OPTICAL MATERIALS
·
2021
·
IF 3.08
Xiaoyi Liu,Haiping Xu,Yunxiao Zhang,Zhendong Fu,Feng Hong,Ge Pang,Guixia Liu,Dan Li,Xiangting Dong,Jinxian Wang
Chrysanthemum-like K 2 LiAlF 6 :Mn 4+ phosphors were synthesized by simple co-precipitation method without using HF. The K 2 LiAlF 6 :Mn 4+ phosphor can be effectively excited through blue light at 465 nm, then produces sharp red-light emission near 634 nm. The luminescence quenching of Mn 4+ is caused by the d-d interaction between Mn 4+ ions. The effects of surfactant and lithium source on the luminescent properties of K 2 LiAlF 6 :Mn 4+ phosphors were discussed. Mn 4+ is located in a strong crystal field environment in the K 2 LiAlF 6 matrix and its emission mechanism is discussed. Warm white light emitting diode (WLED) device, which is fabricated by coating a certain proportion mixture of yellow YAG:Ce 3+ phosphor and red K 2 LiAlF 6 :5%Mn 4+ phosphor on the blue GaN chip, has low correlation color temperature (CCT = 3588 K), high color rendering index (R a = 90.8) and good electroluminescence stability under different currents. These properties illustrate that K 2 LiAlF 6 :5%Mn 4+ phosphor is a promising red light emitting material.
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
Advanced Optical Materials
·
2023
·
IF 9
Sisi Liang,Liping Song,Wendong Nie,Zihao Wang,Dejian Chen,Fulin Lin,Haomiao Zhu
Synthesis of a Mn 4+ -activated fluoride red-emitting phosphor combining high efficiency, excellent thermal stability, and outstanding moisture resistance still remains a challenge. Herein, this work synthesizes a red-emitting phosphor Cs 2 NbF 6 : Mn 4+ (CNF: Mn 4+ ) based on the cation-exchange method. Interestingly, as a result of the redox reaction between Mn 3+ (Mn 2+ ) and Nb 5+ ions during the exchange reaction, the real Mn 4+ concentration is remarkably increased, while Nb 5+ ions are reduced to Nb 4+ . The obtained optimum CNF: Mn 4+ phosphor shows high internal and external photoluminescence (PL) quantum yield (QY) of 92% and 58%, respectively. Moreover, the CNF: Mn 4+ exhibits excellent thermal stability ( I @150 = 105%) and moisture resistance. A white light-emitting diode (LED) packaged by combining blue diode chips, Y 3 Al 5 O 12 :Ce 3+ yellow phosphor, and CNF: Mn 4+ red phosphor demonstrates a low correlated color temperature (CCT) of 3872 K, high color rendering index (CRI) of Ra = 88, and a luminous efficacy of 105 lm W −1 . The high-performance of the white LED suggests the great potential of the CNF: Mn 4+ narrowband red phosphor in display and lighting fields.
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
ChemistrySelect
·
2025
·Vol. 10
·期 17
·e202500785
·
IF 2
Jing Wang,Xingke Zheng,Jiaqi Gao,Yue Luo,Zhe Jiang
Graphical This study reports the synthesis of Ca 2 La(Ta,Mn)O 6 double perovskite red emitters, exhibiting strong red emission at 691 nm, with excellent thermal stability and UV excitation. A wireless power transfer system demonstrates adjustable luminescence under various voltages and frequencies, positioning this material as a promising candidate for indoor lighting and noncontact circuits. The rapid adoption of light emitting diodes technology stems from its high efficiency, long lifespan, and energy-saving capabilities. However, achieving high-quality white light emitting diodes, particularly through the integration of efficient red emitters, remains a significant challenge. This study reports the synthesis of Ca₂La(Ta,Mn)O₆ double perovskite red emitters via high-temperature solid-state reactions. The material exhibits a strong red emission peak at 691 nm, attributed to Mn⁴⁺ ions at symmetrical [TaO₆]⁷⁻ octahedral sites, confirmed by g = 2.008 in electron paramagnetic resonance spectroscopy. The UV excitation spectrum (250–600 nm) and thermal stability were analyzed, showing a retained optical intensity of 41% at 423 K. Additionally, a red emitter was developed, and a noncontact LCC-S wireless power transfer driving system was constructed. The system demonstrated adjustable luminescence under varying input voltages (4–7.3 V) and frequencies (90–110 kHz), highlighting its potential for dynamic lighting applications. These findings suggest Ca 2 La(Ta,Mn)O 6 double perovskite as a promising candidate for indoor lighting and noncontact circuit systems.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Shihang Zhang,Liying Zhang,Haipeng Ji
Mn 4+ -activated fluoride phosphors, exemplified by K 2 SiF 6 :Mn 4+ , exhibit exceptional narrow-band red emission but suffer from severe hydrolysis-driven degradation, significantly limiting their operational longevity. This study systematically investigates the stepwise degradation of K 2 SiF 6 :Mn 4+ upon water exposure, uncovering new insights into its hydrolytic behaviour. Upon immersion, the phosphor suspension undergoes a browning-clearing transition, attributed to the hydrolysis of [MnF 6 ] 2– which generates black suspended MnO 2 that temporarily darkens the solution before sedimentation. The degradation process involves two sequential stages: an initial rapid dissolution-dissociation of K 2 SiF 6 :Mn 4+ , accompanied by a sharp pH decrease, followed by relatively slower hydrolysis of [MnF 6 ] 2– and [SiF 6 ] 2– yielding crystalline MnO 2 and amorphous H 2 SiO 3 . Besides, upon reaching dissolution-ionization equilibrium, the released K + , [SiF 6 ] 2– , and [MnF 6 ] 2– ions would nucleate and precipitate, forming crystalline K 2 SiF 6 and K 2 SiF 6 :Mn 4+ particles with much smaller size compared to the original K 2 SiF 6 :Mn 4+ . Notably, this study reveals that the degradation of K 2 SiF 6 :Mn 4+ is significantly accelerated under both blue and UV light illumination, with UV light inducing faster degradation. These findings provide fundamental insights into the hydrolysis-driven degradation mechanism of Mn 4+ -activated fluoride phosphors, offering a scientific basis for developing strategies to enhance their stability and extend their service life.
研究领域:
材料科学
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化学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2023
·
IF 3.6
Kang Cheng,Xinyue Liu,Rongbo Ma,Bin Li,Chong Yang,Xinyong Gong,Weichao Huang
Li 2 MgTiO 4 :Cr 3+ , Mn 4+ phosphors were successfully synthesized by the high-temperature solid-state reaction method. Cr 3+ , Mn 4+ co-doped Li 2 MgTiO 4 phosphors have two emission peaks at 674 nm and 719 nm, corresponding to 2 E→ 4 A 2 transitions of Mn 4+ and 2 E→ 4 A 2 transitions of Cr 3+ , respectively. The two emission peaks are matched with the absorption of P R and P FR , and the intensity ratio of the two emission peaks is adjusted by changing the doping concentration of Mn 4+ , indicating that the phosphors have potential applications in plant cultivation. In addition, it can be observed that the emission peak corresponding to Mn 4+ can decrease sharply with the increase of excitation wavelength, while the emission peak corresponding to Cr 3+ can change little, which indicates that the phosphors can be used for wavelength detection. The security ink prepared by Li 2 MgTiO 4 :Cr 3+ , Mn 4+ phosphors shows that it can be applied in anti-counterfeiting labels. These results suggest that Li 2 MgTiO 4 :Cr 3+ , Mn 4+ have the great potentiality to be used for plant cultivation, wavelength detection and anti-counterfeiting.
研究领域:
材料科学
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光学工程
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农业科学
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DOI
高影响因子
Science China-Technological Sciences
·
2017
·Vol. 60
·期 10
·1458-1464
·
IF 1.719
Zhu YiWen,Liu Yong,Huang Lin,Xuan TongTong,Wang Jing
Red phosphor K 2 LiAlF 6 :Mn 4+ has been synthesized by a cation-exchange method in HF solution. To optimize their optical properties, phosphors were synthesized using different reaction conditions. The K 2 LiAlF 6 :0.5%Mn 4+ synthesized at 20°C for 4 h shows the highest luminescence intensity. The temperature-dependent emission intensity of the phosphor was investigated, and it was found to exhibit good thermal stability, making it a promising red phosphor candidate for warm WLEDs.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2018
·
IF 2.32
Shuai Zhang,Hengwei Wei,Yang Zhou,Xiaoming Wang,Ling Xu,Huan Jiao
In this work, an airtight solid-state strategy was developed for the synthesis of K 2 TiF 6 :Mn 4+ phosphor without the usage of high concentration HF solution. By heating K 2 TiF 6 , K 2 MnF 6 and KHF 2 in a sealed container at 474 K for hours and then washing the as-synthesized samples several times, K 2 TiF 6 :Mn 4+ phosphor was obtained. The microstructure, luminescent properties of the phosphor were investigated systemically. The reaction mechanism were investigated and discussed in detail. KHF 2 is the key role to obtain the red phosphor, which provides additional pressure and HF gas atmosphere, works as reaction intermediate and contributes to Mn 4+ doping into K 2 TiF 6 host. By using as-prepared K 2 TiF 6 :Mn 4+ phosphor as a red componet for warm W-LEDs, the high color rendering index (Ra = 84) and low color temperature (CCT = 3621 K) device performance proved that this environmental friendly synthesis method would be an efficient way to produce red fluoride phosphor for W-LEDs.
研究领域:
材料科学
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光学工程
✓ 已验证
DOI
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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DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 8
·2069-2076
·
IF 5.976
Xiaodong Yi,Renfu Li,Haomiao Zhu,Jun Gao,Wenwu You,Zhongliang Gong,Wang Guo,Xueyuan Chen
In this work, we propose a co-precipitation method for the synthesis of K2NaAlF6:Mn4+ red phosphor at room-temperature using methanol as the precipitating agent with a synthetic yield of ∼77%. The prepared sample (Mn ion doping concentration of 2.31 at%) exhibits a broad absorption band peaked at 466 nm and sharp emission lines centered at 631 nm with a high photoluminescence quantum yield up to 85%. The electronic/vibronic structures of the Mn4+ ions in the K2NaAlF6 crystal were investigated in detail for the first time by means of low-temperature (3 K) and high-resolution spectroscopy. This revealed that the Mn4+ ions mainly occupy three distinct crystallographic sites, which differs from the hypothesis that the Mn4+ ions will substitute the Al3+ ions in the K2NaAlF6 crystal, likely due to the charge mismatch between the Mn4+ and Al3+ ions. In particular, the unusually high intensity of the zero-phonon line at 622.40 nm implies that the corresponding Mn4+ ions resided in a non-centrosymmetric local site, which was corroborated by the observed energy level splitting of the 2E state. By employing the 2.31 at% sample as a red phosphor, we fabricated a warm white light-emitting diode (WLED) with a low correlated colour temperature (3911 K), a high colour rendering index (Ra = 94) and a luminous efficacy of 89 lm W−1. These findings provide deep insights into the optical properties of Mn4+ ions in hexafluoroaluminate hosts, and they show the great promise of K2NaAlF6:Mn4+ as a red phosphor for highly efficient warm WLEDs and wide-gamut displays.
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
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Xiaoyong Huang,Qi Sun,Balaji Devakumar
Deep-red-emitting phosphors are important for fabricating light-emitting diodes (LEDs) toward applications in plant growth lighting. Herein, we reported on novel efficient deep-red-emitting Mn 4+ -activated Ca 2 LuTaO 6 (CLT) double-perovskite phosphors. A series of CLT: x Mn 4+ ( x = 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) samples were prepared by the conventional high-temperature solid-state reaction technique, and they were characterized by using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), elemental mapping, photoluminescence excitation and emission, decay curves, CIE chromaticity coordinates, internal quantum efficiency (IQE), and temperature-dependent emission spectra . The CLT host crystallized in a monoclinic structure with space group of P2 1 /n, and it contained an octahedral site of TaO 6 for Mn 4+ doping. Impressively, under 351 ultraviolet light excitation these CLT: x Mn 4+ phosphors exhibited bright deep-red emissions around 682 nm with CIE chromaticity coordinates of (0.7272, 0.2728) and full width at half maximum (FWHM) of 25 nm. Notably, the optimal CLT:0.2%Mn 4+ sample possessed an IQE of 37% and good resistance to thermal quenching (I 423 K /I 303K = 47%). Considering the emission spectrum of CLT:0.2%Mn 4+ deep-red-emitting phosphors matched well with the absorption spectrum of phytochrome P FR , the as-prepared CLT:0.2%Mn 4+ phosphors showed great potential in plant growth LEDs.
研究领域:
材料科学
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植物学
·
光学工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 20
·17931-17938
·
IF 2.324
Lu Zuizhi,Zhang Xiaoshan,Huang Meixin,Wen Lingling,Wang Huan,Huang Tianjiao,Zhou Liya
A series of pure Mn 4+ -doped red Sr 2 YNbO 6 (SYN) phosphors were synthesized through the solid-state reaction method. The crystal structure, composition, luminescence properties, and thermal stability of the phosphors were determined through X-ray powder diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectrometry, and photoluminescence excitation (PLE) spectrometry. The photoluminescence decay curve and temperature-dependent photoluminscence spectra of the phosphors were also obtained. A broad absorption band at 200–550 nm is present in the UV–Vis spectra of the phosphors. Moreover, the PLE spectra of the phosphors present two broad excitation bands at 255–420 and 460–540 nm. These results illustrate that the SYN:Mn 4+ phosphors are suitable for application in UV chips. The phosphor emits red light (675 nm) under excitation with 310 nm light. Crystal field analysis indicates that only the Mn 4+ luminescent center is present in the phosphors. The calculated activation energy of the phosphors is 0.381 eV. This result proves that the phosphors possess good thermal stability. The chromaticity coordinates of the phosphors (0.699, 0.302) are close to the standard values set by the National TV Standards Committee (0.666, 0.333). All analytical results show that SYN:Mn 4+ phosphors have considerable potential applications in white-light-emitting diodes.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Mengmeng Zhu,Yuexiao Pan,Mingmei Wu,Hongzhou Lian,Jun Lin
A red phosphor with a broad excitation band in blue region and sharp emission peaks in red region is needed for compensating the red components of white light-emitting diodes (WLEDs) by converting blue light with a yellow phosphor Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce). The red phosphor LiSrAlF 6 :Mn 4+ (LSAF:Mn) with morphology of flaky particles about 50 μm in diameter has been synthesized by an ion-exchange reaction route at room-temperature in air. The as-synthesized phosphors were characterized by x-ray powder diffraction (XRD), scanning electron microscope (SEM), and temperature-dependent photoluminescence (PL) spectra. The excitation spectrum of LSAF:Mn shows a broad-band excitation from 400 to 500 nm that is due to the spin-allowed transition of 4 A 2g → 4 T 2g of Mn 4+ , indicating a potential application for solid state lighting. The optimal PL intensity of the phosphor LSAF:Mn has been obtained by optimizing the synthetic parameters.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）