scholarly journals Luminescent characteristics of Eu2+/Li+ doped (La-Al)2O3 phosphors and PMMA films activated with them

2018 ◽  
Vol 64 (5) ◽  
pp. 447 ◽  
Author(s):  
Roberto Vázquez Arreguín
Keyword(s):  
Solid State ◽  
Methyl Methacrylate ◽  
Luminescence Intensity ◽  
Solid State Reaction ◽  
Broad Band ◽  
Step Process ◽  
Co Doping ◽  
Broad Band Emission ◽  
Band Emission ◽  
Reductive Atmosphere

The effect of Li co-doping on the blue luminescence of Eu2+ doped (La-Al)2O3 phosphors and its incorporation into poly (methyl methacrylate) PMMA films are reported. The phosphors were synthesized by a simple two-step process in which the (La-Al)2O3 powders were obtained by an evaporation method, and the subsequent co-doping with Li+ and Eu2 were made through a solid state reaction in a reductive atmosphere at 1250 0C. The incorporation of those phosphors into PMMA matrix and the synthesis of films with thicknesses between 6 and 12 μm was made by drop-casting. The characteristic blue broad band emission centered at 440 nm associated with the 4f65d1→ 4F7 transition of Eu2+ ions (CIE coordinates 0.6731, 0.3343) was observed when these powders were excited with 297nm light. These luminescence intensity was enhanced when Li was incorporated as co-dopant up to 320% with respect to those phosphors without Li. The luminescent characteristics of these phosphors were preserved when they were embedded into the PMMA films.

Synthesis and Luminescence Properties of Non-Doped Long Persistent Phosphors : Mg2SnO4

2009 ◽  
Vol 421-422 ◽  
pp. 352-355 ◽  
Author(s):  
Akiko Torisaka ◽  
Hiroaki Kaneko ◽  
Kentaro Nomizu ◽  
Sho Abe ◽  
Tadashi Ishigaki ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Spinel Structure ◽  
Single Phase ◽  
Broad Band ◽  
Photoluminescence Intensity ◽  
Inverse Spinel ◽  
Inverse Spinel Structure ◽  
Broad Band Emission ◽  
Band Emission

A white long persistence phosphor was synthesized in a single-phase of Mg2SnO4 which was synthesized by a solid-state reaction. This phosphor crystallized in an inverse spinel structure and showed a broad-band emission from 350nm to 700nm. The afterglow was observed upon the excitation by 254nm. A Li-doped Mg2SnO4 sample showed a higher photoluminescence intensity and a longer lifetime than the non-doped one.

Preparation and Luminescence Property of LaMgAl11O19

2012 ◽  
Vol 519 ◽  
pp. 224-227 ◽  
Author(s):  
Xin Min ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Zhao Hui Huang
Keyword(s):  
Solid State ◽  
Luminescence Property ◽  
Broad Band ◽  
Emission Spectra ◽  
Synthesis Temperature ◽  
Solid State Lasers ◽  
Broad Band Emission ◽  
Band Emission ◽  
Air Atmosphere ◽  
Fluorescent Lamps

Lanthanum magnesium hexaaluminate (LaMgAl11O19, LMA) has attracted much interest as its widely used in solid state lasers, TV phosphors and fluorescent lamps. In this paper, LaMgAl11O19 ceramic was pressureless sintered at 1650 °C for 10 h in air atmosphere using LaMgAl11O19 powders prepared by solid-state reaction at 1500 °C for 4 h. The result indicated that the synthesis temperature of LaMgAl11O19 powders was about 1500 °C. The LMA ceramic sample was dense and had a microstructure of platelet-like gains. The excitation spectrum shows two wide bands with the peaks at about 254 nm and 265 nm by monitoring the strongest 362 nm emission, and the emission spectra is consisted of a broad band emission with their peaks near 362 nm with a half-width about 5 nm exciting with 265 nm wavelength.

Synthesis, Characterization and Photophysical Properties of Rhenium(I) Complexe with 2-(naphthalen-2-yl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline

2014 ◽  
Vol 988 ◽  
pp. 66-69
Author(s):  
Qiang Li ◽  
Le Li ◽  
Rong Feng Zhong ◽  
Hai Di Cai ◽  
Feng Zhao
Keyword(s):  
Experimental Data ◽  
Solid State ◽  
Photophysical Properties ◽  
Broad Band ◽  
High Energy ◽  
H Nmr ◽  
Emission Maximum ◽  
Broad Band Emission ◽  
Band Emission

In this paper, a Re(I) complex [Re(CO)3(E2)Cl], where E2 = 2-(naphthalen-2-yl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline(E2), was synthesized and characterized by 1H NMR successfully. Experimental data confirm that Re(I) complex [Re(CO)3(E2)Cl] is high-energy-emitting one. The broad band emission upon excitation at λ = 400 nm with the emission maximum locates at λ = 581 nm in solid state and 614nm in CH2Cl2 solution were observed.

scholarly journals Synthesis and Luminescence Properties of La2O2S:RE3+ (RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) Submicron Size Phosphors for Lamp Industry

2020 ◽  
Vol 9 (4) ◽  
pp. 1898-1907
Keyword(s):  
Solid State ◽  
Broad Band ◽  
Blue Emission ◽  
Luminescence Properties ◽  
Excitation Spectra ◽  
Yellow Band ◽  
Broad Band Emission ◽  
Band Emission ◽  
Ft Ir ◽  
Down Conversion

RE3+(RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) doped La2O2S phosphors was synthesized by solid state flux fusion method and their down conversion spectral properties were studied as a function different RE3+ concentrations and reported in this paper. The solid state flux fusion results in well crystallized hexagonal shaped phosphor particles. The samples were characterized by XRD, SEM, FT-IR photoluminescence (PL) and CIE colour co-ordinates techniques. The lanthanum oxysulphide (La2O2S) phosphor doped with Ce3+ shows broad band emission with peak at 390 nm and 415 nm when excited at 340 nm excitation. La2O2S:Dy3+ shows efficient blue and yellow band emissions at 480 nm and 572 nm. La2O2S:Eu3+ phosphor shows an orange and red emission at 590 nm and 615 nm. Whereas La2O2S:Tb3+ phosphor shows weak blue emission at 488 nm and strong green 545 nm. The excitation spectra used for the La2O2S:RE3+ (where RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) phosphors is in the near UV region extending from 350 to 400 nm, which is characteristics of near UV excited LED. The effect of the RE3+ (RE3+= Ce3+, Dy3+ , Eu3+ and Tb3+) concentration on the luminescence properties of La2O2S:RE3+ phosphors were also studied. The investigated prepared La2O2S phosphors may be suitable for a near UV excited W-LED. Keywords: Oxysulphide, SEM, FT-IR, PL, SSL, CIE.

scholarly journals Luminescence at low temperature in pure ZnO phosphors

2020 ◽  
Vol 22 (2) ◽  
pp. 1-7
Author(s):  
Edgar Eduardo Mosquera
Keyword(s):  
Solid State ◽  
Low Temperature ◽  
Low Temperatures ◽  
Spectral Properties ◽  
Broad Band ◽  
Strong Broad Band ◽  
Broad Band Emission ◽  
Band Emission ◽  
Electric Dipoles ◽  
State Chemical

In this paper, samples of pure ZnO were prepared through solid-state chemical reaction, and optical spectral properties were investigated at low temperature. It was found that the strong broad band emission was shifted to the blue side with increase of temperature. It is tentatively attributed to the change of local electric field from electric dipoles, orientation of which is sensitive to temperature. The ultraviolet sharp lines observed at low temperatures are assigned to bound excitons and their phonon replicas.

scholarly journals Enhanced ferroelectric and piezoelectric performance of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free ceramics upon Ce and Sb co-doping

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2616-2623
Author(s):  
Weijie Zheng ◽  
Jiaqi Lin ◽  
Xinmei Liu ◽  
Wenlong Yang ◽  
Yuanshuo Li
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Lead Free ◽  
Conventional Solid State Reaction ◽  
Co Doping ◽  
Lead Free Ceramics ◽  
Piezoelectric Performance

(Ba0.85Ca0.15)(Zr0.1Ti0.9−xCex)O3+ySb ceramics prepared by the conventional solid-state reaction.

scholarly journals The challenging SED of AP Librae

2011 ◽  
Vol 7 (S284) ◽  
pp. 411-413 ◽  
Author(s):  
David Sanchez ◽  
Berrie Giebels ◽  
Pascal Fortin ◽  
Keyword(s):  
Spectral Energy Distribution ◽  
Broad Band ◽  
Low Frequency ◽  
Theoretical Models ◽  
Intermediate Frequency ◽  
High Energy ◽  
Spectral Energy ◽  
Broad Band Emission ◽  
Band Emission ◽  
Bl Lac

AbstractMatching the broad-band emission of active galaxies with the predictions of theoretical models can be used to derive constraints on the properties of the emitting region and to probe the physical processes involved. AP Librae is the third low frequency peaked BL Lac (LBL) detected at very high energy (VHE, E>100GeV) by an Atmospheric Cherenkov Telescope; most VHE BL Lacs (34 out of 39) belong to the high-frequency and intermediate-frequency BL Lac classes (HBL and IBL). LBL objects tend to have a higher luminosity with lower peak frequencies than HBLs or IBLs. The characterization of their time-averaged spectral energy distribution is challenging for emission models such as synchrotron self-Compton (SSC) models.

Microscintillator of Ce Doped β-NaLuF4 in Uniform Hexagonal Prism Morphology by a Facile Hydrothermal Method

2014 ◽  
Vol 541-542 ◽  
pp. 220-224
Author(s):  
Li Sha Liu ◽  
Hao Hong Chen ◽  
Bi Qiu Liu ◽  
Bin Tang ◽  
Zhi Jia Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hexagonal Phase ◽  
Broad Band ◽  
High Energy ◽  
Hexagonal Prism ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Strong Broad Band ◽  
Broad Band Emission ◽  
Band Emission

To explore micro-or nanoscintillator with a controllable architecture, a novel facile hydrothermal method easy for commercial run was used to synthesize pure and Ce doped β-NaLuF4 microcrystals at 453K. The morphology of uniform hexagonal prism with 3.3μm in diameter and 1.4 μm in thickness, respectively, is presented by the results of scanning electron microscopy (SEM). Powder X-ray diffraction (PXRD) patterns show the products are both pure hexagonal phase. Different from the undoped product without any irradiation, the Ce doped product has given strong broad band emission attributed to 5d4f transition of Ce3+, which can be potentially used as scintillator for biomedical imaging and detectors for high energy such as X-ray and γray. This synthetical strategy extends the understanding about nanomaterial chemistry and can be also useful for other systems such as fluorides, oxides and sulfides.

A Cooperative Afterglow Enhancement in Second Biological Window of Na2CaSn2Ge3O12 with Co-doping of Pr3+-Yb3+

2021 ◽  
Author(s):  
Xiuping Gao ◽  
Tao Liu ◽  
Xiaohui Jiang ◽  
Kai Huang ◽  
Runlin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Near Infrared ◽  
Co Doping

A novel near-infrared persistent luminescent phosphor Na2CaSn2Ge3O12 (NCSGO) doped with Ho3+, Er3+, Tm3+ and Yb3+ was synthesized by high-temperature solid-state reaction. The afterglow emission bands located at 1553nm, 801nm and...

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