JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Pu Fan,Zefeng Xu,Qi Luo,Zongjie He,Yuhui Chen,Qiqi Miao,Cong Huang,Xiaoguang Liu,Ling Li
Phosphor-converted white LEDs are realized by combining blue InGaN chips with yellow and red emitting materials. Due to the lack of efficient red phosphor materials, we can design a broadband yellow phosphor material containing as many red components as possible. We found an abnormal broadband yellow-emitting Ba 2 CaB 2 Si 4 O 14 :Eu 2+ borosilicate phosphor inspired by natural minerals, which has been synthesized by traditional high temperature solid-state method. The structural information and photoluminescence characteristics of Ba 2 CaB 2 Si 4 O 14 :Eu 2+ were characterized in detail, and applied to the fabrication of white LED devices. Excited by near ultraviolet light at 365 nm, it displays a wide emission band from 400 to 800 nm centered on the 595 nm peak. White LED devices were fabricated by physically mixing the yellow phosphor Ba 2 CaB 2 Si 4 O 14 :Eu 2+ and synthesized blue phosphor BaMgAl 10 O 17 :Eu 2+ with 365 nm UV chip as excitation. The correlation color temperature (CCT) value and the chromaticity coordinates of the fabricated WLED devices were found to be 5522 K and (0.3293, 0.3036) respectively. In conclusion, Ba 2 CaB 2 Si 4 O 14 :Eu 2+ has great potential in the preparation of near UV excited white LEDs.
研究领域:
材料科学
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光电技术
·
光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
R. Vijayakumar,Balaji Devakumar,Xiaoyong Huang
In this paper, Ce 3+ /Tb 3+ co-doped blue-green emitting Ba 2 Gd 5 B 5 O 17 borate phosphors were prepared for the first time. Phase purity, crystal structure, photoluminescence properties, energy transfer, and thermal stability of the as-synthesized samples were studied in detailed. The Ce 3+ ions singly doped Ba 2 Gd 5 B 5 O 17 :Ce 3+ phosphors had a broad excitation band in the 300–400 nm spectral range peaking at 345 nm, and when excited at 345 nm they exhibited a broad blue emission band in the 350–700 nm wavelength range with a maximum at 450 nm. Energy transfer process from Ce 3+ to Tb 3+ ions took place in the Ce 3+ /Tb 3+ co-doped Ba 2 Gd 5 B 5 O 17 phosphors, resulting in color-tunable emission outputs. It was found that under the excitation of 345 nm, the emission spectra of Ba 2 Gd 5 B 5 O 17 :Ce 3+ ,Tb 3+ phosphors displayed the broad blue emission band of Ce 3+ ions and the characteristic sharp green emission lines of Tb 3+ ions. Moreover, the intensity ratio of Ce 3+ blue emission to Tb 3+ green emission was adjusted by increasing the Tb 3+ doping concentration, and the Ce 3+ →Tb 3+ energy transfer mechanism was studied. Furthermore, the thermal stability of Ba 2 Gd 5 B 5 O 17 :Ce 3+ ,Tb 3+ phosphors was estimated, and the activation energy of Ba 2 Gd 5 B 5 O 17 :0.008Ce 3+ ,0.2 Tb 3+ sample was calculated to be 0.205 eV. The obtained results revealed that blue-green emitting Ba 2 Gd 5 B 5 O 17 :Ce 3+ ,Tb 3+ borate phosphors have potential usage in the fabrication of near-UV based white LEDs.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 5
·2607-2618
·
IF 2.779
Gao Zhihua,Fu Fengyan,Niu Lili,Jin M.
In the recent years, luminescent phosphor materials have contributed much to reduce the serious environmental problems such as environmental pollution, greenhouse effect, and energy crisis, but most of them commercially used for fabricating white LEDs are rare earth (RE) ions doped materials. Here, the non-RE Bi 3+ -doped Ba 2 (Y,Sc)NbO 6 solid solution nanocrystals are prepared using a high temperature solid state route followed by a ball milling and griddle selection. Our experiments show that when the Y 3+ ions are replaced by the Sc 3+ ions, the obtained solid solution nanocrystals show a shift of X-ray reflection positions to higher angle, and the emission peaks from blue to blue-green. At the same time, a 1.35 time of PL intensity enhancement under 365 nm excitation is achieved in the Ba 2 (Y 0.58 ,Sc 0.4 )NbO 6 :0.02Bi sample when compared to the Ba 2 Y 0.98 NbO 6 :0.02Bi sample. In addition, this optimal sample shows the quantum efficiency of 76% and good thermal stability with T 50% value of 205 °C. By depositing the Ba 2 (Y 0.58 ,Sc 0.4 )NbO 6 :0.02Bi and commercial red Sr 2 Si 5 N 8 :Eu 2+ phosphors on a 365 nm UV LED chip at a driving current of 30 mA, a white LED device, with a CIE coordinates at (0.364, 0.379), a high color rendering index of 76.8 and luminous efficiency of 67 lm, and a low color temperature of 3469 K, is achieved.
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
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Bingjie Han,Jing Ren,PingPing Teng,JiaBao Zhu,Yu Shen,ZhiAng Li,Xiaoliang Zhu,Xinghua Yang
At present, the combination of red, green and blue light (RGB) is one of the mainstream ways to obtain high-efficiency white light emitting diodes (w-LEDs). In this paper, we have prepared a new type of Sm 3+ activated Ca 2 LaSbO 6 (CLSO) orange-red phosphor by the high-temperature solid-phase method. The phase and morphology of the powders were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The luminescent properties, thermal stability of the materials have been tested and analyzed in detail. The results show that CLSO:Sm 3+ phosphors have several excitation bands in the range of 320–550 nm, and the excitation peak intensity at 405 nm is the largest, indicating that the material can be excited by blue light. The emission peak is composed of 564 nm (yellow), 601 nm (orange) and 648 nm (red), emission intensity reaches the extreme value when the Sm 3+ doping concentration is 5 mol%, the quenching phenomenon is due to the dipole-dipole (d-d) interaction of Sm 3+ ions. The activation energy ( E a ) of Sm 3+ in CLSO is 0.2689 eV. The CIE chromaticity coordinates of CLSO:Sm 3+ located at origin-red region. All results show that CLSO:Sm 3+ phosphor has potential application value in w-LEDs field.
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
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Meiqin Xiao,Ting Xiang,Dohyung Kim,Miaosheng Wang,Wei Zhang,Mahshid Ahmadi,Ting Li,Xiaoyan Wu,Long Xu,Ping Chen
The multiple quantum well structure of a quasi-two-dimensional (quasi-2D) perovskite leads to nonradiative Auger recombination (AR). This is due to high local carrier density in recombination centers, although the radiative recombination is improved by efficient energy transfer. In this study, we suppress the AR by introducing phenethylammonium acetate (PEAAc) into the quasi-2D PEA2Csn–1PbnBr3n+1 perovskite. The recombination centers of n ≥ 4 phases can be promoted because the COO– preferentially coordinates with Pb2+, inhibiting the fast formation of n = 1, 2, 3 phases with phenethylammonium anion (PEA+). Thus, the AR is suppressed due to the lower density of local charge carriers. To balance the AR suppression and decreasing binding energy in promoting the n ≥ 4 phases, the PEAAc:PEABr molar ratios are adjusted. At the optimal molar ratio, perovskite light-emitting diodes (PeLEDs) with a maximum luminescence of ∼29942 cd m–2 and a maximum external quantum efficiency of ∼20.2% are achieved. These results confirm the most efficient PeLEDs based on PEA2Csn–1PbnBr3n+1 without passivation. Moreover, the efficiency roll off is significantly mitigated with a high threshold of over 3.51 mA/cm2. This study develops high-efficiency PeLEDs with a low efficiency rolloff.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Ziyang Wu,Jinmeng Xiang,Changheng Chen,Zexun Li,Xianju Zhou,Yuehui Jin,Chongfeng Guo
As a new generation of near-infrared (NIR) light source, phosphor-converted NIR light emitting diodes (NIR pc-LEDs) have broad application prospects in biological tissue imaging, night vision and chemical composition analysis . However, most NIR emitting phosphors are still limited to short-wavelength, narrow-band emission and low efficiency. Here, based on the multi-site occupation strategy, the NIR phosphor Mg 2 LaTaO 6 :Cr 3+ (MLT:Cr 3+ ) achieves an efficient broadband NIR emission with the full width at half maximum (FWHM) of 203 nm in the range of 600–1300 nm under the excitation of 468 nm blue light. The phosphor MLT:0.01Cr 3+ not only exhibits an excellent internal quantum efficiency (IQE) of 85.6 %, but also has good thermal stability and remains about 64.2 % photoluminescence (PL) intensity of room temperature at 423 K. Furthermore, the MLT:0.01Cr 3+ phosphor was combined with a blue LED chip to fabricate the NIR pc-LED device, and its potential applications were successfully realized in information encryption, bioimaging and the qualitative or quantitative analysis of mixture of ethanol and water.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Halizati Abulimiti,Reziwanguli Yantake,Aierpati Taximaimaiti,Taximaiti Yusufu,Aierken Sidike
Currently, there is a cyan gap in white light-emitting diodes (LEDs) manufactured by combining near-ultraviolet (NUV) chips with tricolour (blue/green/red) phosphors, resulting in a poor colour rendering index (Ra). Broadband blue-cyan phosphors contain blue, cyan and green luminescent components that complement the cyan gap. In this paper, feldspar-structured Ba 0.92- x Sr x Al 2 Si 2 O 8 :0.08Eu 2+ ( x = 0–0.5) phosphors were prepared by a high-temperature solid-phase method and a cation substitution strategy. A phase transition was achieved by varying the concentration of x , which resulted in the formation of two luminescent centres and a 10.33-fold enhancement of the luminescence intensity for Ba 0.92 Al 2 Si 2 O 8 :0.08Eu 2+ . The colour of the emission changed from the original green to blue-cyan, and the strongest emission peak with a half-height width of 94.5 nm was observed at a Sr 2+ concentration of 0.3 (30%) and covered the blue, cyan and green wavelength ranges (390–600 nm). The experimental value of the optical band of the substrate is 5.71 eV, and the luminous intensity of the Ba 0.62 Sr 0.3 Al 2 Si 2 O 8 :0.08Eu 2+ sample at 150 °C was 91.3% of that at room temperature. Ba 0.62 Sr 0.3 Al 2 Si 2 O 8 :0.08Eu 2+ , (Ca, Sr) AlSiN 3 :Eu 2+ and 365 nm NUV chips were successfully packaged into white LED devices. The colour rendering index (Ra) of the prepared white LED devices was 87, R9 was 89, the colour coordinates were (0.3763, 0.3382), and the colour temperature was 3759 K, which effectively solves the problem of the lack of cyan luminescent components in white LED devices and simplifies the manufacturing process of white 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
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Kewei Ma,Yuhang Sheng,Guizhen Wang,Xiaowei Zhang,Yunsong Di,Cihui Liu,Liyan Yu,Lifeng Dong,Zhixing Gan
Mn 2+ doping has been developed to modulate the photoluminescence (PL) of CsPbCl 3 perovskite quantum dots (PQDs). However, the doped Mn 2+ may be expelled from the PQDs host with the long-term storing, resulting in inferior stability. Herein, CsPbCl 3 PQDs doped with different concentrations of Mn 2+ (Mn:CsPbCl 3 ) are prepared by a hot injection method. Our photostability tests reveal that when the doping concentration is <25%, or 40%–50%, the Mn 2+ doped PQDs are intrinsically stable. Anion exchange reactions are conducted between the stable CsPb 0.796 Mn 0.204 Cl 3 and CsPbBr 3 PQDs. Fluorescence color gamut of the resulting Mn:CsPb(Cl/Br) 3 PQDs almost covers the entire visible spectrum except for the deep red color. Benefiting from the intrinsic stability and wide color gamut, multicolor solid-state luminescence are acquired by incorporating the Mn:CsPb(Cl/Br) 3 PQDs in polymethyl methacrylate (PMMA) matrices, which are used as color converters for constructing light-emitting diodes (LEDs) with different colors.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2025
·
IF 6.7
Yurong Guo,Mengyan Yang,Fengsong Tan,Peng Ren,Jing Wan,Yanqing Ye,Huaijun Tang,Qiang Zhou,Zhengliang Wang
Mn 4+ -doped fluoride phosphors are promising red emitters for WLEDs owing to their narrow-band emission and high color purity. However, their practical applications are hindered by severe moisture sensitivity arising from the hydrolysis of [MnF 6 ] 2- units. In this study, a reduction-assisted surface recrystallization strategy using ascorbic acid (AA) was employed to construct an Mn 4+ -free inorganic shell, effectively suppressing hydrolysis and protecting the luminescent centers. The AA-modified Na 2 SiF 6 :6 %Mn 4+ phosphor retained 88.84 % of its emission intensity after 16 days in deionized water and 86.77 % after 6 h of boiling water exposure, whereas the unmodified sample exhibited negligible emission under the same conditions. Additionally, the AA modification led to a 130 % increase in emission intensity, an internal quantum efficiency of 97.6 %, and superior thermal stability with 97.62 % luminescence retention at 423 K. WLEDs fabricated with the AA-modified phosphor demonstrated enhanced luminous efficacy, color rendering, and long-term reliability under high-temperature and high-humidity conditions. This work provides a simple and scalable route to environmentally robust Mn 4+ -activated red phosphors, offering practical potential for next-generation solid-state lighting.
研究领域:
材料科学
·
光子学
·
固态照明
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Yingchun Ge,Tao Wu,Langping Dong,Zhiyu Qin,Jianghua Wu,Guangxiang Jiang,Guoying Zhao,Shuai Yang,Jingshan Hou,Yongzheng Fang
The development of full-spectrum white LEDs is significantly hindered by the “cyan gap” in the 470-510 nm spectral region. Addressing this gap with moderate -quality cyan-emitting phosphors, efficiently excited by violet LED chips, is crucial for achieving high color rendering index (Ra > 90) illumination. In this study, a novel and moderate efficient garnet-structured cyan-emitting phosphor Ca 2 LuZr 2 Al 1.5 Ga 1.5 O 12 :Ce 3+ (CLZAGO:Ce 3+ ) was effectively prepared via a high-temperature solid-state reaction route. When excited at 410 nm, the optimized CLZAGO:0.04Ce 3+ sample displays a robust cyan emission peaking at 484 nm, accompanied by a broad emission band spanning 420-650 nm and a full width at half-maximum (FWHM) of 90 nm, which efficiently fills the cyan gap commonly observed in conventional White light-emitting diodes (WLEDs). The phosphor exhibits available thermal stability, preserving 53% of its room-temperature emission intensity at 423 K, and achieves a moderate external quantum efficiency (EQE) of 45.43%. Finally, when CLZAGO:Ce 3+ was combined with commercial blue-emitting Sr 5 (PO 4 ) 3 Cl:Eu 2+ (SPOC:Eu 2+ ), green-emitting (Ba, Sr) 2 SiO 4 :Eu 2+ (BSSO:Eu 2+ ), and red-emitting CaAlSiN 3 :Eu 2+ (CASN:Eu 2+ ) phosphors and integrated into a 410 nm violet LED chip, a full-spectrum WLED with an enhanced Ra of 95 was achieved. These findings underscore the critical role of CLZAGO:Ce 3+ as a promising cyan-emitting component for next-generation high color-rendering full-spectrum WLEDs.
研究领域:
材料科学
·
光电子学
·
固态照明
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磷光体化学
·
LED技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 35
·21738-21744
·
IF 3.361
Zikuan Shi,Yu Yang,Xin-Yuan Sun,Feng Lang,Yu Xiang,Liangwu Lin
We developed a new ligand and adjuvant dual-assisted room temperature colloidal method for the synthesis of highly luminescent and stable Cs4PbBr6 nanoparticles, in which acetone, oleamine (OM) and oleic acid (OA) were used as precursors, while water and dimethyl sulfoxide (DMSO) were used as adjuvants. In this process, we explored the influencing factors of process parameters (such as the amount of water, the standing time of precursors, and the molar ratio of raw materials), and found that Cs4PbBr6 synthesized by water + DMSO can not only change the morphology and promote crystallization but also improve the lattice strain, reduce the lattice defects and optimize the passivation effect, so as to improve the luminescence properties. Simultaneously, we also found that the pc-LED made of Cs4PbBr6 can still emit bright green light after 4344 h of operation, showing excellent stability and making it promising for solid-state lighting application. This method also provides an important reference value for solving the hydrolysis property of perovskites.
研究领域:
材料科学
·
光学工程
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2026
·
IF 4.9
Yingfang Li,Long Tian,Qingzhe Wu,Xiaohuan Long,Hai Wu,Chaoyong Deng,Weichao Huang
Mn 4+ -doped oxide phosphors with deep-red emission show significant application potential in plant-growth LEDs. In this study, double perovskite Ba 2- x Sr x GdSbO 6 : Mn 4+ deep-red phosphors were developed via a cation substitution strategy. The crystal structure, optical properties, and thermal stability of the phosphors were investigated in detail. The as-prepared phosphors showed an intense deep-red emission band around 625–750 nm. Cationic substitution with Sr 2+ significantly improved the luminescence performance of the Ba 2 GdSbO 6 : Mn 4+ phosphors, and the optimized sample BaSrGdSbO 6 : Mn 4+ was obtained, achieving a nearly 12-fold enhancement in emission intensity. Furthermore, the electroluminescence (EL) spectrum of the prototype LED device fabricated based on the BaSrGdSbO 6 : Mn 4+ phosphor is matched well with the absorption band of plant pigments. These findings demonstrate that the BaSrGdSbO 6 : Mn 4+ phosphors have potential applications in plant-growth LEDs, and also provide some guiding inspirations in the exploration of novel Mn 4+ -doped double perovskite phosphors.
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DOI
高影响因子
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