Sol–gel-derived transparent silica–(Gd,Pr)PO4 glass-ceramic narrow-band UVB phosphors

2018 ◽  
Vol 47 (35) ◽  
pp. 12085-12091
Author(s):  
Mayu Suda ◽  
Ryosui Nakagawa ◽  
Kiyoshi Kanamura ◽  
Koichi Kajihara
Keyword(s):  
Rare Earth ◽  
Quantum Efficiency ◽  
Glass Ceramic ◽  
External Quantum Efficiency ◽  
Narrow Band ◽  
Internal Quantum Efficiency ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Rare Earth Ions

Transparent sol–gel-derived silica–(Gd,Pr)PO4 glass-ceramics free from inert rare-earth ions exhibit narrow-band UVB photoluminescence from Gd3+ ions at ∼313 nm with internal quantum efficiency close to unity and external quantum efficiency higher than 0.9 under excitation into the 5d state of Pr3+ ions.

scholarly journals SiO2-SnO2:Er3+ Glass-Ceramic Monoliths

2018 ◽  
Author(s):  
Lam Thi Ngoc Tran ◽  
Damiano Massella ◽  
Lidia Zur ◽  
Alessandro Chiasera ◽  
Stefano Varas ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Sensors ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Building Blocks ◽  
Spectroscopic Properties ◽  
Silica Matrix ◽  
Rare Earth Ions ◽  
Planar Waveguides

The development of efficient luminescent systems, such as microcavities, solid state lasers, integrated optical amplifiers, optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare earth ions because they exhibit specific morphologic, structural and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in silica matrix, tin dioxide presents some interesting peculiarities, e.g. the presence of tin dioxide nanocrystals allows increase in both solubility and emission of rare earth ions. Here, we focus our attention on Er3+ - doped silica – tin dioxide photonic glass-ceramics fabricated by sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different geometrical systems: thin films, monoliths and planar waveguides we herein limit ourselves to the monoliths. The effective role of tin dioxide as luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.

High Efficiency Light Emission Devices in Silicon

2003 ◽  
Vol 770 ◽  
Author(s):  
Maria E. Castagna ◽  
Salvatore Coffa ◽  
Mariantonietta Monaco ◽  
Anna Muscara' ◽  
Liliana Caristia ◽  
...  
Keyword(s):  
Rare Earth ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Gate Dielectric ◽  
Chemical Vapour ◽  
Rare Earth Ions ◽  
Hot Electrons ◽  
Light Emitting ◽  
The Rare Earth

AbstractWe report on the fabrication and performances of the most efficient Si-based light sources. The devices consist of MOS structures with erbium (Er) implanted in the thin gate oxide. The devices exhibit strong 1.54 μm electroluminescence at 300K with a 10% external quantum efficiency, comparable to that of standard light emitting diodes using III-V semiconductors. Emission at different wavelenghts has been achieved incorporating different rare earths (Ce, Tb, Yb, Pr) in the gate dielectric. The external quantum efficiency depends on the rare earth ions incorporated and ranges from 10% (for an Tb doped MOS) to 0.1% (for an Yb doped MOS). RE excitation is caused by hot electrons impact and oxide wearout limits the reliability of the devices. Much more stable light emitting MOS devices have been fabricated using Er-doped SRO (Silicon Rich Oxide) films as gate dielectric. These devices show a high stability, with an external quantum efficiency reduced to 0.2%. In these devices Er pumping occurs part by hot electrons and part by energy transfer from the Si nanostructures to the rare earth ions, depending by Si excess in the film. Si/SiO2 Fabry-Perot microcavities have been fabricated to enhance the external quantum emission along the cavity axis and the spectral purity of emission from the films that are used as active media to realize a Si based RCLED (resonant cavity light emitting diode). These structures are realized by chemical vapour deposition on a silicon substrate. The microcavities are tuned at different wavelengths: 540nm, 980nm and 1540nm (characteristic emission wavelengths respectively for Tb, Yb and Er). The reflectivity of the microcavities is of 97% and the quality factor ranges from 60 (for the cavity tuned at 980nm) to 95 (for the cavities tuned at 540nm and 1540nm).

scholarly journals SiO2-SnO2:Er3+ Glass-Ceramic Monoliths

2018 ◽  
Vol 8 (8) ◽  
pp. 1335 ◽  
Author(s):  
Lam Tran ◽  
Damiano Massella ◽  
Lidia Zur ◽  
Alessandro Chiasera ◽  
Stefano Varas ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Sensors ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Building Blocks ◽  
Spectroscopic Properties ◽  
Silica Matrix ◽  
Rare Earth Ions ◽  
Planar Waveguides

The development of efficient luminescent systems, such as microcavities, solid-state lasers, integrated optical amplifiers, and optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare-earth ions because they exhibit specific morphologic, structural, and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in a silica matrix, tin dioxide presents some interesting peculiarities, e.g., the presence of tin dioxide nanocrystals allows an increase in both solubility and emission of rare-earth ions. Here, we focus our attention on Er3+—doped silica—tin dioxide photonic glass-ceramics fabricated by a sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different forms, such as thin films, monoliths, and planar waveguides, we herein limit ourselves to the monoliths. The effective role of tin dioxide as a luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.

Photoluminescence Properties and Quantum Efficiency of Eu3+/Mn2+- Doped ZnMoO4 Red Phosphor

2020 ◽  
Vol 843 ◽  
pp. 70-78
Author(s):  
Fan Chen ◽  
Mustafa Hasan Balci ◽  
He Xin Xia ◽  
Muhammad Nadeem Akram ◽  
Xu Yuan Chen
Keyword(s):  
Rare Earth ◽  
Quantum Efficiency ◽  
Lattice Structure ◽  
Internal Quantum Efficiency ◽  
Sol Gel ◽  
Radiative Transition ◽  
Integrating Sphere ◽  
Photoluminescence Properties ◽  
Excitation Peak ◽  
Rare Earth Doped

In this work, fabrication and characterization of a nanostructured rare-earth-doped ZnMoO4 will be reported. Photoluminescence properties and quantum efficiency of the rare-earth-doped ZnMoO4 with different dopant concentrations have been investigated. These samples were synthesized by sol-gel method. Lattice structure of the fabricated samples was characterized by X-ray powder diffraction (XRD); absorption spectrum was performed on UV-2600 photo spectrometer; PL excitation and emission spectra were recorded by Fluorescence Spectrometers; quantum efficiency was measured by an integrating sphere photoluminescence (PL) system. The results showed that the optimized doping concentration of Eu3+ was around 10 mol% for the highest quantum efficiency at 616 nm emission peak and 465 nm excitation peak. The highest internal quantum efficiency was 91% at low power density excitation (around 50 μW/mm2). Introduction of Mn2+ to Eu3+-doped ZnMoO4 lead to reduced quantum efficiency and electronic lifetime, which can be attributed to defects inside the crystal lattice and energy transfer from Eu3+ to Mn2+ (more non-radiative transition occur).

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

Novel Glass-Ceramics for Dental Application by Sol Gel Technique

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Preparation Method ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Dental Restorations ◽  
Gel Technique ◽  
Gel Preparation ◽  
Dental Applications ◽  
Potential Use

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.

A Unique Approach to Characterization of Sol-Gel-Derived Rare-Earth-Doped Oxyfluoride Glass-Ceramics

2012 ◽  
Vol 96 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Go Kawamura ◽  
Ryota Yoshimura ◽  
Kazunari Ota ◽  
Song-Yul Oh ◽  
Norio Hakiri ◽  
...  
Keyword(s):  
Rare Earth ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Oxyfluoride Glass ◽  
Unique Approach ◽  
Rare Earth Doped

Structural evolution of luminescence nanoparticles with rare-earth ions in the oxyfluoride glass ceramics

2019 ◽  
Vol 237 ◽  
pp. 121830 ◽  
Author(s):  
S.E. Kichanov ◽  
Yu.E. Gorshkova ◽  
G.E. Rachkovskaya ◽  
D.P. Kozlenko ◽  
G.B. Zakharevich ◽  
...  
Keyword(s):  
Rare Earth ◽  
Glass Ceramics ◽  
Structural Evolution ◽  
Rare Earth Ions ◽  
Oxyfluoride Glass

The distribution of rare earth ions in a γ-Ga2O3 nanocrystal-silicate glass composite and its influence on the photoluminescence properties

2018 ◽  
Vol 6 (12) ◽  
pp. 2944-2950 ◽  
Author(s):  
Zhigang Gao ◽  
Xiaosong Lu ◽  
Yushi Chu ◽  
Shu Guo ◽  
Lu Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Silicate Glass ◽  
Glass Ceramic ◽  
Glassy Phase ◽  
Rare Earth Ions ◽  
Photoluminescence Properties ◽  
Glass Composite ◽  
Surface Doping ◽  
Phase Surface

The partitioning of rare earth ions (REs: Yb3+, Er3+, Eu3+ and Nd3+) in γ-Ga2O3 nanocrystals (NCs) precipitated in a nanostructured silicate glass ceramic is revealed, and the enrichment of REs in the NCs (bulk doping) rather than on the interfaces between the NCs and the surrounding glassy phase (surface doping) is differentiated.

scholarly journals Promoting luminescence of Yb/Er codoped ferroelectric composite by polarization engineering for optoelectronic applications

Nanophotonics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 2215-2223 ◽  
Author(s):  
Er Pan ◽  
Gongxun Bai ◽  
Yutao Peng ◽  
Liang Chen ◽  
Shiqing Xu
Keyword(s):  
Rare Earth ◽  
Electric Field ◽  
Electrical Resistance ◽  
Near Infrared ◽  
Optoelectronic Devices ◽  
Glass Ceramics ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Luminescent Materials ◽  
Crystal Structural

AbstractFerroelectric oxide nanocrystals, in combination with the robust coupling of an electric field with crystal structure symmetry, makes such systems agreeable to field-induced crystal structural transformation. The luminescent properties of rare earth ions are sensitive to the symmetry of the surrounding crystal field. The luminescence tuning of rare earth ions is an important assignment in the research of luminescent materials. However, the current conditional feasibility and reversibility in the exploration of luminescence modification remain major challenges. In this article, the luminescence modulation of rare earth ions has been developed in Yb3+/Er3+ codoped ferroelectrics glass ceramics containing Bi4Ti3O12 nanocrystals through an electric field. The inclusion of nanocrystals in the glass matrix greatly enhances the electrical resistance. Both upconversion and near-infrared emissions of rare earth ions are effectively enhanced more than twice via polarization engineering. The electric field regulates the photonic properties of rare earth ions with excellent reversibility and nonvolatility in ferroelectrics. The effective modification by electric field provides a new scheme for optical storage and optoelectronic devices.

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