ACS Nano
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2022
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IF 18.027
Huanyu Zhang,Tingxiu Yu,Chaoqiang Wang,Ruofei Jia,Azhar Ali Ayaz Pirzado,Di Wu,Xiujuan Zhang,Xiaohong Zhang,Jiansheng Jie
Micro-/nanosized organic–inorganic hybrid perovskite single crystals (SCs) with appropriate thickness and high crystallinity are promising candidates for high-performance electroluminescent (EL) devices. However, their small lateral size poses a great challenge for efficient device construction and performance optimization, causing perovskite SC-based light-emitting diodes (PSC-LEDs) to demonstrate poor EL performance. Here, we develop a facile liquid-insulator bridging (LIB) strategy to fabricate high-luminance PSC-LEDs based on single-crystalline CH3NH3PbBr3 microflakes. By introducing a blade-coated poly(methyl methacrylate) (PMMA) insulating layer to effectively overcome the problems of leakage current and possible short circuits between electrodes, we achieve the reliable fabrication of PSC-LEDs. The LIB method also allows us to systematically boost the device performance through crystal growth regulation and device architecture optimization. Consequently, we realize the best CH3NH3PbBr3 microflake-based PSC-LED with an ultrahigh luminance of 136100 cd m–2 and a half-lifetime of 88.2 min at an initial luminance of ∼1100 cd m–2, which is among the highest for organic–inorganic hybrid perovskite LEDs reported to date. Moreover, we observe the strong polarized edge emission of the microflake-based PSC-LEDs with a high degree of polarization up to 0.69. Our work offers a viable approach for the development of high-performance perovskite SC-based EL devices.
研究领域:
材料科学
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光电子学
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纳米技术
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半导体器件
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
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2025
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IF 5.6
Bingguo Liu,Jiafu Zhang,Xinrong Chen,Heyu Wang,Feng Wang,Yangzi Li,Dan Zhao,Zhe Guan,Jian Xu,Baoli Du,Dennis Dan Corell,Carsten Dam-Hansen,Ole Bjarlin Jensen
Free from the “curse” of efficiency droop in high-power LEDs, laser-driven phosphor-converted laser diodes (pc-LDs) light sources demonstrate significantly greater potential in achieving ultra-high brightness white light. To mitigate the luminance saturation, rigorous re-optimization of luminescent ion concentration and heat dissipation geometry is essential. Beyond the photometric and colorimetric properties, the low spatial uniformity of pc-LDs poses a critical but often overlooked challenge. Here, we present a systematic investigation of the effect of Ce 3+ concentration and thickness on the luminance and uniformity of YAG:Ce ceramic color converters. To quantitatively assess luminescence uniformity, high dynamic range color images were captured to statistically evaluate spatial chromaticity variations across the luminescent spot. The results firmly demonstrated that the Ce 3+ concentration and thickness are two interdependent parameters closely related to uniform chromaticity and luminance, which should be optimized simultaneously. This study provides critical optimization guidelines for laser lighting development.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2018
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IF 8.097
Peng Zheng,Shuxing Li,Le Wang,Tian-Liang Zhou,Shihai You,Takashi Takeda,Naoto Hirosaki,Rong-Jun Xie
As a next-generation high-power lighting technology, laser lighting has attracted great attention in high-luminance applications. However, thermally robust and highly efficient color converters suitable for high-quality laser lighting are scarce. Despite its versatility, the phosphor-in-glass (PiG) has been seldom applied in laser lighting because of its low thermal conductivity. In this work, we develop a unique architecture in which a phosphor-in-glass (PiG) film was directly sintered on a high thermally conductive sapphire substrate coated by one-dimensional photonic crystals. The designed color converter with the composite architecture exhibits a high internal quantum efficiency close to that of the original phosphor powders and an excellent packaging efficiency up to 90%. Furthermore, the PiG film can even be survived under the 11.2 W mm–2 blue laser excitation. Combining blue laser diodes with the YAG-PiG-on-sapphire plate, a uniform white light with a high luminance of 845 Mcd m–2(luminous flux: 1839 lm), luminous efficacy of 210 lm W–1, and correlated color temperature of 6504 K was obtained. A high color rendering index of 74 was attained by adding a robust orange or red phosphor layer to the architecture. These outstanding properties meet the standards of vehicle regulations, enabling the PiG films with the composite architecture to be applied in automotive lighting or other high-power and high-luminance laser lighting.
研究领域:
光学工程
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光子学
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固态照明
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材料科学
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热管理
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
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2024
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IF 3.7
Huang Pei-Pei,Wu Ting-Ting,Tuo Meng-Qi,Zhang Rui-Ying,Shuai Chun-Jiang,Liu Bo,Song Juan,Zhang Sheng-Rui,Lu Jiu-Fu
In the field of water decontamination, the design of luminance sensor for sensitive detection of heavy metal ion toxic and nitroaromatic compounds are important and challenging. Herein, a new luminescent Cd(II) metal–organic framework (MOF), {[Cd 2 (H 2 O) 3 (4-CPCA) 2 ]·2H 2 O} n ( SNUT-27 ) (H 2 (4-CPCA) = 1-(4-carboxyphenyl)-4-oxo-1,4-dihydropyridazine-3-carboxylic acid) was obtained by the reaction of flexible ligand H 2 (4-CPCA) and Cd(II) ions, characterized by single crystal X-ray diffraction, PXRD, FT-IR, and TGA, the samples were further analyzed. The analysis of single crystal X-ray diffraction showed that SNUT-27 possesses a distinct three-dimensional spatial arrangement and demonstrates impressive fluorescence properties. Particularly, SNUT-27 showed a highly sensitive response to the nitro-aromatic compounds nitrobenzene by fluorescence quenching, and in contrast, showed a fluorescence enhancement response to Al 3+ and Cu 2+ . SNUT-27 can be effortlessly recycled by simply rinsing with water post-sensing experiments, showcasing its reusability. Additionally, potential detection mechanisms have been explored.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2024
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IF 5.2
Jiaying Zheng,Jiao Liu,Gaohong Wu,Tengfei Tian,Haitao Wang,Jie Li,Weiwei Huan,Xiaojuan Liang,Weidong Xiang
Phosphor-in-glass (PiG) films have emerged as the preferred conversion materials for high-brightness laser-driven lighting due to their excellent thermal conductivity and superior optical performance. Screen printing technology was employed to investigate the correlation between the reflective layer thickness and light conversion efficiency. A multilayer-structured Y 3 Al 3.5 Ga 1.5 O 12 :Ce 3+ (YAGG:Ce)-PiG-TiO 2 -aluminium nitride (AlN) film (YG-TAF) converter was constructed by efficiently coupling the optimal thickness of the reflective layer with the PiG layer and the AlN substrate. Notably, the YG-TAF shows an impressive thermal conductivity of 22.6 W/(m·K) and a maximum anti-laser power of 15.84 W, demonstrating superb thermal regulation capability. This anti-laser power of 15.84 W represents a breakthrough in current static laser performance research. Impressively, an YG-TAF phosphor color wheel was designed, which achieves an ultra-high-brightness 4375 lm of green light under 450 nm, 88 W laser power excitation, close to that of commercial phosphor silicone color wheels. This advancement not only demonstrates the excellent performance of YG-TAF in high-brightness dynamic reflective laser applications but also indicates its strong feasibility for practical implementation. Furthermore, the developed YAGG:Ce-Y 1.31 Ce 0.09 Gd 1.6 Al 5 O 12 -TAF spliced phosphor color wheel successfully mitigates the influence of photon reabsorption and achieves a color rendering index of 80.5, showing great potential for advancement of the field of reflective white light laser illumination.
研究领域:
光学材料
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激光技术
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热管理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2019
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IF 4.029
Ran Wei,Le Wang,Peng Zheng,HuaTao Zeng,GuiMing Pan,Hong Zhang,Pei Liang,TianLiang Zhou,RongJun Xie
To investigate the luminance saturation in high-power blue-laser-driven solid state lighting, the Y 3 Al 5 O 12 : Ce (YAG)-based PiG films was co-fired with a high thermally conductive sapphire substrate. When the PtG ratio or the thickness of the PiG film increases, the luminance saturation becomes worse and both of the luminous flux and luminous efficacy decrease. With an additional sapphire substrate coated with an anti-reflection layer on one side and a blue-pass filter on another side attached to the PiG film, the film shows an improvement in luminous flux and efficacy, and produces the white light with a luminous flux of 1709 lm, a luminous efficacy of 211 lm W −1 and a correlated color temperature of 6602 K under the maximum (10.3 W mm −2 ) blue laser light excitation. It indicates that the PiG film could be applied in high power laser-driven solid state lighting when its microstructure is carefully tailored.
研究领域:
光学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Electronic Materials
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2021
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IF 3.314
Shicai Geng,Yanwei Wen,Binze Zhou,Zhaojie Wang,Zhaojin Wang,Pengfei Wang,Yao Jing,Kun Cao,Kai Wang,Rong Chen
Carrier balance and ion diffusive inhibition are crucial to the external quantum efficiency (EQE) and stability of perovskite quantum dot light-emitting diodes (PQLEDs). Herein, an inorganic ZnBr2 ligand is used to passivate the Br vacancy on the surface of the perovskite quantum dots and, thus, near-unity photoluminescence quantum yield is achieved. With respect to energy alignment and carrier balance, poly[bis(4-phenyl) (4-butylphenyl) amine] (poly-TPD) is chosen to match with 1,3,5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene (TPBi), and the fabricated PQLEDs exhibit the maximum luminance as high as 92,279 cd m–2. In addition, an ultrathin Al2O3 layer is introduced between indium tin oxide (ITO) and poly(ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) via atomic layer deposition (ALD). The Al2O3 buffer layer can precisely control the hole transmission rate, balance the carrier injection, and realize the improvement of EQE from 2.86 to 4.81%. The T50 lifetime of the device is extended by about 30 times due to suppression of metal ion diffusion from ITO to the emission layer. Our work demonstrates the promising fabrication of highly efficient and stable PQLEDs via ALD interface engineering.
研究领域:
材料科学
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光电领域
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
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2025
·
IF 3.4
Kaiting Wu,Pengju Xia,Chengyu Ni,Wanyuan Li,Man Xu,Wubin Dai
In pursuit of illumination-grade wLEDs, innovative red-emitting phosphors with sufficient luminance and thermal stability are required. Herein, a Eu3+-incorporated Ba2CaB2Si4O14 (BCBS) phosphor, exhibiting relatively low efficiency, poor thermal stability, and red line peak photoluminescence (PL) at 614 nm, is preliminarily obtained as a result of Eu3+ 4f–4f transitions. The Rietveld refinements and density functional theory (DFT) calculations indicate that Eu3+ is energetically favored in Ca2+ sites. To overcome the above issues of BCBS: Eu3+, heterovalent Dy3+ is codoped into the phosphor to simultaneously realize: (i) ultrahigh thermal stability of red PL based on structure tailoring and trap regulation associated with both Dy(Eu)Ca• and VO″ defects. For comparison, by tridoping Na+ at the expense of Dy(Eu)Ca• via Dy(Eu)3+ + Na+ → 2Ca2+, the red PL performance is becoming very bad and even worse than that of BCBS: Eu3+, indicating that Dy(Eu)Ca• plays a major role, though the effect of VO″ cannot be completely ruled out, (ii) energy transfer (ET) from Dy to Eu for enhancing PL efficiency/intensity, and (iii) color-tunable PL, including “warm” white light, by combination of both autologous “cool” white PL from Dy and red emission from Eu. The assembled phosphor-converted white light-emitting diode (pc-wLED), adopting single-phase BCBS: Dy3+/Eu3+ with n near UV (nUV) LED chip via a remote “capping” packaging strategy, is a promising candidate to be applied as a white-emitting phosphor in wLEDs. Meanwhile, due to a strong mutual relationship between the intensity ratios of PL bands from magnetic/electric dipole transitions (EDT/MDT) for either Dy (Y/B) or Eu (R/O) and the crystal field environment, the obviously visual PL color change under distinct pressures in a wide range of pressure fluctuations indicates that the phosphor could also be used as a potentially optical pressure sensor with high sensitivity.
研究领域:
材料科学
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光学工程
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物理学
✓ 已验证
产品关联
DOI
高影响因子
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