scholarly journals Developments of crystal structures and photoluminescence properties of Sr0.85Eu0.15Al12O19 green phosphors using different synthesis parameters

2021 ◽  
Author(s):  
Jie Li ◽  
Qing-Hao Yang ◽  
Hsin-Hua Li ◽  
Cheng-Fu Yang ◽  
David Jui-Yang Feng
Keyword(s):  
Crystal Structures ◽  
Solid State Reaction Method ◽  
Synthesis Temperature ◽  
Emission Peak ◽  
Photoluminescence Excitation ◽  
Photoluminescence Properties ◽  
Apparent Effect ◽  
Reaction Method ◽  
Pl Spectra ◽  
Synthesis Parameters

First, a solid-state reaction method was used to synthesize a [Formula: see text] phosphor at 1250[Formula: see text]C–1400[Formula: see text]C for 1 h, and its crystal structures and photoluminescence properties were investigated as a function of synthesis temperature. When the furnace reached the synthesis temperature, the 5% [Formula: see text] reduction atmosphere was infused and the reduction atmosphere was removed as the temperature was dropped to 800[Formula: see text]C. When 1200[Formula: see text]C was used as the synthesis temperature, the [Formula: see text], [Formula: see text], and [Formula: see text] phases co-existed; only one weak emission peak was observed in the photoluminescence excitation (PLE) spectra, and two weak emission peaks were observed in the photoluminescence emission (PL) spectra. When the [Formula: see text] phosphors were synthesized at a temperature higher than 1200[Formula: see text]C, the diffraction intensities of [Formula: see text], [Formula: see text], and [Formula: see text] phases were almost unchanged, but the crystal sizes of [Formula: see text] powders increased. For [Formula: see text] phosphors, PLE spectra had one broad exciting band with two centered wavelengths of 317 and 365 nm, and PL spectra had one emission band with one centered wavelength of 513 nm. As the synthesis temperature rose, the emission intensities of PLE and PL spectra increased. Second, we show that the removed temperature of reduction atmosphere of [Formula: see text] phosphors had an apparent effect on their emission properties of PLE and PL spectra.

scholarly journals Effects of synthesizing time and Eu2+ concentration on photoluminescence properties of Ca2−xEuxMgSi2O7 phosphors

2021 ◽  
pp. 21410001
Author(s):  
Yu Fan ◽  
Chin-Ta Chen ◽  
Yen-Tsu Wang ◽  
Cheng-Fu Yang
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Particle Sizes ◽  
Photoluminescence Excitation ◽  
Photoluminescence Properties ◽  
Sem Images ◽  
Photoluminescence Emission ◽  
Reaction Method ◽  
Pl Spectra

Phosphors with the compositions of [Formula: see text] ([Formula: see text], 0.015, 0.025, 0.035, and 0.045) are synthesized in a reduction atmosphere (5% H2 + 95% N2) using a solid-state reaction method. At first, the [Formula: see text] powder is synthesized at 1350[Formula: see text]C with a duration of [Formula: see text] h to find the optimum synthesizing time. SEM images show that the particle sizes increase with synthesizing time and as the synthesizing time is more than 4 h, the abnormal particles appear and the intensities at the emission peaks of photoluminescence excitation (PLE) and photoluminescence emission (PL) spectra decrease. Next, 1350[Formula: see text]C and 4 h are used as synthesized parameters, which are used to find the concentration quench effect of [Formula: see text] phosphors. As the concentration of [Formula: see text] ions of [Formula: see text] phosphors increases, the intensities at the emission peaks of PLE and PL spectra first increase and reach the maximum values at [Formula: see text], and then they decrease as the concentration of [Formula: see text] ions further increases. These results prove that the synthesizing time and concentration of [Formula: see text] ions are two important factors to affect the photoluminescence properties of [Formula: see text] phosphors.

The Effect of Synthesis Parameters on Luminescence Properties of Ca-α-Sialon:Eu2+

2013 ◽  
Vol 58 (4) ◽  
pp. 1309-1312 ◽  
Author(s):  
D. Michalik ◽  
M. Sopicka-Lizer ◽  
T. Pawlik ◽  
R. Lisiecki
Keyword(s):  
Optical Properties ◽  
Phase Composition ◽  
Strong Influence ◽  
Solid State Reaction Method ◽  
Synthesis Temperature ◽  
Luminescence Properties ◽  
Reflection Spectra ◽  
Reaction Method ◽  
Structure And Morphology ◽  
Synthesis Parameters

Abstract The goal of this study was to investigate influence of the synthesis parameters on the luminescence properties of Ca- α -Sialon doped with Eu2+. The compound of Eu0:07Ca0:73Si9:6Al2:4O0:8N15:2 was prepared by the solid state reaction method from the mixture of the relevant oxides, Si3N4 and CaCO3. Synthesis was carried out in the temperature range of 1600-1700°C for 2-8 h in a reduction atmosphere (N2+CO). The structure and morphology of obtained powders were analyzed by XRD and SEM/EDS methods, respectively. Content of nitrogen/oxygen was also measured. Optical properties were investigated by excitation, emission and reflection spectra. Obtained results show strong influence of synthesis temperature on the phase composition and intensity of emission of Ca- -Sialon:Eu2+ powder compound.

Fabrication and Properties of Zinc Silicate Phosphors through Solid State Reaction

2010 ◽  
Vol 160-162 ◽  
pp. 594-598
Author(s):  
Guo Jian Jiang ◽  
Jia Yue Xu ◽  
Hui Shen ◽  
Yan Zhang ◽  
Lin He Xu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Emission Peak ◽  
Zinc Silicate ◽  
Red Phosphor ◽  
Reaction Method ◽  
Long Afterglow ◽  
Luminescent Mechanism ◽  
Silicate Phosphors

Zinc silicate-based (Zn2SiO4:Eu3+) long afterglow phosphors were produced by solid state reaction method. The effects of borax and Eu2O3 additive on the properties of fabricated products have been studied. The results show that, there is not much difference in phase compositions within the borax additive amount; however, their SEM morphologies are different. Borax additive can increase the grain size of the product. Some sintering phenomena could be observed in the sample with Eu2O3 addition. The fluorescence spectroscopy results indicate that, the emission peak of the sample with Eu3+ additive located at 612nm, which may be a good candidate for red phosphor applications. The luminescent mechanism of Zn2SiO4:Eu3+ is also discussed.

Photoluminescence properties of Na1.45La8.55(SiO4)6(F0.9O1.1):Eu for applications as a reddish orange phosphor

2014 ◽  
Vol 07 (05) ◽  
pp. 1450060 ◽  
Author(s):  
Qun Shi ◽  
Dhia A. Hassan ◽  
Renjie Zeng
Keyword(s):  
Spectral Analysis ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Analysis System ◽  
Reddish Orange ◽  
The Eu

Europium-doped Na 1.45 La 8.55-8.55x( SiO 4)6( F 0.9 O 1.1)(0.000 ≤ x ≤ 0.045) phosphors were prepared by a conventional solid-state reaction method at 1200°C and their properties were studied by X-ray diffraction (XRD), and a spectral analysis system. No impurities were observed. The phosphor could be excited at 254 nm, 395 nm and 465 nm to yield a reddish orange emission which was attributed to the 5 D 0 → 7 F j (j = 0–2) transitions of the Eu ion.

Photoluminescence properties of single-component white-emitting Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors for UV LEDs

2015 ◽  
Vol 3 (27) ◽  
pp. 7096-7104 ◽  
Author(s):  
Kai Li ◽  
Mengmeng Shang ◽  
Yang Zhang ◽  
Jian Fan ◽  
Hongzhou Lian ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
White Light ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Reaction Method ◽  
White Light Emitting Diodes ◽  
Uv Leds ◽  
Uv Excitation

A series of Ca9Bi(PO4)7:Ce3+,Tb3+,Mn2+phosphors synthesizedviathe high-temperature solid-state reaction method can emit intense tunable color from purple-blue to red including white under UV excitation, which shows their potential application in UV-pumped white-light-emitting diodes.

Effects of Sm3+ Doping on the Photoluminescence Properties of Ca9Eu1-xSmx(VO4)7 Red-Emitting Phosphors

2012 ◽  
Vol 512-515 ◽  
pp. 1488-1493 ◽  
Author(s):  
Li Hong Liu ◽  
Rong Jun Xie ◽  
Xu Dong Sun ◽  
Qing Huang ◽  
Naoto Hirosaki
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Excitation Energy ◽  
Solid State Reaction ◽  
Emission Intensity ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
Reaction Method ◽  
White Leds ◽  
Uv Led

This paper reports the photoluminescence properties of Ca9Eu1-xSmx(VO4)7 (x=0.2-0.4) synthesized at 1250 oC in air for 12 h using traditional solid-state reaction method. With the increase of Sm3+ substitution amount, purity Ca9Eu1-xSmx(VO4)7 phase was obtained even when the Eu3+ ions were totally substituted by Sm3+. The experimental results showed that when Sm3+ was codoped with Eu3+ into Ca9Eu1-xSmx(VO4)7 crystal structure, Sm3+ would act as a sensitizer and transfer the excitation energy to Eu3+ ions and finally enhance the emission intensity of Ca9Eu1-xSmx(VO4)7 under 405 nm excitation, which leads to more favorite of this kind of phosphor used in UV LED based white LEDs.

Effect of B2O3 or SiO2 Fluxes on Morphology and Size of Pr-Doped CaTiO3 Phosphor Particles and on their Photoluminescence Properties

2011 ◽  
Vol 497 ◽  
pp. 31-37 ◽  
Author(s):  
Toru Kyomen ◽  
Ryuta Motani ◽  
Minoru Hanaya
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Primary Particle ◽  
Solid State Reaction Method ◽  
Particle Sizes ◽  
Photoluminescence Properties ◽  
Conventional Solid State Reaction ◽  
Red Phosphor ◽  
Reaction Method ◽  
Primary Particles

Powder of Pr-doped CaTiO3 red phosphor was prepared at 1473 K by a conventional solid-state reaction method with addition of B2O3 or SiO2 as a flux. Primary particle sizes of the prepared samples were increased by using B2O3 flux but decreased by using SiO2 flux. Clear planes, edges, or steps were observed on surfaces of the primary particles. The intensity of photoluminescence induced by irradiation of light with a wavelength longer than ∼350 nm was enhanced about three times by using B2O3 flux. The intensity of photoluminescence induced by irradiation of light with a wavelength shorter than ∼350 nm was enhanced about twice by using either B2O3 or SiO2 fluxes. The origin for the flux effects is discussed.

scholarly journals Optical Properties of Blue Phosphor

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Mourad Derbal ◽  
Lakhdar Guerbous ◽  
Ouadjaout Djamel ◽  
Chaminade Jean Pierre ◽  
Mohyddine Kadi-Hanifi
Keyword(s):  
Blue Emission ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
Photoluminescence Excitation ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Blue Phosphor ◽  
Emission Transition ◽  
Scanning Electron

(, 0.5, 1, 5, and 10 at.%) polycrystalline powders blue phosphors were prepared via the classical solid-state reaction method. X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation, and emission spectra were used to characterize phosphors. By analyzing the excitation and emission spectra of samples, the result indicates that there exists the energy transfer only from the group to the energy level of ion. On the other hand, the influence of the thulium concentration on the blue emission transition and and the emission of group are investigated.

Photoluminescence properties of Li2+xNb3xTi1−4xO3:Eu3+

2019 ◽  
Vol 12 (04) ◽  
pp. 1950057 ◽  
Author(s):  
Chao-Chao Guo ◽  
Qun Zeng ◽  
Chun-Feng Yao ◽  
Yan-Zhao Feng ◽  
Xi Chen ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Red Emission ◽  
Reaction Method ◽  
X Ray ◽  
Red Phosphors ◽  
Chromaticity Coordinate

Red phosphors with compositions of Li[Formula: see text]Nb[Formula: see text]Ti[Formula: see text]O3:3[Formula: see text]wt.% Eu[Formula: see text] [Formula: see text] were synthesized by solid-state reaction method. The samples were investigated by using X-ray diffraction (XRD) and photoluminescence spectroscopy, respectively. XRD results showed that all samples were main phase of Li2TiO3. Emission spectra of Li[Formula: see text]Nb[Formula: see text]Ti[Formula: see text]O3:3[Formula: see text]wt.% Eu[Formula: see text] powders showed strong red emission at 612[Formula: see text]nm (5D0–7F[Formula: see text] with 396[Formula: see text]nm excitation. In addition, the excitation and emission intensity increased up to [Formula: see text], and then decreased with further increasing of the x values. And the chromaticity coordinate (CIE) of the component with [Formula: see text] was superior to other components.

Synthesis and Optical Characterization of M-α-Sialon (M=Ca, Ba, Sr) Doped by Europium

2014 ◽  
Vol 90 ◽  
pp. 141-148
Author(s):  
Daniel Michalik ◽  
Tomasz Pawlik ◽  
Malgorzata Sopicka-Lizer ◽  
Radosław Lisiecki
Keyword(s):  
Chemical Resistance ◽  
Solid State Reaction Method ◽  
Rare Earth Ions ◽  
Color Temperature ◽  
Broad Emission Band ◽  
White Led ◽  
Photoluminescence Properties ◽  
Synthesis Parameters ◽  
Broad Emission

Oxynitrides compounds are interesting for white LED industry because more covalent matrix's bonds in comparison to oxides enable to obtain higher color temperature of wLED. The Sialon's luminescence material doped by rare earth ions with high mechanical and chemical resistance and a broad emission band may become an alternative for garnet phosphors. The goal of the study was to investigate influence of divalent stabilizing cations on luminescence properties of M-α-Sialon doped with Eu2+in order to estimate its potential for YAG:Ce replacement in WLEDs. The compound of general formula EuxM1-xSi9,6Al2,4O0,8N15,2, where M=Ca, Ba, Sr, was prepared by the solid state reaction method from the mixture of the relevant oxides, nitrides and carbonates. Synthesis was carried out at the temperature of 1650°C for 4 h in a reduction atmosphere (N2+CO). The structure and morphology of obtained powders were analyzed by XRD and SEM/EDS methods, respectively. Optical properties were investigated by excitation, emission and reflection spectra and compared to photoluminescence properties of standard YAG:Ce. The obtained specimens show the significant effect of synthesis parameters on the phase composition and intensity of emission of M-α-Sialon:Eu2+powder.

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