CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Yurun Ma,Pingsun Qiu,Dongfang Xu,Jinrong Lin,Yanxue Tang,Feifei Wang,Xiyun He,Ziyao Zhou,Nianxiang Sun,Xinyang Zhang,Yi Zhou,Dazhi Sun
NaYF 4 nanorods , and nanoparticles co-doping with Yb 3+ and Er 3+ were synthesized by hydrothermal method . The effects of doped ion concentration, the ratio of NaF to Ln (NO 3 ) 3 and the reactant content on the luminescence properties of the nanocrystals were investigated in detail in this paper. The materials were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and photoluminescence (PL) spectra. The results indicate that a doping level of 20 mol% Yb 3+ and 2 mol% Er 3+ gives the strongest luminescence, and concentration quenching occurs, when Er 3+ concentration exceeds 5 mol%. Besides, the reaction of temperature and time were also investigated and the results showed that they have an effect on the shape, size, and crystal phase purity of the nanoparticles . The luminescence mechanism for the NaYF 4 :Yb 3+ , Er 3+ was discussed. Under 980 nm excitation, the Er 3+ ions doped into NaYF 4 samples emitted green fluorescence 520 nm ( 4 H 11/2 → 4 H 15/2 ), 550 nm ( 4 S 3/2 → 4 H 15/2 ) and red fluorescence 650 nm( 4 F 9/2 → 4 I 15/2 ), which were modified and enhanced by Yb 3+ ions.
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DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Jingxin Ding,Huazhen Liao,Libin Pang,Deping Wang,Song Ye
Rare earth ions doped core-shell thermometers exhibit improved up-conversion emission behaviors, while the thermal sensitivity is not higher than the corresponding core-only structured luminescent thermometers via the thermal coupled levels based luminescence intensity ratio (LIR) technique. In this work, the core-only β-NaYF 4 : 16Yb 3+ , 4Er 3+ (C–4Er) up-conversion nanoparticles (UCNPs) and the sub 25 nm core-shell β-NaYF 4 : 16Yb 3+ , 4Er 3+ @0.5NaGdF 4 (CS–4Er@0.5Gd) and β-NaYF 4 : 16Yb 3+ , 4Er 3+ @1NaGdF 4 (CS–4Er@1Gd) UCNPs have been successfully synthesized by seed-mediated growth methods for temperature detection. The spectral study indicated that the up-conversion luminescence intensity of CS-4Er@0.5Gd and CS-4Er@1Gd was obviously enhanced compared withC-4Er. Luminescence intensity ratio originated from thermally coupled Stark sublevels (Stark-LIR) of Er 3+ ( 2 H 11/2 (1)(2), 4 S 3/2 (1)(2)(3)) of CS-4Er@0.5Gd and CS-4Er@1Gd has been firstly applied to calculated the relative thermal sensitivity (S R ) of core-shell UCNPs. As a result, S R of CS-4Er@1Gd is the largest among the considered UCNPs, and is increased from 10.95 × 10 −3 /K (LIR) to 17.80 × 10 −3 /K (Stark-LIR), indicating that with Stark-LIR techniques, the nano core-shell sensors behave a larger S R than core-only structured thermometers. This work may lead to an appropriate approach to improve the temperature sensitivity of core-shell thermometers for temperature sensing.
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DOI
高影响因子
EPL
·
2011
·Vol. 96
·期 1
·18001
·
IF 2.753
A. H. Li,Q. Lü
The knowledge of the power density for which luminescence intensity reversal begins with power increase is of valuable importance for practical applications. Under 980 nm CW diode laser excitation, the maximum upconversion luminescence intensities were obtained at 4800, 5700, and 7100 W/cm2 for 2H9/2→4I15/2, 2H11/2&4S3/2→4I15/2, and 4F9/2→4I15/2 transition luminescences, respectively, in compact powder composed by cubic-phase NaYF4:
Yb3+,Er3+ nanoparticles with a most probable diameter of ∼46 nm. It was revealed experimentally that the reversal power density decreases as luminescent level rises. Excitation increase combined with radiative quantum efficiency decrease as power increase can reproduce this "n"-shape power dependence relationship.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 2
·1395-1403
·
IF 2.599
Yi Mengji,Liu Yuefeng,Gao Huiping,Huang Zhangyu,Liang Jiwei,Mao Yanli
In this manuscript, Ni 2+ ions-doped NaYF 4 :Yb 3+ /Er 3+ nanoparticles have been synthesized via a modified hydrothermal method. The upconversion luminescence intensities of the green (G) and red (R) emission of NaYF 4 :Yb 3+ /Er 3+ co-doped with 20 mol% Ni 2+ ions are the strongest which increase 32.84 and 20.99 times than that without doping Ni 2+ , respectively. In addition, the R/G ratio decreases with the concentration of Ni 2+ increasing from 0 to 40 mol%. The underlying reason for luminescence enhanced and the R/G ratio decreased by Ni 2+ doping is explored by a series of controlled experiments, and the mechanism based on the crystal field asymmetry, different substitution by Ni 2+ , the energy transition of Er 3+ is studied in detail. The study indicates that the misshapen crystal field plays an important role in enhancement fluorescence emission, and several factors affect the R/G ratio including the crystal field, the substitution site and the energy transition. Our result may play a certain function for study and design of high-performance upconversion materials.
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高影响因子
Optical Materials Express
·
2016
·Vol. 6
·期 4
·1056-1064
·
IF 2.657
Lili Huo,Jiajia Zhou,Ruozhen Wu,Junfei Ren,Shengjun Zhang,Junjie Zhang,Shiqing Xu
Hexagonal-phase NaYF4: Yb3+, Er3+ nanoparticles (NPs) have been widely used as the most efficient NIR-to-visible upconversion (UC) luminescent and probe in bioscience. Here, we exploited not only the function of dual-mode emission of β-NaYF4: Yb3+, Er3+ NPs in the near infrared (NIR) and visible regions with single wavelength excitation at 980 nm, but also the function of physiological temperature sensing with the luminescence of Er3+ in the visible region. The structural and optical characteristics of β-NaYF4: Yb3+, Er3+ NPs were obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM),and fluorescence spectral measurements, respectively; the mechanism for the energy transfer has been suggested with emphasis on the optimized Er/Yb concentration for most efficient UC. Due to the UC and down-shifting NIR properties, we achieved the dual-functional nanoparticles with potential application in physiological range temperature sensing and bioimaging simultaneously.
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DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Tie Cong,Yadan Ding,Xueqing Yu,Yue Mu,Xia Hong,Yichun Liu
A series of Cd 2+ doped hexagonal-phase NaYF 4 : Yb 3+ , Er 3+ upconversion nanoparticles (UCNPs) were synthesized via solvothermal method, and the effect of Cd 2+ on the upconversion luminescence (UCL) properties was investigated in detail. It was found that the introduction of Cd 2+ could enhance the UCL intensities of NaYF 4 : Yb 3+ , Er 3+ UCNPs significantly. The maximum enhancement occurred when the doping concentration of Cd 2+ was 7 mol%. Compared with the UCNPs without Cd 2+ doping, the total integral emission intensity was enhanced by ∼38 times. It was related to the unit cell expansion and the generated F − vacancies, which could decrease the crystal symmetry around the Er 3+ ions. The results shall facilitate the improvement of UCL properties and the potential applications of UCNPs in lighting, solar cells, optics encoding and so on.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Lihua He,Xiao Zou,Xiang He,Fengying Lei,Na Jiang,Qiaoji Zheng,Chenggang Xu,Yongfu Liu,Dunmin Lin
A variety of NaYF4:Yb/Er upconversion materials were successfully synthesized via a facile hydrothermal method by altering the volume ratios (0:1, 1:1, 2:1, 3:1, 4:1, 5:1) of ethanol to water and various alcohols (methanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, polyethylene glycol, and phemethylol), and the grain size and luminescence of the materials were effectively tailored. The addition of alcohol effectively reduces the grain size of the materials and simultaneously leads to the surprising enhancement of the UC emission. The increase in the volume ratio of EtOH/H2O causes the transformation of the crystal structure of the materials from hexagonal to cubic phase. The particle size of the material with the EtOH/H2O of 2:1 is almost 1000 times smaller than that of the material without EtOH, and the strongest luminescence is observed at the EtOH/H2O of 2:1. The type of alcohol in the solvent exhibits a significant influence on the luminescent properties of the materials. The NaYF4:Yb/Er nanocrystals obtained using different alcohols as solvent possess much a smaller grain size and stronger upconversion luminescence than that using water as solvent, and the NaYF4:Yb/Er materials with n-propyl alcohol exhibit the strongest luminescence intensity. The mechanism of the reduction of grain size and enhancement in the luminescence of the NaYF4:Yb3+, Er3+ upconversion materials has been proposed. This study may suggest a simple method to significantly reduce the grain size and improve the upconversion luminescence properties of NaYF4-based fluorescence material.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 24
·10435-10452
·
IF 3.553
Zhang Kailian,Zhou Man,Yu Changlin,Yang Kai,Li Xiaoxiao,Yang Shi,Guan Jie,Dai Wenxin,Huang Weiya
Wide spectral responsive photocatalysts are of great importance for making full use of solar energy and broad application in highly efficient photocatalytic wastewater treatment, production of H 2 O 2 , etc. Thereinto, it is significative to open an appropriate way to extend the absorption to the NIR region, in which it accounts for ~ 49% in the solar spectrum. In this work, we synthesized successfully the new-style NaYF 4 :Yb 3+ , Er 3+ /Ag 2 CrO 4 photocatalyst via the hydrothermal and followed precipitation method, and it exhibited the more excellent photocatalytic performances than Ag 2 CrO 4 for the photocatalytic H 2 O 2 production and disposals of pollutants, such as methyl orange (MO), methylene blue (MB), rhodamine B (RhB) and tetracycline (TCs). The morphological, structural and optical behavior were investigated by XRD, SEM, N 2 adsorption/desorption, TEM, XPS, UV–Vis DRS, UC luminescence and photoelectrochemical experiments. It revealed that NaYF 4 :Yb 3+ , Er 3+ /Ag 2 CrO 4 photocatalyst presented stronger absorptive capacity in the visible–NIR region by the benign fluorescence resonance energy transfer (NaYF 4 :Yb 3+ , Er 3+ can convert near-infrared light to visible light via upconversion process), and showed more efficient charge transfer and separation than that of pure Ag 2 CrO 4 . The primary reactive species of ·O 2 − and h + by the trapping experiments played a considerable important role in the photocatalytic process. A promising potent system was suggested for the highly efficient utilization of sunlight in the enhancement of photocatalytic activities.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Qiying Huang,Weihao Ye,Xianfu Jiao,Linliang Yu,Yingliang Liu,Xiaotang Liu
Here, we show a core-shell nanostructure which effectively improves NIR-to-visible upconversion quantum efficiency and luminescence intensity. The NaYF 4 :Yb 3+ , Er 3+ /mNaYF 4 (m = 0, 1, 2, 3, 4, 5) core-shell nanoparticles are synthesized using a thermal decomposition method. The structure, morphology and fluorescence spectrum of the nanoparticles are confirmed by XRD , TEM and fluorometer. The average size of the as-prepared NaYF 4 :Yb 3+ , Er 3+ /mNaYF 4 cores is about 8 nm while the thickness of the shells varies from 0.5 nm to 8 nm for different m values. With 980 nm excitation, the nanoparticles exhibit distinct emission peaks at 522 nm, 544 nm and 650 nm. It is noticed that an increasing shell thickness enhances their fluorescence intensity . The fluorescence lifetime and quantum yield of obtained multilayer NaYF 4 :Yb 3+ , Er 3+ /mNaYF 4 nanoparticles are also discussed.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Xiadiyan Refuhati,Xiaojun Guo,Yanzhen Xiao,Jinze Li,Sihan Wang,Wangze Li,Yifan Zhu,Lei Yan,Zhengkun Fu,Zhenglong Zhang,Hairong Zheng
Integrating upconversion nanoparticles (UCNPs) with nanodiamonds (NDs) constitutes a promising platform for the development of multifunctional systems in photonics and sensing. However, achieving strong interfacial coupling while preserving the unique properties of both components remains a significant challenge. In this study, we introduce a novel composite material formed by covalently conjugating NaYF 4 : Yb 3 + /Er 3 + UCNPs with NDs. Subsequent controlled near-infrared (NIR) laser processing generates a high-phonon-energy, sp 2 -hybridized carbon interface on the NDs while preserving the intrinsic nitrogen vacancy (NV) centers. This leads to the selective quenching of the Er 3 + red emission ( 4 F 9 / 2 → 4 I 15 / 2 ), resulting in green-dominant luminescence and a shortened fluorescence lifetime. The laser-processed composite demonstrates enhanced temperature-sensing performance by utilizing non-thermally coupled levels (NTCLs) of Er 3 + , specifically the 2 H 11 / 2 and 4 F 9 / 2 levels. The composite achieves a maximum relative sensitivity of 4.89% K −1 over a temperature range of 173–523 K. This work establishes laser processing as a powerful strategy for tailoring interfacial properties in hybrid nanomaterials, thereby opening new possibilities for high-performance temperature sensors and multifunctional platforms in quantum sensing and bioimaging.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2014
·
IF 2.726
Chuanying Wang,Xianhua Cheng
Using a facile hydrothermal method , hexagonal β-NaYF 4 :Yb 3+ 20 mol%, Er 3+ 1 mol% crystals with predictable size and morphology were synthesized and the upconversion (UC) luminescence properties were investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterize the samples. The results indicated that the size and morphology of the crystals can be precisely controlled by tuning the pH values of the initial reaction solution and the molar ratio of NaNO 3 to RE 3+ (RE = Y + Yb + Er), and the mechanism was proposed. The UC luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ crystals were found to strongly depend on the crystal morphologies and sizes. The peak area ratio of green to red (R/G) increased from 0.29 to 1.03 with pH values increasing from 3 to 10, and increased from 1.03 to 1.26 with the increase of molar ratio of NaNO 3 to RE 3+ from 0 to 90. The emission colors were tuned from pure green to orange yellow. This study provides a facile way to synthesize β-NaYF 4 :Yb 3+ /Er 3+ crystals with predictable morphology and size, and tunable luminescence properties, which can be applicable for other rare earth fluoride compounds.
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高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2014
·Vol. 14
·期 5
·3711-3717
·
IF 1.339
Liu Yunxia,Liu Baocang,Xu Guangran,Wang Qin,Hu Wenting,Liu Yang,Jia Wenjing,Liu Yongxin,Zhang Jun
Upconversion luminescent NaYF4:Yb3+, Er3+/Tm3+ nanocrystals were successfully synthesized via a facile and one-pot solvothermal method using oleic acid/oleylamine (OA/OM) as surfactants. The effects of synthetic parameters including rare earth
ion doping concentrations and temperatures on the crystal phase structure, size and shape of NaYF4:Yb3+, Er3+/Tm3+ nanocrystals were systematically investigated. By modulating the synthetic parameters, the shape of NaYF4:Yb3+,
Er3+/Tm3+ nanocrystals were controlled in forms of nanorods and nanowires. The reaction temperature has large effects on the phase structure of NaYF4:Yb3+, Er3+/Tm3+ nanorods, exhibiting a phase transformation from cubic phase
(α-) in low temperatures to hexagonal phase (β-) in high temperatures. Moreover, the upconversion luminescence of NaYF4:Yb3+, Er3+/Tm3+ nanocrystals was found to be dependent on the rare earth ion doping concentrations and
temperatures.
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PubMed
高影响因子
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