JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 26
·期 9
·6776-6780
·
IF 1.569
Cao Renping,Xu Haidong,Peng Dedong,Gou Qingdong,Zhou Shenlin,Liu Pan,Yu Xiaoguang
BaWO 4 :Sm 3+ , Mo 6+ /K + phosphors are synthesized by a high temperature solid-state reaction method in air. The very strong emission bands peaking at ~600 and 644 nm and the strongest excitation band peaking at ~403 nm are assigned to the 4 G 5/2 → 6 H J (J = 7/2 and 9/2) and 6 H 5 / 2 → 4 F 7 / 2 transitions of Sm 3+ ion, respectively. The optimal Sm 3+ doping concentration is ~5 mol%. Emission intensity of BaWO 4 :Sm 3+ phosphor is increased more than twice owing to charge compensation when the K + ion is codoped as charge compensator, however, Mo 6+ ions is small influence to its emission intensity. The energy transfers and luminous mechanism are explained by using energy level diagrams of WO 4
2− group and Sm 3+ ion. Lifetimes of Ba 0.925 WO 4 :0.05Sm 3+ , Ba 0.925 W 0.9 Mo 0.1 O 4 :0.05Sm 3+ , and Ba 0.9 K 0.05 WO 4 :0.05Sm 3+ phosphors with excitation 403 nm are about 0.933, 0.882, and 0.693 ms, respectively. The experiment results indicate that BaWO 4 :Sm 3+ , Mo 6+ /K + phosphors will be a potential red phosphor candidate for white LEDs based on near UV (~403 nm) LED chip and research contents are useful to improve luminescence properties of Sm 3+ -doped phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
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DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 11
·3606-3614
·
IF 4.174
Yibing Wu,Yixi Zhuang,Rong-Jun Xie,Kaibin Ruan,Xinhua Ouyang
Red emitters based on CaAl12O19:Mn4+ have been attracting extensive attention due to their advantages of being rare-earth-free and chemically stable. However, their relatively low luminescence efficiencies will seriously hinder their application in light-emitting diodes (LEDs). In this regard, the promising red phosphors of CaAl12O19:Mn4+ were synthesized with enhanced luminous efficiency by introducing the coexisting phase of MgAl2O4. Importantly, an approximately 5 times enhancement of integrated intensity in the emission spectrum was observed for the phosphor with the coexisting phase compared to that with a single phase. Their crystal structures, morphologies and photoluminescence properties and the mechanism of improved luminescence were systematically investigated. Upon exciting them by using near-ultraviolet or blue LEDs, an efficient red emission was achieved with a maximum peak at ∼658 nm. In order to evaluate their potential application, a warm white LED and a plant growth LED were fabricated by using the prepared phosphors in combination with YAG:Ce3+ and InGaN-based blue chips.
研究领域:
材料科学
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光学工程
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DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2020
·Vol. 7
·期 18
·3371-3378
·
IF 5.958
Yang Zhou,Xiaoming Wang,Cuiping Wang,Tian Zhang,Yonggang Wang,Fan Dou,Huan Jiao
A novel red fluoride phosphor BaNbF7:Mn4+ was synthesized via the conventional co-precipitation method. The structure and luminescence properties of BaNbF7:Mn4+ were investigated and discussed under various conditions. The BaNbF7:Mn4+ phosphor shows strong ZPL emission intensity at about 630 nm under ultraviolet (UV) and blue light excitation. It originated from the highly distorted Mn4+ octahedral coordination environment in the C3v group symmetry surrounding. A WLED fabricated with a blend of YAG:Ce3+ and the BaNbF7:Mn4+ phosphor exhibits a low color temperature (CCT = 3715 K) and a high color rendering index (Ra = 81.2), indicating its potential for application as a red phosphor for WLEDs.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
·
2023
·Vol. 78
·期 10
·921-926
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IF 1.8
Cong Liu,Junshen Xing,Zheng Liu,Wenlin Feng
BaSr 2 (PO 4 ) 2 : 4 %Eu 3+ , 4 % A ( A = Li + , Na + , K + ) phosphors were prepared by high-temperature solid-phase method. The crystal structure, photoluminescence properties, thermal stability, chromaticity coordinates, and fluorescence lifetime of the samples were investigated. The excitation and emission spectra of the samples are broadbands and the maximum peak of the emission spectrum is located at 619 nm. Among three charge compensators, the luminescence intensity is optimal for Li + co-doping case, and the quenching temperature of the typical sample is about 500 K. the fluorescence lifetime
τ
is 1469.6 ns, and the chromaticity coordinates exhibit a strong red emission. The present phosphor has a potential application for white light-emitting diodes (LEDs) under the near-ultra violet (n-UV) light excitation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2014
·Vol. 5
·期 1
·1-10
·
IF 10.742
Zhu Haomiao,Lin Chun Che,Luo Wenqin,Shu Situan,Liu Zhuguang,Liu Yongsheng,Kong Jintao,Ma En,Cao Yongge,Liu Ru-Shi,Chen Xueyuan
Mn 4+ -activated fluoride compounds, as an alternative to commercial (oxy)nitride phosphors, are emerging as a new class of non-rare-earth red phosphors for high-efficacy warm white LEDs. Currently, it remains a challenge to synthesize these phosphors with high photoluminescence quantum yields through a convenient chemical route. Herein we propose a general but convenient strategy based on efficient cation exchange reaction, which had been originally regarded only effective in synthesizing nano-sized materials before, for the synthesis of Mn 4+ -activated fluoride microcrystals such as K 2 TiF 6 , K 2 SiF 6 , NaGdF 4 and NaYF 4 . Particularly we achieve a photoluminescence quantum yield as high as 98% for K 2 TiF 6 :Mn 4+ . By employing it as red phosphor, we fabricate a high-performance white LED with low correlated colour temperature (3,556 K), high-colour-rendering index ( R a =81) and luminous efficacy of 116 lm W −1 . These findings show great promise of K 2 TiF 6 :Mn 4+ as a commercial red phosphor in warm white LEDs, and open up new avenues for the exploration of novel non-rare-earth red emitting phosphors.
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
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Renping Cao,Qingqiang Xiong,Wenjie Luo,Donglan Wu,Xiao Fen,Xiaoguang Yu
A series of SrAl [4−(4 x )/3] O 7 : x Mn 4+ (0≤ x ≤1.4 mol%) and Sr (1−0.06/2) Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06R + (R + =Li + , Na + , and K + ) phosphors are synthesized by a conventional solid-state reaction method in air. The PLE bands peaking at~325, 395, and 470 nm and the strongest PL band peaking at~660 nm are assigned to the 4 A 2 → 4 T 1 transition of Mn 4+ ion and O 2− –Mn 4+ change transfer band, 4 A 2 → 2 T 1 , 4 A 2 → 4 T 2 , and 2 E → 4 A 2 transitions, respectively. The optimum Mn 4+ doping concentration is about 0.8 mol%. Li + , Na + , and K + ions used as charge compensator can improve observably the PL intensity of SrAl 4 O 7 :Mn 4+ phosphor with excitation 325 nm. The fluorescence lifetimes of SrAl [4−(4×0.008)/3] O 7 :0.008Mn 4+ and Sr [1−0.06/2] Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06 R + (R + =Li + , Na + , and K + ) are 0.958, 0.97, 1.113 and 0.965 ms, respectively. The luminous mechanism is explained by schematic energy level diagram of Mn 4+ ion. These experiment results indicate that SrAl 4 O 7 :Mn 4+ ,R + (R + =Li + , Na + , and K + ) phosphors can be used as red emitting phosphor candidate for white LEDs based on a UV (~325 nm) and near UV (~395 nm) bands of LEDs chip.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Renping Cao,Yunling Cao,Ting Fu,Shenhua Jiang,Wensheng Li,Zhiyang Luo,Jingwei Fu
Novel red phosphors R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) are synthesized by solid state reaction method in air, and their crystal structures and fluorescence properties are characterized. The excitation bands peaking at ∼440 nm match with the blue LED chip, and their red emission band peaking at ∼658 and 686 nm within the range 580–800 nm owing to 2 P 3/2 (1) → 2 P 1/2 the transition of Bi 2+ ions can be observed, respectively. The relation between Bi 2+ doping concentration and emission intensity is discussed and the optimal Bi 2+ ion doping concentration is ∼3.0 mol%. Decay curves and time-resolved spectra confirm that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have only single Bi 2+ center. The luminous mechanism is explained by energy level diagram of Bi 2+ . The luminescence properties indicate that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have a potential to be used as red emitting phosphor candidate for white LEDs based on ∼440 nm blue LED chip.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 17
·5587-5596
·
IF 4
Zhijian Liao,Yan Li,Jiaxing Zuo,Guang Chen,Heng Liang,Shihao Wu,Jiaqing Peng,Xinyu Ye
For high-efficiency lighting and wide color gamut backlight display, high-quality narrow-band red phosphors for WLEDs are still in high demand. Herein, a novel red-emitting fluoride phosphor Cs2NaGaF6:Mn4+ was successfully synthesized by a simple two-step co-precipitation method and exhibits ultra-intense zero-phonon lines (ZPLs) and long wavelength phonon sidebands under 468 nm blue light irradiation. The ZPL emission peak of Cs2NaGaF6:Mn4+ was located at 627 nm, which is much stronger than its υ6 vibration peak, more matchable with the eye-sensitive region of humans, and beneficial for obtaining higher luminous efficiency of WLEDs. Interestingly, the υ6 vibration peak of this red phosphor is at 636.5 nm, which is larger than that of the common fluoride phosphor A2BF6:Mn4+ (usually at about 630 nm, represented by K2SiF6:Mn4+) at about 6.5 nm. Thanks to the longer wavelength of the υ6 vibration peak, the chromaticity coordinates (0.7026, 0.2910) with a larger x-coordinate value were realized, leading to a potentially wider color gamut of WLEDs. In addition, this phosphor has high thermal stability and its emission intensity at 423 K remains 93.7% of the initial intensity at room temperature. The lumen efficiency of WLED1 packaged with a mixture of Cs2NaGaF6:Mn4+ and YAG:Ce3+ on the InGaN blue chip is 115.7 lm W−1 with the color temperature (Tc) = 3390 K and the colour rendering index (Ra) = 92.5 under 20 mA driving current. The chromaticity coordinates of WLED2 packaged with Cs2NaGaF6:Mn4+ and β-SiAlON:Eu2+ on the InGaN blue chip are (0.3149, 0.3262) and the calculated color gamut is up to 118.4% (NTSC). These results indicate that Cs2NaGaF6:Mn4+ red phosphors have promising applications in the high-quality lighting and display fields.
研究领域:
材料科学
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光学工程
✓ 已验证
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DOI
PubMed
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 2
·208-215
·
IF 2.9
Hui Wang,Lingling Wang,Meihua Wu,Minghao Fang,Zhaohui Huang,Xin Min
This paper reports a sequence of a Ca 3 YAl 3 B 4 O 15 :xEu 3+ red phosphor prepared using a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emitted intense red emission centred at ~623 nm, which could be attributed to the 5 D 0 → 7 F 2 transition of the Eu 3+ ion. The results showed that the optimum Eu 3+ doping concentration of Ca 3 YAl 3 B 4 O 15 :Eu 3+ phosphor was x = 80 mol%, and the concentration quenching mechanism of Ca 3 YAl 3 B 4 O 15 :Eu 3+ red phosphor belonged to the exchange coupling between Eu 3+ ions. The Commission Internationale de l'éclairage (CIE) coordinates and colour purity of Ca 3 Y 0.2 Al 3 B 4 O 15 :0.8Eu 3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca 3 YAl 3 B 4 O 15 :0.8Eu 3+ exhibited a low thermal quenching behaviour with an intensity retention rate of 92.85% at 150°C. The above results manifest that the Eu 3+ -activated Ca 3 YAl 3 B 4 O 15 phosphor is predicted to be a promising red luminescent component for white light-emitting diodes.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 10
·5077-5085
·
IF 3.784
Zhaowu Wang,Haipeng Ji,Zongtao Zhang,Jian Xu,Deliang Chen
The cation exchange method has been demonstrated to be efficient in doping Mn 4+ ions into various fluorides to synthesize the red-emitting LED phosphors. This paper, however, reports the challenge in using this method to dope Mn 4+ into the Na 2 SiF 6 single crystals, to prepare the fluoride phosphor in single-crystal form, a state-of-the-art study in the white LED lighting field. The millimeter-sized Na 2 SiF 6 single crystals with a uniform columnar morphology (2–3 mm in length) were successfully grown in solution by a slow cooling process after optimizing the precursors. Then, the crystals were soaked in the HF solution dissolved with K 2 MnF 6 to implement Mn 4+ -doping via the cation exchange process. Evaluation of the Mn 4+ -doping behavior reveals that the Mn 4+ ↔ Si 4+ cation exchange is less efficient in the case of single crystal host compared with the polycrystalline powdery ones and by-reactions also occur which generates new phases. The Na 2 SiF 6 single crystals doped with Mn 4+ exhibit a series of discrete sharp peaks with intense zero phonon line emission at 617 nm under 450 nm blue irradiation. This study may trigger the exploration of new single crystal fluoride phosphor.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
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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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高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 39
·10241-10250
·
IF 5.256
Mengmeng Zhu,Yuexiao Pan,Luqing Xi,Hongzhou Lian,Jun Lin
Mn4+-activated red phosphors have attracted considerable attention as promising red components in the spectra of white light emitting diodes (WLEDs) to achieve warm white light with superior performance. Herein, a novel red phosphor based on Mn4+-doped dodec-fluoride Li3Na3Al2F12:Mn4+ (LNAF:Mn) with microcubic morphology was obtained at room temperature. To elucidate the underlying relationship between the crystal structure and photoluminescence of LNAF:Mn, a phosphor LiNa2AlF6:Mn4+ with similar composition has been prepared, and their morphology and optical properties were comparatively investigated. The emission of the red phosphor LNAF:Mn is blue shifted compared to LiNa2AlF6:Mn4+ suggesting that the chromaticity coordinates of LANF:Mn are closer to the ideal red point (0.67, 0.33). The luminescence properties of LNAF:Mn have been improved by optimizing the synthetic conditions. This work exhibits a strategy to explore a novel Mn4+-doped fluoride except for the identified hexa-fluorides. Employing the as-prepared red LNAF:Mn as a red component, a high-performance WLED with a correlated color temperature (CCT) of 3874 K and a color rendering index (CRI) of 90.6 was obtained. This suggests the phosphor is a potential commercial red phosphor in warm WLEDs.
研究领域:
材料科学
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光学工程
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高影响因子
危险品化学品经营许可证（带存储）