scholarly journals Электрон-фононное взаимодействие центров окраски с бесфононной линией 436.55 nm в кристаллах LiF-O, OH

2020 ◽  
Vol 128 (5) ◽  
pp. 623
Author(s):  
Л.И. Щепина ◽  
Р.Ю. Шендрик ◽  
Т.С. Лазарева

Absorption spectra were recorded at 7.2–300 K at a LiF-O, OH crystal irradiated and UV. The coupling force (S) with the phonons of the lattice of an electron-vibrational transition with a zero-phonon line of 436.55 nm was determined from the ratio of the intensities in the zero-phonon line and the integral absorption band. The nature of the color center responsible for the absorption band at 390 nm and emission 490 nm is determined from the value of S.

2021 ◽  
Vol 88 (6) ◽  
pp. 887-894
Author(s):  
A. I. Mukhammad ◽  
P. I. Gaiduk

The absorption spectra of Si/SiO2/Si3N4/Si+ and Si/SiO2/Si+ structures with an island surface layer are calculated using the finite difference time domain method. The absorption spectra were modeled depending on the thickness of the substrate and its doping level. It was found that the thickness of the i-Si substrate does not affect the overall absorption of the structure. At the same time, an increase in the thickness of the n-Si substrate leads to an expansion of the absorption band with an intensity of more than 70%. It is established that the doping level of the substrate affects the absorption value of the structures and bandwidth with an absorption value above 80%. It is shown that a wide absorption band with intensity of more than 80% occurs at the doping level of the substrate in the range of 2 . 1019—5 . 1019 cm–3. Dispersion relations in the Si+/SiO2/Si+ structure with an unstructured surface layer are obtained. These dispersion relations may indicate the existence of plasmon oscillations in the system. It is established that a violation of the phase synchronization of the modes at both Si/dielectric interfaces at a significant difference between the doping levels of the substrate and the surface layer can lead to a decrease in the absorption.


2017 ◽  
Vol 96 (7) ◽  
Author(s):  
T. B. Biktagirov ◽  
A. N. Smirnov ◽  
V. Yu. Davydov ◽  
M. W. Doherty ◽  
A. Alkauskas ◽  
...  

2019 ◽  
Vol 61 (5) ◽  
pp. 817
Author(s):  
В.И. Соколов ◽  
Н.Б. Груздев ◽  
В.А. Важенин ◽  
А.В. Фокин ◽  
А.В. Дружинин

AbstractThe results of the study of optical absorption and EPR signals of single crystals of zinc oxide doped with manganese are presented. A broad impurity absorption band with the threshold energy about 2.1 eV, which was treated as a result of charge transfer transitions, has been observed for a long time in ZnO : Mn absorption spectra. In absorption spectra of a polarized light at 4.2 and 77.3 K, we first detected several lines of different intensity in a 1.877–1.936 eV range of energies of the light quanta. The observed lines are attributed to a donor exciton [( d ^5 + h ) e ] that emerges as a result of the Coulomb binding a free s electron and a hole, which is localized on p – d hybridized states. The EPR spectra of Mn^2+ ion signals, when corresponding to the impurity absorption band exposed to light, are found to be not photosensitive. The obtained results indicate that the ZnO : Mn impurity absorption is due to transitions from antibonding p – d hybridized DBH states to the conduction band.


CLEO: 2015 ◽  
2015 ◽  
Author(s):  
Michael Gould ◽  
Nicole K. Thomas ◽  
Yuncheng Song ◽  
Minjoo Larry Lee ◽  
Kai-Mei Fu

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