scholarly journals Intrinsic emission and electron-hole trapping centers in crystals Li2SO4-Cu

2021 ◽  
Vol 5 (2) ◽  
pp. 140-147
Author(s):  
T.N. Nurakhmetov ◽  
Zh.M. Salikhodzha ◽  
M.Y. Dolomatov ◽  
B.N. Yussupbekova ◽  
A.M. Zhunusbekov ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Vacuum Ultraviolet ◽  
Annealed Sample ◽  
Excitation Spectra ◽  
Electron Hole ◽  
Hole Trapping ◽  
Trapping Centers ◽  
Hole Centers ◽  
Intrinsic Emission

In the present work, the emission and excitation spectra in Li2SO4-Cu crystals have been obtained by the methods of vacuum-ultraviolet and thermoactivation spectroscopy. We have studied the nature of emission from a pressed and annealed sample of Li2SO4-Cu powders. It has been revealed that at low temperatures Cu0-SO4--centers are formed during the trap of electrons by Cu+-centers and during localization of SO4--radicals in the form of localized hole centers.

scholarly journals Mechanisms for the creation of intrinsic electron-hole trapping centers in a CaSO4 crystall

2021 ◽  
Vol 5 (3) ◽  
pp. 235-241
Author(s):  
T.N. Nurakhmetov ◽  
K.B. Zhangylyssov ◽  
A.M. Zhunusbekov ◽  
D.H. Daurenbekov ◽  
T.T. Alibay ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
Electron Hole ◽  
Long Wavelength ◽  
Hole Trapping ◽  
Energy Distance ◽  
Anionic Complexes ◽  
Recombination Emission ◽  
Trapping Centers ◽  
The Creation

The mechanism of creation of electron-hole trapping centers in CaSO4 at 15-300 K was investigated by the methods of vacuum-ultraviolet and thermoactivation spectroscopy. It is shown that electron-hole trapping centers are formed upon trap of electrons in the anionic complexes SO4− and localization of holes in the form of SO4− radical. Based on the measurement of the spectrum of excitation of long-wavelength recombination emission at 3.0-3.1 eV and 2.7 eV, the energy distance of the formed electron-hole trapping centers was estimated (4.43 eV and 3.87 eV).

Intrinsic emission and electron-hole trapping centers in irradiated Na2SO4

Optik ◽  
2021 ◽  
pp. 167081
Author(s):  
T.N. Nurakhmetov ◽  
Zh.M. Salikhodzha ◽  
A.M. Zhunusbekov ◽  
A.Zh. Kainarbay ◽  
D.H. Daurenbekov ◽  
...  
Keyword(s):  
Electron Hole ◽  
Hole Trapping ◽  
Trapping Centers ◽  
Intrinsic Emission

scholarly journals Influence of Cu+ impurity on the efficiency of creation of electron-hole trapping centers in irradiated Na2SO4 − Cu crystals

2021 ◽  
Vol 5 (3) ◽  
pp. 200-208
Author(s):  
T.N. Nurakhmetov ◽  
B.N. Yussupbekova ◽  
A.M. Zhunusbekov ◽  
D.H. Daurenbekov ◽  
B.M. Sadykova ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Spectroscopic Methods ◽  
Electron Hole ◽  
Hole Trapping ◽  
Recombination Processes ◽  
Trapping Centers

The mechanisms of creation of impurity and intrinsic electron-hole trapping centers in Na2SO4 − Cu crystals have been investigated by spectroscopic methods. It is shown that impurity and intrinsic electron-hole trapping centers in the crystal lattice Na2SO4 − Cu are created in the same energy distances approximately 3.87-4.0 eV and 4.43-4.5 eV. During the annealing of electron-hole trapping centers, the energy of the recombination processes is transferred to impurities.

scholarly journals Mechanisms formation of electron-hole trap centers in LiKSO4 crystall

2021 ◽  
Vol 5 (1) ◽  
pp. 24-30
Author(s):  
T.N. Nurakhmetov ◽  
Zh.M. Salikhodzha ◽  
A.M. Zhunusbekov ◽  
A.Zh. Kainarbay ◽  
D.H. Daurenbekov ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Hole Trap ◽  
Electron Hole ◽  
Hole Trapping ◽  
Anionic Complexes ◽  
Trapping Centers ◽  
The Creation

The mechanisms of creation of electron-hole trapping centers in LiKSO4 have been investigated by the methods of vacuum and thermal activation spectroscopy. It is shown that electron-hole trapping centers are formed during the trapping of electrons by anionic complexes and localization of a hole in the lattice in the form of the radical SO4−. The appearance of phosphorescence at 3.0-3.1 eV, 2.6-2.7 eV and 2.3-2.4 eV confirms the creation of electron-hole trap centers.

scholarly journals Plasmon enhancement of fluorescence of phthalocyanines metallocomplexes in solutions of silver nanoparticles

2019 ◽  
Vol 220 ◽  
pp. 03003
Author(s):  
Aleksandr Starukhin ◽  
Vladimir Apyari ◽  
Aleksander Gorski ◽  
Andrei Ramanenka ◽  
Aleksei Furletov
Keyword(s):  
Silver Nanoparticles ◽  
Silicon Dioxide ◽  
Binary Mixtures ◽  
Low Temperatures ◽  
Plasmonic Enhancement ◽  
Excitation Spectra ◽  
Fluorescence Excitation ◽  
Hydrophobic Compounds ◽  
Fluorescence Excitation Spectra ◽  
Plasmon Enhancement

A method of creation of aqueous solutions with silver nanoparticles for studying of fluorescence of hydrophobic compounds has been proposed for metallocomplexes of phthalocyanines. The effect of silver nanoparticles on the fluorescence of phthalocyanines metallocomplexes at room and low temperatures was studied. The addition of silver nanoparticles leads to plasmonic enhancement of signals in fluorescence and fluorescence excitation spectra of the compounds of interest from 1,5 to more than 7 times. The lifetimes and quantum yield of fluorescence were measured for solutions of metallophthalocyanines in binary mixtures and in binary mixtures with the addition of silver triangular nanoplates with shells of silicon dioxide.

VUV-Photoluminescence Properties of (Gd, La)2O2CO3: Eu3+

2014 ◽  
Vol 1052 ◽  
pp. 203-206
Author(s):  
Zhi Long Wang ◽  
Shi Qin Wang ◽  
Nin Yao ◽  
Xing Min Wei
Keyword(s):  
Charge Transfer ◽  
Vacuum Ultraviolet ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Photoluminescence Properties ◽  
Flux Method ◽  
Excitation Spectra ◽  
Red Emission ◽  
Ultraviolet Excitation

(Gd,La)2-x O2CO3:Eux3+(0.01 ≤x≤0.04) were synthesized via a flux method at 400°C, and their photoluminescence properties under vacuum ultraviolet (VUV) excitation were examined. The excitation spectra showed two bands in the region from 125 nm to 300 nm, the first band centered at 190 nm was ascribed to absorption of related CO32- complex, and the second broad band centered at 246nm and 278nm in Gd2O2CO3:Eu3+ was ascribed to the charge transfer band of O2-→ Eu3+. Series samples exhibited red emission at around 611 nm under vacuum ultraviolet excitation corresponding to the 5D0→ 7F2.transition of Eu3+.

scholarly journals Copper-nanoparticle-dispersed amorphous BaTiO3 thin films as hole-trapping centers: enhanced photocatalytic activity and stability

RSC Advances ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 5045-5052 ◽  
Author(s):  
Su-Wei Zhang ◽  
Shun Li ◽  
Bo-Ping Zhang ◽  
Dongfang Yu ◽  
Zuotai Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Copper Nanoparticle ◽  
Photoelectrochemical Performance ◽  
Hole Trapping ◽  
Degradation Activity ◽  
Trapping Centers

The photocatalytic degradation activity and photoelectrochemical performance of amorphous BaTiO3 films can be improved after introducing Cu NPs, and the oxidation of Cu is strongly hindered when dispersing in the amorphous BaTiO3 films that serve as h+-trapping centers.

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