JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 23
·27513-27523
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IF 2.478
He Youyi,Liu Jun,Gao Yalei,Yan Lijuan,Lv Fengzhen,Liu Fuchi,Long Lizhen
Mn 4+ -activated phosphors have become a hotspot in the development of inorganic red phosphors due to the fascinating photoluminescent properties. Herein, the synergetic manipulation of the flux effect and charge compensation was employed to improve the performance of Mn 4+ -activated CaAl 12 O 19 red phosphors. The crystallinity was improved by appropriate Zn 2+ -doping, while nonradiative transition between Mn 4+ ions is reduced by charge compensation of the formation of Mn 4+ –Mg 2+ pairs with Mg 2+ dopants. Thus, the emission of Mn 4+ -activated CaAl 12 O 19 red phosphors has been remarkably enhanced. The low probability of nonradiative transition between Mn 4+ ions was demonstrated by the thermal stability analysis. To depict the luminescent process, the crystal-field strength ( D q ), and Racah parameters ( B and C ) were calculated to determine the sequence of the energy levels. Meanwhile, the warm WLEDs with high CRI and low CCT were obtained using the prepared phosphors as red-emitting composition. Our results clearly suggested that the synergetic strategy by combining the flux effect and charge compensation is an effective method to enhance the luminescence of CaAl 12 O 19 :Mn 4+ , and CaAl 12 O 19 :Mn 4+ /Zn 2+ /Mg 2+ red-emitting phosphors, which have potential application value in warm WLEDs.
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
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 22
·10875-10883
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IF 3.3
Cong Ding,Zhongfa Li,Wenjun Zhang,Jun Ou,Xue Wen,Chengyue Xin,Min Su
The optical properties of Mn4+-activated phosphors are heavily affected by the host and the related data are difficult to obtain, which makes quantitative design of novel phosphors with required wavelength particularly challenging. In the era of big data, computation is emerging as a vital complement to materials development. Compared with traditional calculation routes, machine learning (ML) models provide better solutions for the problems wherein understanding the underlying physics is complicated with sparse data. In this study, we developed six ML models based on a sparse and small data set to rapidly predict the peak emission wavelength of novel phosphors and use Recursive Feature Elimination (RFE) to select the best features. Among them, the K-nearest neighbors regression (KNN.r) algorithm using non-parametric regression technology can predict the value of the target variable based on the similarity between the target value and its spatial neighbors, which can tackle sparse data sets with no obvious linear relationship well and has the best prediction accuracy. These models were then used to predict 278 potential Mn4+-activated phosphor hosts extracted from the inorganic crystal structure database (ICSD), and 19 samples were selected to validate these methods. In order to overcome the lack of physical and chemical insight of KNN, a visual data analysis was carried out based on hierarchical clustering analysis (HCA), and the rule between the peak emission wavelength and the structure of host was proposed. Guided by the results of KNN and HCA, six samples were selected for the synthesis and characterization to verify our conclusions. The measured values of all these phosphors exhibit good agreement with the predicted results, suggesting the success of our methodology. Thus, the model established and the rule proposed in this paper provide a new pathway for the rapid discovery of novel phosphors.
研究领域:
材料科学
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光学
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数据科学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 7
·2102141
·
IF 10.05
Hong Ming,Yifei Zhao,Yayun Zhou,Maxim S. Molokeev,Yuanjing Wang,Shuai Zhang,Enhai Song,Shi Ye,Zhiguo Xia,Qinyuan Zhang
The design and discovery of Mn 4+ -activated fluoride phosphors that can secure both high luminescence efficiency and short fluorescence lifetime simultaneously are crucial and urgent for constructing high-quality wide-color gamut (WCG) backlight display applications. Herein, a series of brand-new Mn 4+ -activated narrow-band red-emitting phosphors with both high external quantum efficiency (EQE, >50%) and short fluorescence lifetime (τ ≤ 3.8 ms) are designed by introducing Mn 4+ into newfound tetramethylammonium (Me 4 N)-based organometallic fluoride (Me 4 N) 2 B F 6 ( B = Ge, Ti, Zr) hosts. These intriguing properties of Mn 4+ arise from the larger steric hindrance of (Me 4 N) + cations and low local structure symmetry in the 0D (Me 4 N) 2 B F 6 , as verified by the structural and spectral analyses. (Me 4 N) 2 GeF 6 :Mn 4+ , as a representative, shows a high EQE of ≈64.6% and a short lifetime of ≈3.78 ms. A prototype projector with superb performance is assembled by employing a remote (Me 4 N) 2 GeF 6 :Mn 4+ -based white light-emitting diode with high luminous efficiency (≈143.09 lm W −1 ) and WCG (≈112.02% National Television System Committee (NTSC)) to demonstrate their great potentials for backlight applications. The research brings up a promising alternative as the host materials for Mn 4+ -doped fluoride phosphors and provides a deeper understanding on the correlation between structure and luminescence.
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
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 45
·17180-17191
·
IF 4.569
Liang Li,Qianwen Cao,Jing Xie,Wenming Wang,Yubei Wang,Hongmei Chen,Zhongyuan Li,Yan Pan,Xiantao Wei,Yong Li
Altering the local symmetry of an activator by lattice tuning is considered an effective strategy to optimize the luminescence performance of phosphors. Herein, the novel Mn4+-activated double perovskite phosphor La1.67MgTaO6 (LMTO) with A-site defects was successfully prepared. Benefiting from the random occupation of the nearest A-site by cations and vacancies, the distorted [MnO6] octahedra lack the inversion center. The LMTO:0.4 mol%Mn4+ phosphor has a significant zero-phonon line intensity with a high internal quantum efficiency (IQE) value of 62.97% after the Laporte selection rule is broken. Furthermore, local lattice tuning was performed by increasing the randomness of the A-site and the distortion index of the [MnO6] octahedron by co-doping with Ca2+ or Sr2+ ions. Importantly, the IQE value of the samples was enhanced from 62.97% to 72.65% and the activation energy increased from 0.497 eV to 0.548 eV, which can be well applied in the fields of plant cultivation and warm white light-emitting diodes. These studies provide valid fundamental insights for the selection of excellent luminescent matrices to obtain efficient Mn4+-activated phosphors via local lattice tuning.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Junze Tong,Long Li,Haiqing Su,Feng Hong,Edwin Yue Bun Pun,Hai Lin
Red-emitting Mn 4+ -doped fluoride phosphors are promising fluorescent material for use in high-performance warm white light emitting diodes (WLEDs). However, low stability and non-green synthesis method limit the development and commercialization of such phosphor. Herein, a series of novel (Li/Na/Cs) 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphors with optimized fluorescence properties induced by alkaline metal ions replacement are successfully synthesized via a green and eco-friendly approach. Under the irradiation of 460 nm blue light, Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ red phosphor with narrow band emission peak has the best optical performance. The optimal doping concentration of Mn 4+ in Cs 0.4 Ba 0.8 SiF 6 host and the reason for concentration quenching are systematically analyzed. Furthermore, the moisture resistance and thermal stability of this phosphor are discussed. After being soaked in deionized water for 90 min, the PL intensity of Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphor can maintain at 40% of that in air, which is 4 times higher than commercial K 2 SiF 6 :Mn 4+ . At the operating temperature of LED (423 K), Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ red phosphor can exhibit stable light output intensity and color. A warm WLED with low correlated color temperature of 4336 K, high color rendering index of 88.4 and high lumen efficiency of 105.96 lm/W is fabricated via using Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphor as a component of red-light, and the warm WLED can maintain stable output even at high driving currents. Overall, the alkali metal ion replacement and green synthesis strategies have opened up a new perspective for the synthesis of efficient Mn 4+ -doped fluoride phosphors, which has dual benefits for optimizing the performance of WLED and environmental protection.
研究领域:
材料科学
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光学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2021
·
IF 3.599
Liqin Yao,Shengan He,Wendong Nie,Lei Fu,Zhijian Liao,Wenting Cai,Ruixiang Wang,Jiaqing Peng,Xinyu Ye
Mn 4+ -activated (oxy)fluoride-based red phosphors have received extensive attention. In this work, a phase transformation from K 2 NbF 7 to K 3 HF 2 NbOF 5 was successfully achieved by stoichiometric control during coprecipitation process, resulting in a novel red phosphor K 3 HF 2 NbOF 5 :Mn 4+ with narrow-band emission. A systematic study was carried out on its crystal structure and luminescent properties. By introducing O ions into the local coordinated structure, the emission intensity of K 3 HF 2 NbOF 5 :Mn 4+ phosphors is 2.15 times as high as that of K 2 NbF 7 :Mn 4+ with a photoluminescence internal quantum yield (IQE) of 73.28% and absorption efficiency (AE) of 49.68%, which could be attributed to the layered structure of the oxyfluoride host. High quenching concentration of 8.39 mol% and short decay lifetime of 4.19 ms are realized. Based on K 3 HF 2 NbOF 5 :Mn 4+ and commercial YAG:Ce 3+ , a white light-emitting diode (WLED) for solid state lighting was fabricated, which has low CCT of 3802 K, high Ra of 86.3 and high luminous efficiency (LE) of 126.23 lm/W. Moreover, by employing commercial β-sialon:Eu 2+ and K 3 HF 2 NbOF 5 :8.39%Mn 4+ , another WLED with high LE of 95.78 lm/W and wide color gamut of 108.6% National Television Standard Committee (NTSC) standard for backlight lighting was packaged, indicating a great potential of K 3 HF 2 NbOF 5 :Mn 4+ as a red component in the application of backlight lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Qinan Mao,Gan Li,Xinyu Shen,Junhua Xi,Lang Pei,Xinyue Li,Jiasong Zhong
Currently, Mn 4+ -activated phosphors have attracted extensive attention for their versatile applications in general lighting, display and plant cultivation. Owing to 3d 3 electronic configuration of Mn 4+ ion, modifying its local coordination environment emerges as a potent method to tailor its luminescence behavior. Herein, a heterovalent substitution strategy is reported to greatly enhance the photoluminescence (PL) of Ba 2 CaWO 6 :Mn 4+ . The effects of the substitution of rare-earth ions (Ln 3+ = Lu 3+ , Y 3+ , Gd 3+ , La 3+ ) for Ca 2+ ions on the PL properties of the phosphor are studied in detail. The PL spectral change of Mn 4+ induced by Ln 3+ substitution is clarified in terms of the local structure of [WO 6 ] octahedron and the valence state of Mn. By selection of Ln 3+ ions and optimization of Ln 3+ doping concentration, the emission intensity of Ba 2 Ca 0.85 Gd 0.15 WO 6 :0.25Mn 4+ phosphor reaches up to 46.3 times as that of Ba 2 CaWO 6 :0.25Mn 4+ . Besides, the Ba 2 Ca 0.85 Gd 0.15 WO 6 :0.25Mn 4+ phosphor exhibits an internal quantum yield of 56.9 % and a thermal stability of 72.6 %@423 K. Finally, Ba 2 Ca 0.85 Ln 0.15 WO 6 :Mn 4+ based phosphor conversion LED devices are demonstrated, which can be potentially employed for indoor plant lighting.
研究领域:
材料科学
·
光电技术
·
照明技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Kaiyuan Deng,Yahong Jin,Lifang Yuan,Haoyi Wu,Yihua Hu
Phosphor-converted light-emitting diode (pc-LED) technology, as artificial lighting source, is the most promising option for providing power for plant growth in future smart agricultural factories. However, developing red phosphors with the desired emission spectral range and good thermal stability is still experimental. In this study, an Mn 4+ -doped BaZrGe 3 O 9 red-emitting phosphor with remarkable thermal stability is reported. The red emission, spanning the wavelength range of 600–800 nm, matches the absorption range of chlorophyll a, b and phytochrome (P r ). Its good thermal stability at 150 °C is in addition to its emission intensity, which is 81.7 % of its room-temperature intensity. Co-doping with Ca 2+ contributes to a 1.7-fold increase in the red emission intensity at room temperature. The encapsulation of the present phosphor onto UV LED chips produces red emitting LED devices, which can be used for garlic and corn cultivation. The implementation reveals that the six-hour artificial red light illumination supplement is the most effective and significant means to promote garlic and corn growth. The as-obtained red-emitting phosphor may be a promising candidate for pc-LEDs promotion of crop growth in agricultural factories.
研究领域:
农业工程
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植物生理学
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材料科学
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光电技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）