Effects of Na+ on Spectral Properties of Er3+: CaF2 Transparent Ceramic

2012 ◽  
Vol 531-532 ◽  
pp. 307-311
Author(s):  
Wei Wei Li ◽  
Bing Chu Mei ◽  
Xiaonv Li ◽  
Jing Hong Song ◽  
Guang Lin Zhi
Keyword(s):  
Spectral Properties ◽  
Room Temperature ◽  
Dopant Concentration ◽  
Emission Spectra ◽  
Transparent Ceramic ◽  
Transparent Ceramics ◽  
Photoluminescence Properties ◽  
Pressing Method ◽  
Co Doping ◽  
Optimal Value

Er3+, Na+-co-doped CaF2 transparent ceramics with Er3+ dopant concentration of 5at% and Na+ of 0, 0.5, 1.0 and 1.5at% were fabricated by the vacuum hot pressing method. Absorption spectra, emission spectra and fluorescence lifetimes were measured at room temperature to study the effects of Na+ on the spectral properties of Er3+: CaF2 transparent ceramic. The results showed that after introducing Na ion into Er3+: CaF2 transparent ceramics, charge-neutralized Er3+-Na+ structure formed which prevented Er3+ from clustering, the absorption intensity of ceramics decreased with the increase of Na+ concentration, but the spectroscopy and photoluminescence properties of Er3+ in CaF2 transparent ceramic could be modulated by adjusting the concentration of Na+. Co-doping Na+ to increase fluorescence lifetime should have an optimal value.

Hydrothermal Synthesis and Photoluminescence Properties of Ca(MoO4)x(WO4)(1-X) Microcrystallines

2013 ◽  
Vol 652-654 ◽  
pp. 599-606
Author(s):  
Yan Zhao ◽  
Yan Yan Wei ◽  
Dan Qin ◽  
Xin Lai ◽  
Yun Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Uv Light ◽  
Emission Spectra ◽  
Fluorescence Analysis ◽  
Tetragonal Symmetry ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Structure Surface ◽  
Ft Ir

Ca(MoO4)x(WO4)(1-x)solid solution microcrystallines were synthesized by hydrothermal method at 120 °C; the crystal structure, surface morphology and room temperature photoluminescence properties of the as-synthesized microcrystallines were investigated by through X-ray diffraction (XRD), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR) and fluorescence analysis (FA), respectively. Our results show that the obtained Ca(MoO4)x(WO4)(1-x)microcrystallines are single-phase scheelite structure with tetragonal symmetry. The grain size of the Ca(MoO4)x(WO4)(1-x) microcrystallines gradually increases with the increasing x (except x=0) and their agglomeration also becomes serious with x increasing. Under excited by 245 nm or 280 nm ultraviolet light (UV-light) at room temperature, the emission spectra of the Ca(MoO4)x(WO4)(1-x) microcrystallines vary slightly from 410nm to 490nm with increasing x. Whereas the emission intensity of Ca(MoO4)x(WO4)(1-x) microcrystallines changed markedly, and it increases with the increasing x (x＞0).

Synthesis and Photoluminescence of Rhombic NaLa(MoO4)2:Ln3+ Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3617-3621 ◽  
Author(s):  
Yuping Wang ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Luminescence Intensity ◽  
Dopant Concentration ◽  
Emission Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Rhombic NaLa(MoO4)2:Ln3+ (Ln = Eu and Tb) nanocrystals were synthesized by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results indicated that the crystalline size increased with increasing Na2MoO4 content. The photoluminescence properties of NaLa(MoO4)2:Ln3+ nanocrystals were investigated in detail. In the emission spectra of NaLa(MoO4)2:Eu3+ nanocrystals, the 5D0 → 7F2 is dominant, and the peak positions and spectral shapes of emissions were independent of Eu3+ concentration. The luminescence intensity increased with increasing Eu3+ concentration, up to about 10 mol%, and then decreased. In the emission spectra of NaLa(MoO4)2:Tb3+ nanocrystals, the 5D4 → 7F5 is dominant. The sample with a dopant concentration of 20 mol% showed the highest emission intensity.

Study of the photoluminescence properties of Eu2+-doped Ca(AlxGa1−x)2S4 solid solutions at high excitation intensity and low temperature

2018 ◽  
Vol 32 (25) ◽  
pp. 1850306
Author(s):  
E. G. Asadov ◽  
O. B. Tagiev ◽  
K. O. Tagiev ◽  
G. S. Hadjieva ◽  
M. S. Leanenia ◽  
...  
Keyword(s):  
Power Density ◽  
Solid Solutions ◽  
Room Temperature ◽  
Emission Spectra ◽  
Excitation Power ◽  
Excitation Intensity ◽  
Excitation Power Density ◽  
Photoluminescence Properties ◽  
First Time ◽  
Extreme Stability

The investigation of photoluminescence (PL) properties of Ca(Al[Formula: see text]Ga[Formula: see text]S4:Eu[Formula: see text] solid solutions with [Formula: see text] = 0, 0.1, 0.2 and 0.3 synthesized for the first time was performed in wide temperature and excitation power density ranges. It is shown that PL intensity decreases by only 20–30% for different [Formula: see text] in the temperature range from 10 K to 300 K. The extreme stability of shape and position of the emission spectra was found in the range of excitation power density from [Formula: see text] W/cm2 to [Formula: see text] W/cm2 by nanosecond pulsed radiation. The reversible PL efficiency droop was only above 104 W/cm2 of excitation power density. The PL decay time constant was found to be of about 560 ns to 595 ns for [Formula: see text] ranging between 0.1 and 0.3 at room temperature.

scholarly journals Multicolour single molecule emission and excitation spectroscopy reveals extensive spectral shifts

2015 ◽  
Vol 184 ◽  
pp. 207-220 ◽  
Author(s):  
Lukasz Piatkowski ◽  
Esther Gellings ◽  
Niek F. van Hulst
Keyword(s):  
Single Molecule ◽  
Emission Spectroscopy ◽  
Spectral Properties ◽  
Absorption Maximum ◽  
Room Temperature ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
Ambient Conditions ◽  
Spectral Changes ◽  
Spectral Shifts

We explore the distribution and shape of single molecule spectra at room temperature, when embedded in a polymer host. Multicolour excitation and emission spectroscopy is implemented to capture the full inhomogeneous distribution. We observe dramatic spectral changes in a distribution of single quaterrylene diimide (QDI) molecules isolated in a PMMA matrix. The molecules are strongly blue shifted with respect to the ensemble absorption maximum and spread over a staggering 200 nm range. Despite these strong shifts, the shape of the emission spectra does not differ much between individual molecules. We demonstrate that a considerable number of molecules may be invisible in single molecule experiments, as they typically rely on only a single excitation wavelength, which predetermines which subensemble is probed in the experiment. Lastly, we make a first step towards single molecule excitation spectroscopy under ambient conditions, which allows us to determine the spectral range at which individual molecules absorb light most efficiently. We show how single molecule emission and excitation spectroscopies can complement each other and a combination of both techniques can help in understanding the origin of underlaying spectral properties of individual molecules.

A Sims Study of Electroluminescent Phosphors: SrS:Cu

1999 ◽  
Vol 560 ◽  
Author(s):  
Lily H. Zhang ◽  
Larry Wang ◽  
Wusheng Tong ◽  
YongBao Xin
Keyword(s):  
Material Characterization ◽  
Secondary Ion Mass Spectrometry ◽  
Dopant Concentration ◽  
Thermal Quenching ◽  
Areal Density ◽  
Device Performance ◽  
Cell Temperature ◽  
Co Doping ◽  
Doping Effects ◽  
Secondary Ion

ABSTRACTThis study has used secondary ion mass spectrometry (SIMS) as a technique for thin film EL material characterization. It has shown that the Cu dopant concentration in the SrS films directly correlates with the luminescent brightness of the EL devices. A series of SrS:Cu,Y were grown using MBE to study the Y co-doping effects. It has been found that Y peak concentration and areal density in the SrS increased as the Y evaporation cell temperature was increased. The maximum PL intensity was found in the sample grown in the middle of the Y cell temperature range used. The Y co-doping has shown to reduce the thermal quenching effects in SrS EL devices. Therefore, in this series of samples, a good correlation has been found between Y and Cu concentration and the EL device performance characteristics.

Electronic structure engineering of tin telluride through co-doping of bismuth and indium for high performance thermoelectrics: a synergistic effect leading to a record high room temperature ZT in tin telluride

2019 ◽  
Vol 7 (16) ◽  
pp. 4817-4821 ◽  
Author(s):  
U. Sandhya Shenoy ◽  
D. Krishna Bhat
Keyword(s):  
Electronic Structure ◽  
Synergistic Effect ◽  
Band Gap ◽  
High Performance ◽  
Room Temperature ◽  
Band Offset ◽  
Valence Band Offset ◽  
Co Doping ◽  
Tin Telluride ◽  
Structure Engineering

Resonance states due to Bi and In co-doping, band gap enlargement, and a reduced valence-band offset in SnTe lead to a record high room-temperature ZT.

Fabrication and spectral properties of Yb:(Sc0.9Y0.1)O3 transparent ceramics

2013 ◽  
Vol 35 (4) ◽  
pp. 793-797 ◽  
Author(s):  
Shenzhou Lu ◽  
Qiuhong Yang ◽  
Haojia Zhang ◽  
Yonggang Wang ◽  
Dongdong Huang
Keyword(s):  
Spectral Properties ◽  
Transparent Ceramics

Ferroelectric Tunability Studies in Doped BaTiO3 and Ba1−xSrxTiO3

2000 ◽  
Vol 658 ◽  
Author(s):  
Dong Li ◽  
M. A. Subramanian
Keyword(s):  
Curie Temperature ◽  
Phase Change ◽  
Tetragonal Phase ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Co Doping ◽  
Structure Changes

ABSTRACTAcceptor and Donor codoped BaTiO3 and Ba1−xSrxTiO3 are prepared. For Ba1−xLaxTi1−xFexO3,BaTiO3 remains as tetragonal phase up to about 5mol% LaFeO3. For x ≥0.06, the structure changes to cubic at room temperature. The phase change shifts the Curie temperature to lower value and increases the tunability at room temperature. Doping of other acceptor (Al, Cr) and donor (Sm, Gd, Dy) ions has the same effect although with varying levels of tuning. BaTiO3: 4%LaFeO3 has the highest tunability among the studied systems, which is even higher than Ba0.6Sr0.4TiO3. Co-doping of (La, Fe) and (La, Al) in Ba1−xSrxTiO3 also lowers the Curie temperature and increases the tunability of high Ba content samples at cryogenic temperature.

Preparation and Properties of La2O3-CaO-P2O5 Glasses Doped with Eu3+ Ions

2016 ◽  
Vol 675-676 ◽  
pp. 376-379 ◽  
Author(s):  
Narun Luewarasirikul ◽  
Piyachat Meejitpaisan ◽  
Jakrapong Kaewkhao
Keyword(s):  
Calcium Phosphate ◽  
Molar Volume ◽  
Absorption Spectra ◽  
Room Temperature ◽  
Emission Spectra ◽  
Phosphate Glasses ◽  
Excitation Wavelength ◽  
Melt Quenching ◽  
Volume Measurements ◽  
Doped Glasses

Lanthanum calcium phosphate glasses doped with Eu3+ ions in compositions 20La2O3:10CaO:(70-x)P2O5:xEu2O3 (where x = 0.05, 0.10, 0.50 and 1.50 mol%) were prepared by melt-quenching technique. The density and molar volume measurements were carried out at room temperature. The absorption spectra were investigated in the UV-Vis-NIR region from 200 to 2500 nm. The emission spectra of Eu3+-doped glasses centered at 590 nm (5D0→7F1), 612 nm (5D0→7F2), 652 nm (5D0→7F3) and 699 nm (5D0→7F4) have been observed with 393 nm excitation wavelength.

Investigation on the Spectroscopic Properties of Yb3+-doped Phosphate Glass

2011 ◽  
Vol 335-336 ◽  
pp. 1035-1038
Author(s):  
Qi Sang ◽  
Shao Jun Wang ◽  
Xue Rong Wang ◽  
Jing Wen Lu
Keyword(s):  
Cross Section ◽  
Spectral Properties ◽  
Emission Cross Section ◽  
Emission Spectra ◽  
Spectroscopic Properties ◽  
Pump Intensity ◽  
Doping Content ◽  
Performance Parameters ◽  
Particle Count ◽  
Laser Glass

A series of the Yb3+ -doped phosphate laser glass have been prepared under high temperature and different doping content and the fluorescence and absorption spectrum is observed, respectively. The influences of the Yb3+ -doped content on the spectral properties of the glass are analyzed and the optimal mole fraction is 4 %. The emission cross-section and fluorescent lifetime is calculated with McCumber theory. Furthermore, the integrated absorption cross-section, the full width at half maximum of the emission spectra and the laser performance parameters such as least particle count, saturation pump intensity and lowest pump intensity of Yb3+ -doped laser glass is calculated.

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