Scientific Reports
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2019
·Vol. 9
·期 1
·1-9
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IF 4.011
Liu Ning,Mei Lefu,Liao Libing,Fu Jie,Yang Dan
What ideal w-LED phosphors always aim to do is to achieve a single phase near-sunlight emission phosphor simultaneously with both high luminescence efficiency and high thermal stability at operation temperature. And It is well known that apatite compound phosphors are one of the most promising optical materials to realize those above because of their unique structure enhanced luminescence properties and thermal stability. Here, we synthesized a co-doped single phase apatite phosphors Ca 2 La 8 (SiO 4 ) 6 O 2 :Dy 3+ /Sm 3+ (CLSO:Dy 3+ /Sm 3+ ) for white light emission, which was provided with excellent thermal stability and of which luminescence intensity at 150 °C still was 92 percentage of that at room temperature. Moreover, X-ray diffraction technique, Fourier transform infrared spectroscopy, scanning electron microscope were employed to characterization of phase structure and morphology, and consequently pure apatite structure and gravel-like morphology of phosphors were proved. Analysis of photoluminescence spectra indicated that concentration quenching effect exist in single-doped CLSO:Dy 3+ phosphors owing to dipole-dipole interaction between Dy 3+ ions. It is revealed that maybe exist Dy 3+ ↔ Sm 3+ bilateral non-radiative energy transfer processes in Dy 3+ /Sm 3+ co-doped CLSO system by PL spectra and decay curves. And variation of Sm 3+ ion concentration can control color emission, namely CIE chromaticity coordinates and correlated color temperature, finally to achieve white light emission (0.309,0.309) with CCT 6848 K, able to be a potential candidate for commercial lighting applications.
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高影响因子
JOURNAL OF LUMINESCENCE
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2024
·
IF 3.3
Chenglong Xia,Jiahui Yang,Bingyang Zeng,Chunmiao Cui,Haoyuan Weng,Yue Guo,Xiaoguang Liu,Ling Li
This study successfully synthesized Na 5 Y(WO 4 ) 4 doped with Sm³⁺, Pr³⁺, and Tb³⁺ using a high-temperature solid-state method. Photoluminescence spectra revealed that Na 5 Y(WO 4 ) 4 :Sm³⁺ phosphors emits a strong red glow at 646 nm under the excitation of 405 nm, and has an extremely high quantum yield, suggesting their suitability for plant growth LED lighting applications. In contrast, Na 5 Y(WO 4 ) 4 :Pr³⁺ phosphors displayed a lower efficiency but still aligned well with the red-wavelength absorption spectra of plants. Additionally, Na 5 Y(WO 4 ) 4 :Tb³⁺ phosphors demonstrated strong green emission under UV light, indicating potential applications in fingerprint detection. The Site Occupancy Theory (SOT) was utilized to explain the preferential occupation of dopant ions, showing that Sm³⁺ and Tb³⁺ preferred Y1 sites, whereas Pr³⁺ favored Na2 sites.
研究领域:
材料科学
·
光学
·
农业科学
·
法医学
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Small
·
2020
·Vol. 16
·期 25
·2001551
·
IF 11.459
Shahid Ullah Khan,Waheed Ullah Khan,Wasim Ullah Khan,Dilfaraz Khan,Sumbul Saeed,Syed Badshah,Muhammad Ikram,Tawfik A. Saleh
The luminous efficiency of inorganic white light-emitting diodes, to be used by the next generation as light initiators, is continuously progressing and is an emerging interest for researchers. However, low color-rendering index (Ra), high correlated color temperature (CCT), and poor stability limit its wider application. Herein, it is reported that Sm 3+ - and Eu 3+ -doped calcium scandate (CaSc 2 O 4 (CSO)) are an emerging deep-red-emitting material with promising light absorption, enhanced emission properties, and excellent thermal stability that make it a promising candidate with potential applications in emission display, solid-state white lighting, and the device performance of perovskite solar cells (PSCs). The average crystal structures of Sm 3+ -doped CSO are studied by synchrotron X-ray data that correspond to an extremely rigid host structure. Samarium ion is incorporated as a sensitizer that enhances the emission intensity up to 30%, with a high color purity of 88.9% with a 6% increment. The impacts of hosting the sensitizer are studied by quantifying the lifetime curves. The CaSc 2 O 4 :0.15Eu 3+ ,0.03Sm 3+ phosphor offers significant resistance to thermal quenching. The incorporation of lanthanide ion-doped phosphors CSOE into PSCs is investigated along with their potential applications. The CSOE-coated PSCs devices exhibit a high current density and a high power conversion efficiency (15.96%) when compared to the uncoated control devices.
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ACS Applied Materials & Interfaces
·
2013
·
IF 5.008
Lining Sun,Yannan Qiu,Tao Liu,Jin Z. Zhang,Song Dang,Jing Feng,Zhijuan Wang,Hongjie Zhang,Liyi Shi
A series of ternary lanthanide β-diketonate derivatives covalently bonded to xerogels (named as Ln-DP-xerogel, Ln = Sm, Yb, Nd, Er, Pr, Ho) by doubly functionalized alkoxysilane (dbm-Si) was synthesized in situ via a sol-gel process. The properties of these xerogel materials were investigated by Fourier-transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and fluorescence spectroscopy. The data and analyses suggest that the lanthanide derivatives have been covalently grafted to the corresponding xerogels successfully. Of importance here is that, after excitation with visible light (400–410 nm), the xerogels all show characteristic visible (Sm3+) as well as near-infrared (NIR; Sm3+, Yb3+, Nd3+, Er3+, Pr3+, Ho3+) luminescence of the corresponding Ln3+ ions, which is attributed to the energy transfer from the ligands to the Ln3+ ions via an antenna effect. Exciting with visible light is advantageous over UV excitation. Furthermore, to the best of our knowledge, it is the first observation of NIR luminescence with visible light excitation from xerogels covalently bonded with the Sm3+, Pr3+, and Ho3+ derivatives. Compared to lanthanide complexes (Ln = Er, Nd, Yb) functionalized periodic mesoporous organosilica (PMO) materials that exhibit similar optical properties reported in our previous work, the Ln-DP-xerogel (Ln = Sm, Yb, Nd, Er, Pr, Ho) in this case offer advantages in terms of ease of synthesis and handling and potentially low cost for emerging technological applications. Development of near-infrared luminescence of the lanthanide materials with visible light excitation is of strong interest to emerging applications such as chemosensors, laser systems, and optical amplifiers.
研究领域:
材料科学
·
光学
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ACS Applied Electronic Materials
·
2021
·
IF 3.314
Wasim Ullah Khan,Waheed Ullah Khan,Hao Lin,Zhiyuan Cheng,Muhammad Wajid Shah,Yueli Zhang
The important objectives that have been usually ignored regarding the development of white-light-emitting diodes (WLEDs) are the stability, red spectral region deficiency, high correlated color temperature (CCT), and low color-rending index (CRI) that restrict their effectiveness for practical implementation. Herein, we used systematic screening of multi-doped Ca3LuAl3B4O15 (CLAB) samples to evaluate singly and doubly doped down-converting phosphors that exhibit tuning emission and spectrally pure red emission with high color purity at the ultraviolet light excitation and enhanced thermal stability. A comprehensive kinetic model of the energy transfer (ET) mechanism was developed and validated with the extensive experimental data set. Applying this model, we elucidated the ET mechanisms producing a spectrally pure red emission via dipole–dipole interaction. Moreover, CL0.8AB:0.1Ce3+,0.1Sm3+ revealed excellent chemical stability under 80% relative humidity and 80 °C severe thermal conditions. Interestingly, when the temperature was increased from 300 to 425 K, the intensity of Ce3+ emission was reduced with the production of certain Sm3+ emissions via ET. The WLED containing CL0.8AB:0.1Ce3+,0.1Sm3+ and Sr2SiO4:Eu2+ demonstrated warm white light with a high CRI of 89.8–85.7 and a low CCT equal to 4393–4482 K. These parameters are comparable to that of the commercially available YAG:Ce3+ phosphor combined with a blue LED chip (CCT ≈ 7746 K and CRI ≈ 75).
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