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
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 37
·12658-12666
·
IF 6.4
Qiao Qu,Konglan Chen,Yayun Zhou,Jinsheng Li,Haipeng Ji
A K2SiF6:Mn4+ phosphor with narrow line-type red emission plays an important role in white light-emitting diode (WLED) backlights for liquid crystal displays, but this phosphor exhibits weak zero phonon line (ZPL) emission. The ZPL intensity of the Mn4+ 2Eg → 4A2g transition can be enhanced after relaxing the orbital selection rule. We dope Mn4+ into a host lattice with mixed-anions to introduce a distortion of local coordination octahedra around Mn4+ and relax the orbital selection rule. Remarkably, the Na2MoO2F4:Mn4+ phosphor with [MoO2F4] mixed-anion coordination exhibits a dominant luminescence peak at 625 nm (ascribed to the ZPL) and the ZPL to Stokes v6 intensity ratio reaches an unprecedented high value of 243% under 480 nm excitation. Density functional theory calculations indicate that the most energy-efficient pathway for maintaining charge balance during Mn4+-doping involves the substitution of [MoO2F4]2− by [MnF6]2−, which generates a strong crystal field with a high Dq/B value of 4.05 for Mn4+ in Na2MoO2F4. An optimal composition Na2MoO2F4:1.5%Mn4+ (nominal) exhibits a high color purity of 99.3% and a short luminescence lifetime of 0.62 ms, suggesting its potential in fast-response backlight display applications. When incorporated into WLEDs, the red-emitting Na2MoO2F4:Mn4+ phosphor contributes to a broad color gamut (∼108.3% NTSC). Comparative analysis of a series of Mo6+-based oxyfluoride phosphors demonstrates that Mn4+ more readily exhibits intense ZPL and fast luminescence decay occurs when Mo6+ is coordinated in an O/F ordered octahedron.
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
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Haifeng Zhe,Zongqi Chen,Jie Li,Yayun Zhou,Qiang Zhou,Zhengliang Wang
Modulating phase transitions in fluoride phosphors is essential for developing high-performance luminescent materials, but conventional extreme-condition methods often cause structural damage and efficiency degradation. This study proposes a thermal-pressure coupling strategy to achieve reversible Fm-3m to P6 3 mc phase transformation in K 2 SiF 6 :Mn 4+ under mild conditions. The distorted [MnF 6 ] 2- octahedra in the P6 3 mc enhance d-orbital hybridization, significantly reinforcing the zero-phonon line (ZPL). Consequently, luminescence intensity increases by 1.54-fold, external quantum efficiency (EQE) improves by 29.5%, and 90% intensity is retained at 200 °C. LED devices employing P6 3 mc phosphor sheets achieve a color rendering index (Ra) of 84.4 and luminous efficacy of 138.2 lm/W while maintaining stable Ra and correlated color temperature (CCT) across 20 - 300 mA driving currents. Notably, device temperature at 200 mA operation is reduced by 30% compared to conventional methods. This work establishes an effective approach for optimizing fluoride phosphors and advancing high-performance lighting technologies.
研究领域:
材料科学
·
光学材料
·
固态照明
·
发光二极管
·
无机荧光粉
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Qin Wang,Rui Tian,Duo Zhang,Caiyan Huang,Jiani Shen,Wen Yang,Zhengliang Wang,Peizhi Yang
Herein, Rb 2 LiMF 6 :Mn 4+ (M= Al, In) phosphors were prepared by the non-equivalent doping of Mn 4+ . Mn 4+ in Rb 2 LiAlF 6 exhibits an ultra-intense zero phonon line (ZPL) detected at 627 nm, due to the highly-distorted symmetry. In contrast, the ZPL at 625 nm for Rb 2 LiInF 6 :Mn 4+ is very weak. The 2 E energy of Mn 4+ in Rb 2 LiAlF 6 (15,949 cm −1 ) is lower than that in all reported fluoride phosphors, which may be ascribed to the stronger polarization effect of Li + . Compared with Rb 2 LiInF 6 :Mn 4+ (5.07 %), Rb 2 LiAlF 6 :Mn 4+ (6.33 %) has a high internal quantum efficiency (IQE) values of 69.8 % and excellent thermal stability. The white LED packaged with Rb 2 LiAlF 6 :Mn 4+ (6.33 %) exhibits perfect performances with a high color render index (CRI = 92.3) and low color temperature (CCT =3875 K) as well as a high luminous efficiency (LE = 97.1 lm/W). Therefore, this work provides a promising red-emitting phosphor for high-quality white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 27
·2214497
·
IF 19
Zhichao Liu,Xue Yu,Qingpeng Peng,Xiaodie Zhu,Jianqiang Xiao,Jiangtao Xu,Shouxiang Jiang,Jianbei Qiu,Xuhui Xu
Mechanoluminescence (ML) materials with long-wavelength emission bands are essential for future in vivo bioimaging, non-destructive testing of solids, etc. The lack of a defined mechanism, however, prevents the application of near infrared ML materials above 650 nm in several new fields. Here, the addition of Ga 3+ ions to Y 3 Al 5 O 12 : Cr 3+ manipulates matrix microstructure evolution, boosting near-infrared (NIR) zero-phonon line (ZPL) stress optical output of the Cr 3+ ion at 688 nm. The key factor changing the crystal field intensity D q /B due to the addition of Ga 3+ ions is what causes the luminescence amplification of ZPL. The ML fabricated by composite polydimethylsiloxane and Y 3 Al 4 GaO 12 : Cr 3+ (YAGG: Cr 3+ ) may penetrate chicken feet epidermal tissue and 4 mm pork tissue thanks to the strong NIR ZPL emission of YAGG: Cr 3+ phosphor. This discovery of enhancing near-infrared ZPL intensity by solid solution provides us with a new technique for optimizing NIR ML materials, as well as a new prospect for NIR ML materials in biological applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
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
Inorganic Chemistry Frontiers
·
2022
·Vol. 10
·期 2
·638-650
·
IF 7.779
Siyuan Li,Chenyu Zhang,Qi Zhu,Ji-Guang Li
Zero-phonon line (ZPL) emission of Mn4+, without the participation of phonons, is tightly related to the host crystal structure. However, the intensity of the intrinsic ZPL is much weaker than that of Stokes and anti-Stokes vibrational bands, and it always leads to a discontinuous emission peak. Regulating the ZPL of Mn4+ for a strong emission is very important but remains a challenge for perovskite-type oxides. Here, novel La1−xBaxAl1−xTixO3:0.001Mn4+ (LBAT:0.001Mn4+, x = 0–0.2) and La1−yYyAl1−yGayO3:0.001Mn4+ (LYAG:0.001Mn4+, y = 0–0.2) samples were successfully synthesized through a high-temperature solid-state reaction, and a tunable ZPL of Mn4+ was found by cationic pair substitution of Ba2+–Ti4+ and Y3+–Ga3+ for La3+–Al3+ in LaAlO3:Mn4+. The ZPL intensity is related to the local symmetry around Mn4+ and the ZPL energy corresponds to the Mn–O bond distance and the O–Mn–O bond distortion. Through co-doping Ba2+–Ti4+, the ZPL at 710 nm is enhanced and the intensity increases continuously with increasing the x value, due to the local symmetric degree of Mn4+ decreasing slowly. However, Y3+–Ga3+ co-doping induces a linear and quick increase in the intensity of ZPL at 704 nm with increasing y value, due to the local symmetric degree of Mn4+ decreasing quickly. The octahedral tilting distortion is very important for the local symmetry. Ba2+–Ti4+ co-doping reduces octahedral tilting distortion, but Y3+–Ga3+ co-doping induces a serious octahedral tilting distortion. Consequently, the ZPL emission exhibits an octahedral-tilting dependent behavior. Mainly due to the larger distortion of the O–Mn–O bond, the energy of ZPL for LYAG:0.001Mn4+ is higher than that for LBAT:0.001Mn4+. The outcomes of this work provide a promising way to regulate the ZPL intensity and energy by tuning the local structure around Mn4+, and may have wide implications for Mn4+-doped phosphors and 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 Chemistry C
·
2024
·
IF 5.7
Qiao Qu,Haiyan Zhang,Haipeng Ji
The parity-selection rule for the Mn4+ d→d intra-configurational transition, if being relaxed, would generate Mn4+-doped red-emitting phosphor with short fluorescence lifetime, a desired feature when a phosphor is used in a white light-emitting diode (WLED) lamp applied as backlight in displays. We design non-equivalent substitution of Mn4+ for Mo6+ coordinated with F−/O2− mixed-anions, and obtained K3Na(MoO2F4)2·H2O:Mn4+ red phosphor which exhibits fast decay (luminescence lifetime of ~2 ms) and intense zero phonon line (ZPL) emission at 623 nm (ZPL/ν6 intensity ratio of 65.7% at 300 K) under 470 nm excitation. The local octahedron distortion accounting for the luminescence features was discussed and the crystal field strength and nephelauxetic effect were compared with analogues. The increasing trend of the ZPL/ν6 intensity ratio from 300 K to 80 K was explained, and the luminescence decay of a series of Mn4+ doping concentrations was studuied. The K3Na(MoO2F4)2·H2O:3%Mn4+, when encapsulated with garnet green phosphor on a blue LED, produced a WLED backlight with a wide color gamut above 103.5% of the NTSC standard.
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
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 16
·5614-5621
·
IF 4.099
Luqing Xi,Yuexiao Pan,Shaoming Huang,Hongzhou Lian,Jun Lin
Herein, a novel red phosphor based on seven-coordinated Mn4+ ion-doped tridecafluorodizirconate, Na5Zr2F13 (NZF), has been synthesized by stirring a mixture of K2MnF6, NaF, and H2ZrF6 at room temperature. The crystal structure and morphology of the as-obtained phosphor NZF:Mn have been determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The composition and distribution of Mn4+ ions in NZF have been confirmed by energy-dispersive spectroscopy (EDS) and element mapping via transmission electron microscopy (TEM). The phosphor NZF:Mn exhibits a strong zero phonon line (ZPL) at 616 nm under excitation of blue light from a GaN light-emitting diode (LED) chip; this is attributed to the low symmetry of Mn4+ ions occupied in a seven-coordinated environment. The luminescence intensity of NZF:Mn has been optimized by controlling the synthesis procedure and synthetic parameters. The luminescence mechanism of the red phosphor NZF:Mn has been investigated according to the detailed experimental results. A warm white light has been produced by a WLED fabricated with the red phosphor NZF:Mn and the commercial yellow phosphor Y3Al5O12:Ce3+ (YAG:Ce) on a GaN LED chip.
研究领域:
材料科学
·
无机化学
·
发光材料
·
固态照明
·
晶体化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Lulu He,Mingxin Zhang,Xiaoliang Dong,Liying Zhang,Ce Shi,Haipeng Ji
Macroscopic Mn 4+ -activated fluoride crystals can exhibit improved resistance to hydrolysis and higher quantum efficiency compared to their micro-sized powder counterparts. Among various Mn 4+ -doped fluorides, Na 2 SiF 6 :Mn 4+ is exceptional for its dominant photoluminescence at 627 nm, a notably short wavelength for this class of materials. While traditionally available only as micro-sized powder, this paper presents, for the first time, the growth of Na 2 SiF 6 :Mn 4+ in the form of millimeter-sized crystals. Utilizing a cooling-induced crystallization technique, we have obtained Na 2 SiF 6 :Mn 4+ crystals that exhibit columnar morphology with single-crystal-like characteristics and pronounced zero phonon line emission at 617 nm. The synthesis was meticulously optimized regarding the cooling protocol, cooling rate, and Mn 4+ doping concentration. With increasing dosage of K 2 MnF 6 in the precursor, a phase transformation from Na 2 SiF 6 :Mn 4+ to (Na,K) 2 SiF 6 :Mn 4+ and K 2 SiF 6 :Mn 4+ was observed for the product crystals. The incorporation of Mn 4+ was hindered during the cooling-induced crystallization of the crystals as the nominal Si/Mn concentration ratios significantly exceed the measured values. Comparison of the deterioration behavior in water suggests that the as-grown Na 2 SiF 6 :Mn 4+ crystals displayed significantly improved stability against water attack compared to the Na 2 SiF 6 :Mn 4+ powder phosphor. This work may inspire the development of more durable phosphor crystals for long-lasting white light LED technologies.
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
·
2025
·
IF 6.3
Zhaowu Wang,Zhiyu Min,Liping Tian,Wenrui Zhang,Hao Li,Jinlong Chen,Derong Zhu
Mn⁴⁺-activated fluoride bulk crystals have recently emerged as promising phosphor materials due to their superior water resistance, thermal stability, and quantum efficiency compared to conventional powder forms. Herein, we report the successful growth of millimeter-sized (NH₄)₂SiF₆:Mn⁴⁺ crystals with intense red emission under 365 nm UV excitation via a facile cooling crystallization approach. The as-grown crystals exhibit a distinctive yellow body color and attain dimensions of up to ∼3 mm. Intriguingly, Mn⁴⁺-doping triggers a structural phase transition in the host matrix from cubic symmetry (space group, Fm- 3 m ) to hexagonal symmetry (space group, P 6 3 mc ), accompanied by progressive lattice distortions. This structural evolution manifests spectroscopically through the emergence of a zero-phonon line (ZPL) in photoluminescence spectra, with the ZPL-to- v ₆ intensity ratio escalating from 0 % to 34 % as Mn⁴⁺ concentration increases. Concomitantly, all seven characteristic emission peaks display systematic blueshifts. Furthermore, the microscopic morphology, thermal quenching behavior, and decay property of the crystal are significantly influenced by the doping-induced structural modifications. This study establishes a structural engineering strategy for optimizing luminescent performance in (NH₄)₂SiF₆:Mn⁴⁺ crystal phosphors.
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产品关联
DOI
高影响因子
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