scholarly journals Ag-Sensitized Yb3+ Emission in Glass-Ceramics

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 380 ◽  
Author(s):  
Francesco Enrichi ◽  
Elti Cattaruzza ◽  
Maurizio Ferrari ◽  
Francesco Gonella ◽  
Riccardo Ottini ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Near Infrared ◽  
Uv Light ◽  
Sol Gel ◽  
Rare Earth Ions ◽  
Information Storage ◽  
Efficient Energy Transfer ◽  
Doped Materials ◽  
The Rare Earth

Rare earth doped materials play a very important role in the development of many photonic devices, such as optical amplifiers and lasers, frequency converters, solar concentrators, up to quantum information storage devices. Among the rare earth ions, ytterbium is certainly one of the most frequently investigated and employed. The absorption and emission properties of Yb3+ ions are related to transitions between the two energy levels 2F7/2 (ground state) and 2F5/2 (excited state), involving photon energies around 1.26 eV (980 nm). Therefore, Yb3+ cannot directly absorb UV or visible light, and it is often used in combination with other rare earth ions like Pr3+, Tm3+, and Tb3+, which act as energy transfer centres. Nevertheless, even in those co-doped materials, the absorption bandwidth can be limited, and the cross section is small. In this paper, we report a broadband and efficient energy transfer process between Ag dimers/multimers and Yb3+ ions, which results in a strong PL emission around 980 nm under UV light excitation. Silica-zirconia (70% SiO2-30% ZrO2) glass-ceramic films doped by 4 mol.% Yb3+ ions and an additional 5 mol.% of Na2O were prepared by sol-gel synthesis followed by a thermal annealing at 1000 °C. Ag introduction was then obtained by ion-exchange in a molten salt bath and the samples were subsequently annealed in air at 430 °C to induce the migration and aggregation of the metal. The structural, compositional, and optical properties were investigated, providing evidence for efficient broadband sensitization of the rare earth ions by energy transfer from Ag dimers/multimers, which could have important applications in different fields, such as PV solar cells and light-emitting near-infrared (NIR) devices.

Photolumineszenz und Energietransfer in Seltenerd-aktivierten Granat Gd3Te2Li3O12 / Photolwninescence and Energy Transfer in the Rare Earth Activated Garnet Gd3Te2Li3O12

1984 ◽  
Vol 39 (5) ◽  
pp. 490-494 ◽  
Author(s):  
B. Köngeter ◽  
S. Kemmler-Sack
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Visible Emission ◽  
Luminescence Properties ◽  
Trivalent Rare Earth ◽  
The Rare Earth

By activation of the cubic garnet host lattice Gd3Te2Li3O12 with trivalent rare earth ions the most intense visible emission is observed for Ln3+ = Eu, Tb. Energy transfer from Gd3+ to Sm3+, Eu3+ or Dy3+, from Tb3+ to Eu3+ and from Er3+ to Tm3+ has been found to occur. The luminescence properties are strongly influenced by the substitution of Te6+ by W6+ (systems Gd3-xLnxTe2-yWyLi3O12)

Preparation and tunable luminescence of CaCO3:Eu3+,Dy3+ phosphors

2014 ◽  
Vol 07 (04) ◽  
pp. 1450038 ◽  
Author(s):  
Yanwei Dong ◽  
Ming Kang ◽  
Ping Zhang ◽  
Qijun Cheng ◽  
Jie Wang
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Host Lattice ◽  
Rare Earth Ions ◽  
Precipitation Method ◽  
Scanning Calorimetry ◽  
Chromaticity Coordinates ◽  
Co Precipitation ◽  
Co Doped ◽  
The Rare Earth

Phosphors based on calcium carbonate, co-doped with various Eu 3+ and Dy 3+ concentrations were prepared by microwave co-precipitation method. The prepared phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TG-DSC) and photoluminescence and photoluminescence excitation (PL-PLE) spectroscopy. Results showed that Dy 3+ and Eu 3+ ions were uniformly introduced into the host lattice of CaCO 3 taking the place of Ca 2+ ions. Under the excitation at 382 nm, the emission peak wavelengths were at 487 nm (4 F 9/2 → 6 H 15/2 of Dy 3+), 576 nm (4 F 9/2 → 6 H 13/2 of Dy 3+), and 614 nm (5 D 0 → 7 F 2 of Eu 3+). The luminescent intensities and emitting colors of Eu 3+- Dy 3+ co-doped CaCO 3 phosphors could be controlled by UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+ in phosphors. The chromaticity coordinates and photographs of samples under UV light showed the changes of the luminescence color intuitively through the varing UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+.

Local symmetry and Z-scan analysis of ZnSe/Eu3+ doped sol–gel silica hosts

2010 ◽  
Vol 88 (7) ◽  
pp. 493-500 ◽  
Author(s):  
Siby Mathew ◽  
K. V. Arun Kumar ◽  
C. Sudarsanakumar ◽  
V. P.N. Nampoori ◽  
N. V. Unnikrishnan
Keyword(s):  
Rare Earth ◽  
Sol Gel ◽  
Glass Network ◽  
Local Symmetry ◽  
Wide Distribution ◽  
Rare Earth Ions ◽  
Saturable Absorption ◽  
Rare Earth Ion ◽  
Enhanced Absorption ◽  
The Rare Earth

Vibrational state side-band spectral analysis of silica matrices, doped with ZnSe/Eu3+ ions, associated with the excitation transition 7F0→5D2 is used to analyze the local asymmetry of the rare earth ions in the glass host. The large inhomogeneous linewidth for the ZnSe co-doped samples indicates the wide distribution of the Eu3+ ions in the matrix and is related to the flexibility of the local glass network. The fluorescence spectra reveal that the intensity of the characteristic emission of europium increases considerably in the presence of ZnSe particles. This phenomenon can be explained by the energy transfer resulting from electron–hole recombination in the ZnSe to the rare earth ion. Nonlinear optical absorption of the sample is also investigated at a wavelength of 532 nm, using open aperture Z-scan technique. The sample exhibits reversible saturable absorption (RSA), which is found to depend on excitation fluence. RSA is due to the enhanced absorption resulting from the electron dynamics in nano-crystallites.

scholarly journals Enhanced Optical Properties of Germanate and Tellurite Glasses Containing Metal or Semiconductor Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Cid Bartolomeu de Araujo ◽  
Diego Silvério da Silva ◽  
Thiago Alexandre Alves de Assumpção ◽  
Luciana Reyes Pires Kassab ◽  
Davinson Mariano da Silva
Keyword(s):  
Optical Properties ◽  
Energy Transfer ◽  
Rare Earth ◽  
Semiconductor Nanoparticles ◽  
Rare Earth Ions ◽  
Tellurite Glasses ◽  
All Optical ◽  
Gold Nps ◽  
Anti Stokes ◽  
The Rare Earth

Germanium- and tellurium-based glasses have been largely studied due to their recognized potential for photonics. In this paper, we review our recent studies that include the investigation of the Stokes and anti-Stokes photoluminescence (PL) in different glass systems containing metallic and semiconductor nanoparticles (NPs). In the case of the samples with metallic NPs, the enhanced PL was attributed to the increased local field on the rare-earth ions located in the proximity of the NPs and/or the energy transfer from the metallic NPs to the rare-earth ions. For the glasses containing silicon NPs, the PL enhancement was mainly due to the energy transfer from the NPs to the Er3+ions. The nonlinear (NL) optical properties of PbO-GeO2films containing gold NPs were also investigated. The experiments in the pico- and subpicosecond regimes revealed enhanced values of the NL refractive indices and large NL absorption coefficients in comparison with the films without gold NPs. The reported experiments demonstrate that germanate and tellurite glasses, having appropriate rare-earth ions doping and NPs concentration, are strong candidates for PL-based devices, all-optical switches, and optical limiting.

THE SOL–GEL SYNTHESIS OF RARE-EARTH IONS SUBSTITUTED BARIUM HEXAFERRITES AND MAGNETIC PROPERTIES

2013 ◽  
Vol 27 (26) ◽  
pp. 1350192 ◽  
Author(s):  
S. CAI ◽  
P. H. XIN ◽  
P. F. WANG ◽  
B. B. ZHANG ◽  
Y. B. HAN ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Magnetic Moments ◽  
Sol Gel ◽  
Barium Hexaferrite ◽  
Anisotropy Field ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
Barium Hexaferrites ◽  
The Rare Earth

In this paper, a series of rare-earth-doped barium hexaferrite powders ( Ba 0.95 Re 0.05- Fe 12 O 19 and Ba 0.95 Re 0.05 M 0.05 Fe 11.95 O 19: Re = La , Pr , Sm , Nd , Gd , Dy , Yb ; M = Zn 2+, Mn 2+, [Formula: see text]) were synthesized by the sol–gel self-combustion technology. The phase composition and the magnetic properties of the as-prepared barium hexaferrites were characterized and discussed with X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results showed that the barium hexaferrites exhibited the magnetoplumbite phase structure with the average diameter of 45 nm. Magnetic properties study revealed that the variation of the saturation magnetization (Ms) was similar with the change of the rare-earth ions radius, but the change of Ms was low. This indicated that the magnetic moments of rare-earth ions could not affect Ms. The magnetocrystalline anisotropy field mainly influenced the anisotropism of hexaferrites, and the coercivity (Hc) of the rare-earth ions doped barium hexaferrites basically decreased with the increasing orbital quantum numbers (except Sm 3+ and Gd 3+). Further study showed the co-addition of Zn 2+ and Mn 2+ did not change the trend of Ms and Hc. Thus, it is concluded that the rare-earth ions played an important role for the anisotropy field of barium hexaferrites.

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