Journal of Materials Chemistry C
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2017
·Vol. 5
·期 16
·4025-4033
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IF 5.256
Meihong Liu,Ming Gu,Yue Tian,Ping Huang,Lei Wang,Qiufeng Shi,Cai’e Cui
In this paper, an electrospinning technique was developed to prepare CaSc2O4:Yb3+/Er3+ one dimensional (1D) nanofibers for the first time. X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy and nitrogen adsorption/desorption were utilized to characterize the structure and morphology of the as-prepared nanofibers, indicating that single phase mesoporous CaSc2O4:Yb3+/Er3+ 1D nanofibers with a uniform size and morphology can be prepared via the electrospinning technique. The as-prepared CaSc2O4:Yb3+/Er3+ 1D nanofibers exhibit strong UCL under the excitation of 980 nm. The cross-relaxation (4S3/2 + 4I15/2 → 4I9/2 + 4I13/2) and energy back transfer (4S3/2 + 4F7/2 → 4I13/2 + 4F5/2) processes are found to be responsible for the concentration-dependent UCL properties, confirmed by rate equation modeling. Optical thermometry in the temperature range of 298–623 K was recorded using the FIR technique with two green UC emissions in the as-prepared CaSc2O4:Yb3+/Er3+ 1D nanofibers. The dependence of the sensitivity on the doping concentration of the Yb3+ and Er3+ ions is found. The above results suggest that the as-prepared CaSc2O4:Yb3+/Er3+ 1D nanofibers have great potential for the applications of drug delivery and optical thermometers.
研究领域:
材料科学
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光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2025
·
IF 10
Zhiyu Yang,Guangxiang Lu,Jiani Ma,Tao Yang,Guotao Xiang,Li Li,Xianju Zhou,Zhiguo Xia
The rapid advancements in solid-state lighting have underscored the need for efficient and thermally stable phosphors for light-emitting diode (LED) applications. Herein, a red phosphor CaSc 2 O 4 :Eu 2+ ( λ ex = 450 nm, λ em = 650 nm) is synthesized employing a non-stoichiometric strategy to increase photoluminescence quantum efficiency (PLQY). Spectroscopic and crystallographic properties analysis confirm that the red emission band originates from Eu 2+ ions occupying a single Ca 2+ site with significant nephelauxetic effects and crystal field splitting. Excessive CaCO 3 additions promote the reduction of Eu 3+ and an increase of trap concentration, enhancing the PLQY from 24% to 61% and improving the emission intensities at 150 °C from 8% to 41% of that at room temperature. Versatile LED light sources, including high-quality white LED, red LED in plant growth, and the integrated pixelated intelligent LED matrices have been explored for the practical applications. This study proposes an optimized strategy to enhance the efficiency and thermal stability of Eu 2+ -doped oxide-based red phosphors for multifunctional lighting applications.
研究领域:
材料科学
·
固体照明
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发光材料
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiaoshuai Zhang,Wen Xiong,Chengrun Liu,Zixuan Wang,Xiaoyan Yu,Xiaojie Li,Guodong Zhang,Panlai Li,Zhijun Wang
Exploring oxide-based deep red light-emitting phosphors is crucial for indoor plant lighting applications. In particular, designing Eu 2+ deep red emission in inorganic solids is challenging. In this paper, a cation substitution strategy was used to replace the Ca 2+ ions in the matrix with a certain concentration of Sr 2+ ions. A series of spectrally red-shifted Ca 1-x Sr x Sc 2 O 4 :Eu 2+ deep red phosphors were obtained under 460 nm light excitation. The substitution of Sr 2+ ions changes the local crystal field environment of Eu 2+ . The spectral shift from 656 nm to 702 nm was achieved by changing the centroid shift, the degree of polyhedral distortion and the lattice disorder. Combined with the need for practical applications, Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor and blue chip have been made into phosphor-converted light-emitting diodes for plant lighting, and the results of plant lighting experiments show that Ca 0.5 Sr 0.5 Sc 2 O 4 :0.01Eu 2+ phosphor has a certain application potential in plant lighting. In addition, this study will guide the exploration of new oxide-based deep red phosphors with Eu 2+ activation and for the realization of tunable emission through cation substitution.
研究领域:
材料科学
·
光学工程
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Guotao Xiang,Menglin Yang,Yongxi Ding,Hongxiu Wu,Lu Yao,Yongjie Wang,Xianju Zhou,Li Li,Li Ma,Xiaojun Wang,Jiahua Zhang
Accurate and real-time temperature detection is an urgent requirement in photothermal therapy (PTT). In this work, the CaSc 2 O 4 : Nd 3+ nanorod with an average length of 150 nm has been determined to be an outstanding optical thermometer based on the fluorescence intensity ratio ( FIR ) of thermally coupled Stark sublevels of Nd 3+ : 4 F 3/2 → 4 I 11/2 transition, of which the excitation and emission wavelength are located in the first and second biological window respectively, resulting in an 8 mm penetration depth in the biological tissues. The maximal absolute sensitivity and relative sensitivity as well as the minimal temperature resolution of the present sample is 0.0008 K -1 , 0.0018 K -1 and 0.19 K respectively, which is superior to the vast majority of the same type thermometers. Besides that, the nanorods show a 7 K temperature increment after 180 s’ 808 nm-laser radiation, revealing its photothermal conversion capacity thanks to the considerable nonradiative relaxation processes among the metastable energy levels of Nd 3+ . These results indicate that Nd 3+ single-doped CaSc 2 O 4 nanorods can be utilized as the optical thermometer in the deep-tissue PTT process for real-time thermometry along with the function of light-to-heat conversion.
研究领域:
生物医学工程
·
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
Fuhua Gao,Wasim Ullah Khan,Zhiyuan Cheng,Waheed Ullah Khan,Iqtidar Ahmad,Zhiqi Ye,Shenghong Yang,Yueli Zhang
Broadband near-infrared (NIR)-emitting materials have critical applications in biology, medical detection, and NIR night-vision. However, developing NIR phosphors with promising optical properties and excellent thermal stability is a great challenge for research. In this work, a novel NIR phosphor Cr 3+ and Yb 3+ doped CaSc 2 O 4 (CSO) is an evolving NIR emitting phosphor with decent optical properties , boosted emission intensity, and thermal stability that makes it a promising candidate with potential applications in NIR-LED and infrared night-vision. The implications of the fundamental electronic structure of CSO, including valence-band (VB) and conduction-band (CB) orbital character, are investigated. Under blue light excitation, CSO:Cr 3+ is settled with pure broadband NIR emissions (max = 920 nm, FWHM (full width at half maximum) = ∼310 nm) and good thermal stability . The occupation of two selectable lattice sites of Cr 3+ in CSO is discussed in detail. Furthermore, emission enhancements of samples are done by Cr 3+ and Yb 3+ codoping, effectively broadening FWHM to 351 nm and reducing thermal quenching. The energy transfer (ET) routes in CSO:Cr 3+ ,Yb 3+ are investigated based on PL lifetime and comprehensive kinetic ET model, revealing that the PL enhancements by Cr 3+ and Yb 3+ codoping mainly originate from the ET from Cr 3+ to Yb 3+ emitters with more efficient and thermally stable. Finally, an InGaN-LED device encapsulated using CSO:0.01Cr 3+ and CSO:0.01Cr 3+ ,0.01 Yb 3+ phosphor was fabricated. The fabricated NIR pc-LEDs are excellent candidates for NIR light sources in biological imaging and NIR night vision.
研究领域:
光学材料
·
生物医学成像
·
光电子学
·
无机发光材料
·
红外技术
·
固态照明
·
纳米生物技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）