RSC Advances
·
2019
·Vol. 9
·期 72
·42430-42437
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IF 3.049
Shangxuan Huang,Sen Yang,Qi Wang,Ruirui Wu,Qiuju Han,Wenzhi Wu
Cs4PbBr6/CsPbBr3 perovskite composites are fabricated by room-temperature one-pot mixing synthesis, which is short in time, free from inert gases and delivers a high product yield. Temperature-dependent photoluminescence shows that a larger exciton binding energy of 291.1 meV exhibits better thermal stability compared with that of pure Cs4PbBr6 and CsPbBr3 materials. The CIE chromaticity coordinates (0.1380, 0.7236) of green LEDs designed with Cs4PbBr6/CsPbBr3 perovskite composites show almost no variation under driving current changing from 5 to 30 mA. Furthermore, the ground Cs4PbBr6/CsPbBr3 perovskite composites mixed with red emitting K2SiF6:Mn4+ phosphor are dropped and casted on a blue-emitting InGaN chip. The white light emitting diodes (WLEDs) are presented, which have good luminous efficiency of 65.33 lm W−1 at 20 mA, a correlated color temperature of 5190 K, and the white gamut with chromaticity coordinate of (0.3392, 0.3336). According to the state of art, these excellent characteristics observed are much superior to the reported results of conventional perovskite-based WLEDs, which demonstrate the immense potential and great prospect of Cs4PbBr6/CsPbBr3 perovskite composites to replace conventional phosphors in lighting devices.
研究领域:
材料科学
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光学工程
·
半导体技术
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DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
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2019
·
IF 10.159
Guojun Zhou,Xingxing Jiang,Maxim Molokeev,Zheshuai Lin,Jing Zhao,Jing Wang,Zhiguo Xia
Finding new low-dimensional metal halides with broad-band emission is attracting interest in single-component phosphor for white light-emitting diodes (WLEDs). The full-spectrum white light still remains a challenge as found in the two-dimensional hybrid material (C6H18N2O2)PbBr4 exhibiting the intrinsic free exciton (FE) and broad-band self-trap exciton (STE) emission upon 365 nm ultraviolet excitation, and a combined strategy has been proposed through doping the Mn2+ ions enabling a superposition of multiple emission centers toward the ultra-broad-band warm white light. The occupation of Mn2+ in (C6H18N2O2)PbBr4 has been discussed, and optical investigations verify that the warm white-light emission of Mn2+-doped (C6H18N2O2)PbBr4 originates from the coupling effects of the FE, STEs, and the 4T1–6A1 transition of the doped Mn2+. When the concentration of Mn2+ is 5%, the emission spectrum of the phosphor covers all visible-light areas with a full width at half maximum (FWHM) of about 230 nm. The high Ra (84.9) and warm light CCT (3577 K) values of the as-fabricated WLED lamp demonstrate that (C6H18N2O2)Pb1–xMnxBr4 can be promising as single-component white-light phosphor in solid-state lighting. Our work could provide a new understanding and perspective about hybrid metal halides for designing superior phosphor toward single-component white emission.
研究领域:
材料科学
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光电
·
固态照明
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DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 37
·12944-12950
·
IF 4.099
Mengmeng Zhu,Yuexiao Pan,Mingmei Wu,Hongzhou Lian,Jun Lin
Red phosphors composed of Mn4+-activated complex fluorides have attracted considerable attention for applications in warm white light-emitting diodes (WLEDs). In the present study, we report a facile strategy to synthesize a novel red phosphor LiSrGaF6:Mn4+ (LSGF:Mn) at room temperature, and we also discuss its formation mechanism. Mn4+ ions occupy Ga3+ sites located at the centers of distorted [GaF6]3− octahedrons and emit intense red luminescence when excited by UV or blue light. The effects of synthesis conditions such as the type of strontium salts, the concentrations of K2MnF6 and NH3·H2O, and the reaction temperature have been investigated. The luminescence intensity of the phosphor LSGF:Mn has been improved by optimizing the synthetic parameters. The as-prepared phosphor LSGF:Mn exhibits broad and intense absorption in the blue region and bright luminescence in the red region, which indicate that it is promising for applications in warm WLEDs.
研究领域:
材料科学
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无机化学
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光电子学
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固态照明
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功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xiaobin Zhao,Quansheng Wu,Xufeng Zhou,Shanshan Ye,Jianyan Ding
The realization of Eu 3+ reduction and its reduction mechanism have become focal points in the field of WLED phosphor research. In this study, the reduction of Eu 3+ was successfully achieved through cationic substitution strategy by replacing Zr 4+ with Hf 4+ in Na 2 ZrSiO 5 :Eu 3+ . The effects of substituting Hf 4+ for Zr 4+ on the phase, crystal structure, and luminescence properties of Na 2 Zr 1- x Hf x SiO 5 :Eu 0.03 (0 ≤ x ≤ 1) were thoroughly investigated based on Rietveld refinement , spectral data, DFT calculation and electronegativity of ions. Comprehensive consideration was given to the effect of site size change and site reducibility on Eu 3+ reduction. The results demonstrate that the reduction of Eu 3+ in Na 2 Zr 1- x Hf x SiO 5 :Eu 0.03 is attributed to the alteration in inducible effect caused by cationic substitution and the enhancement in site reducibility rather than changes in site size. Therefore, the cationic substitution strategy based on induction effect presents a novel approach for achieving Eu 3+ reduction and offers a new insight into developing and modifying Eu 2+ -activated phosphors.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2026
·
IF 7.4
Yuan Li,Yao Qian,Haodong Zheng,Ruijing Fu,Yan Chen,Jing Wang
An ultra-broadband green-emitting phosphor K 2 ZnSi 3 O 8 :Eu 2+ with FWHM of 111.8 nm was developed via multi-site occupation of Eu 2+ . • Mg 2+ substitution for Zn 2+ induces local lattice stiffening and defect passivation, boosting PL intensity by 120% . • The optimized phosphor exhibits enhanced thermal stability with increased activation energy (0.261 eV vs. 0.251 eV) and complete intensity recovery after thermal cycling. • A warm WLED fabricated with KZn 0.99 Mg 0.01 SiO 8 :0.01Eu 2+ and commercial red phosphor achieves high color rendering index (Ra = 94.2) and low CCT (3552 K). • This cationic substitution strategy offers an effective route to simultaneously enhance luminescence efficiency, thermal stability, and moisture resistance in rare-earth-doped phosphors. Efficient broadband green-emitting phosphors are essential for human-centric healthy lighting. Herein, an ultra-broadband green-emitting phosphor, K 2 ZnSi 3 O 8 :Eu 2+ , was synthesized by high temperature solid-state reaction method for high-quality white light-emitting diodes (WLEDs). Under ultraviolet excitation, the phosphor exhibits a broad emission band spanning from 400 to 750 nm, peaking at 505 nm with a full width at half maximum (FWHM) of 111.8 nm, which originates from the multi-site occupation of Eu 2+ ions. Moreover, structural engineering via Mg 2+ substitution for Zn 2+ effectively enhances the material's performance. K 2 Zn 0.99 Mg 0.01 Si 3 O 8 :Eu 2+ , shows a 120% increase in emission intensity and improved thermal stability. Finally, a warm WLED fabricated this phosphor with a commercial red phosphor exhibits excellent color rendering index (Ra = 94.2) and a warm correlated color temperature (CCT) of 3552 K, demonstrating its promising application in high-quality healthy solid-state lighting.
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DOI
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Qi Chen,Fang Lei,Ying Shi
Perovskite light-emitting diodes (PeLEDs) employing CsPbX 3 nanocrystals (NCs) face persistent challenges in balancing emission efficiency and spectral stability due to surface halide vacancies, which trigger nonradiative recombination, halide phase segregation, and self-doping effects. In this work, we address these limitations by introducing 3,5-dicarboxyphenylboronic acid (3,5-DA) as a multifunctional bidentate ligand additive. The unique coordination architecture of 3,5-DA, featuring multiple chelating groups, enables strong binding affinity to perovskite NC surfaces. This interaction effectively passivates halide vacancies while suppressing ion migration and defect formation. The optimized CsPb(Br/I) 3 NCs exhibit enhanced stability and suppressed nonradiative losses, enabling high-performance white LEDs (WLEDs). At a driving current of 10 mA, the fabricated WLEDs demonstrate a luminous efficiency of 10.32 lm·W −1 , a CIE coordinate of (0.3379, 0.3391), a correlated color temperature (CCT) of 5260 K, and an external quantum efficiency (EQE) of 6.48 %. This work provides a ligand engineering strategy to concurrently resolve efficiency-stability trade-offs in PeLEDs.
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DOI
高影响因子
Advanced Optical Materials
·
2025
·
IF 7.2
Shan-Ping Wang,Wen-Wen Dong,Pan-Pan Cao,Xue Tian,Dong-Dong Xu,Jun Zhao,Dong-Sheng Li,Qichun Zhang
Although dye-encapsulated metal-organic framework (dye@MOF) phosphors exhibit excellent advantages (e.g., high quantum yield (QY) and luminescence tunability) in white light emitting diodes (WLEDs) lighting, the considerable fluorescence quenching of these dye@MOF phosphors remains an unmet challenge due to their low thermal conductivity and strong thermal accumulation. In this research, a high QY dye@MOF phosphor (QY = 78.4%) is successfully prepared using the secondary growth method. Through in situ doping of hexagonal boron nitride (BN), a yellow phosphor dye@MOF/BN is synthesized to mitigate thermal quenching and improve phosphor stability in WLEDs. The WLEDs constructed with 450 nm blue LED chips exhibit a temperature reduction of 10.2 °C at a current of 10 mA after continuous operation for 8 hours, compared to those fabricated by pristine phosphor. The dye@MOF/BN based WLEDs maintain high performance with a luminous efficacy of 93.89 lm W −1 , color rendering index of 86.4, and QY of 64.4%, indicating that the proposed strategy effectively improves heat dissipation without compromising optical performance.
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
Materials Today Physics
·
2024
·
IF 10
Daiyuan Liu,Ru Zhao,Chao Wang,Zhichao Liu,Jian Zhang,Yuan Wang,Xue Yu,Jianbei Qiu,Xuhui Xu,Yichun Liu
High-quality phosphors with color tunability are urgently needed for the full-spectrum white light-emitting diodes (WLEDs) with healthy and comfortable lighting like the solar spectrum. Here, a Sr 2 Ga 2 SiO 7 : Eu 2+ phosphor with tunable luminescence color is reported, achieving a luminescence tuning from maize-yellow to yellow by changing the Eu 2+ ion concentration. Importantly, the quantum efficiency of BaSrGa 2 SiO 7 : 1.0 % Eu 2+ is as high as 85.7 % compared with 49.1 % of Sr 2 Ga 2 SiO 7 : 5.0%Eu 2+ , and the emission intensity of BaSrGa 2 SiO 7 : 1.0 % Eu 2+ retains 92 % of the room temperature (RT) emission intensity at 473 K by Ba 2+ substitution. Furthermore, the increase of Ba 2+ ion concentration also makes the phosphor achieve tunability from yellow to green. The as-prepared full-spectrum WLEDs exhibits a continuity spectrum like solar spectrum with an extremely high color rendering index of 93.5 and low correlated color temperature of 4562 K. This work provides new insights into the exploration of new phosphors for high-performance full-spectrum WLEDs devices.
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 ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Lili He,Rui Liu,Chunhua Ge,Li Yang,Kai Jia,Xiangdong Zhang
Rare earth (RE)-doped luminescent materials have shown tremendous potential applications in the optical field. However, it is still a challenge to improve its luminescence properties further. In this study, the Tm 3+ -doped zinc borate (4ZnO·B 2 O 3 ·H 2 O, ZBH) with a flaky-like morphology was successfully prepared by a facile hydrothermal reaction . The photoluminescence (PL) performance of ZBH:Tm 3+ is improved through incorporating yellow N-doped carbon dots (yNCDs). Simultaneously, by changing the content of yNCDs in ZBH:Tm 3+ host, the morphological evolution from flaky-like to flower-like of the ZBH:Tm 3+ /yNCDs composite are realized. The ZBH:Tm 3+ /yNCDs composite with flower-like exhibits the strongest white light emission and splendid thermal stability under 360 nm excitation wavelength, matching the current mainstream near-ultraviolet (NUV) LED chip. Thus, ZBH:Tm 3+ /yNCDs composite might be a promising luminescent material in the NUV white lighting and display fields. The findings of this study developed a novel idea for improving the luminescent properties of RE-doped materials. Besides, it also solves fluorescence quenching problems of carbon dots in the solid-state illumination field.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Xinyi Zhang,Jian-Feng Sun
An intriguing novel perovskite-type Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with desirable properties for potential application in the field of white light-emitting diodes was first time synthesized. The Rietveld structural refinement, scanning electron microscopy and high resolution transmission electron microscopy were used to determine the crystallographic parameters, morphology and microstructure of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor. The first principle calculation based on the density functional theory further provided a theoretical understanding of the band structure for the undoped Cs 4 Mg 3 CaF 12 and indicated that it has a large direct band gap of 7.1 eV. Upon the excitation of Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor in the broad range of 250–450 nm, the bright blue light emission was observed with the maximum at 474 nm and a full width at half-maximum of 2808 cm −1 that was attributed to the electric-dipole allowed 4f 6 5 d 1 →4f 7 transition of Eu 2+ ions. Based on the Dexter’s theory, the concentration quenching mechanism among Eu 2+ in the Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor was validated to be the dipole-dipole interaction, and the critical distance was determined to be 23.34 Å. On the basis of temperature-dependent luminescence measurement, an analysis of the origins of thermal quenching behavior was presented. The Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor not only has favorable thermal stability with emission intensity reduction by 20% at T = 473 K in reference to the room temperature level, but also shows the integrated PL intensity 95% as high as that of BaMgAl 10 O 17 : Eu 2+ , internal quantum efficiency of 64% and color purity of 85%. The results of this work indicate that the blue-emitting Cs 4 Mg 3 CaF 12 : Eu 2+ phosphor with promising luminescence properties has a capacity for incorporation as a component to the near-UV based phosphor-converted WLEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhuowei Li,Ge Zhu,Shanshan Li,Shuangyu Xin,Wen Xu,Xixian Luo,Ming He,Bin Dong
High power phosphor converted light emitting diodes (pc-LED) are thought to be the next generation technology for lighting and high-tech electronics applications. To achieve optimal luminous efficiency, maximal color gamut and stable color reproducibility, the discovery of high efficient phosphor materials with suitable excitation matching, narrow band emission and robust thermal stability is essential. Herein, we design and construct a new family of alkaline phosphate phosphors ANa 3 Mg 7 (PO 4 ) 6 :Eu 2+ (ANMP:Eu 2+ , A = K, Rb and Cs) with rigid diamond-like chain structure. The results indicates that ANMP:Eu 2+ (A = K, Rb and Cs) phosphors exhibit ultra-small Stokes shift and efficient blue emission ( λ max = 444–465 nm) with high internal quantum efficiency (IQE = 83.2%, 90.6% and 93.4% for A = K, Rb and Cs), narrow full width at half maximum (FWHM∼50 nm) and low thermal quenching (87.5%, 96.5% and 84.2%@140 °C for A = K, Rb and Cs), which demonstrate to have higher colorful purity, wider color gamut and better wavelength applicability for using in long-wavelength near ultraviolet (LWUV) LEDs, compared with the traditional commercially available blue phosphor BaMgAl 10 O 17 :Eu 2+ (BAM:Eu 2+ ). The Eu 2+ site preferences and thermal quenching mechanism are studied in detail. Moreover, the in situ temperature dependent Raman spectra and density function theory (DFT) are employed to get better comprehensions of the relationship between crystal-electronic structures and luminescent properties from experiment and calculation, which will provide a good guidance for develop new phosphors with high QE and excellent thermal stability. Finally, utilizing the title phosphors, white LED lamps are fabricated with high color rendering index and an appropriate correlated color temperature. Therefore, all the results demonstrate that the blue-emitting phosphor ANMP:Eu 2+ (A = Cs, K, Rb) has great potential for applications in high power LWUV pumped pc-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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wenfeng Sun,Xue Li,Bo Li,Caizheng Wang,Ying Zhao,Xiaotao Zu,Weilie Zhou,Xia Xiang
In this work, the carbon quantum dots@Cs 2 NaInCl 6 (CDs@CNC) composites are presented by a facile solution synthesis. The obtained CDs@CNC composites maintain the octahedral morphology of original CNC host and the characteristic functional groups of original CDs. As a result, the rare-earth-free CDs@CNC composites exhibit green light emission with good stability for UV irradiation, heat, and humidity. In addition, CDs were combined with ion-doped CNC to obtain multicolor phosphor and the corresponding white light emitting diode (WLED) devices were fabricated by coating composites on commercial UV chips. The color render index (CRI) of WLEDs increases significantly from 66.24 to 90.95 while the cold-warm white fluorescence can be flexibly tuned by the change of excitation wavelength. The combination of CDs and double perovskites provide a new route to design white light emission phosphors, which could lead to the fabrication of next generation high-quality lighting devices.
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
危险品化学品经营许可证（带存储）