查找使用阿拉丁产品的科研文献

Luminescence characteristics of SrZnSO:M (M = Bi3+, Mn2+ and Tb3+) phosphors

Xiaolei Zhu,Xiaoping Wang,Xianke Sun

Bi 3+ /Tb 3+ /Mn 2+ -activated SrZnSO phosphors were prepared to investigate their luminescence characteristics. The SrZnSO:Bi 3+ , SrZnSO:Mn 2+ and SrZnSO:Tb 3+ phosphors, excited by the NUV/blue light, show blue, orange and green emissions, respectively. The Bi 3+ → Tb 3+ , Tb 3+ → Mn 2+ and Bi 3+ → Mn 2+ energy transfer processes take place in Bi 3+ /Tb 3+ -, Tb 3+ /Mn 2+ -, Bi 3+ /Mn 2+ - and Bi 3+ /Tb 3+ /Mn 2+ -activated SrZnSO phosphors, which result in tunable luminescence of these phosphors. The CIE coordinates were calculated on the basis of the emission spectra, and they reflect the emission color changes of phosphors. For the Bi 3+ /Tb 3+ -, Tb 3+ /Mn 2+ - and Bi 3+ /Mn 2+ - activated SrZnSO phosphors, the emission points are located in the cyan, yellow and white light regions, respectively. For the Bi 3+ /Tb 3+ /Mn 2+ -activated SrZnSO phosphors, the light is in warm white light region.

(Bi0.5Na0.5)TiO3:Tb3+: A New Green Emission Multifunctional Ferroelectric Material

Sun Hai-Qin,Zhang Qi-Wei,Li Wen-Xin

The photoluminescence of Tb3+-doped (Bi0.5Na0.5)TiO3 (BNT) ferroelectric materials fabricated via the conventional solid-sate reaction method were studied. Under blue light excitation (487 nm), a bright green emission centered at 547 nm is observed at room temperature, originating from the 5D4→7F5 transition of Tb3+ ions. The emission intensity reached its maximum as the doping concentration is 0.02 mol and sintering temperature is 1080°C, respectively. The CIE chromaticity coordinate for x = 0.02 is (0.3222, 0.6711), located in the green light region. These results show that Tb3+-doped BNT materials may have potential applications in white light-emitting diodes and novel multifunctional devices.

Structural, dielectric and luminescent properties of novel Li1.0Nb0.6Ti0.5O3: Tb3+ ceramics

Shi-min Chen,Qun Zeng,Fu-song Ma,Yi-hang Wang,Chun-feng Yao

Novel Li 1.0 Nb 0.6 Ti 0.5 O 3 : Tb 3+ ceramics with favorable luminescent and dielectric properties were prepared by solid-state reaction (SSR) method. The X-ray diffraction (XRD) results indicated that the Tb 3+ ions were effectively dissolved into the “M-phase” matrix synthesized at 1000–1100°C. The ceramic with a dense microstructure could be obtained at 1050°C. The Li 1.0 Nb 0.6 Ti 0.5 O 3 : Tb 3+ ceramics emitted green light at 550 nm and relatively strong red light at 660 nm under the excitation of 440 nm, which were located in the orange-red light region shown in the chromaticity diagram. The color coordinates were (0.5574, 0.4417) for the Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt% Tb 3+ ceramic sintered at 1050°C. The quantum efficiency of Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt%Tb 3+ ceramic was 19%, which was much higher than that of 9.6% for commercial red Y 2 O 3 : Eu 3+ phosphors. Furthermore, for Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt%Tb 3+ ceramic synthesized at 1050°C, the ideal dielectric properties with ε r of 66.263 and Q*f of 5582 GHz were obtained, which might be used as a potentially multifunctional ceramic applied in the fields of LED packaging to improve the lack of red light for blue LEDs combined with yellow phosphors.

CaSnO3:Tb3+ nanofibers with blue/green emission and CaSnO3:Tb3+/Eu3+nanofibers with white-light emission and multi-color luminescence assist photon barcode via energy transfer

Xue Teng,Ning Li,Xiaohan Liu,Xintong Huo,Hong Shao,Yanke Xi,Jiacheng Mi,Dan Li,Guixia Liu,Xiangting Dong

It is crucial to develop color-tunable fluorescent materials with single-matrix. In this study, Electrospinning coupled with oxidative sintering is employed to successfully fabricate CaSnO 3 (CSO):RE 3+ (RE = Tb, Tb/Eu) one-dimensional nanofibers (NFs). To achieve multi-color luminescence and white-light emission in a single matrix, Eu 3+ ions are introduced into CSO:Tb 3+ 1D NFs to gain CSO:Tb 3+ /Eu 3+ 1D NFs. In the CSO:Tb 3+ /Eu 3+ NFs, Tb 3+ ions play a dual role as both luminescent center and sensitizer by virtue of energy level matching engineering. By adjusting the excitation wavelength and doping concentration of Tb 3+ and Eu 3+ ions, the luminescence color of CSO:RE 3+ (RE = Tb, Tb/Eu) NFs can be regulated, achieving multi-color luminescence from blue to blue-green, green, white, and red. Meanwhile, multiple emission peaks in the emission spectra of the CSO:RE 3+ (RE = Tb, Tb/Eu) enable high information storage and anti-counterfeiting capacity.

Synthesis, structure and multicolor-tunable luminescence of the dandelion-like SiO2:Ln3+ (Ln = Eu, Tb) nanophosphors

Xiaoming Xie,Jie Chen,Ye Sheng,Yanhua Song,Xiuqing Zhou,Xiangting Zhang,Zhan Shi,Haifeng Zou,Keyan Zheng

A series of novel color tunable dandelion-like SiO2:Ln3+ (Ln = Eu, Tb) nanophosphors of approximately 70 nm diameter were prepared using a simple hydrothermal route. The phase, time-dependent shape evolution, morphology, sizes, and luminescence properties of the as-prepared products were well characterized by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, and photoluminescence spectra as well as kinetic decay curves. Under ultraviolet excitation, the Eu3+ and Tb3+ singly doped SiO2 samples showed strong red and green emission, respectively. Furthermore, the luminescence colors of the as-prepared Tb3+, Eu3+ co-doped dandelion-like SiO2 nanophosphors could be altered from green to red, including green-yellow, yellow, orange yellow and reddish orange, by simply adjusting the doping concentrations of Eu3+.

NaMgF3:Tb3+@NaMgF3 Nanoparticles Containing Deep Traps for Optical Information Storage

Yikuang Wang,Dunrong Chen,Yixi Zhuang,Wenjing Chen,Hangyu Long,Hongmin Chen,Rong-Jun Xie

Persistent luminescence (PersL) materials containing deep traps have attracted great attention in the field of optical information storage. However, the lack of nanomaterials with satisfactory light storage ability has become one of the main obstacles to the practical applications. In this work, NaMgF 3 :Tb 3+ @NaMgF 3 :Tb 3+ nanoparticles are reported which exhibit excellent light storage ability into deep traps upon X-ray irradiation and controllable photon emissions under thermal stimulation. A surface passivation strategy by constructing a core–shell structure is adopted, which is proved valid to greatly enhance the PersL efficiency. To understand the possible mechanism on the light storage and thermally stimulated PersL in the NaMgF 3 :Tb 3+ @NaMgF 3 nanoparticles, an energy level diagram is built and the electronic transition processes are clarified. According to the proposed mechanism, the Tb 3+ ions possibly serve as both emitting centers and trap centers in the NaMgF 3 host during the X-ray irradiation. Due to the excellent dispersibility and stability in water, luminescent inks containing the nanoparticles are successfully prepared and the applications to inkjet printing optical information storage and information decryption are demonstrated. The developed NaMgF 3 :Tb 3+ @NaMgF 3 PersL nanoparticles may inspire further research on lanthanide-activated fluoride PersL nanoparticles and provide new opportunities to the next-generation information storage and biomedical technologies.

Highly efficient Ce3+ → Tb3+ energy transfer induced bright narrowband green emissions from garnet-type Ca2YZr2(AlO4)3:Ce3+,Tb3+ phosphors for white LEDs with high color rendering index

Liangling Sun,Balaji Devakumar,Jia Liang,Shaoying Wang,Qi Sun,Xiaoyong Huang

Inorganic phosphors play an important role in realizing high-performance white light-emitting diodes (LEDs), and thus highly luminescent phosphors with excellent optical properties are urgently needed. In this paper, novel Ce3+/Tb3+ co-doped Ca2YZr2(AlO4)3 (abbreviated as: CYZA) green-emitting phosphors with broadband excitation and high quantum efficiency were synthesized for potential application in white LEDs, and their phase purity, crystal structure, morphology, photoluminescence properties, energy transfer mechanism, and thermal stability were systematically investigated. It was found that the CYZA:Ce3+,Tb3+ phosphors exhibited two broad excitation bands in the 300–470 nm wavelength range, due to the highly efficient energy transfer from Ce3+ to Tb3+ ions. Under the excitation wavelength of 408 nm, the CYZA:Ce3+,Tb3+ phosphors showed bright green emissions around 492, 543, 591, and 628 nm originating from the 5D4 → 7FJ (J = 6, 5, 4, and 3) transitions of Tb3+ ions. The optimal doping concentrations of Ce3+ and Tb3+ ions in CYZA:xCe3+,yTb3+ phosphors were determined to be x = 0.04 and y = 0.9, respectively. The CIE coordinates and the internal quantum efficiency of the composition-optimized CYZA:0.04Ce3+,0.9Tb3+ phosphors were measured to be (0.342, 0.545) and 56%, respectively. The full width at half-maximum (FWHM) of the dominant green emission band around 543 nm was only about 13.5 nm. Finally, a white LED lamp was fabricated using a 400 nm LED chip together with a phosphor blend of blue-emitting BaMgAl10O17:Eu2+, green-emitting CYZA:0.04Ce3+,0.9Tb3+ and red-emitting CaAlSiN3:Eu2+, which produced warm white light with color coordinates of (0.419, 0.392), excellent color rendering index of 91, correlated color temperature of 3233 K, and luminous efficacy of 30 lm W−1 when driven by a 40 mA current. The above results demonstrated that CYZA:0.04Ce3+,0.9Tb3+ can be a potential green-emitting color converter for white LEDs.

Blue-green emitting ZnS0.75O0.25:Ce3+,x%Tb3+ phosphor with tunable fluorescence lifetime

Xue Xing,Weiwei Cao,Zhaoxin Wu,Xiaohong Bai,Jiarui Gao,Xiaozhen Liang,Bo Wang,Chao Wang,Dalian Shi,Linwei Lv,Yonglin Bai

A series of ZnS 0.75 O 0.25 :0.1%Ce 3+ , x %Tb 3+ phosphors were prepared by high temperature solid state reaction method. These phosphors exhibited two mixed phases consisting of hexagonal phase ZnS and hexagonal phase ZnO with the average particle size of 13.83 μm and emitted blue-green light. The luminescence mechanism consisted of Zn vacancy defects, the 5d 1 → 2 F 5/2 radiative transitions of Ce 3+ , the 5 D 4 → 7 F 5 and 5 D 4 → 7 F 6 radiative transition of Tb 3+ induced by the energy transfer of Ce 3+ → Tb 3+ . An equation for the variation of the fluorescence lifetime of ZnS 0.75 O 0.25 :0.1%Ce 3+ , x %Tb 3+ phosphors with concentration of Tb 3+ fraction was obtained by exponential fitting. The short fluorescence lifetime could be tuned within the range of 113 μs to 550 μs with the increase of Tb 3+ concentration, and the color was tunable from blue to blue-green, which is of important application in the field of high-energy particle detection.

Sb3+ co-doped Cs3EuCl6: Tb3+ nanocrystals: Luminescence enhancement and temperature sensing performance

Yuhang Zhao,Lin Lin,Xin Chen,Xinyu Guo,Chenglin Gong,Yingzhen Wu,Zhuohong Feng,Zhezhe Wang,Zheng Li,Zhiqiang Zheng

Zero-dimensional rare-earth halide Cs 3 EuCl 6 : Tb 3+ , Sb 3+ nanocrystals (NCs) were successfully synthesized via a facile heating method. Their optical temperature sensing properties are systematically investigated. By virtue of the efficient energy transfer of Tb 3+ →Eu 3+ and the reduction in site symmetry of luminescent centers at high temperature, the emission peaks of Tb 3+ and Eu 3+ show different temperature response. Based on this, an optical thermometry system based on the fluorescence intensity ratio (FIR) is constructed. The maximum relative sensitivity of Cs 3 EuCl 6 : 40%Tb 3+ NCs reaches 1.301%·K −1 . Further introduction of Sb 3+ co-doping not only remarkably enhances the luminescence intensity of the material, but also raises the maximum relative sensitivity to 1.32%·K −1 . This work confirms that Cs 3 EuCl 6 : Tb 3+ , Sb 3+ NCs are high-performance optical temperature sensing materials with promising application prospects.

Tunable Photoluminescence of LiTaO3: Tb3+, Sm3+ for Dynamic Multimode Optical Anti-Counterfeiting

Baoqing Sun,Ting Li,Congliang Shen,Mingyue Zhang,Zhaoyu Guang

Graphical Tb 3+ , Sm 3+ mono-/co- doped LiTaO 3 phosphors are prepared by high-temperature solid-state reaction. Emission color of LiTaO 3 : Tb 3+ , Sm 3+ shifts from green to yellow as Sm 3 ⁺ concentration increases due to energy transfer from Tb 3+ to Sm 3+ . Time-resolved color evolution from green to orange is achieved by combining the trap-assisted afterglow of Tb 3+ and stable photoluminescence of Sm 3+ . Currently, static fluorescent anti-counterfeiting technology struggles to cope with the increasingly sophisticated counterfeiting techniques, making the dynamic multimode regulation scheme an urgent necessity. Herein, Tb 3+ , Sm 3+ mono-/co-doped LiTaO 3 (LTO) phosphors are prepared by high-temperature solid-state method. Under 254 nm excitation, the emission chromaticity of LTO: Tb 3+ , Sm 3+ is modulated from green to yellow by increasing Sm 3+ content due to Tb 3+ → Sm 3+ energy transfer. The diverging luminescence thermal stability of LTO: Tb 3+ and LTO: Sm 3+ is uncovered, which is governed by their distinct vacuum-referenced binding energy (VRBE) levels and charge compensation mechanisms. Based on the time-domain difference between the trap-assisted afterglow of Tb 3+ and the photoluminescence of Sm 3+ , a dynamic anti-counterfeiting pattern that changes from green to orange over time is designed. This work provides a novel material design strategy for time-resolved color signatures and multi-modal dynamic optical encryption.

Adenine/adenine contacts defined in G-quadruplex for highly selective Tb3+ binding

Yulu Ru,Jiahui Chen,Qinxin Li,Qiyao Chen,Sihui Huang,Jiahuan Zhou,Dandan Wang,Xiaoshun Zhou,Yong Shao

Folding of nucleic acids is strongly dependent on metal ions. For example, G-quadruplex (G4) structures are usually determined by the specific K+/Na+ coordination. However, G4 constructs highly selective to high-valent metal ions (for instance, trivalent metal ions) have not been found due to their strong and nonspecific phosphate backbone interactions. Herein, a higher-order G4 structure having a heptad junction formed by GGA repeats (for example, GGA8 with eight repeats) of the human c-myb promoter region was found to stoichiometrically recruit three Tb3+ ions. The junction binding of Tb3+ did not affect the global G4 structure of GGA8 because of its high stability in K+. The three context A/A contacts with a proper stacking orientation and an appropriate interbase distance were proved to be the specific binding sites of Tb3+ (A/Tb3+/A). Other high-valent metal ions were unable to interfere with this specific Tb3+ binding, suggestive of the potential of GGA8 serving as an aptamer-like DNA for Tb3+. This A/Tb3+/A binding was also found in another KRAS promoter G4 structure with the same A/A contact, indicating the potential of Tb3+ in selectively probing G4 structures. This work will also inspire more interest in searching higher-order G4 structures for selectively coordinating high-valent metal ions with the purpose of their detection, enrichment, and recovery.

Preparation and characterization of nanosphere and nanorod Gd2O3:Tb3+ by polyol route

Meigui Ou,Huina Qiao,Rong Fu,Yanyan Hu,Chunlin Yang,Hao Yin