JOURNAL OF RARE EARTHS
·
2023
·
IF 4.9
Wei Zhang,Changjian Wang,Xusheng Qiao,Xianping Fan
The rapid development of phosphor-converted white light emitting diodes (pc-WLEDs) requires new red phosphors with efficient and thermally stable luminescence for high-quality warm-white lighting. However, it is still a challenge to discover red phosphors with facile synthesis, high internal quantum efficiency (IQE), excellent thermal stability and high color purity. Herein, a novel red-emitting Eu 3+ activated barium dialuminum digermanate (BaAl 2 Ge 2 O 8 , BAGO) phosphor showing strong red emission at 610 nm was prepared. The IQE is improved from 32.91% to 78.84% by employing a charge compensation strategy. The lithium-ion co-doped BAGO:Eu 3+ phosphor exhibits a nearly twofold increase in integral photoluminescence (PL) intensity and the high color purity reaches 94.17%. Impressively, the PL intensity of the BAGO:Eu 3+ ,Li + phosphor drops by only 2.6% at 150 °C of that at room temperature. Finally, the pc-WLED using the red BAGO:Eu 3+ ,Li + phosphor exhibits white light with the chromaticity coordinate of (0.3515, 0.3495), a high color-rendering index of 92 and a low correlated color temperature of 4746 K. All these results manifest that BAGO:Eu 3+ ,Li + phosphor is a suitable red phosphor for near-ultraviolet (NUV) chip-based pc-WLEDs.
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高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Man Li,Yifei Zhao,Shuai Zhang,Ruirui Yang,Weidong Qiu,Pin Wang,Maxim S. Molokeev,Shi Ye
The photoinduced reversible ion exchanges in mixed halide perovskites and the resulting luminescent variations make them promising for constructing anti-counterfeiting patterns; however, its understanding in an interfacial view is lacking. In this work, nominal CsPbBr1.5Cl1.5 (CPBC) nanocrystals (NCs) were introduced into macroporous Y2O3:Eu3+ (MYE) to realize emission color variations from red emission of MYE to green emission of halide NCs. The large surface area of MYE helps the formation of Y–Cl/Br bonds which induces fluctuation in the halide composition, while water and intrinsic halogen defects have also been proved to be essential in the reversible ion segregation process. The PL variations of several samples with different pore sizes were investigated upon irradiation of light with different photon energies and excitation power at certain temperatures. According to combined results of density functional theory calculation, the research reveals the presence of two energy barriers that would be overcome correspondingly by the excitation photon and the concentration difference in the ion exchange and recovery process. A photochromic anti-counterfeiting quick response (QR) code was constructed facilely with the perovskite composites. This work provides a deeper understanding from the interfacial aspect and also proposes a feasible strategy to realize reversible PL variation for anti-counterfeiting applications.
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PubMed
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Daiwen Xiao,Ka-Leung Wong,Peter A. Tanner
The behavior of nanoparticles in media of different refractive index has received considerable theoretical and experimental investigation. However, the behavior of larger particles, of micron size, has not been established. We have chosen Eu 3+ as a marker of environmental changes. Dilution of this ion into LaPO 4 gives a simple, fingerprint emission spectrum which has been studied via its luminescent lifetime, the R 2 (( 5 D 0 → 7 F 2 )/( 5 D 0 → 7 F 1 ) intensity ratio) and the electric dipole:magnetic dipole intensity ratio, (ED:MD), of spectral features. Measurements of micron-sized particles of LaPO 4 :Eu 3+ synthesized by several methods have been made for dispersions in alcohols, in compressed glass discs, in melted glass discs, in phosphor in glass (PiG) and in melted PiG. The experimental results are discussed and rationalized. The Eu 3+ 5 D 0 emission lifetime is reasonably constant in the bulk powders, powders dispersed in alcohols or compressed discs but is smaller in PiGs and melted glass discs. In the PiGs the structural integrity of LaPO 4 :Eu 3+ is maintained until they are melted at higher temperature. The change in lifetime, when varying the composition of the PiG, follows the Virtual Cavity Model. For dispersal of the particles in solvents there is a cut-off particle size below 1 μm where the electronic spectra of the moiety become insensitive to the environment and the properties are determined by refractive index. The remarkable change in R 2 ratio in the different systems considered – by a factor of nearly 600 % - and the corresponding decrease in 5 D 0 lifetime – by a factor of nearly 60 % - illustrates the versatility of the lanthanide ion.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Xugang Cao,Yue Zhai,Diwen Guan,Xianwei Wang,Qiangqiang Zhu,Shuangqiang Fang,Hong Zhang,Le Wang
Lead-free metal halide double perovskites with non-toxicity and stable self-trapped excitons (STEs) have received considerable attention in the field of photoelectric applications. However, it is difficult to achieve independent control of its photoluminescence performance to meet the requirements of multi-band emission. Herein, a doping strategy was employed to introduce lanthanide ions (Ln 3+ ) into Cs 2 NaInCl 6 :Sb 3+ nanocrystals (NCs), enabling the multicolor emission modulation ranging from blue to red and even white light. Benefiting from the efficient energy transfer from Sb-related self-trapped excitons to Ln 3+ ions, green and red emissions originate from the 5 D 0 → 7 F J (J = 1, 2, 3, 4) transition of Eu 3+ ions and 5 D 4 - 7 F J (J = 6, 5, 4, 3) transition of Tb 3+ ions, respectively. According to the tunable polychromatic photoluminescence characteristics of doped NCs, the dual-mode fluorescent anti-counterfeiting applications were exhibited. Furthermore, the distinct temperature sensitivities exhibited by blue (453 nm) and red (617 nm) emission in Cs 2 NaInCl 6 :Sb 3+ /Eu 3+ NCs provide the opportunity for the optical thermometry, which demonstrates the maximum absolute and relative sensitivity are 0.0018 and 0.43 % K −1 , respectively. These results indicate that the synthesized codoped NCs have the potential applications in multifunctional fields, such as optical thermometer, fluorescence anti-counterfeiting, and multicolor-LEDs.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 24
·28077-28087
·
IF 2.478
Zhao Jiaqi,Hu Chen,Lu Jingyao,Sun Ruyi,Wang Zhen,Yin Yanzhen,Liu Wenlong,Gu Chengcheng,Li Zichao,Zhong Degao,Teng Bing
A series of single-phase white-emitting phosphors Ba 3 Bi(PO 4 ) 3 (BBP):8 at.% Dy, x at.% Eu were successfully synthesized through high temperature solid-phase method. The luminescence properties of BBP:8 at.% Dy, x at.% Eu were systematically investigated. Experimental results indicate the doping of Eu 3+ ions can effectively compensate the red light component in the emission spectrum and tune the correlated color temperature of BBP:8 at.% Dy, x at.% Eu from cool white light (5097 K) to warm white light (3661 K). Moreover, BBP:8 at.% Dy 3+ , 0.8 at.% Eu 3+ phosphor exhibits excellent thermal stability and the fluorescence intensity at 150 °C can still maintain 76% of that at 25 °C, while the activation energy is determined to be ~ 0.23 eV. In addition, the quantum efficiency of BBP:8 at.% Dy 3+ , 0.8 at.% Eu 3+ phosphor were measured to be 61%. These results suggest that BBP:8 at.% Dy 3+ , 0.8 at.% Eu 3+ can be a NUV-pumped single-phase white phosphors with excellent comprehensive performances.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Yan Fan,Xueqin Sun,Wenyuan Zhang,Jiacheng Liu
A novel fluorescent sensor material of Eu 3+ @ Citric acid-functionalized UiO-66 (denoted as Eu 3+ @UiO-66-CA) was prepared successfully via a two-step post synthetic modification towards UiO-66. The as-obtained Eu 3+ @UiO-66-CA presented the characteristic emission of Eu 3+ ions (λ ex = 270 nm), which could be used for rapidly detecting Fe 3+ and Cr 2 O 7 2- ions by luminescence quenching in aqueous solution. The detection process for Fe 3+ ion (detection limit, 18.1 μ M) and Cr 2 O 7 2- ion (detection limit, 8.5 μ M) exhibited the high selectivity and excellent anti-interference ability. Systematic investigations were employed to make clear the mechanism of fluorescence quenching after adding Fe 3+ and Cr 2 O 7 2- ions. Moreover, the Eu 3+ @UiO-66-CA was also used for the determination of Fe 3+ and Cr 2 O 7 2- ions in the Yellow River and tap water.
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高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Lei Zhang,Xuefeng Zhang,Chaoyong Zhao,Xuan Xiao
Eu 3+ -activated Sr 3 −x Ca x La(VO 4 ) 3 phosphors were fabricated via citric-acid-assisted sol combustion. Characterization of the Sr 3 −x Ca x La(VO 4 ) 3 :Eu 3+ samples with different concentrations of Ca 2+ revealed a hexagonal crystal structure belonging to the R -3 m space group. The amount of Ca 2+ added ( x ) was controlled within 0 ≤ x ≤ 2 to yield high-purity phosphors. Scanning electron microscopy results showed that an increase in Ca 2+ concentration resulted in a decrease in the particle size of Sr 3 −x Ca x La(VO 4 ) 3 :Eu 3+ , with the shape gradually changing from nearly equiaxed to lath-shaped. The Sr 2 CaLa(VO 4 ) 3 :Eu 3+ phosphor (denoted as SCLVO:Eu 3+ ) exhibited the strongest photoluminescence (PL) intensity at 618 nm among the samples under excitation of 394-nm near-UV (NUV) light. The study of Eu 3+ doping concentration confirmed that Eu 3+ could enter the lattice of the SCLVO matrix without altering its crystal structure. SCLVO:Eu 3+ was found to strongly absorb 394 nm NUV light and 464 nm blue light. The optimal concentration of the Eu 3+ dopant in the SCLVO host was 0.11, which resulted in the phosphor achieving an excellent PL intensity and a color purity of 98.68%. Tunable luminescence from the orange area (0.5280, 0.4522) of Commission Internationale de l'éclairage (CIE) to the red area (0.6313, 0.3650) was achieved by adjusting the concentration of Eu 3+ . Under 394 nm excitation, SCLVO:0.11Eu 3+ phosphor has a quantum yield (QY) of 28.2% and excellent thermal stability with 0.383 eV activation energy . Consequently, White-light-emitting diode (WLED) based on SCLVO:0.11Eu 3+ phosphor yielded a high color rendering index (CRI), low correlated color temperature (CCT), and CIE coordinates of 91.8, 5196 K, and (0.3407, 0.3612), respectively, under the 20 mA driven current. These results indicated the tremendous potential of SCLVO:0.11Eu 3+ phosphors for application in WLEDs excited by NUV or blue light.
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高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 35
·10802-10809
·
IF 6.641
Peng Du,Weiguang Ran,Weiping Li,Laihui Luo,Xiaoyong Huang
A series of NaTbF4 and Eu3+-activated NaTbF4 nanorods with high luminescent efficiency were designed by using an ingenious reaction technique at room temperature. The effect of the synthesis time on the morphology evolution of NaTbF4 nanorods was investigated. Moreover, the influences of the Eu3+ doping concentration on the crystal structure, morphology, electronic structure and photoluminescence properties of NaTbF4 nanorods were systematically studied. Near-ultraviolet (NUV) light was the proper excitation light source for the final products and the optimum Eu3+ doping concentration was 30 mol%. The critical distance of Eu3+ ions in the NaTbF4 host lattices was 11.42 Å and the concentration quenching mechanism was dominated by electric dipole–dipole interactions. The local symmetry properties of Eu3+ ions in the NaTbF4 host were explored by analyzing the optical transition parameters based on the Judd–Ofelt theory. The resultant nanorods not only exhibited splendid thermal stability but also had a high internal quantum efficiency of 50.2%. Additionally, the fabricated light-emitting diode (LED) device can emit glaring white light emission with admirable color properties (i.e., good color coordinates, high color rendering and low correlated color temperature) which slightly changed at high injection current. These achievements suggested that the Eu3+-activated NaTbF4 nanorods were promising red-emitting candidates for high-powered NUV-pumped white-LEDs.
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2012
·
IF 2.159
Yan-Jing Gu,Bing Yan,Xiao-Fei Qiao
Novel rare earth complex-functionalized mesoporous SBA-16-type hybrid materials are synthesized by the co-condensation of modified 2-methyl-9-hydroxyphenalenone (MHPOSi), from modified 3-(triethoxysilyl)-propyl isocyanate (TEPIC), and tetraethoxysilane (TEOS) in the presence of Pluronic F127 as a template. These inorganic–organic mesoporous hybrids are characterized by FT-IR spectra, small-angle X-ray diffraction (SAXRD), N 2 adsorption–desorption measurements, thermal analysis and spectroscopy. Their photophysical properties, which show novel light conversion properties, are discussed in detail. The Eu 3+ hybrid system shows ultraviolet excitation and visible emission, and the Nd + and Yb 3+ hybrids exhibit visible excitation and NIR emission.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2014
·
IF 3.209
Bing Yan,Qiu-Ping Li
Several kinds of novel lanthanide organic–inorganic mesoporous hybrid luminescent materials have been assembled by introducing the ternary lanthanide ions (Eu 3+ , Tb 3+ ) and beta-diketone (TTA, TAA) into the functionalized mesoporous hosts through the coordination bond and covalent bond by using 3-chloropropyltriethoxysilane modified 1,4,7,10-tetraazacyclododecane (Cyclen-Si) as an organic bridge molecule. These multicomponent hybrids are characterized by FTIR, TEM, XRD, thermogravimetric analysis, diffuse reflectance UV–Vis spectra and nitrogen adsorption–desorption isotherms, especially the photoluminescence properties of them. The luminescent spectra of the hybrids reveal that the MCM-41 based materials show strong emission intensities, high luminescent quantum efficiencies, long luminescent lifetimes and exhibit characteristic red and green luminescence originated from lanthanide ions (Eu 3+ or Tb 3+ ), which suggesting the Cyclen-Si bridge molecule is favorable for the assembly of lanthanide functionalized luminescent hybrids.
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高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2024
·
IF 4.4
Houteng Zhao,Yilian Ran,Xiya Miao,Siyu Cheng,Dongze Li,Yufeng Du,Xiang Liu,Ruijin Yu
A series of novel phosphors, doping Eu 3+ and Na + ions in the Sr 3 MgNb 2 O 9 (SMNO) crystal lattice (SMNO: x Eu 3+ , x Na + , x = 0.5–30 mol%), was successfully synthesized through high-temperature solid-state reaction. X-ray diffraction (XRD) analysis and Rietveld refinement confirmed the successful synthesis of SMNO:Eu 3+ , Na + . The phosphor belongs to the hexagonal crystal system and the P 3 ¯ m 1 (No.164) space group. The bandgap energy of SMNO was calculated with Materials Studio and measured with the use of diffuse reflectance spectroscopy. The excitation spectrum of SMNO:Eu 3+ , Na + displays multiple narrow absorption peaks in the violet-blue region as well as a charge transfer band (CTB) near 300 nm, exhibiting the highest peak at 394 nm. Four distinct characteristic peaks are observed in the emission spectrum of SMNO:Eu 3+ , Na + . Notably, the peak at 601 nm shows the highest emission intensity due to the radiative transition from 5 D 0 → 7 F 2 . By varying doping concentrations, it was determined that an optimal concentration of 5 mol%Eu 3+ resulted in phosphors, with high color purity exceeding 99 %. Concentration quenching is attributed to the nearest neighbor ions interaction. Furthermore, SMNO:Eu 3+ , Na + exhibited good stability in 300–480 K, with luminescent intensity remaining 68.6 % at 420 K and 54.4 % at 480 K compared to room temperature (300 K). The internal quantum efficiency (IQE) of SMNO:5%Eu 3+ , 5 %Na + is 65.0 %. Both red and white light-emitting diodes (LEDs) were prepared using SMNO:Eu 3+ , Na + . The chromaticity coordinates of w-LED were measured as (0.357, 0.376), correlating to a correlated color temperature (CCT) of 4685 K and exhibiting a good color rendering index (CRI, R a = 88). Additionally, the latent fingerprint (LFP) development demonstrated clear visualization of Levels I-III characteristic structures of fingerprints when utilizing SMNO:Eu 3+ , Na + . These findings suggest promising applications for SMNO:Eu 3+ , Na + in w-LED lighting and LFP development.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
·
IF 3.4
Chengyu Ni,Kaiting Wu,Chunxuan Chen,Xiaozhou Zheng,Man Xu,Wubin Dai
The design of a stably efficient and color-tunable photoluminescence (PL) phosphor, depending on the clear relationship between structure/composition and PL properties, remains quite a challenge. Herein, in pursuit of phosphor for white LED (wLED) lighting, chemical modification of the host (K3YSi2O7, KYS) and regulation of the energy transfer of dopants Bi3+/Eu3+ in multiple lattice sites (K/Y) are in detail investigated and achieved via a facile solid-phase reaction under air condition. Based on both experimentally and theoretically comprehensive analysis of structure (i.e., XRD/Rietveld refinement, density functional theory (DFT) calculations) and steady/transient-state spectroscopy (i.e., PL/PL excitation, decay lifetime), the adjustable and broad PL in the blue/cyan region of Bi3+ is originated from both the crystallographic sites of K1/Y2, while Eu3+ ions are more inclined to enter the Y2/Y1 sites and emit the characteristic high-purity red PL. Systematic PL tuning from blue/cyan to red is thus realized via efficient ET from Bi to Eu, and the corresponding PL and ET mechanisms are discussed and proposed. Intriguingly, significant enhancements of the PL intensity, quantum yield (QY), and thermal stability of the KYS: Bi/Eu are achieved via chemical composition modulation by artificially adding excessive K+ ions to the host to enhance the phase purity/crystallinity. By adopting the phosphor as a “warm” white color convertor, a wLED with high efficiency and color rendering index (CRI, 90.5) and low corrected color temperature (CCT, 4126 K) is constructed via a remote “capping” packaging strategy. Further, in view of the different thermal responses of the multisite occupancy of Bi3+, energy-level thermal coupling of Eu3+, and dual centers of Bi/Eu in KYS, a multimode and self-referenced thermometer is also designed based on the fluorescence intensity ratio (FIR) technology with high relative sensitivity.
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高影响因子
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