JOURNAL OF FLUORINE CHEMISTRY
·
2024
·
IF 1.7
Shaohua Wu,Yu Yang,Shuang Wu,Yanhui Dong,Hao Cui,Daguang Li,Weiping Qin
NaLuF 4 :Yb 3+ ,Er 3+ micrometer prismatic crystals are potential materials for the preparation of optical waveguide devices. However, structural defects and OH – groups are generated inside and on their surfaces during growth processes. The structural defects and OH – groups lead to a large depletion of excitation energy and severely quench the downconversion luminescence of Er 3+ . In addition, the Yb 3+ /Er 3+ co-doping ratio significantly affects the downconversion luminescence of the microcrystals, which in turn affects the performance of the optical waveguide amplifiers based on the microcrystals. By adjusting the co-doping ratio of Yb 3+ and Er 3+ in the microcrystals and removing the defects in the crystals, their downconversion luminescence performance was significantly improved. The results showed that the downconversion luminescence under the excitation from a 980 nm laser reached the maximum value when the doping ratio of Yb 3+ and Er 3+ was 20:1.5. In addition, the OH – groups and structural defects in the micrometer crystals were significantly eliminated by ion-exchange and high-temperature annealing treatments, and the crystalline quality was significantly improved. After ion-exchange and high-temperature annealing treatments, the downconversion luminescence enhancement of NaLuF 4 :Yb 3+ ,Er 3+ microcrystals was 2.5 times that of the untreated samples.
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 Materials Chemistry C
·
2020
·Vol. 8
·期 35
·12189-12195
·
IF 7.059
Jun Zhou,Zhiguo Xia,Xiong Li,Xiangyan Yun,Jiayue Sun,Denghui Xu
The development of new luminescent materials with up-conversion (UC) emission falling within the first biological window (650–1000 nm) has drawn extensive attention in biological and medical fields. In this work, LiGaW2O8:Yb3+, Cr3+ UC phosphors were prepared for the first time, and the near-infrared (NIR) emission assigned to the 4T2–4A2 transition of Cr3+ was found to derive from the cooperative sensitization mechanism from Yb3+ to Cr3+. Moreover, the NIR emission of Cr3+ in the range of 700–900 nm can be greatly enhanced by the energy transfer (ET) process from Yb3+ sensitizers to Ho3+/Er3+ bridging centers and finally to Cr3+ emitting centers. Such success in LiGaW2O8:Yb3+, Ho3+/Er3+, Cr3+ provides a new perspective for designing superior UC phosphors with appropriate NIR emission, which could be used in biomedical fields.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 19
·6536-6548
·
IF 6.1
Wen Song,Kaiwen Zhang,Xiaoyi Dong,Liang Xu,Yongjin Li,Rui Hu,Zhaoyi Yin,Zhengwen Yang,Jianbei Qiu,Zhiguo Song
Realizing efficient long-wavelength near-infrared (NIR) emission of Cr3+ ions is still a challenge in spinel-based phosphors due to the limitations of strong crystal fields. Here, we propose three design strategies for obtaining weak crystal fields in spinel-type crystals, and report for the first time designed Cr-activated LiZnNbO4 (LZNO) crystals with unique weak crystal fields and application of an NIR enhancement strategy via heterotopic and heterovalent doping with trivalent rare earth ions. Under irradiation with 468 nm blue light, the phosphor presents ultra-wideband NIR emission centered at 800 nm covering the region of 650–1300 nm, which is attributed to the larger radius, high valence state of cations and the low symmetry of octahedral sites in the LZNO spinel. Supported by XRD refinement, XPS analysis, and density functional theory (DFT) calculation results, it was shown that when Er3+ ions are designedly doped with the Zn2+ sites of the spinel crystals, effective promotion of the valence state transformation of Cr4+ to Cr3+ in the LZNO:Cr3+ system is achieved by defect charge compensation, and this enhances the NIR emission by nearly 3 times. The results of this work not only enrich the material family of Cr3+-activated NIR emitting phosphors, but also offer a novel and simple method for improving the luminescence efficiency of Cr3+-activated phosphors.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 44
·15373-15385
·
IF 4.029
Daqin Chen,Min Xu,Mengfan Ma,Ping Huang
In upconversion nanocrystals where Er3+ acts as the activator, concentration quenching will easily occur when the content of Er3+ is high (generally >5mol%), and the Er3+ spatial distribution which is a key factor affecting the concentration quenching is an important issue that must be considered. Herein, we selected Yb:NaErF4 as a light-emitting layer and investigated its upconversion performance and temperature sensing behaviors in two kinds of core–shell nanoarchitectures. Yb3+ and Er3+ activators were distributed in a three-dimensional sphere and two-dimensional thin layer in Yb:NaErF4@Yb/Nd:NaYF4@NaGdF4 and NaGdF4@Yb:NaErF4@Yb/Nd:NaYF4@NaGdF4 core–shell nanocrystals, respectively. The difference in Er3+ spatial distribution in the core–shell structure resulted in significant modification of red-to-green ratios and decay behaviors upon excitation at 376 nm, 808 nm, 980 nm and 1532 nm, and the related mechanisms were systematically investigated. In addition, the spatial distribution of Er3+ was demonstrated to have no obvious effect on the transitions of Er3+ thermally coupled 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 and the relative sensitivity for temperature determination under 808 nm laser excitation.
研究领域:
材料科学
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纳米技术
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光学
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温度传感
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2012
·Vol. 5
·期 3
·1047-1053
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IF 5.914
Fuyao Liu,Qi Zhao,Hongpeng You,Zhenxin Wang
Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core–shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy groups on the particle surface easily react with amino residues of biomolecules. As an example, we reported on the interactions of Ricinus Communis Agglutinin (RCA 120) conjugated UCNP@SiO2 with HeLa cells. The excellent performance of the RCA 120 conjugated UCNP@SiO2 in cellular fluorescence imaging was demonstrated.
研究领域:
材料科学
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生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2018
·Vol. 124
·期 7
·1-11
·
IF 1.604
Yao Hanyu,Shen Honglie,Tang Quntao,Yang Nannan,Zhai Zihao,Li Yufang
NaY(WO 4 ) 2 : Er 3+ phosphors with various doping concentrations of [Er 3+ ]/([Er 3+ ]+[Y 3+ ]) (0, 5, 7, 10, 12, 15%) were successfully synthesized by high-temperature solid-state reaction. X-ray diffraction (XRD) measurement demonstrated the presence of tetragonal-phase NaY(WO 4 ) 2 phosphors and Fourier transform infrared (FT-IR) spectra showed a strong υ 3 stretching vibration mode of WO 4 2− , indicating the good crystallization of the phosphors. Well-crystallized phosphors showed a fine morphology with particle sizes of 0.8–10 µm by scanning electron microscope (SEM). Under excitation of 980 nm laser, Er 3+ -doped phosphors exhibited strong green emissions centered at 527 and 549 nm in addition to a 665 nm emission band in the red region, which were assigned to the 2 H 11/2 , 4 S 3/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 transitions, respectively. When the doping concentration was 10%, the intensities of green and red emissions reached their maximum values, stronger than that in 5% Er 3+ doped one by 13 times. The double-logarithm plot of the upconversion (UC) emission intensity to the excitation power for different Er 3+ doping concentrations depicted that at least two infrared photons were involved for every emitted green and red photon. UC emission intensity changing with temperature displayed different trends for the phosphors with different Er 3+ concentrations. The enhancement for green emission band centered on 549 nm could reach 50 times at 30 K in sample with 5% Er 3+ concentration. Under excitation by 355 nm laser, all the phosphors showed a strong PL emission band at 430 nm, while green luminescence band locating from 540 to 570 nm was only observed in 7, 10, and 12% Er 3+ -doped phosphors, which was ascribed to 4 S 3/2 → 4 I 15/2 transition.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 31
·26280-26287
·
IF 3.289
Binbin Li,Heng Liu,Chuanbin Sun,Zeeshan Ahmad,Zhaohui Ren,Xiang Li,Gaorong Han
The investigation of nano-carriers with controllable and trackable drug release kinetics has attracted worldwide attention for new tumor theranostic strategies with catabatic side effects. Herein, a range of monodispersed core–shell structured photoluminescent SrTiO3:Yb3+,Er3+@mSiO2 nanoparticles were designed and synthesized. The surfactant cetyltrimethylammonium bromide (CTAB) was used to vary the microstructure of the mesoporous SiO2 shell. The specific surface area and pore volume increase proportionally with the content of CTAB. Consequently, the doxorubicin (DOX) loading capacity increases, and the drug release kinetics possesses a sustained behaviour. More importantly, the DOX release kinetics was found to correspond well to the evolution of the up-conversion luminescence (UCL) phenomenon. More rapid drug release induces more rapid photoluminescence enhancement, and vice versa. This study has therefore been anticipated to suggest another promising multifunctional drug delivery platform for advanced chemotherapies.
研究领域:
纳米医学
·
药物递送系统
·
生物材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Hong Wang,Boyuan Zhang,Jiaqi Zhao,Mingming Xing,Ying Tian,Yao Fu
Thermally enhanced upconversion luminescence (UCL) materials have obvious advantages in the various fields of optical temperature sensing, anti-counterfeiting, and display. Here, we report a novel thermal enhancement UCL phosphor of Ca 2 Gd 8 Si 6 O 26 :Yb 3+ ,Er 3+ (CGSO:Yb 3+ ,Er 3+ ). Benefiting from the thermally enhanced phonon-assisted effect, anti-Stokes sideband excitation of Yb 3+ , energy transfer from Yb 3+ to Er 3+ , and thermal population from selective energy levels of Er 3+ are promoted with increasing temperature, which contributes to the thermal enhancement UCL of 4 F 7/2 → 4 I 15/2 , 2 H 11/2 → 4 I 15/2 , and 4 I 9/2 → 4 I 15/2 radiation transitions of Er 3+ ions. In addition, the rarely thermal enhancement of near infrared emission at 870 nm observed may be attributed to the Yb 3+ -induced effect. Furthermore, thermal quenching occurs for 4 S 3/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 transitions due to thermally enhanced multiphonon relaxation and thermal population. The combination of thermal enhancement and thermal quenching effect, the ratiometric optical thermometer is constructed in the wide temperature range 303–723 K by leveraging of the thermally coupled energy levels 2 H 11/2 and 4 S 3/2 of Er 3+ . This optical thermometer shows excellent temperature measurement performances with a maximum relative sensitivity of 1.1 × 10 −2 K −1 at 303 K and high repeatability of 99 %. These findings indicate that CGSO:Yb 3+ ,Er 3+ phosphors with thermally enhanced UCL have great potential application for temperature sensing.
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
·
2022
·
IF 4.171
Ningning Zhu,Youqiang Huang,Lili Lang,Xiaolei Yang,Lihui Huang,Gongxun Bai,Shiqing Xu
Lanthanide-doped oxide materials generally require high sintering temperatures for optical applications such as temperature sensing and anti-counterfeiting. In this work, the highly crystalline 1%Pr 3+ /1%Er 3+ co-doped Bi 2 Mo 2 O 9 phosphor is reported with a low sintering temperature of 923 K. Pr 3+ in the Bi 2 Mo 2 O 9 host has a narrow emission band of 3 P 0 – 3 H 6 transition at 624 nm due to the suppressed broadening of electronic transitions in the homogeneous crystal field . Multimode temperature sensing is realized based on the upconversion and downshifting emissions as well as the luminescence lifetimes of the as-prepared phosphor. The temperature sensing based on the downshifting emission bands of this phosphor at 530 and 624 nm achieves the maximum absolute and relative sensitivities of 0.693 K −1 at 568 K and 1.88% K −1 at 483 K, respectively. For anti-counterfeiting applications, this phosphor can display bright yellow fluorescence at the liquid nitrogen cooling temperature, rather than white or pale colors. The white-color emission of this phosphor excited by 254 nm can also be used for lighting. The lanthanide-doped Bi 2 Mo 2 O 9 can achieve favorable luminescence performance at much lower sintering temperature than most oxide phosphors, and is not only stable but also has the potential for in-situ sintering on materials that are not resistant to high temperature.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2018
·Vol. 18
·期 12
·8258-8268
·
IF 1.354
Tong Chao,Xie Shaowen,Zhou Hu,Li Na,Gong Liang,Jian Jian,Zhang Changfan,Xu Lijian,Xu Jianxiong
In this study, well-defined PAA-coated NaYF4:Yb3+, Er3+ nanophosphors were synthesized via a poly(acrylic acid) (PAA) mediated hydrothermal process. The rational control of initial reaction conditions, such as hydrothermal temperature, pH value of precursor-solution,
added amount of PAA, and molecular weight of PAA ligand, resulted in upconversion of NaYF4:Yb3+, Er3+ phosphors with varying crystal phases (α and β) and morphologies (e.g., nanosphere, submicrorod, microrod, microtube, and microprism).
By assessing the upconversion luminescent properties of the synthesized NaYF4:Yb3+, Er3+ phosphors upon excitation by 980 nm infrared light, it was demonstrated that the β-phase NaYF4:Yb3+, Er3+ phosphors generally
presented stronger upconversion luminescent than α-phase NaYF4:Yb3+, Er3+ phosphors and orthorhombic phase of YF3:Yb3+, Er3+ sample. Additionally, the β-phase NaYF4:Yb3+, Er3+
phosphors with hollow microtube morphology presented higher upconversion luminescent intensity than phosphors of other morphologies. This may be due to microtubes having larger surface area (inner and outer surfaces), which promoted the absorption efficiency under similar excitation conditions,
therefore generating higher luminescent intensity. Findings form this study suggest for precisely controlled growth of other complex rare earth fluoride compounds and provide a reference for exploration of component-, phase- and morphology-dependent upconversion luminescence properties.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 48
·30006-30019
·
IF 3.361
Zhaoliang Yan,Qingfeng Guo,Libing Liao,Pengfei Shuai,Feifei Huang,Lefu Mei
In this paper, a novel cryolite-type up-conversion luminescent material K3Sc0.5Lu0.5F6: Er3+, Yb3+ with controllable crystal form was synthesized by a high temperature solid state method. K3Sc0.5Lu0.5F6: Er3+, Yb3+ can crystallize in monoclinic or cubic form at different temperatures. The composition, structure and up-conversion luminescence (UCL) properties of K3Sc0.5Lu0.5F6: Er3+, Yb3+ samples with different crystal form were investigated in detail. It is impressive that both monoclinic and cubic forms of K3Sc0.5Lu0.5F6: Er3+, Yb3+ show green emission (2H11/2/4S3/2→4I15/2). The luminescence intensity of cubic K3Sc0.5Lu0.5F6 is much higher than that of the monoclinic form, and the reasons are also discussed in detail. The results show that the luminescence intensity of up-conversion materials can be effectively tuned by controlling the crystal form. According to the power dependent UCL intensity, the UCL mechanism and electronic transition process were discussed. In addition, the fluorescence decay curves were characterized and the thermal coupling levels (TCLs) of Er3+ (2H11/2/4S3/2 → 4I15/2) in the range of 304–574 k were used to study the optical temperature sensing characteristics. All the results show that K3Sc0.5Lu0.5F6: Er3+, Yb3+ can be used in electronic components and have potential application value in temperature sensing fields.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 8
·8254-8270
·
IF 1.798
Xi Junhua,Ding Mingye,Dai Jianbin,Pan Yajing,Chen Daqin,Ji Zhenguo
In this paper, Yb 3+ /Er 3+ co-doped hexagonal NaYF 4 have been successfully synthesized by solvothermal, thermal decomposition, hydrothermal and molten salt method, respectively. The crystal structures, particle morphologies, sizes and corresponding upconversion luminescent properties of β-NaYF 4 :Yb 3+ /Er 3+ nano/microcrystals are systemically studied. It is interesting to observed that the temperature-dependent UC luminescent properties of β-NaYF 4 :20 %Yb 3+ , 2 %Er 3+ samples are strongly related to their synthesis methods. Comparison of the upconversion luminescence and thermal sensitivity between the β-NaYF 4 :Yb 3+ /Er 3+ samples reveals that β-NaYF 4 :Yb 3+ /Er 3+ sub-microplates synthesized by thermal decomposition method have much stronger green emission intensity, better luminescent thermal stability and higher temperature sensitivity. This findings are relevant to the application of β-NaYF 4 :Yb 3+ /Er 3+ in optical temperature sensors and to the further understanding of the UC luminescent mechanism.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
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