OPTICAL MATERIALS
·
2024
·
IF 3.8
Changwen Wang,Lixin Peng,Feng Qin,Meng Kou,Yongda Wang,Lingling Xu,Zhiguo Zhang
The understanding of how radiative transition probabilities change with temperature is crucial for comprehending the relationship between fluorescence behavior and temperature. However, although various models have been proposed to explain the patterns of transition probabilities ( A ) with temperature changes, they lack consistency due to their derivation from distinct microscopic perspectives. In this study, the macroscopic law of the temperature-dependent A for the 4 G 5/2 , 4 F 9/2 , and 5 D 0 energy states in YVO 4 :Re 3+ (Re 3+ =Sm 3+ , Dy 3+ and Eu 3+ ) was obtained. Three rare earth ions (Re 3+ ) were identified for each with unique energy level properties conducive to validating the general rules of A . These ions share a common characteristic: in the visible spectrum , their main emissions originate from the radiative transitions from the same higher energy level ( 4 G 5/2 in Sm 3+ , 4 F 9/2 in Dy 3+ , and 5 D 0 in Eu 3+ ) to lower energy levels, respectively. The A of the main emission levels, varying with T , were obtained by fitting the fluorescence decay curves. The exponential law governing non-radiative transitions was revealed after separating the radiative transition rate ( W R ) from A . The macroscopic law of temperature-dependent transition probabilities of 4 G 5/2 , 4 F 9/2 , and 5 D 0 energy states in YVO 4 :Ln 3+ (Ln 3+ = Sm 3+ , Dy 3+ and Eu 3+ ) has been found to follow the Boltzmann distribution . The results indicate that the non-radiative transitions of the main emission levels of the rare-earth ions are processes from the excited state to adjacent lower energy levels. This macroscopic pattern may serve as a foundational rule for understanding the impact of microscopic factors on A .
研究领域:
光学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 8
·2814-2823
·
IF 5.7
Yixin Sun,Mengmeng Shang,Yining Wang,Yiying Zhu,Xiaole Xing,Peipei Dang,Jun Lin
Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are the ideal light source for next-generation NIR spectroscopy, and developing novel NIR phosphors with high performance is crucial to achieve a wide range of NIR pc-LED applications. In this work, NIR luminescent material Y2Mg2Al2Si2O12 (YMAS):2%Cr3+ with good quantum efficiency (79%) and excellent thermal stability (88%@100 °C) is prepared. Under 430 nm light excitation, YMAS:2%Cr3+ emits 620–1100 nm NIR light with a full-width at half maximum (FWHM) of 153 nm. Fluorescence decay curves, photoluminescence (PL) spectra, 7 K PL spectra, the Rietveld refinement, 27Al solid-state nuclear magnetic resonance (ss-NMR) spectra and time-resolved emission spectroscopy (TRS) confirm that Cr3+ has two different luminescence centers in the YMAS lattice. Benefiting from the site elimination strategy, the double luminescence centers are proven to be derived from Cr3+ ions occupying the two sites [Al1O6] and [Al2O4]. The NIR packaging device prepared using YMAS:2%Cr3+ has outstanding NIR output power and photovoltaic conversion efficiency as high as 45.7 mW@100 mA and 16.7%@100 mA, respectively. Owing to the excellent performance of the YMAS:2%Cr3+ sample, it presents excellent practical performance in plant growth, bioimaging, non-destructive testing and night vision.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xiaotong Zhong,Jiale Guo,Jingkun Chen,Xin Shi,Wei Liu,Lin Li,Qianli Li,Jingtai Zhao
Copper halides are widely used in X-ray imaging because of their green non-toxicity, excellent optical properties and simple preparation. Cs 3 Cu 2 I 5 has a higher high photoluminescence quantum yield (PLQY) than CsCu 2 I 3 , but its fluorescence decay time is up to 1.65 μs. Herein, we report a green non-toxicity and low-cost antisolvent preparation of CsCu 2 I 3 microcrystals with bright yellow emission. The fluorescence decay time of the product is as fast as 123 ns and the PLQY is 11.36 %. At the same time, the light yield obtained by this method is 13,454.3 photons/MeV, which is about twice that of the commercial scintillator single crystal Bi 4 Ge 3 O 12 (BGO). In order to avoid transverse light scattering of scintillation films and improve the spatial resolution of X-ray imaging, we also propose a template-assisted and negative pressure filling method for the pixelated CsCu 2 I 3 scintillation array based on Polydimethylsiloxane (PDMS) micropore template. The crosstalk of scintillation light between each column is effectively suppressed, and the spatial resolution of the pixelated CsCu 2 I 3 /PDMS scintillation array is improved. In conclusion, the CsCu 2 I 3 microcrystals with fast decay, high optical properties and good stability, as well as the pixelated CsCu 2 I 3 /PDMS scintillation array that further improve spatial resolution by avoiding transverse scattering of light, provide a feasible solution for guiding copper halide materials as scintillators for X-ray detection and imaging.
研究领域:
材料科学
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医学影像学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·
IF 6.1
Zhiyuan Li,Xiangjun Wang,Peng Zhao,Jingquan Liu,Xiangxin Tian
Two-dimensional perovskites have demonstrated superior application prospects in optoelectronic fields, such as X-ray detection, light emitting diodes, and photovoltaics, as their tunability of band structures, improved stability, fast responses, and suppressed noise signal. In this work, bulk single crystals of MA3Bi2Br9 (MA+=CH3NH3+) and its two mixed crystal MA3Bi2(Br0.74I0.26)9, MA3Bi2(Br0.62I0.38)9 were successfully grown using the bottom-seeded solution growth method. MA3Bi2I9 crystals were also prepared and characterized for comparisons. X-ray diffraction analysis revealed that all the crystals had quasi-two-dimensional (2D) structures and the partial substitution of I- for Br- did not alter the space group symmetry. However, with the increase of I- concentrations, the incongruently melting temperature gradually decreased from 342 oC for MA3Bi2Br9 to 328 oC for MA3Bi2(Br0.62I0.38)9, respectively. For optoelectronic properties, the MA3Bi2Br9 was measured to have a direct bandgap of 2.60 eV, while the values decreased to 2.15 eV for MA3Bi2(Br0.74I0.26)9, 2.04 eV for MA3Bi2(Br0.62I0.38)9, and 1.97 eV for MA3Bi2I9, respectively. Similarly, the photoluminescence peaks blue-shifted from 550 nm for MA3Bi2Br9, to 453 nm for MA3Bi2(Br0.74I0.26)9, 445 nm for MA3Bi2(Br0.62I0.38)9, and 444 nm for MA3Bi2I9, respectively. Due to the strong dielectric confinement effects and anisotropic exciton transportation characteristics of the 2D structures, the targeted crystals studied all exhibited ultrafast fluorescence decay characteristics, where decay time as short as 0.65 ns the sub-nanosecond, for MA3Bi2Br9, 1.06 ns for MA3Bi2(Br0.74I0.26)9, 3.00 ns for MA3Bi2(Br0.62I0.38)9, and 3.12 ns for MA3Bi2I9, respectively, were observed. Besides, the low dimensional structures also brought the crystals superior environmental stability as the suppressed ion migrations. This work provides simple, straightforward method for the large-sized crystal growth of low dimensional MA3Bi2X9 (X-=Br-, I-), and reveals their promising application prospects in novel optoelectronic fields.
研究领域:
材料科学
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光学
·
晶体生长
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 20
·1-10
·
IF 2.8
Ji Changjian,Zhang Hailong,Wang Wenjing,Yuan Huimin,Zhao Gang
In order to acquire a red light-emitting component for an efficient w -LEDs device, we synthesized a series of Eu 3+ -doped Sr 2 GaTaO 6 (SGT) phosphors using a traditional high-temperature solid-phase technique. The results of UV diffuse reflectance proved that the SGT host possesses a broad optical energy bandgap ( E gap ) of 4.47 eV (calculated value). The relevant characteristic spectra were also tested. By monitoring the emission at 612 nm, the excitation peak at 466 nm matches the blue light region (460–470 nm) of the popular blue LED chips on the market. The photoluminescence (PL) spectra of SGT: Eu 3+ phosphors at room temperature consisting of four obvious PL bands ( 5 D 0 → 7 F 1 , 5 D 0 → 7 F 2 , 5 D 0 → 7 F 3 , and 5 D 0 → 7 F 4 ) in the visible range. And the PL properties are necessarily analyzed by fluorescence decay curves. And it exhibits a decent photoluminescence quantum yield (39.88%). Moreover, the color purity and the ∆E of the SGT: 0.2Eu 3+ sample are 96.5% and 0.29 eV, respectively, demonstrating that the ∆E of SGT: Eu 3+ phosphor is superior to other reported Eu 3+ -doped materials for w -LEDs applications. The results manifest that the Eu 3+ doped SGT phosphors can be outstanding candidates for w -LEDs applications with high color purity and activation energy.
研究领域:
材料科学
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光电
·
固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 7
·4533-4536
·
IF 1.134
Deng Chong,Fu Bowen,Li Lili,Wang Yanlai,Yang Lin
The hot-injection method was used for the synthesis of ternary metal chalcogenide nanocrystals (NCs) CuInS2 (CIS); this was achieved by using the metal precursors (copper iodide and indium acetate) and four different types of sulfur precursor solutions. It was discovered
that CIS NCs synthesized with different sulfur precursor solutions exhibited the chalcopyrite structure with similar particle sizes of ~4.2 nm. As a comparison, CIS NCs synthesized using ODE-S precursor displayed an enhanced luminescence intensity and a long PL decay lifetime, which could
be considered as an evidence of improved interior crystallinity.
研究领域:
材料科学
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纳米技术
·
化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Ligan Ma,Fumin Lu,Qingqing Yu,Peican Dai,Fangfang Hu,Hai Guo,Rongfei Wei
Nowadays, multi-mode luminescent thermometry has emerged as a strongly promising noncontact temperature-sensing technique, in which can realize the temperature determination more reliable and accurate by incorporating the excellent temperature monitoring properties from different modes of sensing. Herein, three-mode optical thermometry technics were triumphantly designed in thermochromic Gd 2 GaSbO 7 (GGS):Bi 3+ ,Eu 3+ phosphors. With ascending temperature, the emission color of GGS:Bi 3+ ,Eu 3+ varies remarkably from pink to yellow with the thermo-caused chromaticity shift reaching 0.2505, being easily differentiated by our eyes. Employing the fluorescence intensity ratio of well-separated emission bands of Bi 3+ and Eu 3+ , outstanding relative sensitivity ( S R ) of 1.03% K - 1 , favorable temperature uncertainty of 0.296 K, excellent reversibility and repeatability are acquired. Moreover, profiting by the rapid decline of fluorescence decay lifetime of Bi 3+ ( 3 P 1 ) in GGS:Bi 3+ ,Eu 3+ with temperature elevating, the optimal S R reaches 0.75% K - 1 at 473 K, higher than most reported optical thermometers. These discoveries indicate that GGS:Bi 3+ ,Eu 3+ phosphors have fantastic prospects in multi-mode temperature detection and high temperature warning areas.
研究领域:
材料科学
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光学工程
·
温度传感技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Li Wang,Fumin Lu,Xiaoman Li,Fangfang Hu,Hai Guo,Rongfei Wei
Luminescence glass is an inspiring scintillating material because of the unique merits including simple preparation process, mass production and low-cost. However, it is still a daunting challenge to explore the scintillating glass which can be applied in practical life. Herein, a novel Cu + doped borate glass scintillator was successfully fabricated under air atmosphere by introducing proper Si 3 N 4 in melting process. The resultant glass exhibits broadband luminescence under ultraviolet (UV) light or X-ray excitation. Through the low temperature thermal treatment, both luminescence induced by UV and X-ray can be significantly enhanced. The quantum efficiency reaches as high as 74.2%. And the sample endows superior thermal stability with the emission intensity at 573 K still maintaining 62.5% of that at 303 K. The X-ray excited luminescence is 37.8% of that of the commercial Bi 4 Ge 3 O 12 (BGO) crystal. Furthermore, the damaged sample even stimulated by high-energy X-ray can be restored to original level completely after heat treatment again. Besides, the sample presents outstanding optical thermometric performance based on the fluorescence decay lifetime. These findings confirm that the as-prepared Cu + doped borate glass is a promising candidate applied in the areas of scintillator and temperature sensor .
研究领域:
材料科学
·
光学
·
闪烁体技术
·
温度传感
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Qiang Li,Xiaomeng Zhou,Li-Li Tan,Li Shang
Ultrasmall gold nanoclusters (AuNCs) with distinct photoluminescence properties are promising fluorophores for optical applications. However, it remains a great challenge to precisely modulate their near-infrared (NIR) fluorescence properties via a simple yet efficient strategy. Herein, we report a new, surface tailoring strategy for effectively modulating the NIR fluorescence property of AuNCs by harnessing the attractive property of metal-organic frameworks. With zeolite imidazolate frameworks-8 (ZIF-8) as the example, we showed that highly fluorescent AuNCs can be in situ encapsulated into ZIF-8 via a one-pot reaction, yielding [email protected] composites with enhanced NIR fluorescence intensity . Particularly, [email protected] composites exhibit an emission maximum at 830 nm, which is 190 nm longer than the emission wavelength of AuNCs without the ZIF-8 encapsulation. Mechanism studies based on fluorescence decay spectra and X-ray photoelectron spectroscopy revealed that ZIF-8 mainly poses a significant effect on the ligand-metal charge transfer process of AuNCs due to the confinement effect . By incorporating Rhodamine B (RhB) into NIR-emitting [email protected] composites, we established a ratiometric fluorescent sensing platform for the detection of acetylcholinesterase (AChE) based on the turn-on fluorescence response of AuNCs towards thiolates. The [email protected] /RhB system exhibits a high sensitivity with a detection limit of 0.4 mU/mL and good specificity towards common biological interferences. Moreover, the present ratiometric fluorescence assay shows good recovery for AChE detection in human serum, suggesting its potential application for real sample analysis. Finally, the fluorescence response mechanism of both [email protected] and AuNCs towards AChE is elucidated by fluorescence lifetime analysis and density functional theory (DFT) calculation. This study demonstrates the feasibility of modulating the NIR fluorescence property of AuNCs by MOF-based surface tailoring strategy towards enhanced biosensing application.
研究领域:
纳米技术
·
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
DOI
高影响因子
OPTICS EXPRESS
·
2020
·Vol. 28
·期 8
·10714-10724
·
IF 3.669
Bin Liu,Bin Liu,Jinkai Li,Jinkai Li,Jinkai Li,Guangbin Duan,Min Ji,Yizhong Lu,Tao Yan,Bingqiang Cao,Zongming Liu,Zongming Liu
Organic-inorganic hybrid perovskite nanocrystals have been widely studied for their excellent photoelectric properties. However, the irregular morphologies of organic-inorganic hybrid perovskite nanocrystals have limited application in the field of lighting and display. From this, the regular morphologies of nanospheres, nanorods, nanoplatelets and MAPbBr3 (MA = CH3NH3+) nanocrystals have been synthesized by regulating the type and proportion of auxiliary ligands. The phase evolution, morphology and fluorescent properties were systematically studied by the various instruments of XRD, TEM, PL/UV-vis spectroscopy and fluorescence decay analysis. With the morphologies changing from nanospheres to nanoplatelets, the emission peaks of MAPbBr3 nanocrystals red-shifted, and the lifetimes have increased gradually. The underlying mechanisms were thoroughly investigated and elucidated. On this basis, the role of acid and amine in the synthesis of MAPbBr3 nanocrystals was systematically studied by regulating the ratio of oleic acid and N-octylamine. The fluorescence kinetics of MAPbBr3 nanocrystals were studied by femtosecond transient absorption spectroscopy, and the charge carrier relaxation mechanism was clarified. Furthermore, the effect of temperature on the fluorescence properties of the nanocrystal was investigated in detail. Organic-inorganic hybrid perovskite nanocrystals with morphologies-controlled and excellent fluorescence properties are expected to be widely used in lighting and display fields.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）