Mn4+doped (NH4)2TiF6and (NH4)2SiF6micro-crystal phosphors: synthesis through ion exchange at room temperature and their photoluminescence properties

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76251-76258 ◽  
Author(s):  
Luqing Xi ◽  
Yuexiao Pan ◽  
Shaoming Huang ◽  
Guokui Liu
Keyword(s):  
Reaction Mechanism ◽  
Ion Exchange ◽  
Room Temperature ◽  
Luminescence Properties ◽  
Photoluminescence Properties

Two red micro-crystal phosphors: (NH4)2TiF6:Mn4+and (NH4)2SiF6:Mn4+have been obtained through ion exchange at room temperature for a few hours. The reaction mechanism and luminescence properties of them have been comprehensively invested.

Luminescence Properties of Rare-Earth Doped α-SiAlONs

2006 ◽  
Vol 317-318 ◽  
pp. 797-802
Author(s):  
Rong Jun Xie ◽  
Mamoru Mitomo ◽  
Naoto Hirosaki
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Room Temperature ◽  
Luminescence Properties ◽  
Activator Concentration ◽  
Photoluminescence Properties ◽  
Host Crystal ◽  
Emission Properties ◽  
White Leds ◽  
Rare Earth Doped

Rare-earth doped Ca-α-SiAlON phosphors, with the compositions of (Ca1-3/2xREx)m/2Si12-m-nAlm+nOnN16-n (RE = Ce, Sm, Eu, Tb, Yb and Dy, 0.5 ≤ m = 2n ≤ 3.0), were prepared by reaction at 1700oC for 2h under 10 atm N2. The concentration of rare earths varied from 3 to 30 at% with respect to Ca. The photoluminescence properties of the powders were investigated at room temperature. The results show that (i) strong visible emissions are observed in rare-earth doped Ca-α-SiAlONs; (ii) the emission properties can be optimized by tailoring the activator concentration and the composition of the α-SiAlON host crystal; and (iii) the yellow Eu2+-doped Ca-α-SiAlON phosphors can be used in warm white LEDs.

A facile room temperature chemical transformation approach for binder-free thin film formation of Ag2Te and lithiation/delithiation chemistry of the film

2016 ◽  
Vol 45 (43) ◽  
pp. 17312-17318 ◽  
Author(s):  
Eun-Kyung Kim ◽  
Dasom Park ◽  
Nabeen K. Shrestha ◽  
Jinho Chang ◽  
Cheol-Woo Yi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Aqueous Solution ◽  
Ion Exchange ◽  
Chemical Transformation ◽  
Room Temperature ◽  
Film Formation ◽  
Synthetic Method ◽  
Binder Free ◽  
Thin Film Formation

An aqueous solution based synthetic method for binder-free Ag2Te thin films using ion exchange induced chemical transformation of Ag/AgxO thin films.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.

Photoluminescence of Ca4Ga2S7:Eu2+ in wide excitation intensity and temperature range

2021 ◽  
pp. 2150392
Author(s):  
B. D. Urmanov ◽  
M. S. Leanenia ◽  
G. P. Yablonskii ◽  
O. B. Taghiyev ◽  
K. O. Taghiyev ◽  
...  
Keyword(s):  
Room Temperature ◽  
Laser Excitation ◽  
Excitation Intensity ◽  
Temperature Measurements ◽  
Constant Time ◽  
Photoluminescence Properties ◽  
Temperature Range ◽  
Chalcogenide Semiconductors ◽  
Time Frames

Photoluminescence properties of [Formula: see text] chalcogenide semiconductors have been studied under the impulse laser excitation in the range of 10–105 W/cm2 at room temperature. This study has shown that as a result of excitation, photoluminescence of [Formula: see text] is characterized by the emission in the interval of 450–575 nm with significant domination in the spectra line at 660 nm. Photoluminescence of [Formula: see text] quenches at wavelengths of 560 nm and 660 nm with constant time frames 258 ns and 326 ns, respectively. Moreover, the temperature measurements of photoluminescence were performed on the samples in the temperature range of 10–300 K.

Study of Photoluminescence Properties of CuxO Thin Films Prepared by Reactive Radio Frequency Magnetron Sputtering

2015 ◽  
Vol 1792 ◽  
Author(s):  
Jiantuo Gan ◽  
Augustinas Galeckas ◽  
Vishnukanthan Venkatachalapathy ◽  
Heine N. Riise ◽  
Bengt G. Svensson ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Room Temperature ◽  
Quartz Substrate ◽  
Rf Magnetron Sputtering ◽  
Considerable Improvement ◽  
Photoluminescence Properties ◽  
Radio Frequency Magnetron Sputtering ◽  
Room Temperature Photoluminescence

ABSTRACTCuxO thin films have been deposited on a quartz substrate by reactive radio frequency (rf) magnetron sputtering at different target powers Pt (140-190 W) while keeping other growth process parameters fixed. Room-temperature photoluminescence (PL) measurements indicate considerable improvement of crystallinity for the films deposited at Pt>170 W, with most pronounced excitonic features being observed in the film grown using Pt=190 W. These results corroborate well with the surface morphology of the films, which was found more flat, smooth and homogeneous for Pt >170 W films in comparison with those deposited at lower powers.

Cubic Boron Nitride as a New Semiconductor for Optoelectronics: Luminescence Properties and Potentialities

1989 ◽  
Vol 162 ◽  
Author(s):  
Koh Era ◽  
Osamu Mishima
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Boron Nitride ◽  
Room Temperature ◽  
Cubic Boron Nitride ◽  
Visible Region ◽  
Vibrational Structure ◽  
Luminescence Properties ◽  
Optoelectronic Applications ◽  
P Type

ABSTRACTIn cubic boron nitride made by high pressure and high temperature technique in our institute, we have found three luminescence bands in the ultraviolet and the short visible region at room temperature by cathode-ray excitation. They are: a band having vibrational structure and ascribable to undoped state of the crystal, a band ascribable to p-type doping and a band ascribable to n-type doping. Discussion is made on differences between the injection luminescence and the cathodoluminescence. Potentialities and difficulties in realizing the potentialities of cBN for optoelectronic applications are discussed.

scholarly journals TfOH-Promoted Reaction of 2,4-Diaryl-1,1,1-Trifluorobut-3-yn-2-oles with Arenes: Synthesis of 1,3-Diaryl-1-CF3-Indenes and Versatility of the Reaction Mechanisms

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3079 ◽  
Author(s):  
Aleksey V. Zerov ◽  
Anna N. Kazakova ◽  
Irina A. Boyarskaya ◽  
Taras L. Panikorovskii ◽  
Vitalii V. Suslonov ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Reaction Mechanisms ◽  
Room Temperature ◽  
Ring Closure ◽  
Nucleophilic Attack ◽  
New Process ◽  
Intramolecular Ring ◽  
Propargyl Alcohols

The TfOH-mediated reactions of 2,4-diaryl-1,1,1-trifluorobut-3-yn-2-oles (CF3-substituted diaryl propargyl alcohols) with arenes in CH2Cl2 afford 1,3-diaryl-1-CF3-indenes in yields up to 84%. This new process for synthesis of such CF3-indenes is complete at room temperature within one hour. The synthetic potential, scope, and limitations of this reaction were illustrated by more than 70 examples. The proposed reaction mechanism invokes the formation of highly reactive CF3-propargyl cation intermediates that can be trapped at the two mesomeric positions by the intermolecular nucleophilic attack of an arene partner with a subsequent intramolecular ring closure.

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