scholarly journals Coherent and Phonon-assisted Tunnelling in Asymmetric Double Barrier Resonant Tunnelling Structures

2000 ◽  
Vol 53 (1) ◽  
pp. 35
Author(s):  
Jun-jie Shi ◽  
B. C. Sanders ◽  
Shao-hua Pan
Keyword(s):  
Phonon Scattering ◽  
Electron Interaction ◽  
Phonon Modes ◽  
Double Barrier ◽  
Resonant Level ◽  
Resonant Tunnelling ◽  
Improved Performance ◽  
Tunnelling Current ◽  
Peak Value ◽  
Interface Phonons

We present a theory for calculating the phonon-assisted tunnelling current in asymmetric double barrier resonant tunnelling structures (DBRTS), in which all of the phonon modes including the interface modes and the confined bulk-like LO phonons and the conduction band nonparabolicity are considered. An important physical picture about coherent and phonon-assisted tunnelling is given. The coherent tunnelling current can be directly determined by both the width of the resonant level and the peak value of the transmission coecient at the resonant level. The phonon-assisted tunnelling current mainly comes from electron interaction with higher frequency interface phonons (especially the interface phonons localised at either interface of the left barrier). Phonon-assisted tunnelling makes a significant contribution to the valley current. The subband nonparabolicity strongly influences on electron?phonon scattering and current-to-voltage characteristics. A specially designed asymmetric DBRTS may have an improved performance over the symmetric DBRTS.

Photocreated holes and their effect on the luminescence, space charge and resonant tunnelling current in double barrier structures

1990 ◽  
Vol 8 (2) ◽  
pp. 195-200 ◽  
Author(s):  
C.R.H. White ◽  
M.S. Skolnick ◽  
P.E. Simmonds ◽  
L. Eaves ◽  
M. Henini ◽  
...  
Keyword(s):  
Space Charge ◽  
Double Barrier ◽  
Resonant Tunnelling ◽  
Tunnelling Current

Resonant tunnelling in AlInas/GaInAs double barrier diodes grown by MOCVD

1988 ◽  
Vol 24 (3) ◽  
pp. 187 ◽  
Author(s):  
P.D. Hodson ◽  
D.J. Robbins ◽  
R.H. Wallis ◽  
J.I. Davies ◽  
A.C. Marshall
Keyword(s):  
Double Barrier ◽  
Resonant Tunnelling

scholarly journals When band convergence is not beneficial for thermoelectrics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Junsoo Park ◽  
Maxwell Dylla ◽  
Yi Xia ◽  
Max Wood ◽  
G. Jeffrey Snyder ◽  
...  
Keyword(s):  
Charge Carrier ◽  
First Principles ◽  
Design Principle ◽  
Phonon Scattering ◽  
Charge Carrier Concentration ◽  
Deformation Potential ◽  
Interband Scattering ◽  
Improved Performance ◽  
Full Heusler ◽  
Electron Phonon Scattering

AbstractBand convergence is considered a clear benefit to thermoelectric performance because it increases the charge carrier concentration for a given Fermi level, which typically enhances charge conductivity while preserving the Seebeck coefficient. However, this advantage hinges on the assumption that interband scattering of carriers is weak or insignificant. With first-principles treatment of electron-phonon scattering in the CaMg2Sb2-CaZn2Sb2 Zintl system and full Heusler Sr2SbAu, we demonstrate that the benefit of band convergence can be intrinsically negated by interband scattering depending on the manner in which bands converge. In the Zintl alloy, band convergence does not improve weighted mobility or the density-of-states effective mass. We trace the underlying reason to the fact that the bands converge at a one k-point, which induces strong interband scattering of both the deformation-potential and the polar-optical kinds. The case contrasts with band convergence at distant k-points (as in the full Heusler), which better preserves the single-band scattering behavior thereby successfully leading to improved performance. Therefore, we suggest that band convergence as thermoelectric design principle is best suited to cases in which it occurs at distant k-points.

Effects of localized phonon modes on magnetotunneling spectra in double-barrier structures

1991 ◽  
Vol 44 (23) ◽  
pp. 12959-12963 ◽  
Author(s):  
P. J. Turley ◽  
S. W. Teitsworth
Keyword(s):  
Phonon Modes ◽  
Double Barrier

Double-barrier resonant tunnelling diode three-state logic

1990 ◽  
Vol 26 (1) ◽  
pp. 61-62 ◽  
Author(s):  
A. Sellai ◽  
M.S. Raven ◽  
D.P. Steenson ◽  
J.M. Chamberlain ◽  
M. Henini ◽  
...  
Keyword(s):  
Double Barrier ◽  
Resonant Tunnelling ◽  
Resonant Tunnelling Diode

Study on Phonon Drag Effect and Phonon Transport in Thin Si-on-Insulator Layers

2015 ◽  
Vol 1117 ◽  
pp. 86-89 ◽  
Author(s):  
Hiroya Ikeda ◽  
Takuro Oda ◽  
Yuhei Suzuki ◽  
Yoshinari Kamakura ◽  
Faiz Salleh
Keyword(s):  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Phonon Scattering ◽  
Phonon Transport ◽  
Infrared Photodetector ◽  
Phonon Drag ◽  
Drag Effect ◽  
Phonon Modes ◽  
Highly Sensitive ◽  
Insulator Layers

The Seebeck coefficient of P-doped ultrathin Si-on-insulator (SOI) layers is investigated for the application to a highly-sensitive thermopile infrared photodetector. It is found that the Seebeck coefficient originating from the phonon drag is significant in the lightly doped region and depends on the carrier concentration with increasing carrier concentration above ~5×1018 cm-3. On the basis of Seebeck coefficient calculations considering both electron and phonon distribution, the phonon-drag part of SOI Seebeck coefficient is mainly governed by the phonon transport, in which the phonon-phonon scattering process is dominant rather than the crystal boundary scattering even in the SOI layer with a thickness of 10 nm. This fact suggests that the phonon-drag Seebeck coefficient is influenced by the phonon modes different from the thermal conductivity.

scholarly journals lntersubband Relaxation in Step Quantum Well Structures

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 289-293
Author(s):  
J. P. Sun ◽  
H. B. Teng ◽  
G. I. Haddad ◽  
M. A. Stroscio ◽  
G. J. Iafrate
Keyword(s):  
Quantum Well ◽  
Form Factors ◽  
Phonon Energy ◽  
Longitudinal Optical Phonon ◽  
Relaxation Rates ◽  
Phonon Modes ◽  
Quantum Well Structures ◽  
Bulk Phonon ◽  
Interface Phonons ◽  
Intersubband Relaxation

Intersubband relaxation due to electron interactions with the localized phonon modes plays an important role for population inversion in quantum well laser structures designed for intersubband lasers operating at mid-infrared to submillimeter wavelengths. In this work, intersubband relaxation rates between subbands in step quantum well structures are evaluated numerically using Fermi's golden rule, in which the localized phonon modes including the asymmetric interface modes, symmetric interface modes, and confined phonon modes and the electron – phonon interaction Hamiltonians are derived based on the macroscopic dielectric continuum model, whereas the electron wave functions are obtained by solving the Schrödinger equation for the heterostructures under investigation. The sum rule for the relationship between the form factors of the various localized phonon modes and the bulk phonon modes is examined and verified for these structures. The intersubband relaxation rates due to electron scattering by the asymmetric interface phonons, symmetric interface phonons, and confined phonons are calculated and compared with the relaxation rates calculated using the bulk phonon modes and the Fröhlich interaction Hamiltonian for step quantum well structures with subband separations of 36 meV and 50meV, corresponding to the bulk longitudinal optical phonon energy and interface phonon energy, respectively. Our results show that for preferential electron relaxation in intersubband laser structures, the effects of the localized phonon modes, especially the interface phonon modes, must be included for optimal design of these structures.

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