CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xiuna Tian,Hongjian Dou,Lingyuan Wu
Based on the luminescence of Bi 3+ , novel temperature sensing materials YNbO 4 :Bi 3+ and YNbO 4 :Bi 3+ /Sm 3+ were successfully synthesized by solid state reaction. The XRD patterns show that the synthesized materials have a pure phase of YNbO 4 . With the excitation of 314 nm, the YNbO 4 :Bi 3+ material shows intense temperature-dependent luminescence in the range of 303 K–463 K. Based on the temperature-dependent luminescence of Bi 3+ in YNbO 4 , the maximum relative sensitivity can be obtained at 434 K (1.72% K −1 ). Under the excitation of 406 nm, the YNbO 4 :Sm 3+ material shows the characteristic emission peaks of Sm 3+ . In YNbO 4 :Bi 3+ /Sm 3+ phosphor, the large overlap between the emission spectra of Bi 3+ and the excitation spectra of Sm 3+ leads to a significant energy transfer from Bi 3+ to Sm 3+ . With the excitation of 314 nm, the emission spectra of YNbO 4 :Bi 3+ /Sm 3+ material shows the characteristic peaks of Bi 3+ and Sm 3+ . The luminescence intensity ratio of Sm 3+ and Bi 3+ shows a strong temperature dependence. Based on the luminescence intensity ratio, a large relative sensitivity is obtained at 455 K (1.57% K −1 ).
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 5
·728
·
IF 5.719
Wei Zhang,Yang Zang,Yanli Lu,Jinghui Han,Qingyun Xiong,Jinping Xiong
In this study. a novel near-infrared fluorescent-driven contrast agent (Ag-doped NaYF4:Yb3+/Er3+@NaYF4:Nd3+@NaGdF4) was synthesized using a coprecipitation-hydrothermal-solvothermal-solvothermal (CHSS) method. The results shows that hexagonal NaYF4:Yb3+/Er3+with a diameter of 300 nm was successfully synthesized by the CHSS method. The new contrast agent was characterized using scanning electron microscopy, fluorescence spectrometry, transmission electron microscopy, energy-dispersive spectrometry and ultraviolet-visible light diffuse reflectance absorption spectroscopy. Even at low concentrations (0.2 M), this proposed contrast agent can be excited by near-infrared light with a wavelength of 980 nm and emits a dazzling green light with a wavelength of 540 nm, and the comparison of the luminescence intensity proves that doping with silver increases the luminescence intensity of the upconverted nanomaterial by nearly 13 times based on the calculated quantum yield. TEM images show the successful preparation of silver nanoparticles with a diameter of 30 nm, and the energy spectrum shows the successful doping of silver nanoparticles and the successful preparation of the core-shell structure of NaYF4:Yb3+/Er3+@NaYF4:Nd3+@NaGdF4. Furthermore, the mechanism of the increased luminous intensity has been studied using simulation calculations. Finally, cytotoxicity tests were used to test material which was modified by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG2K), and the biocompatibility was significantly improved, meeting the standard for biological applications.Keywords:upconversion;near-infrared;intensity;in vivo imaging
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Coatings
·
2021
·Vol. 11
·期 8
·953
·
IF 2.881
Hongyu Chen,Yunfei Wang,Jianing Wang,Wenyan Liu
Nowadays, the excellent performance of metal halide perovskite quantum dots (PQDs) has been demonstrated, but the stability is still a perplexing issue. In this paper, the CsPbBr3QDs were assembled into SBA-15 for the first time. The thermal stability and photoluminescence (PL) intensity of SBA-15@CsPbBr3QDs were improved. The PL spectra of pure CsPbBr3QDs have red-shift (~6 nm) with the increasing temperature. However, that of SBA-15@CsPbBr3QDs have almost no red-shift. The PL intensity of SBA-15@CsPbBr3QDs decreased slightly after heating and cooling for several times. By comparison, the PL intensity of pure CsPbBr3QDs decreased more significantly. The experimental results showed that SBA-15 played a significant role in improving the thermal stability of PQDs, which will have an excellent potential for the application of PQDs in the future.Keywords:CsPbBr3QDs;SBA-15;thermal stability
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 22
·7666-7673
·
IF 7.367
Xin Su,Xiaoqian Sun,Suli Wu,Shufen Zhang
Photonic crystals (PCs) have long been considered effective for tuning upconversion luminescence due to their photonic band gap (PBG) and the redistribution of density of optical states (DOS). Although the emission intensity can be changed obviously by the PC effect, rarely an obvious lifetime change consistent with theory is observed due to the low refractive index of PS or SiO2 spheres in the commonly used PCs. Herein, CdS/NaYF4:Yb3+,Er3+ composite PCs with a high refractive index contrast are fabricated in one step with upconversion nanoparticles filled inside CdS PCs. When the upconversion emission peak lies at the edge of the PBGs of the composite PCs, a dramatic decrease in lifetime by 28% and 41% is observed for the green and red emissions, respectively. At the same time, obvious emission intensity enhancements are also observed. In contrast, PS PCs with a low refractive index contrast show a slight effect on the lifetime of upconversion luminescence with their emission peak at the edge of the PBGs. Our results agree well with theory and prove that a sufficiently large refractive index contrast is necessary for PCs to dramatically tune the luminescence lifetime and intensity simultaneously.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Lin Xiang,Xianju Zhou,Li Li,Faling Ling,Yanhong Li,Jingfang Li,Hongmei Yang
Eu 3+ ions are extensively employed as spectroscopic probes because of the particular emissions due to the unique 4f 6 electronic configuration. Herein, we have developed a series of interesting fluorescent powders of Eu 3+ activated Sr 2 MNbO 6 (M = Ga, In, Gd). When Sr 2 GaNbO 6 :Eu 3+ is excited by the photons in the range of charge transfer band (CTB), the dark red 5 D 0 → 7 F 4 transition predominates the emission, exhibiting an anomalous intensity even higher than that of 5 D 0 → 7 F 1 or 5 D 0 → 7 F 2 . Whilst, if the sample is pumped by f-f characteristic transitions, the hypersensitive 5 D 0 → 7 F 2 transition emerges as the strongest. However, Eu 3+ doped Sr 2 InNbO 6 and Sr 2 GdNbO 6 never demonstrate such results, 5 D 0 → 7 F 1 acts as the most intense one regardless of the excitation wavelength. It is found that Eu 3+ substitutes Sr 2+ site, and cuboctaherdron [SrO 12 ] with O h symmetry is likely to deform to triangular orthobicupola D 3h symmetry, leading to two non-equivalent crystal sites in Sr 2 GaNbO 6 host. But Eu 3+ replaces In 3+ and Gd 3+ position with O h symmetry and has only one site in Sr 2 InNbO 6 and Sr 2 GdNbO 6 . Based on the comparative study on the intensity of 5 D 0 → 7 F 0 transition, as well as the influence factors of temperature, the doping concentration on the relative intensity among 5 D 0 → 7 F J transitions, and the band gaps of these three hosts, the origin of the abnormal intense 5 D 0 → 7 F 4 is ascribed to the mixing of CTB and low-lying 4f 6 configuration as well as two non-equivalent Eu 3+ sites.
研究领域:
材料科学
·
光物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2017
·
IF 2.686
Chao Quan,Wentao Xu,Youfu Zhou,Decai Huang,Zhonghua Deng
A novel Eu-doped strontium magnesium aluminate phosphor (Sr 2 MgAl 22 O 36 :Eu 2+ , SMAO:Eu 2+ ) and its partial nitridation compound (Sr 2 MgAl 22 O 36-3/2x N x :Eu 2+ , SMAON:Eu 2+ ) have been synthesized successfully via a solid state reaction with Al 2 O 3 partly substituted by AlN. The specimen preserves the main phase of Sr 2 MgAl 22 O 36 as a certain amount of AlN incorporated. SMAON:Eu 2+ phosphors showed a broad blue emission band around 460 nm under ultraviolet-light excitation (340 nm), arising from the variation of emission energy between nitrogen doped and un-doped phosphor. The emission intensity of SMAON:Eu 2+ phosphors are increased up to 153% compared with that of SMAO:Eu 2+ . With the increase of Eu 2+ concentration, luminescent intensity of the phosphors increases continuously and reaches a maximum value at the concentration of 0.16 Eu 2+ . It is noteworthy that the PL intensity of SMAON:Eu 2+ increases to 129% at 200 °C in comparison with that of room temperature ( vs 58% for SMAO:Eu 2+ comparably), exhibiting excellent thermal stability.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Suli Wu,Yanhui Ning,Jie Chang,Shufen Zhang
Here, hydro/solvent thermal method was applied to synthesize lanthanide doped NaYF 4 upconversion nanoparticles (UCNPs). In order to overcome the quenching effect of (CH 2 ) n due to their high energy stretching vibration , a series of new chelating ligands such as, butanoic acid , hexanoic acid , decanoic acid , and tetradecanoic acid were selected for hydrothermal synthesis of NaYF 4 :Yb, Er nanocrystals . For comparison, commonly used oleic acid was also used as ligand for hydrothermal synthesis of UCNPs. The effect of the carbon chain length of chelating ligands on the NaYF 4 nanocrystals’ emission intensity was systematically investigated. It was found that relative short length of the carbon chain in chelating ligands resulted in enhancement of luminescent intensity and modulation of the ratios of green to red (RGR) of NaYF 4 :Yb, Er nanocrystals. In contrast to the product prepared with oleic acid as ligand, the enhancement factors of 540 nm emissions were 25, 21, 6.5, and 3 for samples prepared with butanoic acid, hexanoic acid, decanoic acid, and tetradecanoic acid as ligands, respectively. The FT-IR spectra of NaYF 4 :Yb, Er UCNPs prepared with different ligands indicated that ligands with relatively short chain length indeed have weak IR absorption in 2800–2950 cm −1 , which resulted in weak quenching effect of Er 3+ . We also synthesized NaYF 4 :Yb, Tm UCNPs with these ligands. The results showed that chain length of ligands has similar effect on emission intensity of NaYF 4 :Yb, Tm. It is expected that this method can also be applied to enhance the luminescence intensity of other 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
Advanced Photonics Research
·
2022
·Vol. 3
·期 12
·2200197
·
IF 0
Heng Guo,Qingxian Zhao,Peng Ran,Jinping Chen,Yizhi Zhu,Qingsong Jiang,Yuling Tang,Zhenhua Zhang,Lei Song,Chunxiang Xu,Shouhua Luo,Zengliang Shi
Scintillator is a critical component to detect high-energy particles or rays, which is widely used in deep space exploration, security inspection, and nondestructive testing and medical diagnosis, such as X-ray imaging and computed tomography (CT). However, the wider application of traditional inorganic and organic scintillators is limited by the complex operation process or poor adaptability to changeable environment, and there remains a demand to develop green and stable scintillators with high sensitivity and low detection limit. Herein, the one-step preparation of lead-free perovskite Cs 3 Cu 2 I 5 scintillator film for high-definition X-ray imaging by conventional chemical vapor deposition method is reported. Cs 3 Cu 2 I 5 demonstrates good stability and bright-blue emission at 445 nm and superhigh photoluminescence quantum yield (85.14%). Importantly, upon X-ray irradiation, the Cs 3 Cu 2 I 5 perovskite film exhibits light yield (≈39 251 photons MeV −1 ) as high as two times of the commercially available Ce:LuAG single-crystal scintillator (≈22 000 photons MeV −1 ). Furthermore, the practical demonstration for a bamboo stick and insect specimens illustrates sensitive scintillation response to X-ray signals with superior linearity and high-quality images in X-ray photography and CT. Overall, Cs 3 Cu 2 I 5 film provides nontoxicity, high radioluminescence intensity, and good stability, it can be regarded as a competitive material for X-ray imaging.
研究领域:
材料科学
·
医学影像
·
辐射探测
✓ 已验证
DOI
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Ruichan Lv,Liyang Xiao,Yanxing Wang,Fan Yang,Jie Tian,Jun Lin
In this research, four heuristic algorithms (HAs), including simulated annealing (SA), improved annealing with a harmony search algorithm (HSA), particle swarm optimization (PSO), and genetic algorithm (GA), were used to optimize the luminescent intensity of phosphor. Among the four HAs, the improved algorithm HSA got better phosphors than SA (without using the known coded concentration). The PSO algorithm got gradually better results with increased generation, and the GA could find the best local phosphors with shorter time. After further analysis of the 340 phosphors, we found that the final brightness has an optimized activator concentration (Tb: 0.21–0.26), and the results were further proved by another uniform host of NaGdF4:Ce,Tb nanoparticles. The HA was proper to find the optimal concentration of the activator of Tb. Furthermore, the optimal phosphor could be used as a bioimaging agent and improved QR code.
研究领域:
材料科学
·
光学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Qiangsheng Gao,Lili Meng,Lixia Zhang,Qi Pang,Lifang Liang
Luminescent materials with the chemical formula Sr 3− x Eu x AlO 4− y N y F were prepared by a solid-state reaction. X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), photoluminescence emission and excitation spectra, the lifetime, the temperature-dependent luminescence, and the effects of Eu 3+ and N 3− concentrations were investigated in detail. Partial substitution of Sr 2+ by Eu 3+ and O 2− by N 3− in Sr 3− x Eu x AlO 4− y N y F contributes to form quadrangular crystals, and enhance the thermal stability against the temperature quenching effect. After the partial replacement of Sr 2+ by Eu 3+ and O 2− by N 3− ions in the Sr 3 AlO 4 F host structure, the emission intensity was enhanced and the charge-transfer band of O 2p →Eu 4f shifted to higher wavelength.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2021
·Vol. 19
·期 2
·729-738
·
IF 1.968
Xiao Ma,Zhifeng Huang,Hailong Yuan,Xiangyu Lu,Yujuan Zhou,Qiang Shen,Fei Chen
The traditional model for wLEDs usually encapsulates the phosphor and resin mixture on the InGaN blue-emitting chip. However, the poor thermal stability of silicone resin will lead to the reduction of the luminescent intensity of the wLED devices. Glass has excellent thermal stability and transparency, which is a promising alternative to resins. In this work, Ce-doped silicate luminescent glasses have been developed by a high-temperature melting quenching method in air atmosphere. The luminescent intensity can be enhanced by increasing the heat treatment temperature and extending the heat treatment time in 10%H 2 /Ar atmosphere because Ce 4+ ions can be reduced to Ce 3+ ions. However, when the heat treatment temperature reaches 850°C, the generation of precipitates in the glass can reduce the luminescent intensity. The transmittance of glass can reach 87%, and the highest luminous intensity obtained when heat treated at 800°C. The glass transition temperature is 740°C and the thermal conductivity of the glass is .95 W m −1 K −1 , which is about five times higher than that of resin. The results show that the emerging Ce-doped silicate luminescent glass could be the potential material for wLED applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2023
·Vol. 31
·期 5
·9123-9134
·
IF 3.8
Hanyu Xu,Zuoling Fu,Yanling Wei
The susceptibility of Cs-based fluorides to deliquescence has led to the fact that lanthanide-doped Cs-based fluorides and their related applications have hardly been reported. Herein, the method to solve the deliquescence of Cs3ErF6 and its excellent temperature measurement performance were discussed in this work. Initially, the soaking experiment of Cs3ErF6 found that water had irreversible damage to the crystallinity of Cs3ErF6. Subsequently, the luminescent intensity was ensured by the successful isolation of Cs3ErF6 from the deliquescence of vapor by the silicon rubber sheet encapsulation at room temperature. In addition, we also removed moisture by heating samples to obtain temperature-dependent spectra. According to spectral results, two luminescent intensity ratio (LIR) temperature sensing modes were designed. The LIR mode which can quickly respond to temperature parameters by monitoring single band Stark level emission named as “rapid mode”. The maximum sensitivity of 7.362%K-1 can be obtained in another “ultra-sensitive mode” thermometer based on the non-thermal coupling energy levels. This work will focus on the deliquescence effect of Cs3ErF6 and the feasibility of silicone rubber encapsulation. At the same time, a dual-mode LIR thermometer is designed for different situations.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）