JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Guo-Juan Wang,Qiang-Qiang Zhu,Gan-Yu Cai,Yue Zhai,Shuang-Qiang Fang,Juan Kang,Le Wang
The realization of high-quality laser-driven white light remains challenging due to the limited heat dispersion and inconsistent light uniformity of color converters. In this study, ZnO particles with high thermal conductivity and a high index of refraction were induced into phosphor-in-glass (PiG) films to form a Y 3 Al 5 O 12 (YAG):Ce 3+ -ZnO composite structure. The influences of ZnO particles on the luminescence, optical properties, thermal dissipation performance, and light uniformity of PiG films were studied in detail. Benefiting from the improved thermal dissipation, the luminescence saturation threshold of the YAG:Ce 3+ PiG film was improved from 10.97 to 12.96 W/mm 2 , and the luminous flux was improved from 1271 to 1468 lm. The increased light scattering attributed to ZnO particles also effectively dispersed both laser and emitted light. This significantly enhanced the angular consistency of the color rendering index (Ra) and correlated color temperature (CCT). It indicates that the YAG:Ce 3+ -ZnO composite PiG film would be an interesting color converter for producing high-quality laser-driven white light.
研究领域:
材料科学
·
光学工程
·
发光材料
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2018
·Vol. 10
·期 47
·22237-22251
·
IF 7.233
Guo-Hui Pan,Huajun Wu,Shuai He,Liangliang Zhang,Zhendong Hao,Xia Zhang,Jiahua Zhang
The most common yellow phosphor for wLEDs, Y3Al5O12:Ce3+ (YAG:Ce3+), suffers from a deficiency of red in its spectral content of light. In this paper, a new strategy is provided to tailor the Ce3+ spectral profile through surface-located dye molecules of ATTO-Rho101, which feature intense, broad absorption in the green-yellow spectral region of Ce3+ emission as well as bright red emission. Sphere-shaped and highly dispersed micrometer and nanometer-sized YAG:Ce3+ (micro/nano-YAG:Ce3+) was synthesized through a modified solvothermal method. Surface SiO2 coating and simultaneous dye embedding were performed on the solvothermally derived YAG:Ce3+, heat-treated micro-YAG:Ce3+ and commercial phosphors. Efficient radiative transfer/reabsorption from Ce3+ in the inner core of YAG to the dye molecules in the SiO2 outer shell, irrespective of the size of the phosphors, was demonstrated in the accumulated YAG:Ce3+@SiO2 + dye powder upon blue light excitation; this enhanced its red emission. Fluorescence microscopy was demonstrated to be a powerful tool to identify the reabsorption phenomenon of the powdered materials. Packaging the heat-treated micro-YAG:Ce3+@SiO2 + dye phosphors on blue LED chips yielded a warm wLED (Ra ∼ 93), but an Ra of only ∼79 was obtained for the wLED with commercial YAG:Ce3+@(SiO2 + dye)5 due to the low concentration of phosphors dispersed in the epoxy resin and the resulting decreased reabsorption by dye molecules. Surface-protonated amine species were found to induce Ce3+ → Ce4+ oxidation upon activation by heating or photoirradiation and then quench the photoluminescence (PL) of micro-YAG:Ce3+ even after surface modification by SiO2, YAG or being embedded in an epoxy resin matrix. High calcination temperatures greatly improved the PL stability of micro-YAG:Ce3+ through the removal of surface-capped species. The dye in the silica matrix showed high stability against heating and irradiation due to the so-called “caging effects”; however, decreased photo-stability was found in commercial YAG:Ce3+@(SiO2 + dye)5 due to the incomplete and/or loose SiO2 layer grown during multiple surface modifications.
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 Optical Materials
·
2024
·
IF 0
Lei Jin,Shuting Liu,Haoran Zhang,Wei Li,Jianle Zhuang,Chaofan Hu,Yingliang Liu,Mingtao Zheng,Xuejie Zhang,Bingfu Lei
The development of laser-driven lighting is progressing toward achieving high-power and high-brightness capabilities. However, all-inorganic color converters still face significant challenges arising from heat accumulation. Herein, we propose an effective approach to enhance the thermal conductivity of the light converter by closely sintering Y3Al5O12:Ce3+ (YAG:Ce3+) phosphor-glass films on a highly thermally conductive BN substrate (abbreviated as PBNC) for localized heat dissipation. This results in a significant increase in the luminescence saturation threshold when exposed to blue laser irradiation. The laser bearing capacity of PBNC is effectively optimized by adjusting the ratio of phosphor to glass and the thickness of the BN substrate. Under a laser irradiation level of 4.47 W/mm2 for 3 min, the maximum surface temperature of the PBNC is 92 °C, representing a significant reduction of 44 °C compared to that of the phosphor-glass film on the AlN substrate (136 °C). A laser-driven lighting device employing a PBNC with a thickness of 2.5 mm gives a luminous flux of 590.4 lm and luminous efficacy of 173.6 lm/W under a laser power density of 5.07 W/mm2. These findings confirm that the BN substrate enhances the thermal conductivity of phosphor-glass films, enabling them to become highly promising color converters for laser-driven lighting.
研究领域:
光学工程
·
材料科学
·
照明技术
✓ 已验证
DOI
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 35
·8952-8957
·
IF 5.256
Yuting Zhang,Xvsheng Qiao,Jun Wan,Li-ang Wu,Bing Chen,Xianping Fan
Spherical cerium-doped yttrium aluminum garnet (YAG:Ce3+) phosphor particles can achieve both higher packing densities and lower scattering of light, and thus make it possible to obtain excellent white-light-emitting diode performance. In this study, monodisperse YAG:Ce3+ microspheres have been synthesized through a fast epoxide-driven sol–gel route and subsequent heat treatment under a reducing atmosphere. The spherical morphology was mainly influenced by the phase separation and gelation process, which could be controlled by the ratio of water/ethanol. Pluronic F127 was introduced into the sol–gel system to control the size of the YAG:Ce3+ microspheres, which significantly increased the luminescence intensity of the YAG:Ce3+ microspheres. The luminescence quantum yield of the 6 mol% Ce3+ ion doped YAG microspheres was measured to be more than 90%, which was as high as that of commercial YAG:Ce3+ phosphors. This approach may be readily applied to prepare a broad range of rare earth doped microspheres, implying a new route for the preparation of LEDs phosphors with regular shape and high quantum yield.
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
CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
Yuguo Yang,Jing Li,Bing Liu,Yuanyuan Zhang,Xianshun Lv,Lei Wei,Xuping Wang,Jianhua Xu,Huajian Yu,Yanyan Hu,Huadi Zhang,Ling Ma,Jiyang Wang
A series of YAG:Ce 3+ /Eu 3+ , YAG:Ce 3+ /Eu 3+ /Bi 3+ and YAG:Ce 3+ /Gd 3+ phosphors were synthesized by a co-precipitation method. The results suggest that all of phosphors have the cubic phase and nearly spherical morphology. However, the red emission can be produced by codoping Eu 3+ and Eu 3+ /Bi 3+ ions in YAG:Ce 3+ , and the codoped Gd 3+ ions can induce the red-shift of Ce 3+ emission. These results suggest that the Eu 3+ , Eu 3+ /Bi 3+ and Gd 3+ ions can be used to decrease the correlated color temperature and increase the color-rendering index of white light-emitting diodes based on InGaN blue chip and YAG:Ce 3+ 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
ACS Applied Optical Materials
·
2025
·
IF 3.8
Qianxing Huang,Jiaqi Cheng,Leqi Yao,Jie Zhang,Shijie Yu,Kai Li,Yan Dong,Jianqing Jiang,Qiyue Shao
Phosphor-in-glass (PiG) is a promising all-inorganic color converter for high-power solid-state lighting applications. However, strong interfacial diffusion degrades the phosphor performance and impedes the progress of PiG-based white light-emitting diodes (WLEDs) in achieving high brightness and efficacy. In this study, a glass matrix (SiO2–B2O3–Al2O3–CaO-Y2O3–Na2O) designed specifically for Y3Al5O12:Ce3+ (YAG:Ce3+) phosphors was proposed aiming to suppress interfacial diffusion. The glass design principles involved confining ionic diffusion through modulation of the glass coordination structure and reducing interfacial concentration gradients through introduction of phosphor elements into the glass matrix. Consequently, interfacial diffusion in the synthesized YAG:Ce3+-PiG was effectively suppressed, with an interfacial reaction layer thinner than 55 nm. The internal quantum efficiency of YAG:Ce3+-PiG was sustained at 97%, while its fluorescence lifetime decreased by only 0.6 ns compared to that of the original phosphor. The WLED fabricated with YAG:Ce3+-PiG exhibited a high luminous efficacy of 122 lm/W under a high input power of 3 W. Additionally, simultaneous incorporation of YAG:Ce3+ and CaAlSiN3:Eu2+ phosphors further enhanced the white-light quality of the WLED, achieving a high color rendering index of 92.6. The findings underscore the importance of rational glass composition design for PiG composites and will facilitate the development of efficient high-power WLED devices.
研究领域:
材料科学
·
光学材料
·
固态照明
·
玻璃化学
·
光子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 101
·期 5
·1801-1805
·
IF 2.841
Yunyun Zhao,Xiuyun Zhang,Dongliang Yan,Guisheng Zhu,CaiHang Liang,Xiaoqing Yang,Huarui Xu,Aibing Yu
Mono-dispersed spherical YAG:Ce 3+ nano-phosphors were successfully synthesized by a one-pot glycol-thermal process using aluminum isopropoxide, yttrium, and cerium acetate hydrates as the precursor, (1,4)-butanediol as the solvent, ethidenediamine as the additive agent that can both control the morphology and improve the optical performances of the as-achieved products. The as-prepared YAG:Ce 3+ nano-phosphors displayed mono-dispersed spheres of about 150 nm and an improved optical performance with a quantum yield (QY) of 41% and good photostability, indicating that they have a considerable potential to be applied in solid-state lighting or used as coatings in other optical electronic devices.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
固态照明
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Lei Jin,Shuting Liu,Shuaichen Si,Xikun Zou,Haoran Zhang,Yingliang Liu,Wei Li,Mingtao Zheng,Jianle Zhuang,Chaofan Hu,Xuejie Zhang,Bingfu Lei
Thermal stability and heat dissipation of all-inorganic color convertors are the key obstacles for high-power laser-driven lighting devices. Herein, we proposed an efficient heat dissipation approach to solve these issues by blending high thermal conductivity AlN in a YAG:Ce 3+ -based phosphor-sapphire composite (abbreviated as PSC) plate. Notably, the most elevated surface working temperature of the AlN-filled PSC (AlN-PSC) is dramatically decreased by 266.9 °C at a blue laser power density of 10.99 W/mm 2 compared with that of without AlN-filled PSC (AlN-Free-PSC), implying that the AlN particles effectively acted as heat transfer channels to dissipate the accumulated heat to ambient air and sapphire substrate. Benefitting from the AlN particles also act as scattering centers, a transmissive mode solid-state laser lighting device was fabricated using 10 wt% AlN-PSC and 442 nm blue laser, which maintains a luminous efficacy of 133 lm/W and a luminous flux of 1000 lm without sacrificing the optical performance in comparison with AlN-Free-PSC based white LDs. The proposed method aims at enhancing the heat removal in phosphor glass films and may lead to the development of adding other new reinforcing fillers with high thermal conductivity in heat-conducting PSC.
研究领域:
材料科学
·
光学
·
照明工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2022
·
IF 7.613
Wenjing Wang,Tao Tan,Shangwei Wang,Su Zhang,Ran Pang,Da Li,Lihong Jiang,Huimin Li,Chengyu Li,Hongjie Zhang
Near-ultraviolet-pumped white light-emitting diodes (LEDs) based on the combination strategy of traditional RGB phosphors (blue/green/red) or blue/yellow phosphors have the drawback of inadequate color rendering index due to the cyan-gap (480–500 nm) in the emission spectrum . It is quite promising to find efficient cyan-emitting phosphors that can offset the cyan-gap to produce white LEDs with full-spectrum emission. In our work, we synthesized a Ce 3+ -activated ScCaO(BO 3 ) (SCB:Ce 3+ ) phosphor with a broadband blue-cyan emission. Under near-ultraviolet 396 nm excitation, the optimum SCB:0.005Ce 3+ sample shows a blue-cyan emission band with a peak of 473 nm, which is competent for filling the cyan-gap. Meanwhile, the SCB:0.005Ce 3+ blue-cyan phosphor possesses a high quantum efficiency (internal quantum efficiency = 66.5%, external quantum efficiency = 38.5%) and weak chromaticity shift (ΔE s = 1.29 × 10 −2 ). We produce white LED devices based on 395 nm LED chips and RGB or blue/yellow/red phosphors strategies. By comparing the performance parameters of white LED devices with or without blue-cyan SCB:0.005Ce 3+ phosphor, it is proved that SCB phosphor can offset the cyan gap of commercial RGB phosphors and the cyan emission lack of commercial Y 3 Al 5 O 12 :Ce 3+ phosphor. Furthermore, SCB:0.005Ce 3+ phosphor can substitute for commercial BaMgAl 10 O 17 :Eu 2+ phosphor in RGB or blue/yellow/red phosphors combinations. The prepared white LEDs based on SCB:0.005Ce 3+ blue-cyan phosphor, green/red or yellow/red phosphors show a lower proportion of high-energy blue light and are suitable for healthy lighting applications.
研究领域:
材料科学
·
光电子学
·
固态照明
·
荧光粉化学
·
发光材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiao-Fei Wang,Gui-Gen Wang,Jia-Bing Li,Zheng Liu,Wen-Feng Zhao,Jie-Cai Han
In this article, a new application of using S, N co-doped graphene quantum dots (S, N-GQDs) as ideal color converters in solid-state white light-emitting diode (WLED) is reported. To this end, the S, N-GQDs with an average diameter of ∼4.46 nm are obtained by a hydrothermal approach using citric acid and thiourea as source materials. The PL spectra of S, N-GQDs show an excitation-independent behavior in the range of 300–380 nm. Under UV illumination, the S, N-GQDs display intense blue-light with the quantum yield of 51.2%. The PL mechanism is also investigated. Then, we fabricate freestanding luminescent composite films in a solution casting method by combining S, N-GQDs with YAG:Ce 3+ phosphors based on a polyvinyl alcohol (PVA) matrix. The luminescent films have superior foldability and photostability and excellent heat resistance, and retain their optical performances in the solid-state. To realize their potential, a high-powered remote WLED has been demonstrated. The results indicate that S, N-GQDs and YAG:Ce 3+ can be homogeneously dispersed in the PVA without aggregation so that uniform white-light emission can be obtained. These composite films containing S, N-GQDs are promising to be used in state-of-the-art UV-pumped remote WLED according to their wide wavelength emission and collapsible illumination device.
研究领域:
材料科学
·
光电技术
·
纳米技术
·
光子学
✓ 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）