Kinetics of radiative recombinations in GaSe and influence of Cu doping on the luminescence spectra

1983 ◽  
Vol 28 (8) ◽  
pp. 4620-4627 ◽  
Author(s):  
Vito Capozzi
Keyword(s):  
Luminescence Spectra ◽  
Cu Doping ◽  
Kinetics Of

scholarly journals Kinetics of luminescence calcium gallate activated by Yb3+, Er3+ ions

2020 ◽  
Vol 23 (3) ◽  
pp. 213-221
Author(s):  
A. P. Mar`in ◽  
U. A. Mar`ina ◽  
V. A. Vorob`ev ◽  
R. V. Pigulev
Keyword(s):  
Rare Earth ◽  
Luminescence Intensity ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Luminescence Spectra ◽  
Excitation Spectra ◽  
Semiconductor Laser Diode ◽  
Intracenter Luminescence ◽  
Trivalent Rare Earth ◽  
Kinetics Of

The paper presents the results of a study of the luminescent properties of calcium gallate activated by trivalent rare earth ions Yb3+ and Er3+. IR luminescence spectra of samples with a single activator Ca1‑хYbxGa2O4,Ca1‑хErxGa2O4 were studied when excited by radiation sources with a wavelength of 940 and 790 nm, respectively. The dependence of the luminescence intensity of samples on the concentration of rare earth ions is obtained. When the two-activator composition of Ca1‑х‑yYbxEryGa2O4 is excited by a semiconductor laser diode with a wavelength of 940 nm, IR luminescence is registered in the regions of 980-1100 nm and 1450-1670 nm. The radiation in these bands corresponds to electronic transitions in Yb3+ and Er3+ ions, respectively. For a luminescence band with a maximum at a wavelength of 1540 nm, the excitation spectra were measured, the maximum intensity is at the wavelengths: 930, 941, 970, 980 nm. The dependence of the IR luminescence intensity of a solid solution of Ca1‑х‑yYbxEryGa2O4 on the concentration of Er3+ ions was studied. With an increase in the concentration of Er3+ ions in the luminescence spectra, there is a redistribution in the intensity of the bands belonging to Yb3+ and Er3+ ions, which indicates the presence of energy transfer processes between these ions. The kinetics of IR luminescence attenuation was studied for series with one and two activators: Ca1‑хYbxGa2O4,Ca1‑хErxGa2O4, Ca1‑х‑yYbxEryGa2O4. It is established that the luminescence attenuation occurs mainly according to the exponential law, which indicates the predominance of the intracenter luminescence mechanism in the studied structures. Based on the analysis of the excitation and luminescence spectra of experimental samples, conclusions are made about the interaction of Yb3+ and Er3+ activator ions in the crystal lattice of calcium gallate.

Improved electrochemical properties and kinetics of an LiMn2O4-based cathode co-modified via Cu doping with truncated octahedron morphology

2020 ◽  
Vol 44 (25) ◽  
pp. 10569-10577 ◽  
Author(s):  
Shimin Wang ◽  
Honglei Liu ◽  
Mingwu Xiang ◽  
Junming Guo ◽  
Wei Bai ◽  
...  
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Cycle Life ◽  
Structural Distortion ◽  
Cu Doping ◽  
Truncated Octahedron ◽  
Kinetics Of

Spinel LiMn2O4 has been widely investigated as a cathode material for lithium-ion batteries, but it suffers from a limited cycle life due to the dissolution of Mn and structural distortion.

Subnanosecond Scintillations in Diamond

1994 ◽  
Vol 348 ◽  
Author(s):  
Vladimir Gavrilov ◽  
Eduard Aluker ◽  
Stanislav Chernov
Keyword(s):  
Luminescence Spectra ◽  
Electron Lifetime ◽  
Band Electron ◽  
Synthetic Diamonds ◽  
Kinetics Of ◽  
Natural And Synthetic

ABSTRACTData about fast luminescence of natural and synthetic diamonds are presented. Analysis of the luminescence spectra and the kinetics of both the luminescence and pulse conductivity leads to the conclusion that these processes are determined by the band electron lifetime.

scholarly journals Резонансный безызлучательный перенос энергии в гибридных ассоциатах молекул тионина и коллоидных квантовых точек Ag-=SUB=-2-=/SUB=-S с различными механизмами люминесценции-=SUP=-*-=/SUP=-

2019 ◽  
Vol 126 (1) ◽  
pp. 69
Author(s):  
М.С. Смирнов ◽  
О.В. Овчинников ◽  
А.С. Перепелица
Keyword(s):  
Energy Transfer ◽  
Thioglycolic Acid ◽  
Nonradiative Energy Transfer ◽  
Luminescence Spectra ◽  
Recombination Luminescence ◽  
Luminescence Centers ◽  
Luminescence Kinetics ◽  
Exciton Mechanism ◽  
Kinetics Of ◽  
Quenching Of Luminescence

AbstractWe have considered the resonant nonradiative energy transfer in hybrid associates of thionine dye (TH^+) molecules and Ag_2S colloidal quantum dots (QDs) passivated with thioglycolic acid (Ag_2S/TGA) and Ag_2S QDs stabilized with gelatin (Ag_2S/Gel). Used samples of Ag_2S QDs possess luminescence, which arises by the exciton mechanism, as well as by the recombination mechanisms of holes with electrons localized at luminescence centers and of electrons with holes localized at the luminescence centers. The quenching of luminescence of Ag_2S/TGA QDs (1.8 nm) with a maximum at 630 nm and a decrease in the luminescence lifetime from 13.7 to 6.5 ns, which occurs upon association with TH^+ molecules, have been established. On the contrary, for associates of Ag_2S/TGA QDs (5.5 nm) with TH^+ molecules, we have observed the quenching of luminescence of the dye and a decrease in the lifetime of this luminescence from 0.43 to 0.3 ns, as well as an enhancement of luminescence of QDs. In the case of hybrid association with TH^+ molecules, the luminescence enhancement of Ag_2S/Gel QDs (1.6 nm) has been established, which results from the recombination of free holes with electrons localized at luminescence centers. Based on our analysis of the luminescence kinetics of the dye, we have inferred the occurrence of resonant nonradiative energy transfer from TH^+ molecules to centers of recombination luminescence in Ag_2S/TGA (5.5 nm) and in Ag_2S/Gel (1.6 nm) QDs with its maxima at 950 and 1205 nm, respectively. For Ag_2S/TGA QDs (2.2 nm), which luminesce with a maximum at 620 nm by the exciton mechanism, we have observed a significant overlap both between the luminescence spectra of QDs and TH^+ and between their absorption spectra. Close parameters of the luminescence kinetics for both the initial components and their associates indicate the energy transfer, which is realized in opposite directions.

Time-Resolved Spectroscopy of Scintillation Materials using X-RAY Synchrotron Radiation

1994 ◽  
Vol 348 ◽  
Author(s):  
Andrey N. Belsky ◽  
Vitaly V. Mikhaihin ◽  
Andrey L. Rogalev ◽  
Eduard I. Zinin
Keyword(s):  
Synchrotron Radiation ◽  
Spectral Composition ◽  
Emission Spectra ◽  
Luminescence Spectra ◽  
Electronic Excitations ◽  
Decay Kinetics ◽  
Time Resolved ◽  
X Ray ◽  
Exponential Law ◽  
Kinetics Of

ABSTRACTThe time-resolved luminescence spectra and decay kinetics of BaF2, BGO, and CeF3, were measured with the dissector technique using X-ray synchrotron radiation (SR)of different spectral composition from wiggler mounted at VEPP-3 storage ring (Novosibirsk).Two effects of X-ray excitation energy on the luminescence parameters were observed: modifications of the emission spectrum and acceleration of decay kinetics. Under the excitation by soft X-ray SR the 220 nm emission band for BaF2 is broadened, whereas shorter wavelength part of CeF3 and BGO emission spectra increases. For luminescence decay of excitons and crossluminescence the degree of the deviation from the single exponential law depends on the photon energies and increases under soft X-ray excitation as well. These effects are supposed to be due to the interaction of electronic excitations created after the relaxation of deep core holes.Fast intrinsic luminescence was observed for Cdl2, and CsPbCl3 under X-ray SR excitation. 500 nm band of Cdl2 has characteristic time τ=4.6 ns, whereas 420 nm band of CsPbCl3 shows very fast decay with τ=0.2 ns.

scholarly journals Luminescence spectra and kinetics of disordered solid solutions

1999 ◽  
Vol 59 (20) ◽  
pp. 12947-12972 ◽  
Author(s):  
A. Klochikhin ◽  
A. Reznitsky ◽  
S. Permogorov ◽  
T. Breitkopf ◽  
M. Grün ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Luminescence Spectra ◽  
Kinetics Of
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