Luminescence Behavior of Organo-Ruthenium Complexes Entrapped Within Sol-Gel Hosts

1993 ◽  
Vol 329 ◽  
Author(s):  
Lowell R. Matthews ◽  
Xiao-Jun Wang ◽  
E. T. Knobbe
Keyword(s):  
Ruthenium Complex ◽  
Sol Gel ◽  
Emission Spectra ◽  
Visible Spectrum ◽  
Europium Complex ◽  
Matrix Composition ◽  
Strong Fluorescence ◽  
Optical Source ◽  
Luminescence Characteristics ◽  
Luminescence Behavior

AbstractCompounds of europium(III) and ruthenium(II) are of interest for potential optical source applications in the red portion of the visible spectrum. Our previous work showed that the organo-europium complex tris(4,4,4-trifluoro-l-(2′-thienyl)-l,3-butanedionato-O, O′)europium( III), Eu(ttfa)3, demonstrated superior fluorescence properties to salts like europium(III) chloride when doped into sol-gel materials. The ruthenium complex tris(2,2′- bipyridyl)ruthenium(II) chloride, ‘Ru(bpy)3’Cl2, also shows strong fluorescence when doped into sol-gel materials.Luminescence behavior of the ‘;Ru(bpy)3’Cl2 complex has been investigated as a function of matrix composition using three sol-gel-derived hosts: silica, an acrylate ORMOSIL, and an epoxide ORMOSIL. Luminescence characteristics have also been studied as a function of fluorophore concentration. Fluorescence lifetime, excitation and emission spectra, and quantum efficiency values have been determined.

Preparation of Y4MgSi3O13:Tb3+,Ce3+ Green Emitting Phosphor for White Light Emitting Diodes and its Luminescence Study

2011 ◽  
Vol 415-417 ◽  
pp. 1333-1339
Author(s):  
Guo Hua Song ◽  
Bin Jiang ◽  
Jian Wen Miao ◽  
Bang Dong Ding
Keyword(s):  
Sol Gel ◽  
Emission Spectra ◽  
Green Emission ◽  
Green Phosphor ◽  
Preparation Temperature ◽  
Light Emitting ◽  
Optimal Doping ◽  
Optimal Doping Concentration ◽  
White Light Emitting Diodes ◽  
Luminescence Characteristics

The Y4MgSi3O13:Tb3+,Ce3+green phosphors are synthesized by sol-gel method, the preparation temperature, reduction atmosphere and luminescence characteristics of Y4MgSi3O13doped with single Ce3+ions and Ce3+,Tb3+ions have been studied. The excitation and emission spectra of phosphors is determined by fluorescence spectrophotometer. The results show that: luminous intensity of Y4MgSi3O13:Tb3+phosphors increased after doped with Ce3+ions and the optimal doping concentration of Ce3+is 0.04. Y3.94MgSi3O13: 0.02Tb3+,0.04Ce3+green phosphor has the best luminescence characteristics under reduction atmosphere(H2:N2=1:3) at 1000°C, the phosphor gives intense green emission at 550nm originating from the5D4→7F5transition of Tb3+ions.

Luminescence of Rare Earth Metalorganic Complexes in Sol-Gel Derived Host Materials

1992 ◽  
Vol 286 ◽  
Author(s):  
Lowell R. Matthews ◽  
E. T. Knobbe
Keyword(s):  
Rare Earth ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Inorganic Salts ◽  
Optical Source ◽  
Matrix Interaction ◽  
Host Materials ◽  
Sol Gel Process ◽  
Intense Emission ◽  
Luminescence Behavior

ABSTRACTThe narrow, intense emission bands of europium(III) make its compounds of interest for various optical source applications. Previous studies have shown that europium thenoyltrifluoroacetonate complexes, e.g. Eu(TTFA)3, have superior fluorescence properties in select media with respect to inorganic salts like EuCl3. It has been shown that such complexes may be incorporated into solid-state matrices via the sol-gel process. The present research examines the luminescence behavior of a metalorganic complex (Eu(TTFA)3) doped into a sol-gel derived silica-acrylate ORMOSIL host and extends our earlier work on doped silica gel materials. The present study focuses on the effects of dopant concentration and dopant-matrix interaction, and seeks to compare the behavior of Eu(ITFA)3 in silica and ORMOSIL gel host materials.

scholarly journals Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 937
Author(s):  
Katarzyna Halubek-Gluchowska ◽  
Damian Szymański ◽  
Thi Ngoc Lam Tran ◽  
Maurizio Ferrari ◽  
Anna Lukowiak
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Emission Spectra ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Diffraction Patterns ◽  
Size Of Particles ◽  
Average Size

Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

Synthesis of Cu Loaded TiO2 Nanoparticles for the Improved Photocatalytic Degradation of Rhodamine B

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660002 ◽  
Author(s):  
V. Kavitha ◽  
P. S. Ramesh ◽  
D. Geetha
Keyword(s):  
Titanium Dioxide ◽  
Rhodamine B ◽  
Sol Gel ◽  
Average Particle Size ◽  
Visible Spectrum ◽  
Xrd Analysis ◽  
Bandgap Energy ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
Photoexcited Electron

Copper doped Titanium dioxide TiO2 nanoparticles were synthesized by sol–gel method using titanium tetraisopropoxide and copper sulfate as precursors. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), Photoluminesce spectroscopy (PL) and atomic force microscopy (AFM). XRD analysis confirms the formation of anatase titanium dioxide and average particle size was 35[Formula: see text]nm. Cu– TiO2 exhibits a shift in the absorption edge toward visible spectrum. The rate of recombination and transfer behavior of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. From SEM spherical shaped nanoparticles was observed. Comparing with pure TiO2 nanoparticles, Cu doped TiO2 photocatalyst exhibited enhanced photocatalytic activity under natural sunlight irradiation in the decomposition of rhodamine B aqueous solution. The maximum 97% of degradation efficiency of Rhodamine B was observed at 0.6% Cu–TiO2 within 180[Formula: see text]min. The photocatalytic efficiency of Rhodamine B of Cu doped TiO2 nanoparticle was higher than the pure TiO2, which could be attributed to the small crystallinity intense light absorption in Sunlight and narrow bandgap energy of Copper.

Synthesis and Characterization of Y2O3:Eu3+ Film Derived by Sol-Gel Processing

2007 ◽  
Vol 336-338 ◽  
pp. 593-596
Author(s):  
Chun Yang ◽  
Jun Ying Zhang ◽  
Hai Bing Feng ◽  
Wei Chang Hao ◽  
Tian Min Wang
Keyword(s):  
Raw Materials ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Dip Coating ◽  
Organic Additive ◽  
Excitation Spectra ◽  
Excitation Peak ◽  
Close Relationship ◽  
Dip Coating Technique

Y2O3:Eu3+ thin film was synthesized by sol-gel method with inorganic salt raw materials, and the crystal structure and luminescent properties were investigated. By adding organic additive to the sol, a homogeneous film with high luminescent intensity could be obtained by dip-coating technique on the surface of alumina sheet and quartz glass. Structures of the films were studied by XRD and SEM. The excitation spectra of the films showed a wide excitation peak from 200nm to 260nm, and the emission spectra had a strongest emission peak at 611nm which revealed a close relationship with the calcining temperature.

Nanocrystalline α-Fe2O3: A Superparamagnetic Material for w-LED Application and Waste Water Treatment

2021 ◽  
Author(s):  
Mahesh Gaidhane ◽  
Deepak Taikar ◽  
Pravin Gaidhane ◽  
Kalpana Nagde
Keyword(s):  
Photocatalytic Activity ◽  
Waste Water Treatment ◽  
Sol Gel ◽  
Average Particle Size ◽  
Emission Spectra ◽  
Broad Emission Band ◽  
Average Particle ◽  
X Ray ◽  
Prepared Material ◽  
Cie Chromaticity

Abstract Nanocrystalline α-Fe2O3 is synthesized by sol-gel technique. The prepared nanomaterial was characterized by X-ray diffraction (XRD), SEM, TEM, Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometry (VSM) and photoluminescence (PL) techniques. X-ray powder diffraction analysis confirmed the formation of α-Fe2O3. Electron microscopy showed spherical morphologies with an average particle size of 30-40 nm. The magnetic property of the prepared material was studied by VSM at room temperature. VSM study shows superparamagnetic nature of the synthesized nanoparticles. Photoluminescence (PL) emission spectra show intense broad emission band centered at 570 nm with 393 nm excitation indicating its usefulness for w-LED application. The CIE-chromaticity color coordinates of prepared material were calculated. The photocatalytic activity of the α-Fe2O3 nanoparticles was analyzed and the nanopowder exhibited good photocatalytic activity for the removal AO7 from its aqueous solution.

scholarly journals Luminescence of SiO2-BaF2:Tb3+, Eu3+ Nano-Glass-Ceramics Made from Sol–Gel Method at Low Temperature

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski
Keyword(s):  
Sol Gel ◽  
Three Dimensional ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Scanning Calorimetry ◽  
Light Emitting ◽  
Co Doping ◽  
Dsc Measurements ◽  
Decay Times

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.

Structural and Spectroscopic Assessment of Er3+-Activated SiO2-HfO2 Glass Ceramics Planar Waveguides

2008 ◽  
Vol 55 ◽  
pp. 56-61
Author(s):  
L. Minati ◽  
Giorgio Speranza ◽  
Yoann Jestin ◽  
Cristina Armellini ◽  
Andrea Chiappini ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Spinodal Decomposition ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Planar Waveguides ◽  
Material Structure ◽  
Crystalline Environment ◽  
Concentration Threshold

Two series of xHfO2 - (100-x) SiO2 (x=10, 20, 30 mol%) glass-ceramics planar waveguides doped with 0.3 mol% Er3+ ions were prepared by the sol-gel route. A thermal treatment at 1000°C was applied to the second series of samples to nucleate HfO2 crystals. The waveguides were analyzed by X-ray photoelectron spectroscopy to study the effect of the Hf concentration and of the annealing on the material structure. XPS shows that in the first series of samples a Hf concentration threshold exists. Above this threshold the material undergoes a spinodal decomposition with formation of HfO2 rich domains. In the second series of samples the presence of thermal treatment lowers the concentration threshold so that the phase separation occurs also at a Hf concentration of 10%mol. In the waveguides where spinodal decomposition in present, the emission spectra from the Er3+ ions reveal a sensible narrowing of the 4I13/2 → 4I15/2 line. This demonstrates the presence of a crystalline environment for the Er3+ ions since the inhomogeneous broadening due to the disordered glassy network is suppressed. These results may have important implications for the fabrication of photonic devices with increased efficiency.

scholarly journals Energy Transfer Study on Tb3+/Eu3+ Co-Activated Sol-Gel Glass-Ceramic Materials Containing MF3 (M = Y, La) Nanocrystals for NUV Optoelectronic Devices

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2522 ◽  
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Wojciech A. Pisarski
Keyword(s):  
Heat Treatment ◽  
Energy Transfer ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Optoelectronic Devices ◽  
Emission Spectra ◽  
Ceramic Materials ◽  
Near Ultraviolet ◽  
Glass Ceramic Materials ◽  
Significant Prolongation

In the present work, the Tb3+/Eu3+ co-activated sol-gel glass-ceramic materials (GCs) containing MF3 (M = Y, La) nanocrystals were fabricated during controlled heat-treatment of silicate xerogels at 350 °C. The studies of Tb3+ → Eu3+ energy transfer process (ET) were performed by excitation and emission spectra along with luminescence decay analysis. The co-activated xerogels and GCs exhibit multicolor emission originated from 4fn–4fn optical transitions of Tb3+ (5D4 → 7FJ, J = 6–3) as well as Eu3+ ions (5D0 → 7FJ, J = 0–4). Based on recorded decay curves, it was found that there is a significant prolongation in luminescence lifetimes of the 5D4 (Tb3+) and the 5D0 (Eu3+) levels after the controlled heat-treatment of xerogels. Moreover, for both types of prepared GCs, an increase in ET efficiency was also observed (from ηET ≈ 16% for xerogels up to ηET = 37.3% for SiO2-YF3 GCs and ηET = 60.8% for SiO2-LaF3 GCs). The changes in photoluminescence behavior of rare-earth (RE3+) dopants clearly evidenced their partial segregation inside low-phonon energy fluoride environment. The obtained results suggest that prepared SiO2-MF3:Tb3+, Eu3+ GC materials could be considered for use as optical elements in RGB-lighting optoelectronic devices operating under near-ultraviolet (NUV) excitation.

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