VUV-Photoluminescence Properties of (Gd, La)2O2CO3: Eu3+

2014 ◽  
Vol 1052 ◽  
pp. 203-206
Author(s):  
Zhi Long Wang ◽  
Shi Qin Wang ◽  
Nin Yao ◽  
Xing Min Wei
Keyword(s):  
Charge Transfer ◽  
Vacuum Ultraviolet ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Photoluminescence Properties ◽  
Flux Method ◽  
Excitation Spectra ◽  
Red Emission ◽  
Ultraviolet Excitation

(Gd,La)2-x O2CO3:Eux3+(0.01 ≤x≤0.04) were synthesized via a flux method at 400°C, and their photoluminescence properties under vacuum ultraviolet (VUV) excitation were examined. The excitation spectra showed two bands in the region from 125 nm to 300 nm, the first band centered at 190 nm was ascribed to absorption of related CO32- complex, and the second broad band centered at 246nm and 278nm in Gd2O2CO3:Eu3+ was ascribed to the charge transfer band of O2-→ Eu3+. Series samples exhibited red emission at around 611 nm under vacuum ultraviolet excitation corresponding to the 5D0→ 7F2.transition of Eu3+.

Photoluminescence behavior of Al3+, Pr3+ doped perovskite La2/3TiO3 and pyrochlore La2Ti2O7

2001 ◽  
Vol 16 (9) ◽  
pp. 2568-2571 ◽  
Author(s):  
J. K. Park ◽  
C. H. Kim ◽  
K. J. Choi ◽  
H. D. Park ◽  
S. Y. Choi
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Charge Transfer Band ◽  
Critical Distance ◽  
Photoluminescence Properties ◽  
Red Emission ◽  
Pyrochlore Type ◽  
Perovskite Type ◽  
Photoluminescence Behavior

The purpose of this study is to develop an understanding of the photoluminescence properties of Al3+, Pr3+ doped perovskite-type La2/3TiO3 and pyrochlore-type La2Ti2O7 phosphor, which is characterized by the red emission (1D2 →3H4 transition) of the Pr3+ ion. The explanation for the energy transfer and the corresponding critical distance is proposed on the basis of the role of Al3+ ions in the perovskite-type La2/3TiO3:Pr phosphor. To clarify the distinction of photoluminescence properties between the perovskite-type La2/3TiO3 and the pyrochlore-type La2Ti2O7, the trap-involved process and the charge transfer band have been investigated, respectively.

scholarly journals Synthesis and Luminescent Properties of Eu3+/Tb3+ Rare Earth Ions Doped Li2SrSiO4 Phosphors

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Kaitao Yu ◽  
Lifang Wei ◽  
Jiaqi Shen
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Luminescent Materials ◽  
Excitation Spectra ◽  
Solid State Method ◽  
X Ray ◽  
Uv Visible

The series of luminescent materials of Eu3 +, Tb3 + doped Li2SrSiO4 were synthesized by a high-temperature solid-state method. The phase purity of the samples was measured by X-ray powder diffraction (XRD). The luminescent properties of the samples were studied by UV-visible excitation spectra and emission spectra The It is found that the strong absorption of Eu3 + doped Li2-xSr1-xEuxSiO4 is from the 250 ~ 290 nm charge transfer band of Eu3 + and the 7F0 → 5L6 absorption transition of 393 nm. The strongest emission of the emission spectra at 393 nm is 614 nm and 701 nm, respectively, from the 5D0 → 7F2 and 5D0 → 7F4 transitions of Eu3 +. Tb3 + doped sample Li2-xSr1-xTb xSiO4 excitation spectrum is mainly composed of Tb3 + ion fd transition and charge transfer band composed of broadband, the strongest absorption at 269 nm, the emission of the main emission of 5D4 → 7F5 transition (542 nm).

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.

Photoluminescence Properties and Energy Transfer in a Novel Yellow Emitting Phosphor GdTaO4:Dy3+

2016 ◽  
Vol 16 (4) ◽  
pp. 3994-3997 ◽  
Author(s):  
Huijuan Zhang ◽  
Xinyu Tan ◽  
Yuhua Wang
Keyword(s):  
Energy Transfer ◽  
Vacuum Ultraviolet ◽  
Emission Spectra ◽  
Host Lattice ◽  
Excitation Spectra ◽  
Light Emitting ◽  
Ultraviolet Excitation ◽  
Plasma Display Panels ◽  
Chromaticity Coordinates ◽  
Plasma Display

The phosphor Dy3+ doped M type gadolinium orthotantalate GdTaO4 was prepared successfully by traditional solid state reaction and the photoluminescence of GdTaO4: xDy3+ (0.01 ≤ x ≤ 0.10) has been investigated under ultraviolet and vacuum ultraviolet excitation. In the excitation spectra of GdTaO4:Dy3+, the overlap appears between the host lattice excitation, the excitation lines of Gd3+ and the f–f transitions of Dy3+, which indicates that the energy transfer could occur from the host to the Dy3+ ions. In the emission spectra of the samples, the intense emissions of Dy3+ have been expectably revealed both upon excitation at 365 nm and 147 nm. And the chromaticity coordinates of GdTaO4: xDy3+ have been correspondingly calculated. The results indicate that GdTaO4:Dy3+ would be a novel yellow emitting phosphor applied in light emitting diodes (LEDs), plasma display panels (PDPs) and mercury-free fluorescent tubes.

Photoluminescence properties of YAG:Tb nano-powders under vacuum ultraviolet excitation

2009 ◽  
Vol 485 (1-2) ◽  
pp. 561-564 ◽  
Author(s):  
Guifang Li ◽  
Quanxi Cao ◽  
Zhimin Li ◽  
Yunxia Huang ◽  
Yunge Wei ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
Photoluminescence Properties ◽  
Ultraviolet Excitation

Red and Green Phosphors Glow on the Basis of Oxide Glass-Ceramics Doped with Eu3+ and Tb3+

2015 ◽  
Vol 670 ◽  
pp. 107-112 ◽  
Author(s):  
Seseg Yu. Tsyretarova ◽  
Nina M. Kozhevnikova ◽  
Nina S. Ereminа ◽  
Gennady M. Mokrousov
Keyword(s):  
Emission Spectrum ◽  
Glass Ceramic ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Glass Ceramics ◽  
Green Emission ◽  
Luminescent Properties ◽  
Inorganic Materials ◽  
Oxide Glass ◽  
Excitation Spectra

Glass-ceramics phosphors were obtained by the introduction of the crystalline phase NaMg3Sc (MoO4)5:Eu3+,Tb3+ in the glass composition 8SiO2-20B2O3-5Lu2O3-31Bi2O3-36ZnO. The properties were characterized by X-ray diffraction (XRD), photoluminescence (PL) and photoluminescent excitation spectra (PLE). The XRD patterns were indicated NaMg3Sc (MoO4)5:Eu3+,Tb3+ crystallize well with the novel structure type and were assigned to the triclinic phase (space group PĪ, Z = 6). Glass-ceramic phosphors are well-known and promising as solid electrolytes, laser, luminescent and other inorganic materials. Luminescent properties of the phosphors are performed at room temperature. The excitation spectra of Eu-doped phosphor present strong absorption at 300 nm and the sharp peaks in the 350-500 nm range. Under the 394 nm excitation, intense red emission peak at 616 nm corresponding to 5D0→7F2 transition of Eu3+ is observed in the emission spectrum. The luminescence property indicates that the local symmetry of Eu3+ ion has no inversion center. The excitation spectra of Tb-doped phosphor by monitoring wavelength at 546 nm shows the intense broad band from 260 to 420 nm and the line at 234 nm, which is mainly attributed to charge-transfer band transition in MoO42- group, indicating the existence of energy transfer from MoO42- to Tb3+ in the Tb3+:glass-ceramic. The measured emission spectrum of Tb-doped phosphor has intense green emission at 546 nm corresponding to 5D4→7F5 transition of Tb3+, with λex=368 nm. The as-prepared phosphors may find potential applications in the field such as color displays, light-emitting diodes (LEDs) and optoelectronic devices.

UV-vis and Binding Studies of Cobalt Tetrasulfophthalocyanine–Thiolate Complexes as Intermediates of the Merox Process

1999 ◽  
Vol 03 (07) ◽  
pp. 654-666 ◽  
Author(s):  
ALI NAVID ◽  
EDUARD M. TYAPOCHKIN ◽  
CHARLES J. ARCHER ◽  
EVGUENII I. KOZLIAK
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Spectral Feature ◽  
Binding Constants ◽  
Kinetic Studies ◽  
Binding Studies ◽  
Π Stacking ◽  
Vis Spectroscopy ◽  
Major Factors

Intermediates of the cobalt tetrasulfophthalocyanine ( CoTSPc )-catalyzed thiol autoxidation were studied by UV-vis spectroscopy. All thiolates react with CoTSPc resulting in the formation of 1:1 complexes. Three major factors control both the stability and aggregation of the complexes: thiolate basicity, metal-to-ligand charge transfer (MLCT) and π stacking. Basic thiolates partially reduce C oII TSPc , whereas CoTSPc complexes with low-basicity aliphatic thiolates ( p K a < 4) do not exhibit Co (II) reduction, based on the absence of the characteristic Co (I) charge transfer band at 450 nm. CoTSPc complexes with aliphatic and bulky aromatic thiolates appear to be aggregated in aqueous solutions and are characterized by a broad band at 650 nm. Non-bulky aromatic thiolates of low basicity ( p K a < 6) form unique stable monomeric Co II TSPc complexes. This unique spectral feature can be attributed to π stacking between the phthalocyanine ring and thiolate. Comparison of binding constants shows that the partial reduction of Co (II) significantly contributes to the thiolate binding. A combination of aromatic π stacking and MLCT appears to be responsible for the observed 1000-fold stronger binding of non-basic aromatic thiolates as compared with aliphatic ligands of similar basicity. Kinetic studies confirm the importance of the thiolate binding type for catalysis.

Sol-Gel Deposition and Luminescence Properties of Spherical Phosphors Ca2Y8(SiO4)6O2:Eu3+

2008 ◽  
Vol 368-372 ◽  
pp. 378-380
Author(s):  
Xiu Mei Han ◽  
J. Lin ◽  
M. Yu ◽  
C.K. Lin ◽  
Xi Wei Qi ◽  
...  
Keyword(s):  
Grain Size ◽  
Charge Transfer ◽  
Diffraction Analysis ◽  
Charge Transfer Band ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Red Emission ◽  
X Ray ◽  
Average Grain Size ◽  
Sol Gel Process

Spherical SiO2 particles were coated with Ca2Y8(SiO4)6O2:Eu3+ phosphor layers through a sol-gel process. The results of XRD (X-ray diffraction) analysis indicated that the phosphors crystallized completely at 1000oC. AFM study revealed that the average grain size is 500 nm. In Ca2Y8(SiO4)6O2:Eu3+ spherical phosphors , the Eu3+ showed its characteristic red emission at 612 nm(5D0-7F2) upon excitation into its charge transfer band of Eu3+-O2- at 242nm.

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