INORGANIC CHEMISTRY
·
2017
·
IF 4.857
Hongzhou Lian,Qingming Huang,Yeqing Chen,Kai Li,Sisi Liang,Mengmeng Shang,Manman Liu,Jun Lin
Narrow band red-emitting A2GeF6:Mn4+ (A = Na, K, Rb, Cs) phosphors were prepared through a two-step precipitation–cation exchange route using a K2MnF6 precursor as the Mn4+ source. The phase purity, morphology, and constituent were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), and electron paramagnetic resonance (EPR) examination. Optical properties were investigated by photoluminescence spectra (PL and PLE) and high-resolution PL. A temperature-dependent PL examination was performed to investigate the electron–phonon coupling emission mechanism of Mn4+ in these alkali fluorogermanates. The PL data show that both ordered distribution and appropriate distance between Mn4+ ions are propitious for enhancement of the emission intensity. A resonance emission enhancement (REE) mechanism has been proposed to explain the intensity increment among these products. These phosphors present bright red emission under blue light (467 nm) illumination, among which Cs2GeF6:0.03Mn4+ exhibits the most excellent optical properties with a quantum yield (QY) of 93%. A WLED (white light-emitting diode) fabricated with blend of commercial YAG:Ce3+ and this phosphor emits intense warm white light with low color temperature (CCT = 3385 K) and high color rendering index (Ra = 90.5), implying its potential application as red phosphor in WLEDs.
研究领域:
材料科学
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光学
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光子学
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照明技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yayun Zhou,Hong Ming,Shuai Zhang,Tingting Deng,Enhai Song,Qinyuan Zhang
Mn 4+ -doped fluoride red-emitting phosphors are widely used in white light-emitting diodes (WLEDs) for wide-color-gamut backlight display. However, the long fluorescence decay time (τ > 5 ms) are easy to cause image-retention while images rapidly switch compare to Eu 2+ -doped red phosphors (0.2–2 μs). Herein, we report a novel Rb 2 MoO 2 F 4 :Mn 4+ (RMOF) phosphor with short fluorescence lifetime (τ < 4 ms) and characteristic zero phonon line emission, realized via equivalent doping of [MnF 6 ] 2− into [MoO 2 F 4 ] 2− group lattice. Theoretical calculations reveal that the formation energy of [MnF 6 ] 2− occupying [MoO 2 F 4 ] 2− only needs a low energy to balance the charge mismatch between Mn 4+ and Mo 6+ . A wide color gamut (~101.6% NTSC) WLED without obvious image-retention was fabricated by using Rb 2 MoO 2 F 4 :Mn 4+ as red component, showing a faster switching speed than the commercial K 2 SiF 6 :Mn 4+ (τ > 8 ms) based LEDs. This [MnF 6 ] 2− group equivalent doping strategy would pay a way to explore Mn 4+ occupation in oxy-fluoride phosphors and open a new perspective on designing short fluorescence decay time phosphors for wide color gamut fast-response displays.
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2013
·
IF 1.977
Renping Cao,Kaniyarakkal N. Sharafudeen,Jianrong Qiu
Red-emitting SrMgAl x O 17±δ : y Mn 4+ composite phosphors ( x = 10–100; y = 0.05–4.0 mol%) are synthesized by solid-state reaction method in air. Addition of Al 2 O 3 leads to the formation of two concomitant phases, i.e., SrMgAl 10 O 17 and Al 2 O 3 phases in the composite phosphor. Red emission from Mn 4+ ions in the composite phosphors is greatly enhanced due to multiple scattering and absorption of excitation light between SrMgAl 10 O 17 and Al 2 O 3 phases. SrMgAl x O 17±δ : y Mn 4+ composite phosphors would be a promising candidate as red phosphor in the application of a 397 nm near UV-based W-LED.
研究领域:
材料科学
·
光学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 32
·8670-8678
·
IF 5.976
L. Y. Wang,E. H. Song,Y. Y. Zhou,T. T. Deng,S. Ye,Q. Y. Zhang
A Rb-based fluorotitanate stable narrow band red-emitting phosphor Rb2TiF6:Mn4+ with an internal quantum efficiency of 91% was synthesized through an efficient and mild coprecipitation method. Herein, by simultaneously using H2TiF6 as a Ti source to replace TiO2 and using H2O as a substitute for solvent HF, the total consumption of toxic HF can be effectively reduced in the synthesis processes. Further optimization of phosphors can be achieved by investigating the impact of doping concentration, amount of solvent added and reaction stirring time on the luminescence properties of the phosphors. The crystal structures, morphologies, luminescence performance, thermal stability, moisture resistance, and device performance of the as-synthesized phosphors were systematically investigated. The obtained Rb2TiF6:Mn4+ presents more exceptional luminescence properties, thermal stability and longevity under LED working conditions compared to Rb2ZrF6:Mn4+, and worthy of note, its unmodified moisture resistance is obviously superior to that of other Rb-based fluoride red phosphors. By using Rb2TiF6:Mn4+ as a red-light component, a high-quality LED device with desirable performance (Ra = 89, CCT = 3730 K and LE = 158.8 lm W−1) can be obtained, and the variable drive current and temperature tests revealed that the resultant device exhibits excellent performance, which further demonstrates that Rb2TiF6:Mn4+ has efficient and stable light-emitting properties and can be used to fabricate high power WLEDs with preferable heat resistance.
研究领域:
材料科学
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光电子学
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固态照明
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荧光粉化学
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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
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产品关联
DOI
PubMed
高影响因子
MATERIALS LETTERS
·
2017
·
IF 2.572
Meizhu Rong,Xinyun Zhou,Ruimei Xiong,Nan Wang,Qin Wang,Zhengliang Wang
Rb 2 GeF 6 :Mn 4+ red phosphor was synthesized by ion exchange method, and its crystal structure and luminescent properties were investigated in detail. Rb 2 GeF 6 :Mn 4+ has sharp red emissions with high thermal stability under the blue light excitation. White light-emitting diode ( w -LED) based on this red phosphor exhibits intense warm white light with excellent optical performances ( T c = 3746 K, R a = 86.1), so Rb 2 GeF 6 :Mn 4+ might be a potential candidate for warm w -LED.
研究领域:
材料科学
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光电子学
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固态照明
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Qiying Peng,Renping Cao,Yujiao Ye,Siling Guo,Zuofu Hu,Ting Chen,Guotai Zheng
A new non-rare-earth deep-red-emitting Na 2 MgAl 10 O 17 :Mn 4+ phosphor is prepared successfully by high temperature solid-state reaction method in air. All samples are a single pure phase, which is confirmed by X-ray powder diffractions patterns . Excitation spectrum shows some absorption bands in the range of 220–600 nm, which are line with the wavelength of ultraviolet (UV), near UV, and blue light-emitting diode chips. Deep-red emission of Na 2 MgAl 10 O 17 :Mn 4+ phosphor with excitation UV, near UV, and blue light can be observed in the range of 600–810 nm due to the 2 E → 4 A 2 transition of Mn 4+ ion in octahedral symmetry with aided the lattice vibration . The full width at half maximum (FWHM) is ∼105 nm. The optimal Mn 4+ concentration is ∼1%. Decay curve and time-resolved spectra indicate that there is only a Mn 4+ ion luminescent center in Na 2 MgAl 10 O 17 :Mn 4+ phosphor. The thermal stability is investigated and analyzed by the configuration coordinate diagram of Mn 4+ ion.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Renping Cao,Xun Ouyang,Yuming Jiao,Xuantian Wang,Qianglin Hu,Ting Chen,Chenxing Liao,Yajie Li
Novel deep-red-emitting SrLa 2 Sc 2 O 7 :Mn 4+ phosphors with different Mn 4+ contents are successfully synthesized in air by the conventional high-temperature solid-state reaction method. The crystal structure, morphology, phase purity, luminescence properties, concentration quenching, decay lifetimes, and temperature dependent emission spectra are systematically investigated and analyzed. SrLa 2 Sc 2 O 7 :Mn 4+ phosphor presents broad excitation band with different excitation peaks from 220 nm to 620 nm owing to the O 2− - Mn 4+ charge transfer and 4 A 2 → ( 4 T 1 , 2 T 2 , and 2 T 2 ) transitions of Mn 4+ ion and shows intense deep-red emission peaking at 704 nm in the range of 650–800 nm because of the 2 E → 4 A 2 transition of Mn 4+ ion. The optimal Mn 4+ concentration in SrLa 2 Sc 2 O 7 :Mn 4+ phosphor is ∼0.6 mol%. The chromaticity coordinates of the SrLa 2 Sc 2 O 7 :0.6%Mn 4+ phosphor are (x = 0.732, y = 0.268), locating in deep-red region. The mechanism of concentration quenching is inferred to be dipole-dipole interaction. The luminous mechanism, concentration quenching, and temperature quenching are explained by using the Tanabe–Sugano diagram and configurational coordinate diagram of the Mn 4+ ion in SrLa 2 Sc 2 O 7 :Mn 4+ phosphor. The experimental results on SrLa 2 Sc 2 O 7 :Mn 4+ phosphor can offer the helps for the development of other Mn 4+ doped deep-red-emitting phosphor.
研究领域:
材料科学
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光学材料
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发光材料
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固态化学
·
光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2021
·
IF 3.712
Jiannan Jia,Mengting He,Jun Wan,Yuting Zhang,Hai Guo,Xianping Fan,Xusheng Qiao,Shiguo Chen
With narrow red photoluminescence (PL) bands, tetravalent Mn 4+ doped phosphors show promising prospect in commercial application to effectively expand color gamut of phosphor converted LED displays. Here, we report a type of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ phosphors with regular cage-like micro-spherical morphologies. The micron size spherical precursors were synthesized with a propylene oxide (PO) driven fast sol–gel method. The cage -like spherical morphology is beneficial to efficiently trapping much incident light to enhance the PL of the phosphors. Being calcined at 1300 ° C, Sr 2 MgAl 21.978 O 36 :0.022Mn 4+ only exhibits the internal quantum efficiency (IQE) of 24.91%. With the Mg 2+ -Mn 4+ codoping and Y 3+ /Sr 2+ substituting strategies, to fulfill charge balance and produce John-Teller distortion, IQE of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ can be further improved up to 36.45%. The CIE color coordinates of Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ under near ultraviolet excitation can be stably fixed to (0.723, 0.227) at deep red region. It thus finds a potential application as pc-LED display with much broader color gamut than that of the NTSC standard. Therefore, Sr 2– z Mg 1+ y Y z Al 22– x O 36 : x Mn 4+ micron size spheres can be employed as promising red phosphors for high performance LED displays.
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 LUMINESCENCE
·
2024
·
IF 3.3
Hong Li,Li Li,Lingsong Mei,Wei Zhao,Xianju Zhou,Huajing Gao,Xiaobing Luo,Yongbin Hua
Due to the huge food demand of the population, the luminescent materials with excellent performance applied for indoor plant cultivation have been extensively studied. In this work, a series of Mn 4+ -doped LaBaZnTaO 6 phosphors in were synthesized and its luminescence mechanism has been researched in detail. Due to their broad absorption band, they could be effectively excited by the NUV to blue LED chip. Importantly, suitable emission in the red region overlapped with the absorption of plant pigments making it possible to be used in indoor plant cultivation. On the other hand, high-sensitivity non-contact optical temperature sensor is the focus of current research, so the optical thermometer-based lifetime model also was designed and investigated in this work. Interestingly, the maximum relative sensitivity was 1.38 %K −1 @473 K, suggesting a good development potential of the sample in optical thermometry. Finally, the warm WLED device was fabricated and achieved a superior CRI value of 90.95 and a good CCT of 3582 K. All the obtained results suggest that it could become a promising red component to be applied in optical thermometer and lighting sources.
研究领域:
材料科学
·
植物学
·
光学工程
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产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Huaiyong Li,Lulu Xing,Shifang Wang,Mingzheng Sun,Yangbo Wang,Xufeng Zhou,Shanshan Du,Wanying Geng,Jigong Hao,Wei Li
Oxyfluorides activated with Mn 4+ have great potential in phosphors converted LED. Phosphors with intensive zero phonon line (ZPL) emission are expected to improve the performance of the light sources. Microcrystalline powders of oxyfluoride K 2 WO 2 F 4 ·H 2 O activated with Mn 4+ were synthesized by using a coprecipitation method. The structural parameters and atomic coordinations of K 2 WO 2 F 4 ·H 2 O were determined by both refinement and calculation. K 2 WO 2 F 4 ·H 2 O crystallizes in the monoclinic crystal system with C2/m group space. The unit cell could be considered as a stack of KWO 2 F 4 slices with another K + ion and H 2 O molecule in the interstitial. The morphology and photoluminescence properties of K 2 WO 2 F 4 ·H 2 O: Mn 4+ were studied as a function of Mn 4+ concentration. It is revealed that the microcrystalline shows highly orientational preferred growth. Mn 4+ shows bright red emission upon the excitation of blue light. The emission is due to the 2 E g → 4 A 2g transition. Furthermore, the photoluminescence features intensive ZPL emission and short excitation state lifetime, which is ascribed to the highly distorted coordination environment. The effects of octahedron distortion and the second coordination sphere on the ZPL emission intensity are discussed.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Jiacheng Zhang,Qing He,Deyun Gao,Min Liu,Jiaqing Peng,Xinyu Ye
Mn 4+ -activated oxy-fluoride red phosphors have garnered increasing attention. However, the majority of oxy-fluoride phosphors necessitate the utilization of HF during the synthesis process, which brings a huge threat to the human health and the environment. In this work, K 3 MoO 3 F 3 :Mn 4+ red phosphors were prepared by a mechanical grinding method. The process is environmentally friendly, streamlined, and minimally detrimental to the environment. This phosphor shows narrow emission around ∼631 nm excited by 470 nm blue light with high color purity of 99.60 %. Satisfactorily, in Mn 4+ -doped oxy-fluoride molybdate phosphors, the K 3 MoO 3 F 3 :3 % Mn 4+ red phosphor has a very short fluorescence lifetime (1.87 ms) and good thermal stability, which still maintains 65.84 % of its original intensity at 423 K. The fabricated warm WLED device has a low correlated color temperature (4085 K) and a high color rendering index (Ra = 85). The results suggest that K 3 MoO 3 F 3 :Mn 4+ possesses significant potential for applications in white LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
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