Hot-Electron—Phonon Interaction in the Nonparabolic Conduction Band of Degenerate InSb at 4.2 K

The photocatalyst BaZn1/3Nb2/3O3 with ABO3 perovskite structure has been synthesized by using a solid-state reaction process. It was characterized by x-ray diffraction and photoluminescence spectroscopy. The luminescence band centers around 285 nm and shows a large Stokes shift compared with the excitation spectrum, indicating a strong electron–phonon interaction in the photocatalyst BaZn1/3Nb2/3O3. The electronic structure of BaZn1/3Nb2/3O3 was calculated by using the pseudopotential method of the density function theory. It shows that the conduction band should be mainly composed of the Nb 4d states, and the valence band should be mainly composed of the O 2p state. The densities of the O 2p states and the Zn 4s states at the bottom of the conduction band are very low. The Zn 4s states show an expanded structure, which was proposed to be helpful for the migration of the photoexcited carriers, thus favoring the photocatalytic activity of BaZn1/3Nb2/3O3.

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Hot Electron-Phonon Interaction in Metals

Japanese Journal of Applied Physics ◽

10.1143/jjap.5.1036 ◽

1966 ◽

Vol 5 (11) ◽

pp. 1036-1038 ◽

Cited By ~ 3

Author(s):

Fusako Koshiga ◽

Takuo Sugano

Keyword(s):

Hot Electron ◽

Phonon Interaction ◽

Electron Phonon Interaction

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Influence of electron - phonon interaction on piezoresistance of single crystals n-Ge

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v7i3.1589 ◽

2015 ◽

Vol 7 (3) ◽

pp. 1931-1938

Author(s):

Sergiy Luniov ◽

Olexandr Burban ◽

Petro Nazarchuk ◽

Andriy Zimych

Keyword(s):

Single Crystals ◽

Conduction Band ◽

Theoretical Calculations ◽

Uniaxial Pressure ◽

Phonon Interaction ◽

Absolute Minimum ◽

Electron Phonon Interaction ◽

Intervalley Scattering ◽

Increasing Temperature ◽

The Given

Piezoresistance of uniaxially deformed along the crystallographic direction [100] single crystals n-Ge for different fixed temperatures has been investigated. Presence of the significant piezoresistance for given conditions of the experiment is explained by increase in the effective mass and decrease in the relaxation time for electrons at the expense of the inversion of (L1-âˆ†1) type of an absolute minimum in n-Ge. Temperature dependencies of resistivity for undeformed (L1model of conduction band) and deformed under uniaxial pressureP=3Â GPÐ° (âˆ†1model of conduction band) single crystals n-Ge are obtained. Resistivity for undeformed single crystals n-Ge is changed according to the law Ï~T1.66. Resistivity for uniaxially deformed single crystals n-Ge is changed as Ï~T1.53. The given dependencies show that for L1 model of the conduction band in contrast to âˆ†1model one must equally with intravalley scattering of electrons on acoustic phonons take into account scattering of electrons on optical and intervalley phonons. Therefore reduction of the magnitude piezoresistanceÂ n-Ge with the increasing temperature is associated with â€œturning-offâ€ at the expense of the inversion of (L1-Î”1) type of absolute minimum under uniaxial pressure P>2.7 GPÐ° mechanism for scattering of electrons on intervalley and optical phonons. Comparison of results of theoretical calculations with relevant experimental data shows that peculiarities of piezoresistance n-Ge under uniaxial pressures Â 1.6<P<2.7Â GPÐ° for (L1-Î”1) model of conductionÂ bandÂ n-Ge can be described only taking into account nonequivalent intervalley scattering of electrons between the minima L1 andÂ Î”1.

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Parametric dependence of hot electron relaxation timescales on electron-electron and electron-phonon interaction strengths

Communications Physics ◽

10.1038/s42005-020-00442-x ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Richard B. Wilson ◽

Sinisa Coh

Keyword(s):

Relaxation Times ◽

High Energy ◽

Hot Electron ◽

Electronic Subsystem ◽

Electron Dynamics ◽

Phonon Interaction ◽

Photoexcited Electron ◽

Electron Phonon Interaction ◽

Electron Relaxation ◽

Scattering Rates

AbstractUnderstanding how photoexcited electron dynamics depend on electron-electron (e-e) and electron-phonon (e-p) interaction strengths is important for many fields, e.g. ultrafast magnetism, photocatalysis, plasmonics, and others. Here, we report simple expressions that capture the interplay of e-e and e-p interactions on electron distribution relaxation times. We observe a dependence of the dynamics on e-e and e-p interaction strengths that is universal to most metals and is also counterintuitive. While only e-p interactions reduce the total energy stored by excited electrons, the time for energy to leave the electronic subsystem also depends on e-e interaction strengths because e-e interactions increase the number of electrons emitting phonons. The effect of e-e interactions on energy-relaxation is largest in metals with strong e-p interactions. Finally, the time high energy electron states remain occupied depends only on the strength of e-e interactions, even if e-p scattering rates are much greater than e-e scattering rates.

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