JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Zongliang Xiao,Niwang Tang,Yun Gu,Lei Li,Yuhang Wang,Weizhen Liu,Qian Zhang,Lei Han,Xiuxun Han
Quantum dot (QD) materials, characterized as quasi-zero-dimensional nanocrystals , have garnered considerable attention due to their distinct optical properties arising from quantum size confinement effects , distinguishing them from bulk materials. Despite these advantages, challenges persist in achieving long-term stability and high luminescent efficiency. Addressing these issues, CdS QDs were successfully precipitated in a silicate glass matrix through a combination of melt-quenching and controlled crystallization techniques. Structural and morphological analyses confirmed the in-situ precipitation of CdS QDs with sizes < 20 nm within the glass matrix. Under 395 nm light excitation , the light color emitted from the CdS QD glass transitions from yellow to red, exhibiting an impressive internal quantum efficiency (IQE) of 67.14 %, notably surpassing other CdS QD glasses. Furthermore, the QD glass retained 85 % of its luminescent intensity at room temperature even when exposed to a high temperature of 150°C, demonstrating superior thermal stability compared to colloidal QDs. As a proof of concept , a full-spectrum luminescent white-light emitting diode (W-LED) device was encapsulated using the UV LED chip, CdS QD glass, BaMgAl 10 O 17 :Eu 2+ blue phosphor, and Ba 2 SiO 4 :Eu 2+ green phosphor. This device exhibited suitable chromaticity coordinates of (0.3473, 0.3750), a correlated color temperature of 4996 K, and an impressive color rendering index of 92.5. Additionally, the X-ray imaging performance of CdS QD glass was assessed using a customized optical system, underscoring its promising potential in scintillation imaging applications such as non-destructive testing. In summary, the compositional optimization and controllable crystallization techniques employed in this study offer valuable insights for developing QD glasses with exceptional properties. The substantial potential benefits of CdS QD glasses are convincingly demonstrated through physical demonstration, particularly in the realms of W-LED lighting and X-ray scintillation imaging.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Journal of Materials Chemistry C
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2024
·
IF 5.7
Zhibin Ye,Ziwang Zhang,Nan Yang,Zhuo Li,Weijie Huang,Jianxin Shi
Artificial light sources have a significant impact on the cultivation of houseplants. In this work, a novel single-phase dual-emission phosphor, Ca18Na3Y(PO4)14:Eu2+,Mn2+ (CNYPO:Eu2+,Mn2+), was synthesized and the emission spectra were modulated by co-doping of Mg2+ to better match the absorption of plants. The occupancies of Eu2+, Mn2+ and Mg2+ are analyzed by using the data of bond length from XRD Rietveld refinements and the emission spectra. The energy transfer process from Eu2+ to Mn2+ is proved through the photoluminescence spectra and decay curves. Benefiting from the efficient energy transfer, two broadband emissions peaking at 500 and 650 nm can be achieved, which meets the requirements of plant growth, and the luminescence colour can be tuned from cyan to white and finally to red by changing the ratio of Mn2+ to Eu2+. The internal quantum efficiency of CNYPO:0.18Eu2+,0.18Mn2+ is 76.8% under 340 nm excitation. The introduction of Mg2+ can regulate the occupation sites of Eu2+ and the emission peak position, improve the responsiveness to the plant absorption spectra, and tune the luminescence colour to white. Finally, a white light-emitting diode (WLED) device fabricated using CNYPO:0.18Eu2+,0.18Mn2+,2.16Mg2+ on a 365 nm chip has a high colour rendering index of 89.0 and a low correlated colour temperature of 3580 K, indicating that the prepared phosphor has potential applications in plant lighting and WLEDs.
研究领域:
材料科学
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光学工程
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农业科学
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DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Noor Zamin Khan,Sayed Ali Khan,Weilong Chen,Jahangeer Ahmed,Muhammad Amin Padhiar,Nisar Muhammad,Marcin Runowski,Saad M. Alshehri,Shu-Sheng Pan,Ren-Kui Zheng
The advancement of double perovskite oxide phosphors has expanded their applications, encompassing white light-emitting diodes (LEDs) to optical thermometry and scintillation detection. We have synthesized novel Ca 2 LuTaO 6 phosphors characterized by double perovskite structures by employing the high-temperature solid-state reaction technique. Upon excitation with 312 nm UV light, these undoped phosphors emit a broad blue light centered at 424 nm. We thoroughly investigated the origin of this blue emission using computational and experimental methods. The Ca 2 LuTaO 6 phosphors were further doped with Dy 3+ or Dy 3+ and Sm 3+ ions, which results in a broadband tunable-color emission covering the entire visible region (400–700 nm). Under 354 nm excitation, the single doped Ca 2 LuTaO 6 :Dy 3+ exhibits two emission bands due to the 4 F 9/2 → 6 H 15/2 (blue) and 4 F 9/2 → 6 H 13/2 (yellow) transitions of Dy 3+ . The single doped Ca 2 LuTaO 6 :Sm 3+ generates a red emission (603 nm) when excited at 407 nm from 4 G 5/2 to 6 H 7/2 transition. The optimized Ca 2 LuTaO 6 :0.05Dy 3+ and Ca 2 LuTaO 6 : 0.05Dy 3+ /0.04Sm 3+ phosphors show excellent thermal stability. Even at a temperature of 150 °C, i.e. typical temperature of the working LED electronics, the luminescence intensity for the single-doped sample with Dy 3+ maintains 82 % of its initial value. On the other hand, at the same temperature conditions, for the phosphors co-doped with Dy 3+ and Sm 3+ , the intensity remains at 90 % of Dy 3+ peaks with a slight chromaticity shift. A study of the electroluminescent performance of the Ca 2 LuTaO 6 :0.05Sm 3+ and Ca 2 LuTaO 6 :0.05Dy 3+ /0.04Sm 3+ phosphors were conducted using 365 nm LED chips to investigate their applications in white light-emitting diodes (WLEDs). The results confirm that Ca 2 LuTaO 6 :Dy 3+ /Sm 3+ phosphors have great potential for general illumination purposes, as the single-phase light sources.
研究领域:
材料科学
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光学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2024
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IF 4.3
Fengli Xu,Ruoyu Dong,Junchao Cui,Yufei Zhang,Weijie Ren,Kai Song,Shuai Meng,Rui Zhang,Kun Li,Jingjing Bai,Zhenxing Qin
Regulation of the fluorescence through crystalizing from the matrix in the Carbon dots (CDs)-based solid-state materials has been verified to be one of the effective methods, yet there are not only challenges in preparing such materials efficiently, but also insufficient insight into their regulation mechanisms. Here, a one-pot solvothermal route to synthesize a series of CDs-based composites with crystalline matrix is reported. These crystals exhibited multicolor fluorescence with the feature of multi-peaks emissions with increasing temperatures from 140 ℃ to 220 ℃, in which the orange emitting O-CDs@PA and the yellow emitting Y-CDs@PA crystals obtained the FLQYs of 22% and 68% respectively due to relatively stable crystalline structures. After comparative analysis to both crystals in detail, the core and the groups associated with them on the interface between CDs and matrix were adjusted in size and species during structural transformation of the crystal matrix, which changes radically the energy band structures to influence fluorescent emitting of both crystals ultimately. In addition, the reasons resulting in higher FLQY for Y-CDs@PA were provided leveraging the schematic illustration presumed based on the PL properties of both crystals. Because of the optimal optical performances, these fluorescent materials promised to fabricate WLED devices and obtained a number of photometric parameters endowed these WLED devices with the feature of warm-white light.
研究领域:
材料科学
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光学
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DOI
PubMed
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
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2024
·
IF 3.9
Lihan Deng,Jin Li,Jiachen Chen,Jin He
Nanoporous Al 2 O 3 -SiO 2 glasses were prepared using a sol–gel method. These sintered nanoporous Al 2 O 3 -SiO 2 glasses have a transmittance greater than 85 % and possess high mechanical strength, enabling them to contain and protect RE ions. Owing to the presence of nanopores in nanoporous Al 2 O 3 -SiO 2 glasses, Eu ions can easily enter the nanoporous Al 2 O 3 -SiO 2 glasses via an ex-situ dipping method. After drying at room temperature (RT) and then heating at 400 °C, 600 °C, 800 °C, and 1200 °C, we obtained a series of Eu doped nanoporous Al 2 O 3 -SiO 2 glasses. The thermal reduction process from Eu 3+ ions to Eu 2+ ions can occur at a lower sintering temperature (400 °C), enabling a detailed analysis of the thermal reduction mechanism at both low and high temperatures in detail. Under the conditions where Al 3+ ions are present in the samples that are under calcination, Eu 2+ -doped nanoporous Al 2 O 3 -SiO 2 glasses are more easily obtained at relatively low temperatures. Owing to the adjustable composition of Eu 3+ /Eu 2+ in the nanoporous Al 2 O 3 -SiO 2 glasses, tunable emission from red-orange light to blue-violet light can be achieved in the samples. This new type of transparent Eu-doped NPGs has the advantages of high mechanical strength and good processability and is non-toxic and harmless, thereby showing great potential for use in tunable light sources and LED devices.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2024
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IF 5.1
Meiting Li,Bingxin Yuan,Xiangyang Zheng,Bo Chen,Chi Zhang,Xuejiao Wang,Ji-Guang Li
A series of LaNbO 4 :RE 3+ (RE = Tb and Eu) phosphors were successfully synthesized via a calcination-assisted hydrothermal reaction, where the vital roles of solution pH, calcination temperature and NbO 4 3− /La 3+ molar ratio in phase/morphology evolution of LaNbO 4 nanocrystals were elaborated. It was unambiguously demonstrated that monoclinic LaNbO 4 can be crystallized at solution pH = 8–13 after calcination at 900 °C. With pH = 10 precursor for example, higher calcination temperature led to phase transformation from orthorhombic to monoclinic structure. LaNbO 4 nanoparticles exhibit self-activated broad-band excitations ( 1 A 1 → 1 T 1,2 ) and emissions ( 3 T 2,1 → 1 A 1 ) within the NbO 4 3− ligand. Intriguingly, Tb 3+ /Eu 3+ incorporations allow for phase tailoring and full-visible-spectrum color-tunable luminescence, where the latter benefits from the effective NbO 4 3− → Tb 3+ → Eu 3+ energy transfer. LaNbO 4 :0.01 Tb 3+ ,0.01Eu 3+ phosphor exhibits stronger white-light emission, which gradually drifts to yellowish green at high heating temperature. This phosphor is an attractive candidate for optical thermometers and warm pc-WLED owning to excellent thermal stability, a low correlated color temperature of ∼5694 K and a high color rendering index of ∼90.
研究领域:
材料科学
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光学
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DOI
高影响因子
INORGANIC CHEMISTRY
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2024
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IF 4.3
Xiaowei Liu,Kailei Li,Wei Shao,Wei Shen,Ming Li,Lei Zhou,Rongxing He
Low-dimensional hybrid metal halides are an emerging class of materials with highly efficient photoluminescence (PL), but the problems of poor stability remain challenging. Sn(IV)-based metal halides show robust structure but exhibit poor PL properties, and the structure–luminescence relationship is elusive. Herein, two Sn(IV)-based metal halides (compounds 1 and 2) with the same constituent ((C6H16N2)SnCl6) but different crystal structures have been prepared, which however show poor PL properties at room temperature due to the absence of active ns2 electrons. To improve materials’ PL properties, Sb3+ with active 5s2 electrons was embedded into the lattice of Sn4+-based hosts. As a result, efficient emissions were achieved for Sb3+-doped compounds 1 and 2 with a maximum PL efficiency of 14.28 and 62%, respectively. Experimental and calculation results reveal that the smaller distorted lattice structure of the host could result in the blueshift of the emission from Sb3+. Thus, a tunable color from red to orange was realized. Benefiting from the broadband efficient emission from Sb3+-doped compound 2, an efficient white light-emitting diode with a high color rendering index of up to 92.3 was fabricated to demonstrate its lighting application potential. This work promotes the understanding of the influence of robust Sn(IV)-based host lattice on the PL properties of Sb3+, advancing the development of environmentally friendly, low-cost, and high-efficiency Sn(IV)-based metal halides.
研究领域:
材料科学
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光学
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DOI
PubMed
高影响因子
ChemPhotoChem
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2024
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IF 3
Lulu Wei,Shubing Tian,Mingze Sun,Ruili Song,Yunhu Wang,Mingming Zhang,Lei Wang,Zhanhua Wei,Jun Xing
Graphical The influence of perovskite components, preparation conditions, and device structures on the spectral stability of mixed-halide perovskite blue LED is investigated systematically. Among these factors, A-site cations, annealing temperature and the content of the passivator affect the spectral stability significantly. After optimization, a spectra-stable and efficient mixed-halide perovskite blue LED is successfully fabricated. Metal mixed-halide perovskite has demonstrated considerable potential in the development of solution-treated blue light-emitting diodes (LEDs) with high external quantum efficiency, excellent color purity, and tunable wavelength. However, the severe phase segregation of mixed-halide perovskite under bias voltage would lead to the spectral instability of LEDs. Therefore, suppressing phase segregation of Br/Cl perovskite towards spectrally stable blue perovskite LEDs (PeLEDs) is a big challenge. In this work, we systematically explore the influence of perovskite component, preparation conditions, and device structures on the spectral stability of PeLEDs. We have observed that the stable spectra increased the proportion of Cs in the A-site cations, passivator, and the annealing temperature of perovskite films. Finally, we achieve a spectra-stable and high-performance blue PeLED under optimized conditions. Our findings provide important guidance for preparing spectrally stable PeLEDs.
研究领域:
材料科学
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光电工程
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DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 19
·10771-10780
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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
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光学工程
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2020
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IF 4.65
Shuang Shu,Yu Wang,Yuee Ke,Bin Deng,Rixin Liu,Qinyang Song,Jianxu Wang,Ruijin Yu
Novel orange-red-emitting tantalate NaCaTiTaO 6 (NCTT): x Sm 3+ ( x = 0.005–0.25) phosphors are synthesized via a solid-state reaction technique at 1300 °C. The phosphors exhibit an orthorhombic perovskite structure with a space group of Pnma (No. 62). At 407 nm excitation, the phosphors show the strongest emission peak at 647 nm belonging to the 4 G 5/2 → 6 H 9/2 transition. The optimal Sm 3+ concentration is 0.05 mol, and concentration quenching is caused by dipole–dipole interaction. The NCTT:0.05Sm 3+ phosphor exhibit a broad bandgap of 3.44 eV and a high color purity of 99.9%. At 420 K, the decrease in intensity is only 10% of the initial value at 300 K for NCTT:0.05Sm 3+ phosphor but 15% for Y 3 Al 5 O 12 :Ce 3+ phosphor. Consequently, the fabricated white light-emitting diodes exhibit a high rendering index value of 89, a good correlated color temperature of 5257 K, and CIE coordinates of (0.339, 0.364). Hence, the Sm 3+ -doped orange-red-emitting NCTT phosphors have potential applications for w-LEDs.
研究领域:
材料科学
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光学
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DOI
高影响因子
Advanced Optical Materials
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2020
·Vol. 8
·期 6
·1901859
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IF 8.286
Yi Wei,Zhiyu Gao,Siwei Liu,Shuoting Chen,Gongcheng Xing,Wei Wang,Peipei Dang,Abdulaziz A. Al Kheraif,Guogang Li,Jun Lin
Highly efficient green/yellowish-orange phosphors with low thermal quenching behavior are urgently required to improve the luminescence efficiency, color stability, and color rendering of phosphor-converted white light emitting diodes (w-LEDs). Herein, a novel green Cs 2 BaP 2 O 7 :0.01Eu 2+ phosphor with high luminescence efficiency (82.7%) and thermal quenching behavior (92.5% at 423 K) is reported. Besides, a further luminescence improvement in the quantum yield (98.9%) and thermal quenching resistance (120% at 448 K) is successfully achieved in green/yellowish-orange color-tunable Cs 2 MP 2 O 7 :0.01Eu 2+ (M = Ba, Sr, and Ca) phosphors. Surprisingly, these green/yellowish-orange Cs 2 MP 2 O 7 :0.01Eu 2+ (M = Ba, Sr, and Ca) phosphors even have a prior advantage over the commercial green β-SiAlON:Eu 2+ and yellow YAG:Ce 3+ phosphors. The corresponding spectral adjustment and thermal stability mechanisms are revealed, related to the optimization of local lattice symmetry. The prototype w-LEDs exhibit warm white light with CIE color coordinate at (0.337, 0.322). The color rendering index, corrected color temperature, and luminescence efficiency can reach 92.6, 4044 K, and 152.56 lm W −1 , respectively. In general, the as-reported green/yellowish-orange Eu 2+ -doped pyrophosphate phosphors are promising candidates in the future high-quality w-LEDs applications. The proposal of local lattice symmetry modulation can provide a new approach to exploit novel phosphors with excellent thermal quenching resistance.
研究领域:
材料科学
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光学工程
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发光材料
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
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2025
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IF 10
Yongfeng Liu,Xinyi Wang,Qingyu Xie,Jia Wang,Wenbin Yu,Liang Zhao,Jinpeng Yang,Daofu Wu,Xiaosheng Tang,Shengnan Tian,Li Song,Dongdong Yan,Min Zhou
Quantum-confinement-based blue CsPbBr 3 perovskite quantum dots (PeQDs) have attracted significant research interest in light-emitting diodes (LEDs) due to their outstanding optoelectronic properties, solution-processability, and free from spectral separation. However, their performance lags behind due to low film quality, high trap density, and mismatched carrier transporting. To address these issues, a bifunctional-additive interface engineering is proposed on in situ formed blue Cs 4 PbBr 6 heterostructured CsPbBr 3 (CsPbBr 3 @Cs 4 PbBr 6 ) PeQDs. The introduction of glycine, with an amino group and a carboxyl group, enables the PeQD film high surface uniformity and photoluminescence quantum yield up to 51.6% from mere 14.1% with a peak wavelength at 489 nm, but low trap density and matched transporting of electron and hole. Surprisingly, glycine-treated PeQD films show significantly enhanced stability against air and ultraviolet lamp exposure. Experimental results and density functional theory calculations reveal that the carboxyl group contributes to maintaining the quantum confinement effect, while the amino group promotes optical emission due to its strong binding ability. Furthermore, the resulting CsPbBr 3 @Cs 4 PbBr 6 PeQD-based LEDs demonstrate outstanding performance, with an increase by a factor of 10 in external quantum efficiency to 5.8% and of 13 in operating life to 405 s. This study offers a straightforward approach for developing high-performance blue PeQD LEDs.
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高影响因子
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