Journal of Materials Chemistry C
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2017
·Vol. 5
·期 36
·9255-9263
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IF 5.256
Luqing Xi,Yuexiao Pan,Mengmeng Zhu,Hongzhou Lian,Jun Lin
A kind of red-emitting phosphor NaKSnF6:Mn4+ (NKSF:Mn) has been obtained from NaF and KF with a certain molecular ratio in HF solution at room temperature. The phosphor NKSF:Mn exhibits superior optical properties including high color purity with narrow-band emissions as well as better chromaticity coordinates compared to the red phosphors Na2SnF6:Mn4+ (NSF:Mn) and K2SnF6·H2O:Mn4+ (KSFH:Mn). The composition and structure of NKSF:Mn have been identified by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The formation mechanism of NKSF:Mn is discussed and the morphology, thermal stability, and optical properties of NKSF:Mn have been investigated. The luminescence intensity of NKSF:Mn has been improved by optimizing synthetic parameters. A white light-emitting diode (WLED) fabricated using a blue GaN chip, a yellow YAG:Ce phosphor, and the as-prepared red phosphor NKSF:Mn exhibits superior warm white light with a color rendering index (CRI) of 90.3 at a correlated color temperature (CCT) of 3746 K.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 39
·10241-10250
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IF 5.256
Mengmeng Zhu,Yuexiao Pan,Luqing Xi,Hongzhou Lian,Jun Lin
Mn4+-activated red phosphors have attracted considerable attention as promising red components in the spectra of white light emitting diodes (WLEDs) to achieve warm white light with superior performance. Herein, a novel red phosphor based on Mn4+-doped dodec-fluoride Li3Na3Al2F12:Mn4+ (LNAF:Mn) with microcubic morphology was obtained at room temperature. To elucidate the underlying relationship between the crystal structure and photoluminescence of LNAF:Mn, a phosphor LiNa2AlF6:Mn4+ with similar composition has been prepared, and their morphology and optical properties were comparatively investigated. The emission of the red phosphor LNAF:Mn is blue shifted compared to LiNa2AlF6:Mn4+ suggesting that the chromaticity coordinates of LANF:Mn are closer to the ideal red point (0.67, 0.33). The luminescence properties of LNAF:Mn have been improved by optimizing the synthetic conditions. This work exhibits a strategy to explore a novel Mn4+-doped fluoride except for the identified hexa-fluorides. Employing the as-prepared red LNAF:Mn as a red component, a high-performance WLED with a correlated color temperature (CCT) of 3874 K and a color rendering index (CRI) of 90.6 was obtained. This suggests the phosphor is a potential commercial red phosphor in warm WLEDs.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
MATERIALS RESEARCH BULLETIN
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2021
·
IF 4.641
Yanzhen Yin,Zhen Wang,Maochen Zhu,Yue Zhang,Jianhong Li,Chao Dou,Shijia Sun,Bing Teng,Yang Che,Degao Zhong
A single-phased warm white phosphor of α-Sr 2 V 1.98 P 0.02 O 7 : 0.5 % Eu 3+ with low correlated color temperature (CCT) and high color rendering index (CRI) was synthesized by high temperature solid phase method. By changing the ratio of PO 4 3− /VO 4 3− , the emission intensity of VO 4 3− and the energy transfer efficiency of VO 4 3− →Eu 3+ can be effectively tuned, and the full-spectrum warm white light emission of phosphors in the range of 400−700 nm can be realized. Moreover, the temperature-dependent emission spectra and thermal quenching properties were investigated in detail. On this basis, the WLED prototype devices were packaged with the synthesized phosphors α-Sr 2 V 1.98 P 0.02 O 7 : 0.5 % Eu 3+ and 365 nm near-ultraviolet (NUV) chips and high-quality warm white light emission with CCT = 3188 K and CRI Ra = 93.5 were achieved. These findings provide new insights into exploring single-phased white phosphors for NUV-pumped warm w-LEDs with high CRI property and low CCT value.
研究领域:
材料科学
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光学工程
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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
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光学工程
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2024
·
IF 18.5
Yuhang Kuang,Jiance Jin,Gaochao Liu,Weibin Chen,Zhiguo Xia
Single-phase white-light emitters in the lighting technology overcome the challenges of re-absorption and color shift. However, achieving the broadband white emission in single-phase phosphor remains a challenge. Here, crystallized KBaScSi 3 O 9 :Eu 2+ (KBSSO:Eu 2+ ) glass-ceramics (GC) with abundant cationic sites have been developed and an ultra-broad emission band ranging from 460 to 800 nm have been found, in which the asymmetric green emission is ascribed to the Eu 2+ ions in [KO 8 ] and [BaO 7 ] polyhedra, while the red emission centered at 620 nm is originated from Eu 2+ ions in [ScO 6 ] sites. The optimized GC-converted white LED (WLED) exhibits a high color rendering index ( R a = 89.8) and low correlated color temperature (CCT = 4241 K). Moreover, the encapsulant-free GCc-WLED can operate continuously under high drive currents. This work paves the way for the design and future development of single-phase high-power white light sources.
研究领域:
材料科学
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光学工程
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照明技术
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产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2021
·
IF 3.599
Yanzhen Yin,Maochen Zhu,Yue Zhang,Chen Hu,Zhen Wang,Yang Che,Jingyao Lu,Ruyi Sun,Jiaqi Zhao,Bing Teng,Jianhong Li,Shijia Sun,Degao Zhong
High quantum efficiency and thermal stability have always been the goals to pursue and challenges for lighting application. In this work, sunlight-like white emission has been achieved in a new prepared single phased Rb 2 CaP 2 O 7 : 0.005Ce 3+ , 0.01Eu 2+ phosphor, which exhibits high internal quantum efficiency (IQE = 74.36%), external (EQE = 56.77%) quantum efficiency and excellent thermal stability. Based on the broadband emission from 4f-5d transitions of Ce 3+ /Eu 2+ ions and high energy transfer efficiency of Ce 3+ →Eu 2+ (measured up to 60%), the extremely wide color-tunable emission from blue-violet to white and then to orange-yellow is realized in Rb 2 CaP 2 O 7 : 0.005Ce 3+ , xEu 2+ phosphors. Moreover, a prototype WLED device is packaged by combing the prepared Ra 2 CaP 2 O 7 : 0.005Ce 3+ , 0.01Eu 2+ white phosphors with an UV LED chip (λ = 310 nm), and the obtained WLED emits bright sunlight-like white light with color coordinates of (0.377, 0.324). The correlated color temperature (CCT) and the color rendering index (CRI) value of the WLED are 3208 K and 88.4, respectively. These results can provide effective guidance for the design of color-tunable single-phase white phosphors with high luminous efficacy and thermal stability.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Advanced Science
·
2020
·Vol. 7
·期 4
·1902688
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IF 15.84
Zifei Wang,Yang Liu,Shijie Zhen,Xiaoxi Li,Weiguang Zhang,Xun Sun,Baoyuan Xu,Xue Wang,Zhenhua Gao,Xiangeng Meng
Fluorescent carbon dots (CDs) are compelling optical emitters to construct white light-emitting diodes (WLEDs). However, it remains a challenge to achieve large-scale and highly efficient single-component white-light-emissive CDs suitable for WLED applications. Herein, a low cost, fast processable, environmentally friendly, and one-step synthetic approach is developed for the preparation of gram-scale and highly efficient single-component white-light-emissive carbonized polymer dots (SW-CPDs). It is revealed that hybrid fluorescence/phosphorescence components cooperatively contribute to the emergence of white light emission. The SW-CPDs exhibit a record quantum yield (QY) of ≈41% for the white light emission observed in solid-state CD systems, while the QY of the phosphorescence is ≈23% under ambient conditions. Heavy doping of N and P elements as well as presence of covalently cross-linked polymer frameworks is suggested to account for the emergence of hybrid fluorescence/phosphorescence, which is supported by the experimental results and theoretical calculations. A WLED is fabricated by applying the SW-CPDs on an UV-LED chip, showing favorable white-light-emitting characteristics with a high luminous efficacy of 18.7 lm W −1 that is comparable to that of state-of-the-art WLEDs reported before.
研究领域:
材料科学
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光学工程
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化学工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
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2021
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IF 5.165
Yijia Liu,Gengxin Zhang,Junben Huang,Xiaoma Tao,Guihua Li,Gemei Cai
Single-phase white-emission phosphors possess a judicious usage potential in phosphor-converted white-light-emitting diodes (WLEDs). Recently, numerous efforts have been made toward the development of new patterns of white-emitting phosphors that achieve excellent quantum yield, superior thermal stability, and applaudable cost effectiveness of WLEDs. Finding suitable single-component white phosphor hosts to provide an ideal local environment for activators remains urgent. Inspired by the original discovery of the promising host MgIn2(P2O7)2 (MIP) and its structural dependence on alkali-metal cations, we synthesized a brand-new phosphor host, SrIn2(P2O7)2 (SIP), via the traditional solid-state reaction. Its crystal structure was determined using an ab initio analysis and the Rietveld method. It belongs to a monoclinic unit cell with the space group C2/c. Besides, SIP exhibits a special layered three-dimensional framework in which the monolayer [SrO10]∞ was surrounded by a bilayer [In2P4O14]∞ made of the InO6 octahedra and P2O7 groups. A series of pure SIP:Tm3+,Dy3+ phosphors with tunable blue–white–yellow emission were prepared by adjusting the dopant concentration and utilizing the Tm3+–Dy3+ energy transfer. The daylight-white-emitting phosphor SIP:0.01Tm3+,0.04Dy3+ (the correlated color temperature is 4448 K) exhibits an abnormal thermal antiquenching property, and the emission intensity of 423 K reaches 103.7% of the initial value at 300 K. On the basis of the temperature-dependent lattice evolution and microenvironment analysis, the reduction of β and lattice distortion can lead to lower asymmetry of the activators and benefit the compensation of trapped-electron thermal activation. In this work, an integration study was carried out on the crystal structure of the new matrix, the occupation of the luminescent center, the interaction of different activators in the host, and the distortion degree of the local structure for the activators, which is of great practical sense for producing a novel single-matrix white phosphor possessing superior thermal endurance for UV-light-stimulated WLEDs.
研究领域:
材料科学
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光学
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
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2022
·
IF 5.436
Haiping Xu,Zhizhuan Zhang,Xuehua Dong,Ling Huang,Hongmei Zeng,Zhien Lin,Guohong Zou
Organic–inorganic hybrid metal halides (OIMHs) exhibiting white-light emission are a splendid class of emitters and are regarded as desired phosphors for solid-state lighting applications. Here we report a single-component white-light-emitting hybrid metal halide, namely, [C6H7ClN]CdCl3 (C6H7ClN = 4-(chloromethyl)pyridinium), which features a corrugated 1D anionic double chain composed of edge-shared CdCl6 octahedrons and exhibits broadband white-light emission with a photoluminescence quantum yield of 12.3% under 365 nm UV light irradiation. Density functional theory calculations and temperature-dependent emission spectral analysis unveil that the broadband emission of [C6H7ClN]CdCl3 is ascribed to self-trapped excitons. Moreover, a single-component white-light-emitting diode device with a correlated color temperature of 5214 K and color rendering index of 83.7 can be fabricated via coating [C6H7ClN]CdCl3 on a 365 nm UV light-emitting diode chip. Such a promising luminescent material provides guidance for the design and synthesis of OIMHs with unique structures and desired properties.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2025
·Vol. 17
·期 18
·2558
·
IF 4.9
Qiming Huo,Zhuo Lv,Shengyu Feng,Dengxu Wang,Hongzhi Liu
The development of a straightforward strategy for preparing organic fluorescent materials, fine-tuning white-light emission, and subsequently constructing white light-emitting diodes (LEDs) is of great significance. Herein, we report on the modulation of white-light emission and the fabrication of white LEDs using polyhedral oligomeric silsesquioxane (POSS)-based fluorescent hybrid porous polymers (HPPs) through simple physical blending. Two HPPs, namely HPP-1 and HPP-2, which emit blue and red light, respectively, were synthesized via the efficient Heck reactions of octavinylsilsesquioxane with 4,4′-dibromobiphenyl and 1,3,6,8-tetrabromopyrene. By physically doping of HPP-1 and HPP-2 in variable ratios in solvent suspensions, it was discovered that white-light emission is significantly influenced by the concentrations of the materials and the excitation wavelength. Similar findings were also observed in the solid-state physical doping. An ideal white light emission with a CIE coordinate of (0.33, 0.33) can be achieved when excited at 380 nm with a mass ratio of HPP-1 to HPP-2 of 1:2. Finally, the two HPPs were dispersed in polysiloxane matrices, and a white LED with a CIE coordinate of (0.42, 0.36) was obtained. The LED exhibited a color rendering index of up to 90 and a correlated color temperature of 2858 K, realizing warm white light emission. This simple and convenient white-light regulation strategy holds great promise for application in the development of novel white LEDs based on organic fluorescent porous materials.
研究领域:
材料化学
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光电子学
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高分子科学
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发光材料
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固态照明
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2024
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IF 8.3
Linyuan Lian,Peng Zhang,Guijie Liang,Yong Xia,Jianbo Gao,Daoli Zhang,Jianbing Zhang
Low-dimensional metal halides with broadband emissions are expected to serve as downconversion luminescent materials for solid-state lighting (SSL). However, efficiently generating full-spectrum white-light emission with a high color-rendering index (CRI) in single-phase emitters remains a challenge. Here, we report a novel zero-dimensional (0D) hybrid mixed-metal halide (TPA)2CuAgI4 (TPA = tetrapropylammonium), in which individual [CuAgI4]2– dimers are completely isolated and surrounded by the organic cations TPA+. Cu+ and Ag+ share the same crystallographic site in [CuAgI4]2– dimers with the same statistical probability. Upon photoexcitation, single crystals exhibit a full-spectrum white-light emission with a full width at half-maximum (fwhm) of up to 314 nm and a high quantum efficiency of 46.8%. Detailed photophysical studies and theoretical calculations reveal that the ultra-broadband emission of (TPA)2CuAgI4 originates from the radiative recombination of red-, green-, and blue-emitting self-trapped excitons in [CuAgI4]2– dimers. In addition, (TPA)2CuAgI4 nanocrystals were successfully synthesized and exhibited optical properties similar to those of single-crystal counterparts. Finally, a prototype ultraviolet (UV)-pumped white-light-emitting diode (WLED) and a composite thin film employing this new white-light emitter produces a well-distributed full-spectrum white light with a high CRI of 91.4 and a warm correlated color temperature (CCT) of 4135 K, indicating the potential application of this white-light emitter in SSL. These results provide a new perspective for designing superior single-phase white-light emitters.
研究领域:
材料科学
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光学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
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IF 6.371
Shuai Wei,Zhijun Li,Zeyu Lyu,Dashuai Sun,Sida Shen,Jianhui Wang,Chengyu Zhuo,Hongpeng You
In this work, we provide a paradigm how to realize white light emission by utilizing the energy transfer from the Bi 3+ to Eu 3+ ions. First, a novel Bi 3+ activated phosphor set of highly oxygen-deficient perovskite derivatives (Ba 3 YGa 2 O 7.5 , BYGO) were synthesized through the conventional high-temperature solid-state method. The crystal structure was confirmed by Rietveld refinement . Then, Eu 3+ was introduced to the phosphor composition to construct energy transfer pathway with Bi 3+ . The emission color of the BYGO:Bi 3+ ,Eu 3+ phosphors can be changed from cyan to white and orange-red by altering the Bi 3+ /Eu 3+ doping ratio. The energy transfer from the Bi 3+ to Eu 3+ ions was ascribed to dipole-dipole interaction. Finally, a single-component WLED device with a color-rendering index of 84.9 was successfully prepared by employing a near-ultraviolet chip and the BYGO:Bi 3+ ,Eu 3+ phosphors. This work not only indicates that the as-prepared BYGO:Bi 3+ ,Eu 3+ phosphors are a potential candidate for near-ultraviolet WLED, but also demonstrated that energy transfer is an avenue for single-phased white light emission.
研究领域:
材料科学
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光学
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DOI
高影响因子
危险品化学品经营许可证（带存储）