New red phosphor Na3EuB8O15 with an open-window tubular structure

2021 ◽  
Vol 77 (5) ◽  
pp. 235-239
Author(s):  
Wen-Yan Bi ◽  
Wei Wang ◽  
Rui-Juan Zhang
Keyword(s):  
Uv Light ◽  
Emission Spectra ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Triclinic Space Group ◽  
Chromaticity Index ◽  
Open Window ◽  
Light Excitation ◽  
Cie Chromaticity

A new rare-earth polyborate, trisodium europium octaborate, Na3EuB8O15, was prepared using the high-temperature molten-salt method and structurally determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic space group P\overline{1} and contains a one-dimensional [B8O15]∞ tube structure that is constructed from BO3 and BO4 polyhedra. The Eu3+ and Na+ cations reside in this structure to ensure cohesion and neutrality. The excitation spectra, emission spectra, decay time and Commission Internationale de l'Éclairage (CIE) chromaticity index of Na3EuB8O15 were studied. Under near-UV light excitation (393 nm), the polyborate shows an intense red emission, which mainly originates from the highest intensities of the 5D0→7F1 and 5D0→7F2 transitions.

Photoluminescence and Energy Transfer of Ce3+ and Tb3+ Co-Doped Ba5(PO4)3Cl Phosphor for Light-Emitting Diodes

2013 ◽  
Vol 401-403 ◽  
pp. 796-799 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Bing Xue ◽  
Guang Chao Sun
Keyword(s):  
Energy Transfer ◽  
Single Phase ◽  
Uv Light ◽  
Green Light ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Effective Energy Transfer ◽  
Light Excitation

Single-phase Ba5(PO4)3Cl:Ce3+,Tb3+ (BPCl:Ce3+,Tb3+) samples have been synthesized via solid-state reaction method. The phase structure and luminescence properties are characterized using powder X-ray diffraction (XRD), photoluminescence excitation and emission spectra. Effective energy transfer occurs from Ce3+ to Tb3+ due to the observed spectral overlap between the emission band of Ce3+ and the excitation band of Tb3+. Ce3+/Tb3+-codoped Ba5(PO4)3Cl shows more intense yellowish-green light compared to that of Tb3+-doped sample under UV light excitation.

Luminescent Properties of La3PO7:Eu3+ Nanoparticles

2008 ◽  
Vol 8 (3) ◽  
pp. 1410-1413 ◽  
Author(s):  
Shaozhe Lü ◽  
Jishen Zhang
Keyword(s):  
Charge Transfer Band ◽  
Emission Spectra ◽  
Local Environment ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Time Resolved ◽  
Transmission Electron ◽  
Light Excitation ◽  
Average Size

La3PO7:Eu3+ samples were prepared by combustion and annealing and characterized by X-ray diffraction and transmission electron microscopy. It was found that the average size of the particles is about 80 nm. The red emission from the 5D0 → 7F2 transition of the Eu3+ ions under ultraviolet light excitation is much stronger than the orange emission from the 5D0 → 7F1 transition. The emission spectra, charge transfer band, laser selective excitation spectra, and time-resolved spectra indicate that symmetry of the local environment of Eu3+ lacks an inversion center and Eu3+ ions occupy at least two types of sites in the La3PO7 crystal. The superior color chromaticity compared to other phosphates and borates doped with Eu3+ means La3PO7:Eu3+ may have potential as a luminescent material.

scholarly journals Novel red-emitting Lu3Te2Li3O12: Eu3+ phosphor with high color purity for n-UV WLEDs

2020 ◽  
Vol 185 ◽  
pp. 04044
Author(s):  
Mingyang Qu ◽  
Xiyan Zhang ◽  
Xiaoyun Mi ◽  
Quansheng Liu ◽  
Shaoqiu Xu
Keyword(s):  
Emission Spectra ◽  
Dipole Interaction ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Chromaticity Coordinate ◽  
Chromaticity Coordinates ◽  
Optimal Doping Concentration ◽  
Cie Chromaticity ◽  
First Time ◽  
High Color Purity

In this work, a series of red emitting Lu3Te2Li3O12: Eu3+ phosphors were synthesized for the first time by high temperature solid state reaction. The structure was characterized by X-ray diffraction. The excitation spectra, emission spectra and CIE chromaticity coordinate were studied. The phosphors show strong red emission at 611 nm due to the 5D0-7F2 transition of Eu3+ ions. The optimal doping concentration of Eu3+ in LTL host is x = 0.5 due to the concentration quenching mechanism of dipole-dipole interaction. The CIE chromaticity coordinates of the LTL: 0.5Eu3++ phosphor is (0.644,0.355), and the purity of the color is up to 93.61%. The phosphor can be considered as a potential red-emitting candidate for near UV WLEDs.

Luminescence Properties of Phosphor (Sr1-xBax) 1.95 SiO4: 0.05Eu2+

2015 ◽  
Vol 815 ◽  
pp. 304-308
Author(s):  
Zi Xu Jiang ◽  
Ke Hui Qiu ◽  
Xue Guang Lu ◽  
Kun Zhao ◽  
Xia He
Keyword(s):  
Intermediate Phase ◽  
Broad Band ◽  
Emission Spectra ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Barium Concentration ◽  
Light Excitation ◽  
Two Phases ◽  
Thermal Stability Of

The luminescence properties of green-yellow emitting (Sr1-xBax)1.95SiO4:0.05Eu2+ (0≤x≤1) phosphors were discussed in this paper. These phosphors were synthesized through the high temperature solid-state reaction technique and characterized by X-ray diffraction. The experimental results indicated that all the major phase of prepared phosphors gradually varied from α-Sr2SiO4 (x=0) phase to Ba2SiO4 (x=1) phase, and an intermediate phase between the two phases was observed at x=0.5. The excitation spectra (λem λem=524 nm) and emission spectra (λex λex=400 nm) showed a broad band character with peak located at 365 nm and range from 579 nm to 508 nm, respectively. With the increase of concentration of barium, the thermal stability of the phosphors increased first when x is less than 0.5, and then it decreased when x surpasses 0.5. In addition, luminescence intensity was enhanced with the barium concentration. Under the 400 nm NUV light excitation the (Sr1-xBax) 1.95SiO4:0.05Eu2+ phosphors have a potential application in white LED.

Photoluminescence and Energy Transfer from Sm3+ to Eu3+ in Na3YSi2O7 Phosphor for Light-Emitting Diodes

2014 ◽  
Vol 597 ◽  
pp. 117-120 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Qiu Mei Di ◽  
Qi Guang Xu ◽  
Liu Han
Keyword(s):  
Energy Transfer ◽  
Uv Light ◽  
Red Light ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Light Emitting ◽  
X Ray ◽  
Effective Energy Transfer ◽  
Light Excitation

A series of Na3YSi2O7: Eu3+, Sm3+ samples have been synthesized via solid-state reaction technique. The phase structure and luminescence properties are characterized using powder X-ray diffraction, photoluminescence excitation and emission spectra. Effective energy transfer occurs from Sm3+ to Eu3+ and Sm3+/Eu3+-codoped Na3YSi2O7 shows more intense red light compared to that of Eu3+-doped sample under UV light excitation.

scholarly journals Photoluminescence characteristics and energy transfer phenomena in Ce3+-doped YVO4 single crystal

2021 ◽  
Vol 28 (1) ◽  
pp. 205-214
Author(s):  
Shuai Wang ◽  
Pengfei Wang ◽  
Yongfeng Ruan ◽  
Youfa Wang ◽  
Shouchao Zhang
Keyword(s):  
Energy Transfer ◽  
Single Crystals ◽  
Emission Spectra ◽  
Czochralski Method ◽  
Color Temperature ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Chromaticity Coordinates ◽  
Diffraction Patterns ◽  
Cie Chromaticity

Abstract The undoped YVO4 and Ce3+-doped YVO4 single crystals have been successfully grown by the Czochralski method in a medium frequency induction furnace. The X-ray diffraction patterns testified that all samples exhibited the pure tetragonal YVO4 crystalline phase without any parasitic phases. The optical properties of Ce3+-doped YVO4 single crystals with different doping concentrations were investigated via a combination of absorption, emission, and excitation spectra. Dependence of luminescence and absorption intensity on Ce3+ doping concentration was discussed at different excitation wavelengths. The typical transitions of Ce3+ ions and the unusual intrinsic luminescent phenomena of VO 4 3 − {\text{VO}}_{4}^{3-} groups were observed and investigated in Ce3+-doped YVO4 crystals. More attentions were paid to ascertaining the corresponding transition states, analyzing luminescent mechanism, and revealing the energy transfer from VO 4 3 − {\text{VO}}_{4}^{3-} to Ce3+ ions. In addition, the CIE chromaticity coordinates and correlated color temperature were calculated on a basis of emission spectra under different excitation wavelengths.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

Syntheses, crystal structures and photoluminescence properties of two rare-earth molybdates CsLn(MoO4)2 (Ln=Eu, Tb)

2018 ◽  
Vol 233 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Dan Zhao ◽  
Fa-Xue Ma ◽  
Bao-Zhong Liu ◽  
Yun-Chang Fan ◽  
Xue-Feng Han ◽  
...  
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Layer Structure ◽  
Green Emission ◽  
Salt Flux ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Light Excitation ◽  
Rare Earth Molybdates

AbstractSingle crystals of two cesium rare-earth molybdates CsLn(MoO4)2(Ln=Eu, Tb) have been prepared using the high temperature molten salt (flux) method. Single-crystal X-ray diffraction analyses reveal that they crystallize in the orthorhombic space groupPccm(No. 49) and features a 2D layer structure that is composed of [Ln(MoO4)2]∞and [Cs]∞layers. Under near-UV light excitation, emission spectrum of CsEu(MoO4)2consists of several sharp lines due to the characteristic electronic transitions of Eu3+ions, whereas CsTb(MoO4)2exhibits characteristic green emission of Tb3+ions.

K3Eu5(PO4)6: hydrothermal synthesis, crystal structure and photoluminescence properties

2019 ◽  
Vol 75 (7) ◽  
pp. 883-890 ◽  
Author(s):  
Ya-Li Xue ◽  
Ai-Yun Zhang ◽  
Xiao-Yang Han ◽  
Xiao-Qi Cui ◽  
Ling Deng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Uv Light ◽  
Three Dimensional ◽  
Visible Region ◽  
Monoclinic Space Group ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Strong Luminescence ◽  
Light Excitation

An anhydrous orthophosphate, K3Eu5(PO4)6 (tripotassium pentaeuropium hexaphosphate), has been prepared by a high-temperature solid-state reaction combined with hydrothermal synthesis, and its crystal structure was determined by single-crystal X-ray diffraction analysis (SC-XRD). The results show that the compound crystallizes in the monoclinic space group C2/c and the structure features a three-dimensional framework of [Eu5(PO4)6]∞, with the tunnel filled by K+ ions. The IR spectrum, UV–Vis spectrum and luminescence properties of polycrystalline samples of K3Eu5(PO4)6, annealed at temperatures of 650, 700, 750, 800 and 850 °C, were investigated. Although with a full Eu3+ concentration (9.96 × 1021 ions cm−3), the self-activated phosphor K3Eu5(PO4)6 shows s strong luminescence emission intensity with a quantum yield of 37%. Under near-UV light excitation (393 nm), the series of samples shows the characteristic emissions of Eu3+ ions in the visible region from 575 to 715 nm. The sample sintered at 800 °C gives the strongest emission and its lifetime sintered at 800 °C (1.88 ms) is also the longest of all.

Study on UV Excitation Properties of Y2O3:Ln3+ (Ln = Eu3+ or Tb3+) Luminescent Nanomaterials

2008 ◽  
Vol 8 (3) ◽  
pp. 1443-1448 ◽  
Author(s):  
Qingyu Meng ◽  
Baojiu Chen ◽  
Xiaoxia Zhao ◽  
Xiaojun Wang ◽  
Wu Xu
Keyword(s):  
Particle Size ◽  
Charge Transfer ◽  
Charge Transfer Band ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
Excitation Spectra ◽  
X Ray ◽  
Long Wavelength ◽  
Uv Excitation

Y2O3:Ln3+ (Ln = Eu or Tb) nanocrystals with different Ln3+ doping concentrations and average sizes were prepared by chemical self-combustion. The corresponding bulk materials with various doping concentrations were obtained by annealing the nanomaterials at high temperature. The emission spectra, excitation spectra, and X-ray diffraction spectra were used in this study. It was found that the charge transfer band of Y2O3:Eu3+ red-shifted as particle size decreased, and the charge transfer band in the 5-nm particles obviously broadened toward the long wavelength. It was also found that the profile of excitation spectra corresponding to the 4f5d (4f8 → 4f75d1) transition changed a lot with the variation of the particle size. The dependence of the excitation spectra of Y2O3:Ln3+ on particle size was investigated.

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