CERAMICS INTERNATIONAL
·
2026
·
IF 6
Ying Peng,Xinyi Tang,Yuhuan Tan,Dequan Liu,Pengyan Fu,Jilin Zhang,Shixun Lian,Wenli Zhou
Heterovalent Ca 2+ -Si 4+ co-substitution tunes local coordination of Cr 3+ . • Double NIR luminescence without altering Cr 3+ average crystal field. • Optimized phosphor achieves greatly improved absorption and quantum efficiency. • High-brightness pc-NIR-LED is fabricated for imaging and plant lighting. Cr 3+ -doped near-infrared (NIR) phosphors are highly desirable for NIR illumination, biological detection and auxiliary imaging. Herein, we propose a heterovalent Ca 2+ -Si 4+ co-substitution strategy to replace Ga 3+ sites in β -Ga 2 O 3 :Cr 3+ . This approach precisely tailors the local coordination and defect structures surrounding Cr 3+ , leading to remarkable enhancement in NIR luminescence. Characterizations demonstrate that Ca 2+ -Si 4+ co-substitution barely changes the average crystal field of Cr 3+ , but introduces local lattice distortion and reduces coordination symmetry. Such local structure engineering relaxes the d-d transition selection rules of Cr 3+ , thereby enhancing the absorption of the 4 A 2g → 4 T 1g and 4 T 2g transitions and strengthen the broadband NIR emission from the 4 T 2g → 4 A 2g transition. For the optimal Ga 1.81 Ca 0.08 Si 0.08 O 3 :0.03Cr 3+ phosphor, the NIR emission intensity is approximately two times higher relative to pristine β -Ga 2 O 3 :Cr 3+ . Its internal quantum efficiency increases from 81.8% to 88.6%, and absorption efficiency rises from 10.9% to 30.6%. A comparative study on various M A 2+ –M B 4+ ion pairs (M A = Mg, Ca, Sr, Ba; M B = Si, Ge, Sn) verifies that Ca 2+ -Si 4+ yields the strongest luminescence enhancement for β -Ga 2 O 3 :Cr 3+ . Moreover, this universal strategy also improves blue light absorption and NIR emission of MgGa 2 O 4 :Cr 3+ and LiGa 5 O 8 :Cr 3+ . The assembled phosphor-converted NIR light-emitting diode achieves a NIR output power of 107.9 mW at 400 mA and a photoelectric conversion efficiency of 14.8% at 40 mA. The as-prepared phosphors possess promising practical values for NIR imaging and plant lighting. Download: Download high-res image (288KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Qinghong Meng,Ji-Guang Li,Qi Zhu,Xiaodong Li,Xudong Sun
A series of phase-pure [(Gd 0.6 Lu 0.4 ) 1- y Ce y ] 3 [Al 1- z (Mg/Si) z ] 5 O 12 ( y = 0–0.012, z = 0–0.15) garnet phosphors were synthesized via gel-combustion, and the effects of Mg 2+ /Si 4+ substitution on characteristics of the garnet host and Ce 3+ luminescence were investigated in detail. The maximum amount of equimolar Mg 2+ /Si 4+ dopants that can be incorporated into the garnet lattice and the optimal Ce 3+ content for luminescence were determined to be around z = 0.15 and y = 0.010, respectively. Mg 2+ /Si 4+ codoping was analyzed to narrow bandgap of the host, non-uniformly compress the [CeO 8 ] dodecahedron , enlarge the [Al-O] polyhedrons and meanwhile alter bond angles. Increasing Mg 2+ /Si 4+ content was found to lower the intensity, fluorescence lifetime and thermal stability of Ce 3+ luminescence and meanwhile red-shift the 4f-5d 1 excitation/emission peaks. The results were interpreted by considering band structure and crystal field splitting of the Ce 3+ 5d energy level. The y = 0.01 and z = 0.15 phosphor exhibited a broad emission peaked at ∼561 nm under 457 nm excitation, with CIE color coordinates of around (0.449,0.527), a correlated color temperature of ∼3567 K, a fluorescence lifetime of ∼43 ns, and an activation energy for thermal quenching of ∼0.267 eV. Electroluminescence indicated that the phosphors may find potential application in warm-white LEDs excited by blue-LED chips.
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高影响因子
APPLIED SURFACE SCIENCE
·
2026
·
IF 6.6
Xianyue Zhang,Yongguang Zhang,Nianxue Dong,Jiawei Fan,Haipeng Li,Baoe Li
The slow Na + diffusion and low intrinsic electrical conductivity of Na 3 V 2 (PO 4 ) 3 (NVP) limit its practical application in sodium-ion batteries (SIBs). A synergistic enhancement approach of Si 4+ substitution and N-doped carbon coating has been introduced in this paper to produce a porous coral-like Na 3.1 V 2 (PO 4 ) 2.9 (SiO 4 ) 0.1 @NC-2 (NVPS@NC-2) composite. Si 4+ incorporation into the NVP lattice expands the Na + migration channels and decreases the bandgap so that intrinsic electronic conductivity of NVP was enhanced as confirmed by density functional theory calculations. Additionally, the N-doped carbon coating forms numerous extrinsic defects and creates a novel porous coral-like morphology that boosts the specific surface area. The initial specific capacity of NVPS@NC-2 cathode achieves 115.7 mAh g −1 at a current density of 0.1C. And even at 60/120C, NVPS@NC-2 cathode still exhibits 98.9/66.2 mAh g −1 , maintaining 92.9% and 90.6% capacities after 5000/10000 cycles, respectively, showing its viability for advanced SIBs applications.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
·
IF 5.316
Xin Li,Xusheng Wang,Rui Hu,Yanxia Li,Xi Yao
We report a novel mechanoluminescent phosphor Li 1−x Ca x Si x Ta 1−x O 3 :0.01Pr 3+ (x = 0–0.04). The crystal structure, photoluminescence (PL), optical diffuse reflectance spectra, afterglow (AG), fluorescence decay curves, and mechanoluminescence (ML) properties were investigated. To clarify the defect types and the mechanoluminescence mechanisms, an X-ray photoelectron spectroscopy (XPS) and thermoluminescence curve (TL) were measured. The dopants Ca 2+ and Si 4+ ions occupied the Li+ and Ta 5+ sites, respectively. An optimal sample Li 0.98 Ca 0.02 Si 0.02 Ta 0.98 O 3 :Pr 3+ was obtained with great enhancement in mechanoluminescence intensity, higher than that of non-doped sample LiTaO 3 :Pr 3+ by 262%. And the compression threshold, over which the ML intensity could not maintain the linear increase, has also been greatly improved. Furthermore, the stable output of Tribo-L was achieved, which was visible to the naked eye. A probable mechanism was proposed to illustrate the mechanoluminescent process in Li1-xCaxSixTa1-xO3:0.01Pr3 + (x = 0–0.04). The study indicates that adjusting trap distribution by substituting host ions may be a novel way to develop high-quality mechanoluminescence.
研究领域:
材料科学
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光学
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DOI
高影响因子
Biomaterials Research
·
2024
·
IF 8.1
Shiguo Yuan,Boyuan Zheng,Kai Zheng,Zhiheng Lai,Zihang Chen,Jing Zhao,Shaoping Li,Xiaofei Zheng,Peng Wu,Huajun Wang
Skull defect repair is a complex and critical medical challenge, and there is an urgent need to develop multifunctional tissue engineering scaffolds for skull regeneration. The success of bone tissue engineering depends on the construction of scaffolds that can regulate the immune microenvironment of bone regeneration and mimic the liquid crystal and viscoelastic properties of natural bone extracellular matrix. Hence, a smart hydrogel (PEGDA5/AM15/CLC-BMP-4@MBG) with good biocompatibility and the ability to modulate the wound immune microenvironment has been developed for the repair of skull defects. The hydrogel consists of chitin liquid crystal hydrogel (PEGDA5/AM15/CLC) and mesoporous bioactive glasses (MBGs) loaded with bone morphogenetic protein-4 (BMP-4). The liquid crystal hydrogel not only offers the necessary biological support and mechanical properties but also maintains the stability of the liquid crystal state, facilitating adhesion and regeneration of surrounding bone tissue. In addition, BMP-4@MBG intelligently regulates the release rate of BMP-4 in response to changes in wound microenvironment, thus effectively promoting the transformation of macrophages from M1 to M2 macrophages. At the same time, Ca2+ and Si4+ released by MBG degradation and BMP-4 synergically promote bone repair process. The PEGDA5/AM15/CLC-BMP-4@MBG hydrogel shows excellent immunomodulatory and osteogenic properties of bone microenvironment and is a promising scaffold material for bone tissue engineering.
研究领域:
生物医学工程
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组织工程
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材料科学
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免疫学
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DOI
PubMed
高影响因子
Laser & Photonics Reviews
·
2025
·Vol. 19
·期 12
·2500026
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IF 10
Yeping Ge,Ming Zhao,Yifei Zhao,Xinping Zhang
Filling the cyan gap (470–500 nm) in white light-emitting diodes (WLEDs) is crucial for full-spectrum illumination. However, the traditional approach of adding cyan phosphor to red, green, and blue phosphors can lead to reabsorption and color aberrations due to spectral overlap and varying degradation rates among the mixed phosphors. Herein, a blue-cyan-emitting phosphor (λ em = 475 nm) is developed through Si 4+ -P 5+ heterovalent substitution in blue-violet-emitting Rb 3 Y(PO 4 ) 2 :Eu 2+ phosphor (λ em = 425 nm), which can serve as the blue component in WLEDs to fill the cyan gap without adding extra phosphor. Initially, Eu 2+ primarily occupy the Rb2O 12 sites (426 nm) in Rb 3 Y(PO 4 ) 2 :Eu 2+ , with minimal occupation in the Rb1O 7 sites (456 nm) and YO 6 sites (522 nm). The Si 4+ -P 5+ substitution results in a red-shift of the Eu 2+ @Rb1 emission peak from 456 to 475 nm and the preferred occupation of the Rb1 sites by Eu 2+ , synergistically achieving the blue-cyan luminescence. Employing the blue-cyan-emitting phosphor instead of the blue-violet-emitting phosphor in WLEDs significantly improves the color rendering index from 90 to 97.2, thus enhancing the overall color reproduction quality. This research demonstrates a facile composition modification method to modulate the properties of inorganic luminescent materials and provides an alternative solution for full-spectrum healthy lighting.
研究领域:
材料科学
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发光材料
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固态照明
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无机化学
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光电子学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Qinghong Meng,Yuning Zhang,Xiangming Li,Wanjun Yu,Zhijun Xu,Ji-Guang Li
Doping Gd 3 Ga 3 Al 2 O 12 :Cr 3+ with Mg 2+ /Si 4+ pair to develop Gd 3 Ga 3 – y Al 2 – 2 x Mg x Si x O 12 : y Cr 3+ ( x = 0–1.0; y = 0.005–0.05) new garnet solid solution was implemented for the regulation of structure and photoluminescence. Rietveld refinement, SEM/TEM, and UV-Vis-NIR/photoluminescence spectroscopy analysis clarified that Mg 2+ /Si 4+ incorporation increasing resulted in the enlargement of the unit cell, the expansion/larger distortion of [(Ga,Al,Mg,Cr)O 6 ] octahedron, the decrease of crystal field strength, red-shifting and broadening of emission band, and shortening decay times. The optimal Gd 3 Ga 2.97 MgSiO 12 :0.03Cr 3+ phosphor realized broadband NIR emission (centered at ∼760 nm, full-width at half-maximum ∼114 nm) under 450 nm light excitation and exhibited high quantum efficiency (IQE=71.0 %, EQE=29.4 %) and good thermal stability (78.5 %@423 K). The NIR pc-LED fabricated by combining this optimal phosphor with a 450 nm blue LED chip showed satisfactory output power (∼26.83 mW) and conversion efficiency (10.02 %) under a driving current of 100 mA, indicating that this phosphor has huge potential utilized in the construction of NIR pc-LED applied in night vision and noninvasive medical diagnosis.
研究领域:
材料科学
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光学材料
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固态照明
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无机化学
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光子学
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Wenrui Zhang,Zhaowu Wang,Shiyu Jia,Yayun Zhou,Haipeng Ji
Luminescent bulk crystals exhibit fewer grain boundaries and defects compared with conventional microsized powdery ones. Herein, targeting Mn4+-activated fluoride crystals with a sharp line-type red luminescence spectrum, we propose a new cooling-induced crystallization method to grow the fluoride crystals. By this new method, we successfully grew millimeter-sized K2MnF6:Si4+, NH4+ crystals, featuring an AEmax (absorption efficiency) of 93.5% and an EQEmax (external quantum efficiency) of 68.9%, which are among the best values for Mn4+-activated fluoride red phosphors. The influence of doping Si4+ and/or NH4+ in K2MnF6 on the local coordination structure and luminescence properties was studied. The anomalous thermal quenching behaviors were discussed, the luminescence decay from the excited state was compared, and the origin for the high quantum efficiencies was analyzed.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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