Light scattering on free electrons in semiconductors in the presence of electron-relaxation processes

1982 ◽  
Vol 26 (10) ◽  
pp. 5730-5742 ◽  
Author(s):  
P. Hertel ◽  
J. Appel
Keyword(s):  
Light Scattering ◽  
Relaxation Processes ◽  
Free Electrons ◽  
Electron Relaxation

Photoexcited hot electron relaxation processes in n-HgCdTe through impact ionization into traps

1991 ◽  
Author(s):  
D. G. Seiler ◽  
J. R. Lowney ◽  
C. L. Littler ◽  
I. T. Yoon ◽  
M. R. Loloee
Keyword(s):  
Impact Ionization ◽  
Relaxation Processes ◽  
Hot Electron ◽  
Electron Relaxation

Fast relaxation processes in glasses as revealed by depolarized light scattering

2007 ◽  
Vol 353 (16-17) ◽  
pp. 1491-1500 ◽  
Author(s):  
S.V. Adichtchev ◽  
N.V. Surovtsev ◽  
J. Wiedersich ◽  
A. Brodin ◽  
V.N. Novikov ◽  
...  
Keyword(s):  
Light Scattering ◽  
Relaxation Processes ◽  
Fast Relaxation ◽  
Depolarized Light Scattering

Light scattering studies of high-frequency relaxation processes in organic glass formers

1996 ◽  
Vol 8 (47) ◽  
pp. 9593-9598 ◽  
Author(s):  
R M Pick ◽  
A Aouadi ◽  
C Dreyfus ◽  
R Torre ◽  
P Bartolini
Keyword(s):  
Light Scattering ◽  
High Frequency ◽  
Organic Glass ◽  
Relaxation Processes ◽  
Frequency Relaxation

Probing the Phonon-Assisted Relaxation Processes in DNA-wrapped Carbon Nanotubes Using Photoluminescence Spectroscopy

2004 ◽  
Vol 858 ◽  
Author(s):  
S. G. Chou ◽  
F. Plentz ◽  
J. Jiang ◽  
R. Saito ◽  
D. Nezich ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Transitions ◽  
Radiative Energy ◽  
Relaxation Processes ◽  
Electronic Relaxation ◽  
Semiconducting Materials ◽  
Excitation Energies ◽  
Photoluminescence Study ◽  
Electron Relaxation ◽  
Physical Interactions

AbstractWe present a detailed photoluminescence study of a (6, 5) enriched DNA-wrapped single wall carbon nanotube (DNA-CNT) solid sample and an as-produced DNA-CNT solution. Multiple strong PL peaks were observed at excitation energies that do not correspond to the interband electronic transitions that are strongly enhanced by electronic van Hove singularities. These strong PL peaks are assigned to different mechanisms of excitation and relaxation, including one phonon, two phonon, hot luminescence processes, as well as radiative and non-radiative energy transferring mechanisms between neighboring nanotubes. These processes are assigned to different channels of phonon-assisted electron relaxation. The study shows that the electronic relaxation processes observed in PL can be used as a means to probe different physical interactions between photons, electrons, and phonons that are not separately identified in bulk semiconducting materials.

scholarly journals Упругие свойства растворов гуанидин гидрохлорида различной концентрации в гигагерцовом диапазоне частот

2020 ◽  
Vol 90 (9) ◽  
pp. 1546
Author(s):  
А.И. Федосеев ◽  
И.П. Колударов ◽  
А.В. Фронтцек ◽  
А.В. Дмитриев ◽  
С.Г. Лушников
Keyword(s):  
Activation Energy ◽  
Light Scattering ◽  
Guanidine Hydrochloride ◽  
Adiabatic Compressibility ◽  
Relaxation Processes ◽  
Arrhenius Law ◽  
Absolute Value ◽  
Thermally Activated ◽  
Low Concentrations ◽  
Temperature Dependences

Temperature dependences of hypersound velocity V(T) in solutions with different guanidine hydrochloride (GdnHCl) concentrations have been studied by Brillouin light scattering at temperatures from 263 to 353 K. It has been shown that for low GdnHCl concentrations the V(T) dependence has a pronounced maximum. An increase in the GdnHCl concentration in the solution is accompanied by a shift of the maximum towards lower temperatures and also an increase in the absolute value of hypersound velocity and, hence, a decrease in the adiabatic compressibility in the entire temperature range studied. The temperature dependence of adiabatic compressibility at low concentrations of GndHCl is ploted. The contribution of relaxation processes to the temperature behavior of hypersound attenuation in GndHCl solutions is determined. It is shown that their behavior is thermally activated and described by Arrhenius ' law. The values of activation energy of relaxation processes are calculated. Possible mechanisms underlying the effects observed are considered.

scholarly journals Ultrafast dynamics and mechanisms of non-stationary absorption in thin gallium selenide samples

2021 ◽  
Vol 57 (1) ◽  
pp. 99-107
Author(s):  
S. A. Tikhomirov
Keyword(s):  
Conduction Band ◽  
Dynamic Equilibrium ◽  
Time Range ◽  
Relaxation Processes ◽  
Ultrafast Dynamics ◽  
Gallium Selenide ◽  
Edge States ◽  
Free Electrons ◽  
Induced Absorption ◽  
Induced Changes

Herein, the dynamics and mechanisms of induced absorption in thin samples of gallium selenide under various excitation conditions are studied using femtosecond kinetic spectroscopy. We have registered several types of induced changes including induced absorption on free charge carriers (“hot” and thermalized electrons), bleaching and absorption due to the population of near-edge trap or exciton states, as well as rapid changes in the absorption of probing radiation in the region of the overlap of the exciting and probing pulses due to two-quantum two-frequency interband transitions. The time ranges of the relaxation processes are estimated. It is shown that when using relatively low-intensity long-wave excitation (790 nm), the resonant excitation of the near-edge states occurs mainly due to two-quantum two-frequency transitions followed by the formation of the dynamic equilibrium between bound and free electrons in the time range up to 5 ps. When electrons are excited deeply into the conduction band with the formation of hot free electrons and their subsequent thermalization to the bottom of the conduction band in the time range up to 1 ps, the population of the near-edge states and the establishment of the dynamic equilibrium between bound and free electrons is realized in the same time range (5 ps) as when they are excited “from below”.

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