Yellow-Orange Upconversion Luminescence in NaYF4:Er3+, Yb3+ Phosphor Synthesized by Microwave Combustion Method

2011 ◽  
Vol 295-297 ◽  
pp. 551-554 ◽  
Author(s):  
Jia Yue Sun ◽  
Chun Cao ◽  
Hai Yan Du
Keyword(s):  
Laser Excitation ◽  
Upconversion Luminescence ◽  
Green Emission ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Yellow Orange ◽  
Photon Process ◽  
Microwave Combustion Method

Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+(2H11/2→4I15/2and4S3/2→4I15/2), and the weaker red emission at 652 nm was from Er3+(4F9/2→4I15/2), which belong to the two photon process.

Structure and Up-Conversion Luminescence Properties of Er3+-Yb3+Co-Doped TiO2 Nanocrystals Prepared by Sol-Gel Method

2009 ◽  
Vol 66 ◽  
pp. 167-170 ◽  
Author(s):  
Zhen Zhong Zhang ◽  
Ji Hong Zhang ◽  
Wei Zhou ◽  
Ming Xia Song ◽  
Wei Li ◽  
...  
Keyword(s):  
Titanium Tetrachloride ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Red Emission ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

Er3+/Yb3+ co-doped TiO2 nanocrystals were prepared by Sol-gel method in which titanium tetrachloride was adopted as the precursor. The structure, particle size, and optical properties of samples were characterized by X-ray diffraction(XRD), Field emission-Scanning Electron Microscopy(FE-SEM) and photoluminescence(PL) spectra. Er3+ concentration was fixed at 1.0mol%, and Yb3+ concentration was changed from 3 to 10mol%. Intense upconversion luminescence was observed when the samples were excited by 980nm laser. The dependence of upconversion luminescence on Yb3+ concentration was presented. The results show that the upconversion luminescence increases with the Yb3+ concentration and gets its peak at 5%. The ratio of red emission to green emission(R/G) was strikingly enhanced with the increase of Yb3+ concentration. Under the excitation of 980nm, the green emission in the range of 520-570nm (2H11/2, 4S3/2→4I15/2) and the red emission in the range of 640~690nm (4F9/2 →4I15/2) are both due to two photons process. The possible upconversion mechanism was discussed.

Up-Conversion Luminescence Properties of Ho3+ Doped and Yb3+/Ho3+ Co-Doped Y2WO6 Phosphors

2017 ◽  
Vol 727 ◽  
pp. 618-622 ◽  
Author(s):  
Xue Dong Gao ◽  
Deng Hui Xu ◽  
Yao Hui Zhu ◽  
Zai Fa Yang ◽  
Jiang Nan Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Pump Power ◽  
Energy Level ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Two Photon ◽  
Photon Process ◽  
Co Doped

In this article, Ho3+ doped and Yb3+/ Ho3+ co-doped Y2WO6 phosphors were successfully prepared via high temperature solid method. Their structures were investigated with X-ray diffraction, the up-conversion (UC) excitation from a 980 nm diode laser, and the developed phosphor shown two UC emission bands in the visible region 540 and 643 nm. Based on the result, the intensity of the frequency up-conversion emission was enhanced significantly through co-doping with Yb3+ ions in the Y2WO6: Ho3+ phosphor. The dependence of emission intensity on the pump power indicated that the up-conversion emission was a two-photon process. At last, the energy level diagrams was discussed. The results show that Y2WO6 is a promising host material for UC phosphors.

Concentration-Dominated Temperature-Dependence of Upconversion Luminescence in Gd6WO12 Nanophosphor Co-Doped with Er3+ and Yb3+

2016 ◽  
Vol 16 (4) ◽  
pp. 3534-3541
Author(s):  
Yanqiu Zhang ◽  
Baojiu Chen ◽  
Xiangping Li ◽  
Jiashi Sun ◽  
Jinsu Zhang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Thermal Quenching ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Microscopic Morphology ◽  
Co Precipitation ◽  
Co Doped ◽  
Scanning Electron

Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the Er3+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.

Upconversion Luminescence of ZnO-TiO2: Ho3+/Yb3+ Phosphor Powder

2018 ◽  
Vol 922 ◽  
pp. 32-39 ◽  
Author(s):  
Krisana Kobwittaya ◽  
Yushi Oishi ◽  
Toshio Torikai ◽  
Mitsunori Yada ◽  
Takanori Watari
Keyword(s):  
Emission Intensity ◽  
Upconversion Luminescence ◽  
Green Emission ◽  
Excitation Power ◽  
Mixing Ratios ◽  
Two Photon ◽  
Mixing Method ◽  
Photon Process ◽  
Xrd Patterns ◽  
Luminescence Characteristics

Ho3+/Yb3+ co-doped ZnO-TiO2 composite system were synthesized by powder-solution mixing method and their upconversion (UC) luminescence characteristics were investigated under the 980 nm laser excitation. The effect of various ZnO/TiO2 mixing ratios, and Ho3+ and Yb3+ concentrations were also studied. The XRD patterns showed that the product fired at 1300 °C consisted of Zn2TiO4, TiO2, RE2Ti2O7, and RE2TiO5 (RE = Ho3+ and/or Yb3+) phases. The green emission centered at 538 nm wavelength was detected as the strongest emission intensity which it was in accordance with the 5F4,5S2 → 5I8 transition of Ho3+ ion. The emission intensity of the product changed by varying ZnO/TiO2 mixing ratios, and Ho3+ and Yb3+ concentrations. Brightest UC emission was observed in the sample of 1ZnO:1TiO2 (in mole) doped with 0.03 mol% Ho3+, 9 mol% Yb3+ fired at 1300 °C for 1 h. Besides, the dependence of the UC emission intensity on the excitation power indicated that the two-photon process was responsible for this UC system.

Upconversion Luminescence and Temperature Sensing of InNbO4:Er3+/Yb3+ Phosphors

2021 ◽  
Vol 13 (4) ◽  
pp. 563-568
Author(s):  
Xingbang Dong ◽  
Huanjun Zhang ◽  
Yi Li ◽  
Zheng Wang ◽  
Yang Yang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Solid State Reaction Method ◽  
Temperature Sensing ◽  
Fluorescence Intensity Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Two Photon ◽  
Maximum Value ◽  
Optical Thermometry

Er3+/Yb3+ co-doped InNbO4 phosphors were synthesized using solid state reaction method. Crystal structure was characterized using X-ray diffraction (XRD), which confirm all obtained phosphors had a monoclinic-wolframite structure and no impurity phase was introduced upon doping. Upon 980 nm excitation, upconversion (UC) emission from Er3+ ions was observed in green and red range. UC emission was obviously enhanced after co-doping Yb3+ ions and reached the maximum for 10 mol% Yb3+ ions. The relation between emission intensity and pump power was performed, revealing that the UC emission result from two-photon processes. Optical temperature sensing property was investigated by exploiting fluorescence intensity ratio (FIR) between 2H11/2 and 4S3/2 levels of Er3+ ions. Its maximum value of absolute sensitivity obtained was 0.0091 K-1, suggesting InNbO4:Er3+/Yb3+ phosphors show potential application in optical thermometry.

scholarly journals Rapid Synthesis of Bismuth Molybdate Nanoplates for Supercapacitor Applications by Microwave Combustion Method

2019 ◽  
Vol 9 (1S3) ◽  
pp. 324-328
Keyword(s):  
Average Crystallite Size ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Bismuth Molybdate ◽  
Active Electrode ◽  
One Pot ◽  
X Ray ◽  
Microwave Combustion ◽  
Ft Ir ◽  
Microwave Combustion Method

Orthorhombic structured bismuth molybdate (Bi2MoO6) is obtained by one pot microwave combustion method. The characteristic performance of Bi2MoO6 nanocatalyst are described by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) furnished with Energy - dispersive X-ray spectroscopy (EDS) and Fourier change infrared (FT-IR) spectroscopy. The average crystallite size for Bi2MoO6 estimated from XRD is about 28.9 nm. The surface morphology from SEM pictures displays nanoplates. The FTIR is utilized to recognize the structural coordination and the presence of functional group. The electrochemical studies are taken to readily comprehend the electrochemical performance of the modified active electrode with notable specific capacitance value are found 234.9 Fg-1 at 5 mVs-1 and cyclic retention is stable up to 900 cycles (98.7 %). The as-synthesized dynamic material acts as a novel electrode material for supercapacitor.

Yellow Upconversion Luminescence in Ho3+/Yb3+ Co-Doped La2(WO4)3 Phosphor

2013 ◽  
Vol 401-403 ◽  
pp. 758-761 ◽  
Author(s):  
Jia Yue Sun ◽  
Bing Xue ◽  
Guang Chao Sun ◽  
Dian Peng Cui
Keyword(s):  
Light Emission ◽  
Upconversion Luminescence ◽  
Solid State Reaction Method ◽  
Excitation Power ◽  
Yellow Emission ◽  
Excitation Power Density ◽  
X Ray Diffraction ◽  
Two Photon ◽  
Photon Process ◽  
Co Doped

The strong yellow upconversion (UC) light emission has been observed in Ho3+/Yb3+ co-doped La2(WO4)3 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state reaction method. The phrase structures of the samples were characterized by X-ray diffraction (XRD). The doping concentration of Yb3+ was determined to be 20mol% for the strongest yellow emission. Then, the dependence of UC emission intensity on excitation power density showed that the green and red UC emissions are involved in two-photon process. The possible UC mechanisms for the strong yellow emission were also investigated.

Comparative Study of Pure and Ni-Doped ZnFe2O4 Nanoparticles for Structural, Optical and Magnetic Properties

2013 ◽  
Vol 699 ◽  
pp. 524-529 ◽  
Author(s):  
A. Manikandan ◽  
J. Judith Vijaya ◽  
L. John Kennedy
Keyword(s):  
Magnetic Properties ◽  
Combustion Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Microwave Combustion ◽  
Ni Content ◽  
Maximum Value ◽  
Microwave Combustion Method

Pure and Ni-doped ZnFe2O4 nanoparticles, Zn1-xNixFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized by microwave combustion method (MCM). The structural, morphological and magnetic properties of the products were determined by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM) and vibrating sample magnetometer (VSM). X-ray analysis showed that all the compositions crystallize with cubic spinel structure. The broadband visible emission is observed in the entire photoluminescence (PL) spectrum and the estimated energy band gap is about 2.1 eV. VSM measurements shows superparamagnetic behavior for lower concentration of Ni (x ≤ 0.2), whereas for higher concentration (x ≥ 0.2), it becomes ferromagnetic. The saturation magnetization (Ms) varies considerably with Ni content to reach a maximum value for Ni0.5Zn0.5Fe2O4 composition, i.e. 57.89 emu/g.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

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