JOURNAL OF FLUORINE CHEMISTRY
·
2023
·
IF 1.9
Shuang Wu,Yanhui Dong,Hao Cui,Daguang Li,Weiping Qin
The morphology and size of LiYF 4 :Yb,Er nanoparticles were controlled using an automatic nanomaterial synthesizer by changing the reaction time at high temperature. It was found that the nanoparticles underwent a growth and change process from small to large and then to small, and then remained at a basically stable size, reflecting the different growth stages of the nanoparticles, such as nucleation, growth, phase transition, and internal Ostwald ripening, etc. XRD analyses showed that LiF nanocrystals were first formed during the reaction process, and then all the products were converted into LiYF 4 nanocrystals. Under the excitation of a 980 nm laser, the LiYF 4 :Yb,Er nanoparticles showed regular downconversion and upconversion luminescence properties, which was basically consistent with the regularity of nanocrystal growth. The experimental results showed that the upconversion luminescence and downconversion luminescence intensities of nanocrystals increasd rapidly when the synthesis time was between 0 and 50 min, and they increased slowly after the synthesis time exceeded 50 min.
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 LUMINESCENCE
·
2020
·
IF 3.28
Weichang Li,Qiang He,Jixi Xu,Chongyun Shao,Shiyu Sun,Shaohua Fan,Lili Hu
The efficient NIR-to-NIR upconverter of LiYF 4 :Yb 3+ ,Tm 3+ (simplified as LYF:Yb,Tm) was synthesized by a modified hydrothermal method in this work. The synthesized LYF:Yb,Tm has well controlled morphology of monodisperse micrometer sized octahedrons. XRD pattern confirms its pure tetragonal LiYF 4 structure. The LYF:Yb,Tm exhibits a dominating NIR UC emission at ~793 nm along with relative weak blue and red UC emissions under 976 nm LD excitation. The optimal concentrations of Yb 3+ and Tm 3+ ions for NIR up-conversion (UC) emission are 20 mol% and 0.6 mol%, respectively. The internal UC quantum yield (IUCQY) of this LYF:Yb,Tm in NIR band is tested to be 5.1% at 959 nm LD excitation power density (PD) of 120 W/cm 2 . The UC emission mechanism is discussed based on UC fluorescent behaviors of Yb 3+ and Tm 3+ . The results of fluorescent labeling indicate its potential applications in fluorescent markers, solar cells and 3D flat panel displays .
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 Physical Chemistry C
·
2017
·
IF 4.536
Yiru Zhu,Shuwen Zhao,Bin Zhou,Hao Zhu,Youfa Wang
In this work, we report a phenomenon that upconversion emission intensity of Er3+ was enhanced by cadmium. Cd2+ was taken with 0, 3, 10, 20, 30, and 40 mol % as a new dopant to codope LiY0.78Yb0.20Er0.02F4, meanwhile the doping effects on the crystal structure, morphology, and upconversion fluorescence emission are investigated by XRD, Rietveld refinement, TEM, and upconversion spectroscopy analysis methods in detail. The green upconversion emission intensity was enhanced, and the maximum emission intensities were enhanced to twice when 10 mol % Cd2+ was codoped into tetragonal LiYF4, while its decay lifetime was reduced. Additionally, we further designed the synthesis of the homogeneous LiYF4:20%Yb,2%Er,10%Cd@LiYF4 of which the emission intensity is 11 times higher than that of the Cd2+-free nanocrystals, meanwhile an intriguing morphology of core–shell nanocrystals was obtained. This investigation may be useful for the design and improvement of upconversion materials for fulfilling the prerequisite of the practical application.
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 ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Weichang Li,Lili Hu,Wei Chen,Shiyu Sun,Malgorzata Guzik,Georges Boulon
Optical thermometry is a non-contact temperature detective technique that has high sensitivity and rapid response. In present work, we developed LiYF 4 :20Yb 3+ , 1Ho 3+ (mol%) micro octahedrons obtained by a modified hydrothermal method . The temperature dependent up-conversion (UC) emission and luminescence decays for LiYF 4 :20Yb 3+ , 1Ho 3+ under 976 nm LD excitation with various power density were studied systematically in the temperature range from 100 K to 500 K. The green and red UC emissions are sensitive to the sample temperature whereas the excitation power density in the studied temperature ranges plays a negligible role on the red to green UC emissions ratio. The non-contact optical temperature sensing behaviors were investigated based on the fluorescence intensity ratio (FIR) of red (R3 + R4) and green (G3) at temperature from 100 K to 500 K, which are ascribed to non-thermally coupled levels of Ho 3+ : 5 F 5 and 5 F 4 , respectively. The maximum absolute sensitivity (S a ) of 0.0477 K −1 and maximum relative sensitivity (S r ) of 0.0129 K −1 at the temperature range of 100–500 K based on FIR of (R3 + R4)/G3 were found. The mechanism of temperature effect on UC emission was discussed. The heating and cooling cycle test indicates the high thermal stability of LiYF 4 :20Yb 3+ , 1Ho 3+ . These results imply the LiYF 4 :20Yb, 1Ho has potential application in ratiometric thermometers and temperature sensing devices.
研究领域:
光学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 11
·期 1
·172-185
·
IF 7
Kejie Li,Mengmeng Dai,Zuoling Fu,Zhiying Wang,Hanyu Xu,Rong Wang
Fluorides have garnered tremendous attention in rare-earth-doped fluorescent probes owing to their low phonon energy and excellent optical transparency. However, the latest generation of fluorides, LiYF4, is plagued by extremely complex and uncontrollable synthesis methods, which greatly restricts its further exploration and application. Herein, a straightforward one-step method for the synthesis LiYF4:Ln3+ with micron-sized cones and nano-spheres is reported. Astonishingly, self-sensitized luminescence was achieved under multi-wavelength excitation when Er3+ was singly doped. LiYF4:Yb3+,Er3+ demonstrated superior luminescence intensity to those of commercial green phosphors (NaYF4:Yb3+,Er3+); this ultra-efficient photoluminescence was confirmed from the crystal structure, electronic band properties, morphological analysis and Debye temperature calculations. Further, by constructing cross-relaxation between the Ce3+ and Er3+ ions (4I11/2 + 2F5/2 → 4I13/2 + 2F7/2), the specific four-peak emission (SFPE) intensity of Er3+ in NIR-IIb was significantly increased, further enhancing the relative sensitivity of thermally coupled temperature sensing based on SFPE. Subsequently, non-thermally coupled temperature sensing based on SFPE was also achieved through the construction of phonon-assisted energy transfer between Ho3+ 5I6 and Er3+ 4I13/2. In summary, this paper not only puts forward theoretical and experimental arguments for the use of LiYF4 to replace the conventional NaYF4, but also substantiates the extraordinary prospects of LiYF4 as a temperature-sensitive fluorescent probe in nanomedicine.
研究领域:
材料科学
·
纳米医学
✓ 已验证
DOI
高影响因子
Nano Research
·
2020
·Vol. 13
·期 10
·2803-2811
·
IF 8.183
Zhang Ling,Li Xiaodan,Wang Wang,Zhao Xu,Yan Xu,Wang Chenguang,Bao Haoqiang,Lu Yang,Kong Xianggui,Liu Fengmin,Liu Xiaomin,Lu Geyu
LiErF 4 was commonly used as a dipolar-coupled antiferromagnet, and was rarely considered as a luminescent material. Herein, we achieved the strong red upconversion emission of LiErF 4 simply by an inert shell coating, i.e., LiErF 4 @LiYF 4 . Owing to the unique and intrinsic ladder-like energy levels of Er 3+ ions, this LiErF 4 core-shell nanostructures present red emission (∼ 650 nm) under multi-band excitation in the near-infrared (NIR) region (∼ 808, ∼ 980, and ∼ 1,530 nm). A brighter and monochromic red emission can be further obtained via doping 0.5% Tm 3+ into the LiErF 4 core, i.e., LiErF 4 : 0.5% Tm 3+ @LiYF 4 . The enriched Er 3+ ions and strong monochromic red emission natures make LiErF 4 : 0.5% Tm 3+ @LiYF 4 nanocrystals very sensitive for trace water probing in organic solvents with detection limit of 30 ppm in acetonitrile, 50 ppm in dimethyl sulfoxide (DMSO), and 58 ppm in N , N -dimethylformamide (DMF) under excitation of 808 nm. Due to their superior chemical and physical stability, these nanoprobes exhibit excellent antijamming ability and recyclability, offering them suitable for real-time and long-term water monitoring.
研究领域:
材料科学
·
分析化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Qingming Huang
The preparation of high performance upconversion luminescence materials with stronger shortwave emissions is still a challenge. In this work, the feature of hexagon circles sublattice structure of tetragonal LiYF 4 was revealed, and the sublattice level energy clusters of 4 Yb 3+ -1Tm 3+ were constructed by the substitution of 70 mol% Yb 3+ for Y 3+ in tetragonal LiYF 4 matrix. The sensitizing ions concentration quenching was inhibited by the hexagon circles sublattice structure, and the upconversion luminescence was dramatically enhanced, especially, the UV band emission was enhanced about 20 times and the intensity ratio of UV to blue emissions was improved about 10 folds under the excitation power density of 0.230 W/cm 2 . Photon numbers of upconversion emissions obviously decreased with the increasing of sublattice level energy clusters that the upconversion process of three photons was changed to two steps of two photons process. The upconversion luminescence mechanism of sublattice energy cluster construction was system investigated. The material with high performance of UV and blue UC luminescence can be a well candidate for the applications of photodynamic therapy and photocatalytic, etc. The work may be an inspiration for high efficient UC luminescence materials design and preparation.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2021
·
IF 5.221
Feng Qilong,Zheng Wenjing,Pu Jie,Chen Qiaoli,Shao Wei
The availability of colloidal nano-materials with high efficiency, stability, and non-toxicity in the near infrared-II range is beneficial for biological diagnosis and therapy. Rare earth doped nanoparticles are ideal luminescent agents for bio-applications in the near infrared-II range due to the abundant energy level distribution. Among them, both excitation and emission range of Er3+ ions can be tuned into second biological window range. Herein, we report the synthesis of ∼15 nm LiYF4, NaYF4, and NaGdF4 nanoparticles doped with Er3+ ions and their core-shell structures. The luminescent properties are compared, showing that Er3+ ions with single-doped LiYF4 and NaYF4 nanoparticles generate stronger luminescence than Er3+ ions with doped NaGdF4, despite the difference in relative intensity at different regions. By epitaxial growth an inert homogeneous protective layer, the surface luminescence of the core-shell structure is further enhanced by about 5.1 times, 6.5 times, and 167.7 times for LiYF4, NaYF4, and NaGdF4, respectively. The excellent luminescence in both visible and NIR range of these core-shell nanoparticles makes them potential candidate for bio-applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 10
·2202884
·
IF 9
Ling Zhang,Zhongling Lang,Yang Lu,Xu Zhao,Bin Jiang,Xu Yan,Peng Sun,Fengmin Liu,Guangdong Zhou,Mi Zhou,Yanchao Wang,Xiaomin Liu,Geyu Lu
Local structural engineering is an endogenous approach to modulate upconversion luminescence (UCL) from upstream to meet the needs of specific application scenarios. Herein, high pressure is utilized as a means to modulate the local structure, and the designed LiErF 4 :0.5%Tm 3+ @LiYF 4 (Er:Tm@Y) nanoparticles with fast energy transfer rates, abundant cross-relaxation processes, and multiple near-infrared wavelengths (808, 980, 1530 nm) excitation properties are tailored as local structure-sensitive hosts. A unique excitation wavelength-dependent UCL enhancement of Er:Tm@Y upconversion nanoparticles is observed by pressure-induced local structure distortions. When the pressure of ≈6 GPa is applied, the UCL is enhanced by a factor of 2.6 at 980 nm excitation only. After pressure release, the luminescence diminishes and recovers. Density functional theory calculations show that the symmetry distortion of the LiErF 4 crystal reaches a maximum at pressurization to 6 GPa, while a new Er-4f state emerges, greatly reducing the bandgap from 8.3 to 5.7 eV. Comparative experiments demonstrate that the local symmetry distortion caused by 0.5%Tm 3+ doping and the different energy transfer patterns of Er 3+ to Tm 3+ at different excitations are responsible for this wavelength-dependent luminescence enhancement.
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 ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Maohui Yuan,Kai Han,Linxuan Wang,Xu Yang,Zining Yang,Hongyan Wang,Xiaojun Xu
Lanthanide-based optical ratiometric thermometer is a promising temperature detecting tool for noninvasive temperature measurements. However, owing to the thermal quenching of upconversion luminescence (UCL), the traditional temperature sensing range is limited to less than 600 K. In this work, highly thermally stable UCL is observed through introduced appropriate Cu 2+ ions into LiYF 4 :Yb/Er (20/2 mol%) microcrystals (MCs) and on which are further used for temperature sensing applications. As gradually increases the doping of Cu 2+ ions, the octahedron morphology of LiYF 4 MCs with smooth surfaces gradually aggregates smaller particles on their surface forming diamond-like micro-clusters. Based on the single-particle spectroscopy technique , the temperature-dependent UCL properties were systematically investigated and demonstrated. Doping of Cu 2+ ions can efficiently adjust and enhance the UCL in the LiYF 4 :Yb/Er (20/2 mol%) MCs. The UCL thermal quenching temperature is less than ~670 K for Cu 2+ -free MCs. In contrast, the quenching temperature extends to as high as ~870 K when doping with 2 mol% Cu 2+ ions. Furthermore, these highly thermal stable MCs are utilized to detect the temperature in a wide temperature ranging from 298 K to 873 K. A maximum relative sensitivity ( S r ) of 1.23%K −1 at 298 K is obtained and temperature uncertainty δ T < 0.091 K is determined under the measured temperature for the 2 mol% Cu 2+ -doped MCs. The highly thermally stable UCL properties and excellent thermometer performance of these MCs, particularly conducted at single-particle spectroscopy technique , can be potentially applied to micro-scale thermometers.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Weichang Li,Jixi Xu,Qiang He,Yan Sun,Shiyu Sun,Wei Chen,Malgorzata Guzik,Georges Boulon,Lili Hu
The development of novel phosphors with stable and efficient green and red up-conversion (UC) emission is important for many applications such as fluorescent labeling , color display and anticounterfeiting. In this work, we report a stable and efficient green and red up-converter of LiYF 4 :Yb 3+ ,Ho 3+ octahedrons obtained by modified hydrothermal method . The UC emission and luminescence decays of LiYF 4 :Yb 3+ ,Ho 3+ with various Yb 3+ and Ho 3+ ion concentrations were studied systematically under 976 nm LD excitation. The Yb 3+ and Ho 3+ ion concentrations were optimized to be 20 mol% and 1 mol% respectively, for efficient green and red UC emissions. LiYF 4 :Yb 3+ ,Ho 3+ presents not only controlled morphology of monodisperse octahedrons with length of ∼20 μm and width of ∼10 μm, but also performs efficient green and red UC emissions, which is about four times stronger than that of β-NaGdF 4 : 20 Yb 3+ ,0.5Ho 3+ (NaGdF 4 : 20 Yb 3+ ,0.5Ho 3+ ). More importantly, the stable UC emission with variation of green intensity ratio ΔG% (G% = I 520-570nm /I 500-700nm , ΔG%= (G%) max -(G%) min ) and red intensity ratio ΔR% (R% = I 625-685nm /I 500-700nm , ΔR%= (R%) max -(R%) min ) < 1% was found over 976 nm LD excitation power density (PD) ranging from 1.0 to 5.6 W/cm 2 . Whereas, their variations of ∼6% and 25% are observed at the same excitation PD for NaGdF 4 :20 Yb 3+ ,0.5Ho 3+ and commercial β-NaYF 4 :20 Yb 3+ ,2Er 3+ (NaYF 4 : 20 Yb 3+ ,2Er 3+ ), respectively. The mechanism of green and red UC emissions in LiYF 4 : Yb 3+ ,Ho 3+ as a consequence of energy transfer processes has been briefly discussed taking into account the UC emission kinetics. The highly stable intensity ratio of G% and R% combined with the efficient green UC color hints the potential application of LiYF 4 : Yb 3+ ,Ho 3+ in fluorescent labeling and color display.
研究领域:
材料科学
·
光学材料
·
发光学
·
光子学
·
纳米技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 20
·6588-6596
·
IF 6.4
Yingying Ma,Ting Wen,Ke Liu,Dequan Jiang,Mei-Huan Zhao,Chuanlong Lin,Yonggang Wang
Lanthanide ion (Ln3+)-codoped inorganic materials have been widely studied owing to their unique upconversion photoluminescence (UC PL) performance, which can be employed for promising applications in imaging, sensing, detection, and treatment. However, the forbidden transition of 4f inner shell and the nonradiative relaxation from the interaction of Ln3+ and a host lattice lead to low emission efficiency, limiting the industrial application. In this study, we report pressure-induced 1.2–2.6 times UC PL enhancement in the range of 10.0–25.0 GPa in Ln3+ (19%Yb3+/1%Er3+, 19%Yb3+/1%Ho3+, and 19.9%Yb3+/0.1%Tm3+)-codoped LiYF4 and LiLuF4. In situ X-ray diffraction pattern and Raman spectra indicated that both LiYF4 and LiLuF4 underwent structure transitions at a pressure around 10.0 GPa. Moreover, improved UC emissions were observed for the released sample in a completely amorphous state. The luminescence spectra of Eu3+-doped LiYF4 and LiLuF4 probes revealed that the phase transitions resulted in the reduction of Ln3+ site symmetry. Our research shows that pressure would be a powerful implement to design high-efficiency UC PL materials. Simultaneously, research on the “structure-luminescence” relationship can provide a deeper insight into the exploitation of potential UC PL materials and optimization of current luminescent materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）