan Ding,Jiangcong Zhou
The systems of Si-Al-O-N originated from the outstanding nitrogen ceramic of Si 3 N 4 have received considerable attention due to their significant luminescence properties . In this work, to explore its potential in the full-spectrum lighting applications, a novel oxynitride based phosphor Lu 4 SiAlO 8 N: Ce 3+ was investigated in detail by using the Rietveld refinement , DFT calculations, photoluminescent (PL) and time-resolved PL (TRPL) spectra. The results indicate that Lu 4 SiAlO 8 N performs a tight host lattice formed by the edge-sharing LuO 6 polyhedrons and (Si, Al) (O, N) 4 tetrahedrons; the multiple crystallographic Lu 3+ sites in the host lattice contribute to the broad emission band. Under the near ultraviolet (NUV) light excitation, Lu 4 SiAlO 8 N: Ce 3+ emits a bright cyan light peaked at 470 nm, and its full width at half maximum (FWHM) can reach 120 nm, which well replenishes the “cyan cavity”. Moreover, the energy transfer between the multiple luminescent centers was verified through the TRPL spectra . The temperature-dependent spectra of Lu 4 SiAlO 8 N: Ce 3+ was measured to prove its acceptably thermal stability. All the results indicate the Lu 4 SiAlO 8 N: Ce 3+ to be a promising candidate for the application in WLEDs .
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DOI
高影响因子
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