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
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
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
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS
·
2024
·
IF 2
Qian Du,Yu-Guo Yang,Xiao-Na Shen,Yuan-Yuan Zhang,Shen-Ao Hu,Bing Liu,Qing-Gang Li,Xian-Shun Lv,Hua-Jian Yu,Lei Wei,Cheng-Cheng Qiu,Jing-Feng Li,Rui Zhang,Xu-Ping Wang
Sr(La, Y)Ga 3 O 7 : Mn 4+ phosphors were prepared by sintering at 1400 ℃. The structural characteristics of phosphors were analyzed by means of XRD measurements. Surface compositions and chemical state of the elements were gained from XPS measurements. And the vibration and rotation information of the molecular structure was detected in Raman spectra. The phosphors show characteristic excitation spectrum of Mn 4+ , which puts down to the electronic transition of 4 A 2g → 4 T 1g and 4 A 2g → 4 T 2g . Exciting at 380 nm, the phosphors emit deep red light resulting from the 2 E g → 4 A 2g transition. The Y 3+ substitution influences crystal structure and photoluminescence performance obviously. The incorporation of a small amount of Y 3+ reduces the cell volume and induces impurity phase of Y 3 Ga 5 O 12 in all prepared phosphors. The band peaking at 715 nm decreases highly and the band becomes stronger when x ≥ 0.4.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICS LETTERS A
·
2019
·
IF 2.087
Renping Cao,Longxiang Xu,Yaqin Ran,Xinyan Lv,Siling Guo,Hui Ao,Ting Chen,Zhiyang Luo
Ba 2 LaSbO 6 :Mn 4+ , Ba 2 LaSbO 6 :Mn 4+ , Dy 3+ , and Ba 2 LaSbO 6 :Mn 4+ , H 3 BO 3 phosphors are synthesized in the air by high temperature solid state reaction method. The particle sizes and sintering degree of Ba 2 LaSbO 6 :Mn 4+ phosphor may be changed by doping Dy 3+ ion and H 3 BO 3 . When the small amount of Dy 3+ ion and H 3 BO 3 are codoped, the emission intensity of Ba 2 LaSbO 6 :Mn 4+ phosphor can be enhanced 1.2–1.3 times and the quantum efficiency of Ba 2 LaSbO 6 :Mn 4+ phosphor can be improved. The lifetime of Ba 2 LaSbO 6 :Mn 4+ phosphor may be changed by doping Dy 3+ ion and H 3 BO 3 . The experimental results are valuable in research of luminescence property of Mn 4+ -doped luminescence materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
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
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Renping Cao,Wudi Wang,Jinlong Zhang,Shenhua Jiang,Zhiquan Chen,Wensheng Li,Xiaoguang Yu
Novel Li 2 SnO 3 :Mn 4+ red-emitting phosphor is synthesized by high-temperature solid-state reaction method in air. Emission band of Li 2 SnO 3 :Mn 4+ phosphor within the range 620–760 nm is attributed to the 2 E → 4 A 2 electron transition of Mn 4+ ion. Excitation bands peaking at 330, 395, and 480 nm are attributed to O 2- → Mn 4+ charge transfer and 4 A 2 → ( 4 T 1 , 2 T 1 , and 4 T 2 ) transitions of Mn 4+ ion, respectively. The optimal Mn 4+ concentration is ∼0.4 mol% and the corresponding quantum efficiency and lifetime are ∼42.3% and 16.3 μs. The influences of temperature and Mn 4+ concentration to emission intensity are discussed and analysized. Lifetime data and time resolved spectra confirm that there is only a single type of Mn 4+ ion luminescent center in Li 2 SnO 3 :Mn 4+ phosphor. The influences of the crystal field and the “Mn 4+ -ligand” bonding to luminescence properties of Mn 4+ ion are summaried and analysized. The luminous mechanism is explained via Tanabe-Sugano energy level diagram and the configuration coordinate diagram of Mn 4+ in the octahedron. The results indicate that Li 2 SnO 3 :Mn 4+ phosphor has a hope to be used as red phosphor candidate for solid-state lighting.
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 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
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yufan Wei,Qianxing Huang,Shijie Yu,Qiyue Shao,Jianqing Jiang
The K2SiF6:Mn4+ (KSFM) phosphor featuring efficient ultranarrow red emissions is an outstanding candidate for white light-emitting diode (WLED) applications. However, poor moisture resistance seriously affects its application performance. In this study, a two-step surface reconstruction strategy is proposed to dramatically enhance the moisture resistance of commercially available KSFM phosphors, involving treatment with H2NbF7 and subsequent hydrothermal treatment. The modified KSFM phosphor exhibits a high internal quantum efficiency (IQE) of 98.9% after the two-step surface treatment. Meanwhile, nearly 100% of the initial emission intensity is retained for the modified KSFM phosphor even after aging in high temperature (85 °C) and high relative humidity (85% RH) environments for 6 days, in sharp contrast to only 18.6% retention for the original KSFM phosphor. The relative emission intensity of the modified KSFM remains at 98.9% even after being immersed in water for 6 h. Additionally, the phosphor-converted LED fabricated with the modified KSFM phosphor demonstrated excellent long-term stability, retaining up to 97.9% of initial luminous efficacy after aging under 85 °C and 85% RH conditions for 500 h. The moisture-resistance mechanism is elucidated on the basis of spectroscopic analysis as well as structural and compositional characterization of the phosphor surface layer, which can be attributed to the formation of a robust Mn4+-rare shell with high crystalline quality following this two-step surface treatment. The findings contribute to the performance improvements of KSFM phosphors for industrial applications.
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
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Hong Ming,Shuifu Liu,Lili Liu,Jiaqing Peng,Junxiang Fu,Fu Du,Xinyu Ye
A new generation of red phosphors of complex fluoride matrices activated with Mn4+ has gained a broad interest in getting high color quality and low color temperature of solid-state white light-emitting diodes (WLEDs). However, besides their instability toward moisture, the extremely irregular and nonuniform morphologies of these phosphors have limited their practical industry applications. In the present study, a novel type of K3ScF6:Mn4+ red phosphor with highly regular, uniform, and high color purity was obtained successfully through a facile coprecipitation route under mild conditions. The crystal structure was identified with aids of the powder X-ray diffraction, Rietveld refinement, and density functional theory calculations. The prototype crystallizes in the space group Fm3m with a cubic structure, and the lattice parameters are fitted well to be a = b = c = 8.4859(8) Å and V = 611.074(2) Å3. The Mn4+ ions occupy Sc3+ sites and locate at the centers of the distorted ScF6 octahedrons. A wide band gap of approximately 6.15 eV can provide sufficient space to accommodate impurity energy levels. Unlike most other Mn4+ ion-activated fluoride phosphors, the as-prepared K3ScF6:Mn4+ phosphors demonstrate highly uniform and regular morphologies with shapes transforming from cube to octahedron with increasing Mn4+ ion concentration. Under blue light excitation, the as-prepared K3ScF6:Mn4+ sample exhibits intense sharp-line red fluorescence (the strongest peak located at 631 nm) with high color purity. An excellent recovery in luminescence upon heating and cooling processes implies high stability of K3ScF6:Mn4+. Furthermore, a warm WLED fabricated with blue GaN chips merged with the mixture of K3ScF6:Mn4+ and the well-known commercial YAG:Ce3+ yellow phosphors exhibits wonderful color quality with lower correlated color temperature (3250 K) and higher color-rendering index (Ra = 86.4). These results suggest that the K3ScF6:Mn4+ phosphor possesses stupendous potentiality for practical applications.
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
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Lei Chen,Peng Cheng,Guifang Zheng,Gang Yao,Pingjuan Zhang,Haiwu Zheng,Lei Ding,Xuemei Ding,Shizhong Wei,Haiyong Ni
K 2 TiF 6 :Mn 4+ , along with K 2 SiF 6 :Mn 4+ and K 2 GeF 6 :Mn 4+ , is a red phosphor with narrow-band emission for wide-gamut display backlight LEDs. However, its poor absorbance results in low external quantum efficiency, which is a major obstacle for commercial utilization. This paper describes our pursuit of a new path to synthesize the K 2 TiF 6 :Mn 4+ phosphor through cation-exchange-assisted recrystallization achieving excellent performance. The absorbance and the internal and external quantum efficiencies of the as-prepared phosphor reached up to 74.27, 93.06, and 69.09%, respectively; the luminescence intensity at 150 °C was 97.5% of that at 25 °C. The color gamut of white LEDs packaged with optimized K 2 TiF 6 :Mn 4+ covers 98.61% of the NTSC (National Television Standard Committee) color gamut and the amount of phosphor used was reduced by 37.55%, as compared with commercially available LEDs achieving similar performance. These breakthroughs strongly support the commercial implementation of K 2 TiF 6 :Mn 4+ phosphors.
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
OPTICAL MATERIALS
·
2017
·
IF 2.238
Renping Cao,Jinlong Zhang,Wudi Wang,Ting Chen,Qingdong Gou,Yufeng Wen,Fen Xiao,Zhiyang Luo
Novel deep red-emitting Ca 3 Al 4 ZnO 10 :Mn 4+ (CAZO:Mn 4+ ) phosphor is synthesized by high-temperature solid-state reaction method in air. The crystal structures and optical characterizations of the phosphors are described. X-ray diffraction patterns indicate that all samples are a pure phase. CAZO:Mn 4+ phosphor with excitation 330 and 465 nm exhibits strong deep red emission in the range of 650–790 nm. CAZO:Mn 4+ phosphor can be efficiently excited by near-ultraviolet and blue light from 300 to 500 nm. The optimal Mn 4+ ion concentration in CAZO:Mn 4+ phosphor is ∼0.6 mol%. Lifetimes of CAZO:xMn 4+ (0.3 ≤ x ≤ 1.8 mol%) phosphors decrease from 1.95 to 1.56 ms with increasing Mn 4+ ion concentration in the range of 0.3–1.8 mol%. The paper content is help to develop other Mn 4+ ion doped luminescence materials.
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
·
2022
·
IF 3.841
Bang Lan,Renping Cao,Ting Chen,Lan Li,Ru Liu,Xuehua Yi,Shuijing Nie,Jing Wang
LaSrRO 4 :Mn 4+ (R = Al and Ga) are prepared by the high-temperature solid-phase method in air. Their luminescence properties, crystal structure, concentration dependent spectra, time-resolved spectra, fluorescence lifetime, and luminous mechanism are systematically researched, respectively. Mn 4+ ion is the luminescence center of LaSrRO 4 :Mn 4+ (R = Al and Ga). The excitation spectra of LaSrRO 4 :Mn 4+ (R = Al and Ga) under monitored at 715 nm lie in the range 210 – 650 nm with two main excitation peaks at ∼360 nm and 520 nm. With the excitation at 360 and 520 nm, LaSrRO 4 :Mn 4+ (R = Al and Ga) emit far-red light and have the emission spectra covering the region from 650 to 800 nm due to the 2 E g → 4 A 2g transition of Mn 4+ ions. The ideal Mn 4+ concentration in LaSrAlO 4 :Mn 4+ and LaSrGaO 4 :Mn 4+ are ∼ 0.4 mol% and 0.6 mol%, respectively. The spectral properties of samples verify the crystal field s via the Tanabe-Sugano energy level diagram of Mn 4+ ion. LaSrRO 4 :Mn 4+ (R = Al and Ga) have the emission spectra match with the absorption spectra of the plant photosensitive pigments red light and far-red light, which infers their promising application in plant growth light-emitting diode (LED) lamp
研究领域:
材料科学
·
光学
·
植物学
✓ 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）