Synthesis and Luminescent Properties of Eu3+ Doped CaGd4O7 Phosphors by Solvothermal Reaction Method

2015 ◽  
Vol 15 (10) ◽  
pp. 8028-8033 ◽  
Author(s):  
Yeon Woo Seo ◽  
Mi Noh ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
Hyun Kyoung Yang ◽  
...  
Keyword(s):  
Broad Band ◽  
Luminescent Properties ◽  
Solvothermal Reaction ◽  
Sem Images ◽  
Reaction Method ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Potential Applications ◽  
Xrd Patterns ◽  
Cie Chromaticity

Eu3+ doped CaGd4O7 phosphors have been newly synthesized using a solvothermal reaction method and sintered at 1400 °C. The phase, composition, morphologies, and photoluminescent properties of the phosphors have been well characterized by means of the X-ray diffraction (XRD) patterns, energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectroscopy, and decay curves, respectively. The XRD patterns of the as-prepared phosphors confirm their monoclinic structure and the FE-SEM images reveal flower-like morphology, formed through agglomeration. The calculated size of the crystallites was approximately 83 nm. The photoluminescence excitation (PLE) spectra of CaGd4O7: Eu3+ phosphors consist of a broad band due to the charge transfer (CT) electronic transition, and several sharp peaks that can be attributed to the f–f transitions of Eu3+ and Gd3+. The PL spectra exhibited a stronger red emission corresponding to the 5D0→7F2 transition. The CIE chromaticity coordinates of the phosphors were calculated and all the chromaticity coordinates have been placed in the red spectral region. These luminescent powders are expected to have potential applications for white light-emitting diodes (WLEDs) and optical display systems.

Effects of Charge Compensators on Structure and Luminescent Properties of Microwave Synthesized CaMoO4:Eu3+ Red Phosphors

2017 ◽  
Vol 727 ◽  
pp. 592-597
Author(s):  
Ying Han ◽  
Zhi Lin Li ◽  
Wan Zhang ◽  
Yan Jie Yin ◽  
Yan Mei Li ◽  
...  
Keyword(s):  
Broad Band ◽  
Luminescent Properties ◽  
Emission Peak ◽  
Luminous Intensity ◽  
Main Peak ◽  
Doping Amount ◽  
X Ray ◽  
Red Phosphors ◽  
Charge Compensator ◽  
Pure Phase

Red phosphors CaMoO4:Eu3+ were synthesized by microwave method with MnO2 as microwave absorbent. The phase structure and luminescent properties of the as-synthesized phosphors were investigated by X-ray powder diffraction and Fluorescence spectrophotometer. The results show that when the reaction time was 40 min, microwave power was medium-high fire (~560 W), we got the tetragonal CaMoO4:Eu3+ pure phase. The excitation spectrum of CaMoO4:Eu3+ was composed by a broad band between 200 nm and 350 nm and a series of peaks from 350 nm to 500 nm. The main peak was at 305 nm. The emission spectrum was composed of a series of peaks in the range of 550~750 nm and the main peak was at 617 nm due to the 5D0→7F2 transition of Eu3+. Doping charge compensator Li+, Na+ or K+ could improve the luminous intensity of the sample. When the doping amount of Li+, Na+ or K+ were 8 mol%, the luminous intensity of the sample reached the maximum. The intensity of the emission peak at 617 nm was 4.04, 3.42, 3.48 times of sample without doping charge compensator.

Synthesis and Characterization of Cadmium with Titanium Oxide (Cd-TiO2) Nanocomposite: Testing its Antibacterial Effect

2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  
Keyword(s):  
Sol Gel ◽  
Gram Negative Bacteria ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Gram Negative ◽  
X Ray ◽  
Weight Percentage ◽  
Inhibition Concentration ◽  
Xrd Patterns

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.

Formation of p-type Cu3BiS3 absorber thin films by annealing chemically deposited Bi2S3–CuS thin films

1997 ◽  
Vol 12 (3) ◽  
pp. 651-656 ◽  
Author(s):  
P. K. Nair ◽  
L. Huang ◽  
M. T. S. Nair ◽  
Hailin Hu ◽  
E. A. Meyers ◽  
...  
Keyword(s):  
Thin Films ◽  
Visible Region ◽  
Atomic Diffusion ◽  
Optical Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Structures ◽  
Potential Applications ◽  
Xrd Patterns ◽  
P Type

Formation of the ternary compound Cu3BiS3 during annealing of chemically deposited CuS (∼0.3 μm) films on Bi2S3 film (∼0.1 μm on glass substrate) is reported. The interfacial atomic diffusion leading to the formation of the compound during the annealing is indicated in x-ray photoelectron depth profile spectra of the films. The formation of Cu3BiS3 (Wittichenite, JCPDS 9-488) is confirmed by the x-ray diffraction (XRD) patterns. The films are optically absorbing in the entire visible region (absorption coefficient 4 × 104 cm−1 at 2.48 eV or 0.50 μm) and are p-type with electrical conductivity of 102−103 Ω−1 cm−1. Potential applications of these films as optical coatings in the control of solar energy transmittance through glazings and as a p-type absorber film in solar cell structures are indicated.

Photocatalytic Comparative Study of TiO2, ZnO, Ag-G-ZnO and Ag-G-TiO2 Nanocomposite Films

2017 ◽  
Vol 751 ◽  
pp. 825-830 ◽  
Author(s):  
Phuri Kalnaowakul ◽  
Tonghathai Phairatana ◽  
Aphichart Rodchanarowan
Keyword(s):  
Colloidal Solution ◽  
Nanocomposite Films ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities ◽  
Xrd Patterns

In this study, the photocatalytic properties and morphology of TiO2, ZnO, Ag-graphene-zinc oxide (Ag-G-ZnO) and Ag-graphene-titanium dioxide (Ag-G-TiO2) nanocomposite were compared. The Ag-G-ZnO and Ag-G-TiO2 nanocomposite were successfully prepared by thermal decomposition of colloidal solution. These prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and photocatalytic activities. The results from XRD patterns show that Ag-G-TiO2 composites and the Ag-G-ZnO nanocomposites were in the form of fcc and hcp crystal structure, respectively. The SEM images show that at calcination of 500 °C for 3 h, the composite thin film of Ag-G-ZnO and Ag-G-TiO2 were homogenous. In the case of the photocatalytic experiments using methylene blue dye (MB) under UV irradiation, the order of the photocatalytic activities from high to low performances are Ag-G-ZnO, Ag-G-TiO2, ZnO and TiO2, respectively.

Study on Synthesis and Characterization of AgCl Microparticle Materials Based on One-Step Solution Phase Route

2012 ◽  
Vol 568 ◽  
pp. 295-298
Author(s):  
Juan Liao ◽  
Kai Zhang ◽  
Wen Zhong Wang ◽  
Yong Gang Wang ◽  
Li Yu
Keyword(s):  
Reaction Times ◽  
Average Diameter ◽  
Solution Phase ◽  
Synthesis And Characterization ◽  
Sem Images ◽  
X Ray ◽  
Potential Applications ◽  
One Step ◽  
Size And Morphology

AgCl microparticle materials, with novel heart-like morphology, were successfully prepared by means of a simple solution phase route, in which a small amount of hydrochloric acid, ethylene and PVP were introduced to the conventional polyol process. The obtained microparticle materials were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and UV-Vis absorption spectrum. SEM images show that the obtained AgCl microparticle materials have heart-like morphology with an average diameter of 3 um. The influence of different reaction times on size and morphology of the microparticle materials were also investigated. A possible growth mechanism of AgCl microparticle materials has been proposed on the basis of experimental results and analysis. The as-prepared AgCl microparticle materials would find possible potential applications in photocatalytic fields.

A New Deep Red-Emitting Mn2+-Activated SrLaGa3S6O Phosphor

2012 ◽  
Vol 531-532 ◽  
pp. 145-148 ◽  
Author(s):  
Rui Jin Yu ◽  
Jin Young Park ◽  
Hyun Kyoung Yang ◽  
Byung Kee Moon ◽  
Byung Chun Choi ◽  
...  
Keyword(s):  
Broad Band ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
White Led ◽  
Photoluminescence Excitation ◽  
Led Lighting ◽  
Display Devices ◽  
Chromaticity Coordinates ◽  
Standard Values ◽  
Cie Chromaticity

A new deep red-emitting Mn2+-activated SrLaGa3S6O phosphor was first prepared by a solid-state reaction method. Their luminescence properties were investigated by photoluminescence excitation and emission spectra. The emission spectrum shows a broad band with an emission maximum at 668 nm under the host excitation of 340 nm. The full width at half maximum (FWHM) of the emission peak is about 83 nm. The CIE chromaticity coordinates (x = 0.673 and y = 0.312) shows that the phosphor emission is in the deep red region and were very near to the NTSC standard values for red. Since the excitation band of the phosphor lies in the near UV excitable region, giving a deep red emission, it can be used for applications in near UV phosphor converted white LED lighting and display devices.

scholarly journals Lead Borate Glasses and Glass-Ceramics Singly Doped with Dy3+ for White LEDs

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5022
Author(s):  
Agata Górny ◽  
Marta Kuwik ◽  
Wojciech A. Pisarski ◽  
Joanna Pisarska
Keyword(s):  
White Light ◽  
Glass Ceramics ◽  
Borate Glasses ◽  
Spectroscopic Techniques ◽  
Lead Borate ◽  
White Leds ◽  
Lead Borate Glasses ◽  
Chromaticity Coordinates ◽  
Potential Applications ◽  
Cie Chromaticity

In this paper, some series of lead borate glasses and glass ceramics singly doped with Dy3+ ions were prepared and then studied using spectroscopic techniques. Our research includes mainly studies of the luminescence properties of received materials for white light. The luminescence bands associated with the characteristic 4F9/2→6H15/2 (blue), 4F9/2→6H13/2 (yellow) and 4F9/2→6H11/2 (red) transitions of trivalent dysprosium in lead borate systems are well observed. In particular, the Commission Internationale de I’Eclairage (CIE) chromaticity coordinates (x, y) were calculated in relation to potential applications for white light-emitting diodes (W-LEDs). Their values depend on the relative B2O3/PbO ratios and PbX2 contents (where X = Cl, F, Br) in glass composition. For glass-ceramics, the chromaticity coordinates are changed significantly under different excitation wavelengths.

scholarly journals Synthesis of Na-Doped Lithium Metatitanate and Its Absorption for Carbon Dioxide

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liu Zhirong ◽  
Zhang Huan ◽  
Wang Yun ◽  
Zhan Xinxing
Keyword(s):  
Carbon Dioxide ◽  
Solid State Reaction Method ◽  
Absorption Capacity ◽  
Absorption Kinetics ◽  
X Ray Diffraction ◽  
Carbon Dioxide Absorption ◽  
Reaction Method ◽  
X Ray ◽  
Xrd Patterns ◽  
The Relationship

Na-doped lithium metatitanate (Na-doped Li2TiO3) absorbent was doped with Na2CO3and lithium metatitanate (Li2TiO3) was prepared by a solid-state reaction method from mixture of TiO2and Li2CO3. The Na-doped lithium metatitanate was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and surface area. Carbon dioxide absorption on Na-doped lithium metatitanate was investigated using TG-DTA. The results reveal an increase of the CO2absorption capacity of the Na-doped materials with respect to pure Li2TiO3. XRD patterns of the doped samples suggest a limited substitution of Li by Na atoms within the Li2TiO3structure. The results of experimental and modeling work were summarized to better understand the relationship between the sorbent microstructure and carbon dioxide absorption kinetics.

Photoluminescence of Eu3+-Doped La2Mo2O9 Phosphors

2010 ◽  
Vol 663-665 ◽  
pp. 332-335
Author(s):  
En Guo Wang
Keyword(s):  
Sintering Temperature ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
Obvious Effect ◽  
Reaction Method ◽  
X Ray ◽  
Europium Ion ◽  
Scanning Electron

Eu3+-doped La2Mo2O9 phosphor was fabricated by sold-state reaction method. The as-prepared samples were characterized by the application of X-ray diffraction (XRD), scanning electron microscopy (SEM), and emission spectra. The effect of the sintering temperature and doping amount of europium ion on the luminescent properties of La2Mo2O9:Eu3+ was investigated. The results show that the luminescent intensity will reach the strongest when the sintering temperature is equal to 1073 K. The Eu3+ doping amounts also have obvious effect on the luminescent properties.

Effect of Different Excitation Wavelengths on Luminescent Properties of ZnO/Anodic Alumina Membrane (AAM) Arrays

2018 ◽  
Vol 10 (3) ◽  
pp. 409-412
Author(s):  
Shihua Zhao
Keyword(s):  
Emission Spectra ◽  
Luminescent Properties ◽  
Anodic Alumina ◽  
Anodic Alumina Membrane ◽  
X Ray Diffraction ◽  
Alumina Membrane ◽  
Sem Images ◽  
Diffraction Peaks ◽  
Lattice Planes ◽  
Xrd Patterns

ZnO/AAM (anodic alumina membrane) arrays were prepared by an electrodeposition method and X-ray diffraction (XRD) patterns show that the characteristic diffraction peaks of ZnO appear, such as the lattice planes of (100), (002), and (102), moreover, the diffraction peaks of Al2O3 are dominated. Scanning electron microscopy (SEM) images show that the average sizes of the ZnO particles are about 100 nm corresponding to the channel diameters of AAM, and the ZnO arrays are composed of those close particles linked together. The photoluminescence emission spectra express that the as-prepared ZnO arrays can give out relatively pure ultraviolet light (395 nm) from the excitons.

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