Laser & Photonics Reviews
·
2022
·Vol. 16
·期 6
·2100722
·
IF 10.947
Taoli Deng,Linhui Huang,Shuxing Li,Qiangqiang Zhu,Le Wang,Takashi Takeda,Naoto Hirosaki,Rong-Jun Xie
Laser-driven solid-state lighting with super-brightness and compactness is recognized as a promising alternative to white light-emitting diodes. However, it is quite difficult to achieve laser-driven warm white light with long-term stability due to the shortage of robust orange- or red-emitting laser phosphors. In this work, an efficient and thermally robust orange-red (La,Y) 3 Si 6 N 11 :Ce 3+ (LYSN)-BN phosphor-in-glass (PiG) film is proposed to realize warm white light, where h -BN acts as an optical medium to enhance light scattering, a heat sink to reduce the temperature, and a protective layer to prevent LYSN from oxidation. The “LYSN+15 wt.% BN” PiG film shows an internal quantum efficiency of 70% and a luminance saturation threshold of 12.82 W mm −2 , much higher than those without h -BN (i.e., 57.5% and 7.63 W mm −2 ). A warm white light lamp fabricated by combining “LYSN+15 wt.% BN” PiG film with blue laser diodes, showing tunable correlated color temperatures (2800–5000 K), has a maximal luminous flux of 740 lm and a luminous efficacy of 133.5 lm W −1 , which promises high collimation and penetration lighting in the rainy or foggy weather. By designing a composite orange-red-emitting phosphor converter, this work lays a foundation for realizing high quality laser-driven warm white lighting source.
研究领域:
光学材料
·
固态照明
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yue Yang,Rong Tang,Yuqi Lei,Di Gao,Houteng Zhao,Samra Jabeen,Yufeng Du,Ya Yang,Chenyi Wang,Xinyue Zhang,Ruijin Yu,Xianchao Du
To realize full-spectrum illumination systems for daily applications, the development of cyan-emitting phosphors capable of addressing the spectral deficiency in the 480-520 nm region (between blue and green emissions) has emerged as a critical research frontier in solid-state lighting technology. In this investigation, a scandium silicate phosphor, KSr 6 ScSi 4 O 16 :Eu 2+ , was initially synthesized via a high-temperature solid-state reaction under a reducing atmosphere. The target compounds crystallize in an orthorhombic system with a centrosymmetric space group of Pnma (No. 62). KSr 6 ScSi 4 O 16 :2 mol%Eu 2+ shows asymmetric broadband mainly at 481 nm under excitation of 359 nm. Based on Gaussian fitting and Van Uitert's equation, the Eu 2+ ion was confirmed to occupy two different coordination environments of Sr 2+ , producing two different luminescent centers at 477 nm and 528 nm. The optimal doping concentration of KSr 6 ScSi 4 O 16 : x Eu 2+ cyan phosphors was founded to be 2 mol%. Within the temperature range of 300 to 480 K, CIE coordinates remain stable during the heating process, and an activation energy of 0.35 eV has been determined. The color rendering index ( R a ) of the full spectrum WLED produced by KSr 6 ScSi 4 O 16 :Eu 2+ , reached 92.5, which is higher than the WLED packaged with commercial powder, effectively supplementing the cyan light component and closer to the full-spectrum lighting LEDs.
研究领域:
材料科学
·
固态照明技术
✓ 已验证
产品关联
DOI
高影响因子
Small Structures
·
2024
·Vol. 5
·期 7
·2400096
·
IF 13.9
Tianxin Bai,Qiujie Wang,Yunfei Bai,Qichao Meng,Hongyuan Zhao,Ziying Wen,Haibo Sun,Li Huang,Junke Jiang,Dan Huang,Feng Liu,William W. Yu
The rich and unique energy level structure arising from 4f n inner shell configuration of trivalent lanthanide ions (Ln 3+ ) renders them highly attractive for light-emitting applications. Currently, research primarily focuses on Ln 3+ doping in either traditional garnets or the recently developed perovskite phosphors. However, there have been few reports on stable phosphors crystallized with pure lanthanide elements. Herein, a universal solution-based route to eight Ln 3+ -based metal halides from the organic-inorganic A 4 LnX 7 family is described, where A + = 4,4-difluoropiperidinium (DFPD + ), Ln 3+ = Nd 3+ , Eu 3+ , Ho 3+ , Sm 3+ , Tm 3+ , Tb 3+ , Yb 3+ , Er 3+ , and X − = Cl − , Br − . Visible photoluminescence (PL) is observed from Tb 3+ -, Eu 3+ -, Ho 3+ -, and Sm 3+ -based compounds with Tb and Eu compositions exhibiting high PL quantum yields of 90–100%; Nd 3+ -, Tm 3+ -, Yb 3+ -, and Er 3+ -based crystals show fascinating near-infrared emission. Light-emitting diodes (LEDs) fabricated with (DFPD) 4 TbCl 7 yield characteristic emission of Tb 3+ , representing the first demonstration of electroluminescence from these organic-inorganic Ln 3+ -based metal halides. Moreover, these materials exhibit distinct excitation wavelength-dependent emission after alloying with different Ln 3+ ions, making them interesting for multicolor display and multilevel information encryption applications. It is foreseen that this study will open up the way to a possible design of robust optoelectronic devices based on lanthanide metal halides.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 19
·10771-10780
·
IF 6.895
Guangqi Hu,Xiaokai Xu,Bingfu Lei,Jianle Zhuang,Xuejie Zhang,Haoran Zhang,Chaofan Hu,Xiaotang Liu,Yingji He,Yingliang Liu
C-Dots and composites based on them face the challenges of poor stability, especially under photo-radiation, and low solid-state photoluminescence quantum yields (PLQYs), which hinder their application in optical devices. Herein, a novel 2-dimensional hybrid material of polysiloxane embedded with Si-doped carbon dots (P-E-Si-CDs) was synthesized by a self-assembly approach, and the hybrid composite exhibited broadband blue-green fluorescence emission, outstanding photostability, high thermal stability, and a high PLQY of 82.8%. Moreover, the dual fluorescent emissions were demonstrated the creation of two closed-loop fluorophores. Using the as-prepared hybrid fluorescent material, fabricated light-emitting diodes (LEDs) based on UV and blue-emitting LED chips present safe warm white light emission and adjustable white emission with a high color rendering index of up to 91, respectively. This work provides a novel strategy for the design and realization of Si-CD-based hybrid composites, thus promising their prospective use commercially in LED lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 22
·期 2
·311-319
·
IF 3.382
Wei Wang,Hang Yang,Yixin Liu,Xiaohan Yun,Yi Wei,Guogang Li
Establishing effective methods to optimize luminescent materials has been a significant challenge for white light-emitting-diode (WLED) applications. Herein, we successfully realized the adjustment of the photoluminescence and enhancement of the thermal stability of Ln3+ (Ln3+ = Ce3+, Eu3+)-doped Ca10−x/yBax/y(PO4)6O phosphors. First, Ba2+ ions from raw BaCO3 material realized a spectral red shift from 464 nm to 506 nm, which we suggested to be due to a synergistic effect from a centroid shift and crystal field splitting. When using BaHPO4 as a raw material, the PL intensity was 6.5 times that of the initial intensity. Surprisingly, the thermal stability was also improved, which was attributed to the increasing lattice distortion introducing many traps. Second, the Ca10(PO4)6O:Eu3+ red phosphor exhibited an abnormal emission phenomenon involving the 5D0 → 7F0 peak at 575 nm becoming the strongest emission peak and the 5D0 → 7F1 peak at 585 nm becoming particularly weak. The site symmetry and charge transfer states were speculated to be closely related to this phenomenon. The charge transfer states were not only correlated with the crystal field strength, but also related to f-electron delocalization, which significantly influenced the energy-level structure of Eu3+. More importantly, according to the relationship between the I(5D0 → 7F0)/I(5D0 → 7F1) ratio and the lattice structure, Eu3+ in the Ca10(PO4)6O compound could be applied as a probe to explore the matrix information, which would provide a helpful method to investigate the lattice structures of compounds and also guide researchers to design new suitable red phosphors.
研究领域:
材料科学
·
光学材料
·
无机化学
·
固体物理
·
发光学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·Vol. 26
·期 38
·25232-25239
·
IF 2.9
Jielong Li,Rongbin Deng,Muci Li,Jingwei Wu,Bingyu Wang,Liming Liu,Zichuan Yi,Honghang Wang,Xiaowen Zhang
Light emission from carbon dots (CDs) is of great interest in both electroluminescence and photoluminescence. Herein, we construct electroluminescent and photoluminescent light-emitting diodes (LEDs) from emitters of CDs. The electroluminescent LED with host–guest-doped dual emissive layers (EMLs) of [poly(9-vinylcarbazole) (PVK)-CDs] × 2 gives satisfactory electro-optical properties, with maximum luminance of 560 cd m−2 at 16 V, luminous efficiency of 0.183 cd A−1, power efficiency of 0.082 lm W−1, and external quantum efficiency of 0.25%, which are superior to the counterparts with single-EML of CDs, single-EML of [PVK-CDs], and triple-EMLs of [PVK-CDs] × 3. These enhanced properties are rationally ascribed to optimization of the device architecture, carrier balance improvement, and reduction in concentration-induced quenching. The electroluminescent LEDs also show color evolution from PVK to CDs, and/or to the PVK/CDs interface, with increasing driving voltages, owing to incomplete energy transfer from PVK to CDs. Highly efficient photoluminescent LEDs with 365- and 395-nm UV excitation are demonstrated. With a CDs : polyvinyl pyrrolidone ratio of 1 : 3, the 365-nm excited photoluminescent LED gives a maximum luminance of 512 347 cd m−2 with a power efficiency of 25.2 lm W−1, while the 395-nm excited photoluminescent device gives a maximum luminance of 670 954 cd m−2 with a power efficiency of 22.0 lm W−1, with both showing yellow emission. Our experiments provide some new ideas for broadening CD applications and advancing LEDs.
研究领域:
材料科学
·
光学工程
·
电子工程
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2021
·Vol. 9
·期 21
·2101132
·
IF 9.926
Yongcheng He,Haohua Liang,Meihua Chen,Licheng Jiang,Zhishen Zhang,Xiaobo Heng,Lin Yang,Yanpeng Hao,Jiulin Gan,Zhongmin Yang
Soft actuators, an emerging field in robotics, have great potential for wide-ranging applications in biology, medicine, engineering, and oceanography. Photoactuators that are stimulated by light to produce reversible mechanical deformation have attracted significant interest in recent years owing to their advantages of high resolution, fast switching, flexible controllability, and electromagnetic interference immunity. Conventional photoactuators rely on free-space illumination, which limits the control in light-obstructed surroundings. A low loss optical fiber waveguide-based soft photoactuator composed of photothermally responsive material hinges and high-transparency elastomer fiber arms is proposed. When light travels in the elastomer fiber arms, the hinges exhibit a very large shape change so that the arms bend by themselves, with a maximum repeatable bending angle of approximately 145°. The angle is determined by the injected optical power. A fiber photoactuator with dual hinges is designed that is capable of reversible complex deformation. Moreover, in a narrow silicone tube, the fiber photoactuator can still be stimulated with considerable deformation by the light injected along the fiber. A fiber photoactuator-constructed microhook is demonstrated for grabbing object in water.
研究领域:
机器人学
·
生物医学工程
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2019
·
IF 2.155
Xiaoqing Guo,Shuangju Song,Xue Jiang,Xue Wang,Jiahui Guo,Qingwei Song,Yuanyuan Han,Liyong Wang
Eu 3+ activated CaWO 4 (CWO) phosphors were prepared via a modified hydrothermal process. In present work, the phosphors illustrated enhanced emission properties by the assistance of poly acrylic acid (PAA). The phase structure, micromorphology, photoluminescence properties and luminescence enhancement mechanism of the as-prepared samples were investigated. The as-prepared PAA assisted samples exhibited significantly enhanced red emission peaking at 595 nm and emission intensity increased by about 8 times. The results indicated that CWO: Eu 3+ samples could be a potential candidate of red phosphor for white light-emitting diodes (WLEDs).
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 SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 8
·8094-8099
·
IF 1.798
Cao Renping,Peng Dedong,Fu Ting,Luo Zhiyang,Zhou Shenlin,Jiang Shenhua,Fu Jingwei
KSrVO 4 :Eu 3+ phosphors are synthesized by solid-state reaction method in air. Host KSrVO 4 under excitation at 345 nm emits green–yellow light with the CIE chromaticity coordinates (0.3466, 0.4425), and its broad emission band peaking at ~545 nm covers the range 400–750 nm due to 3 T 1,2 → 1 A 1 transitions in [VO 4 ] 3− group. KSrVO 4 :Eu 3+ phosphor under excitation at 315 and 394 nm shows red emission with the CIE chromaticity coordinates (0.6279, 0.3717), and the emission spectra in the range of 560–750 nm contains four narrow emission bands owing to 5 D 0 → 7 F
J
( J = 1, 2, 3, and 4) transitions of Eu 3+ ion, respectively. The optimal Eu 3+ doping concentration is ~4 mol%. The lifetime decreases from 0.991 to 0.893 ms with increasing Eu 3+ concentration within the range 0.5–6 mol%. The possible luminous mechanism is analyzed by the simplified energy level diagrams of VO 4
3− group and Eu 3+ ion, and energy transfer process in KSrVO 4 :Eu 3+ phosphor. The experimental results indicate that KSrVO 4 :Eu 3+ phosphor will be possible to be used as red phosphor candidate for white light-emitting diode (LED) based on ultraviolet (~315 nm) and near ultraviolet (~395 nm) LED chips.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2019
·Vol. 9
·期 3
·130
·
IF 2.061
Lu Zhou,Xuefeng Chu,Yaodan Chi,Xiaotian Yang
In this study the effects of 1-Octadecanethiol (ODT, 1-CH3[CH2]17SH) passivation on GaAs (100) surface and GaAs/Al2O3MOS capacitors are investigated. The results measured by X-ray photoelectric spectroscopy (XPS), Raman spectroscopy and scan electron microscopy (SEM) show that the ODT passivation can obviously suppress the formation of As-O bonds and Ga-O bonds on the GaAs surface and produce good surface morphology at the same time, and especially provide better protection against environmental degradation for at least 24 h. The passivation time is optimized by photoluminescence (PL), and the maximum enhancement of PL intensity was 116%. Finally, electrical property of a lower leakage current was measured using the metal-oxide-semiconductor capacitor (MOSCAP) method. The results confirm the effectiveness of ODT passivation on GaAs (100) surface.Keywords:GaAs;passivation;XPS;RAMAN;PL
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Xiao Gong,Wenwen Ma,Yunxia Li,Lingqi Zhong,Wenjing Li,Xiujian Zhao
Luminescent solar concentrators (LSCs) as alternatives to solar cells are suitable for photovoltaic windows. Generally semiconductor quantum dots are employed as emitters for LSC fabrication due to their advantages such as photostability, spectral tunability, and high photoluminescence quantum yield . In this paper, we used low cost and environmentally friendly N-doped carbon-dots (N-CDs) as phosphors to fabricate N-CDs/PMMA slab based luminescent solar concentrators. The high-performance N-CDs/PMMA slab based LSCs with an external optical efficiency of 12.23% could be achieved when the concentration of N-CDs within the PMMA matrix is 0.08 wt%. Our results showed that N-CDs/PMMA slab based luminescent solar concentrators make the practical use of LSCs more feasible because of the unique properties of N-CDs.
研究领域:
材料科学
·
可再生能源
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Xiaojiao Kang,Yanchun Yang,Lan Wang,Song Wei,Daocheng Pan
Cadmium-free and water-soluble AgInS2/ZnS core/shell quantum dots (QDs) with a cost of 2.5 $/g are synthesized in an electric pressure cooker. The QD powders with different Ag/In ratios exhibit bright yellow, orange, and orange-red luminescence under UV light. Their absolute photoluminescence quantum yields (PLQYs) can reach as high as 50.5, 57, and 52%, respectively. Because gelatin is used as the capping agent, the concentrated QDs/gelatin solution can be directly utilized as phosphor for the fabrication of white light-emitting diodes (LEDs) by a simple drop-drying process without the need of resin package. Warm-white LEDs are obtained by combining orange-emitting QDs with blue InGaN chip. As-fabricated warm-white LED exhibits a luminous efficacy of 39.85 lm/W, a correlated color temperature (CCT) of 2634 K and a color rendering index (CRI) of 71 at a drive current of 20 mA. Furthermore, the electroluminescence (EL) stability of LED device and thermal stability of as-prepared QDs are evaluated.
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
危险品化学品经营许可证（带存储）