scholarly journals COORDINATION COMPLEX [Eu(μ 2 -OC 2 H 5 )(btfa)(NO 3 ) (phen)] 2 ·phen WITH HIGH LUMINESCENT EFFICIENCY

2021 ◽  
Vol 20 (1) ◽  
pp. 73-83
Author(s):  
Mihail S. Iovu ◽  
◽  
Victor I. Verlan ◽  
Ion P. Culeac ◽  
Olga Bordian ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Quantum Yield ◽  
Coordination Complex ◽  
Time Decay ◽  
Photoluminescence Spectra ◽  
Strong Emission ◽  
Luminescence Time ◽  
Low Symmetry ◽  
Narrow Emission ◽  
The Eu

Experimental results on the bis[(μ 2 -etoxi)(benzoyl trifluoroacetonato)(nitrato)(1,10- phenantroline)europium(III)]1,10-phenantroline europium(III) coordination complex (hereafter, [Eu(μ 2 -OC 2 H 5 )(btfa)(NO 3 )(phen)] 2 ·phen) are described. The complex is characterized by photoluminescence (PL) and infrared spectroscopy. Photoluminescence spectra of the complex exhibit strong emission with specific narrow emission bands associated with the 5 D 0 → 7 F j (j = 0–4) transitions. The pattern of emission band splitting and the luminescence time decay suggest the presence of at least two different sites of the Eu 3+ ion in a low-symmetry environment. The absolute PL quantum yield of the complex is determined to be 49.2%.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

Synthesis and Characterization of Lightweight Beryllium Chloro Silicate Phosphor

2022 ◽  
pp. 89-100
Author(s):  
Khushbu Sharma
Keyword(s):  
Blue Emission ◽  
Emission Peak ◽  
Excitation Band ◽  
Photoluminescence Spectra ◽  
Strong Emission ◽  
White Leds ◽  
Long Afterglow ◽  
Silicate Phosphor ◽  
Low Weight

In this chapter, low weight barium-based cholorsilicate Ba5Cl6Si2O6:Eu2+ is prepared through a solid-state reaction. To confirm the structure of the synthesized phosphors, powder photographs were obtained using an x-ray diffractometer. Photoluminescence spectra and FTIR spectra were recorded. Photoluminescence spectra are studied. The emission peak is observed at 407 nm at excitation 275 nm. The intense violet-blue emission is obtained. The broad excitation band and strong emission indicate that Ba5Cl6Si2O6:Eu2+could be a good phosphor candidate for blue LED and white LEDs. Decay curve indicates the phosphor has a long afterglow feature.

scholarly journals Coordination Assemblies of Zn(II) Coordination Polymers: Positional Isomeric Effect and Optical Properties

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 664 ◽  
Author(s):  
Chang-Jie Liu ◽  
Tong-Tong Zhang ◽  
Wei-Dong Li ◽  
Yuan-Yuan Wang ◽  
Shui-Sheng Chen
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Quantum Yield ◽  
Coordination Polymers ◽  
Square Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Ligands ◽  
Isomeric Effect

Two Zn(II) coordination polymers (CPs) [Zn(L)(pphda)] (1) and [Zn(L)(ophda)]·H2O (2) were prepared by reactions of ZnSO4·7H2O based on the N-donor 1,4-di(1H-imidazol-4-yl)benzene (L) ligand and two flexible carboxylic acids isomers of 1,4-phenylenediacetic acid (H2pphda) and 1,2-phenylenediacetic acid (H2ophda) as mixed ligands, respectively. Structures of CPs 1 and 2 were characterized by elemental analysis, Infrared spectroscopy (IR), thermogravimetric analysis and single-crystal X-ray diffraction. The CP 1 is a fourfold interpenetrating 66-diamond (dia) architecture, while 2 is a 2D (4, 4) square lattice (sql) layer based on the Zn2(cis-1,2-ophda2−)2 binuclear Zn(II) subunits. The luminescent property, including luminescence lifetime and quantum yield (QY), have been investigated for CPs 1 and 2.

scholarly journals Mid-Infrared Spectroscopy of Four 21μm Emission Band Sources

1993 ◽  
Vol 155 ◽  
pp. 341-341
Author(s):  
K. Justtanont ◽  
M. J. Barlow ◽  
C. J. Skinner
Keyword(s):  
Infrared Spectroscopy ◽  
Wavelength Range ◽  
Emission Band ◽  
Emission Feature ◽  
Full Spectrum ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Long Wavelength ◽  
Spectroscopic Observations ◽  
Narrow Emission

We report 10 and 20μm spectroscopic observations of four C–rich post–AGB objects which exhibit the unidentified emission feature at 21μm. The observations were carried out in October 1990 and May 1991 using CGS3 on UKIRT. The spectral resolutions were 70 for the wavelength range of 7.4–13.3μm and 80 for the region between 15.4–24.1μm. Three of the sources reported here are from the list of Kwok, Volk & Hrivnak (1989), i.e., IRAS 04296+3429; IRAS 07134+1005 and IRAS 22272+5435. Figure 1 shows the full spectrum of IRAS 04296+3429 and IRAS 22272+5435. The 10μm spectra of these objects exhibit UIR bands whose peaks all fall longwards of the usual peak wavelengths associated with such features. This may be related to the fact that they are the lowest excitation objects so far found to exhibit UIR emission bands. We also found narrow emission features superimposed on the long wavelength wing of the 21μm emission bands of IRAS 04296+3429 and IRAS 22272+5435. The fourth object we observed, SAO 163075, was found to also exhibit a (weak) 21μm emission feature. However, there is no PAH features in the 10μm region, apart from the plateau at 12μm.

Luminescence time decay from Cu+ ions in sol–gel silica coatings

2001 ◽  
Vol 93 (3) ◽  
pp. 253-259 ◽  
Author(s):  
M.A Garcı́a ◽  
E Borsella ◽  
S.E Paje ◽  
J Llopis ◽  
M.A Villegas ◽  
...  
Keyword(s):  
Sol Gel ◽  
Time Decay ◽  
Silica Coatings ◽  
Luminescence Time ◽  
Cu Ions

Photoluminescence of ZnO:Eu3+ Nanoflowers

2008 ◽  
Vol 8 (3) ◽  
pp. 1307-1311 ◽  
Author(s):  
Peter A. Tanner ◽  
Lixin Yu
Keyword(s):  
Low Temperature ◽  
Conduction Band ◽  
Selective Excitation ◽  
Ftir Spectra ◽  
Photoluminescence Spectra ◽  
Defect States ◽  
Hydrothermal Route ◽  
Broadband Emission ◽  
The Eu

The synthesis of ZnO:Eu3+ nanoflowers by a low-temperature hydrothermal route is described. Characterization of the materials was performed by ESEM, XRD and FTIR spectra. The 355 nm excited photoluminescence spectra at 10 K do not indicate the presence of Eu2+ or the ZnO defect states which give rise to green or red broadband emission. Excitation into the ZnO conduction band at low temperature does not give emission from Eu3+. Selective excitation of the Eu3+ emission shows that Eu3+ ions occupy a variety of different sites, of which one of them is similar to Eu3+ in C-type Eu2O3.

Different ZnIIcation coordination geometries in di-μ-acetato-bis{2-chloro-6-[(pyridine-2-ylmethylimino)methyl]phenol}dizinc(II) chloroform monosolvate

2013 ◽  
Vol 69 (11) ◽  
pp. 1348-1350 ◽  
Author(s):  
Young-Inn Kim ◽  
Jin Young Lee ◽  
Young-Kwang Song ◽  
Sung Kwon Kang
Keyword(s):  
Quantum Yield ◽  
Title Compound ◽  
The Other ◽  
Bidentate Coordination ◽  
Strong Emission ◽  
Pyramidal Geometry ◽  
Trigonal Bipyramidal ◽  
Coordinate Geometry ◽  
Square Pyramidal Geometry ◽  
Distorted Trigonal Bipyramidal

In the title compound, di-μ-acetato-κ2O:O;κ2O:O′-bis[(6-chloro-2-{(E)-[(pyridin-2-yl)methylimino]methyl}phenolato-κ3N,N′,O)zinc(II)], [Zn2(C13H10ClN2O)2(C2H3O2)2]·CHCl3, the ZnIIcation adopts a five-coordinate geometry and is coordinated by two N atoms and one O atom of a tridentate 6-chloro-2-{(E)-[(pyridin-2-yl)methylimino]methyl}phenolate ligand and two O atoms of two bridging acetate groups, but their coordination geometries differ. One ZnIIcation adopts a distorted trigonal bipyramidal geometry and the other a square-pyramidal geometry. The two acetate ligands bridge two ZnIIcations with mono- and bidentate coordination modes. The title compound exhibits a strong emission at 460 nm upon excitation at 325 nm with a quantum yield of 23.1%.

Red-tunable LuAG garnet phosphors via Eu3+→Mn4+ energy transfer for optical thermometry sensor application

2021 ◽  
Author(s):  
Bing Yan ◽  
Yi Wei ◽  
Wei Wang ◽  
Meiqian Fu ◽  
Guogang Li
Keyword(s):  
Energy Transfer ◽  
Red Light ◽  
Thermal Quenching ◽  
Garnet Structure ◽  
Sensor Application ◽  
Optical Thermometry ◽  
Narrow Emission ◽  
The Eu

The Eu3+→Mn4+ energy transfer strategy is designed in the Lu3Al5O12 garnet structure to achieve color-adjustable narrow emission from orangish-red to deep-red light and remarkable thermal quenching improvement for optical thermometry sensors.

scholarly journals Characterizing distant blue galaxies with HST images and Keck spectra

1996 ◽  
Vol 171 ◽  
pp. 229-232
Author(s):  
Garth D. Illingworth
Keyword(s):  
Emission Lines ◽  
Length Scales ◽  
Strong Emission ◽  
Blue Galaxies ◽  
Low Mass ◽  
Emission Line Galaxies ◽  
Galaxy Population ◽  
Measured Length ◽  
Field Galaxy ◽  
Narrow Emission

Keck spectra and HST images have been used to derive characteristic velocity and length scales for an enigmatic component of the faint, blue, field galaxy population: the compact, narrow emission-line galaxies (CNELGs). These galaxies are very luminous, but have been found to be quite low mass systems (with typical masses ∼ 109 M⊙). Their blue colors and strong emission lines indicate that they are undergoing a major burst of star formation. Following the completion of their current burst they will fade, becoming, in the absence of further major bursts, objects very similar to contemporary spheroidal galaxies. With mean sizes Re ∼ 1.4 kpc and Gaussian velocity profiles with mean σ = 45 km s–1, the length scales and velocity widths of CNELGs are also quite consistent with the measured length scales and velocity widths of current spheroidals.

Sign in / Sign up

Export Citation Format

Share Document